Clinical and electroencephalogram characteristics of pilomotor seizures

Clinical and electroencephalogram characteristics of pilomotor seizures | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Clinical and electroencephalogram characteristics of pilomotor seizures Zhijun Le, Bingqian Li, Hesheng Zhang, Yujie Chen, Raowei Yan, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9071232/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Apr, 2026 Read the published version in Acta Epileptologica → Version 1 posted You are reading this latest preprint version Abstract Background Piloerection, a physiological response to cold or emotional stimuli, is a rare autonomic manifestation of epileptic seizures. The literature on pilomotor seizures remains limited, with its anatomical correlates and electrophysiological mechanisms poorly understood. Methods We conducted a retrospective analysis of 13 patients with pilomotor seizures identified from 8,482 individuals monitored at Epilepsy Center of West China Hospital. Demographic data, seizure characteristics, neuroimaging, and neurophysiological findings were analyzed to determine the epileptogenic zone and associated etiologies. Results Our case series revealed a strong predilection for temporal lobe origin (11/13 patients), with distinctive ictal EEG patterns including rhythmic delta activity. Piloerection was consistently accompanied by other autonomic or psychic symptoms. Most patients responded favorably to anti-seizure medications. Conclusion Pilomotor seizures are associated with temporal lobe epilepsy and are characterized by distinctive ictal EEG patterns, particularly rhythmic delta activity, and are frequently associated with specific etiologies such as autoimmune encephalitis. Figures Figure 1 Introduction Piloerection, often referred to “goose bumps”, is a physiological phenomenon characterized by contraction of the arrector pili muscles in response to cold exposure or emotional stimuli[1]. Autonomic control of choriocapillaris movements was reported in a very small number of cases[2]. It suggests that this response is primarily mediated by autonomic nervous system, with the hypothalamus, limbic system, and frontal cortex involved in key regulatory roles. Piloerection is defined as an autonomic phenomenon descriptor in the ILAE 2025 position paper on the classification of epileptic seizures[3]. In clinical practice, pilomotor seizures are often misdiagnosed as anxiety or depression if accompanied by emotional symptoms such as fear or other autonomic manifestations[4]. We summarized in detail the clinical features and epileptogenic zones of 13 cases of pilomotor seizures and provided a literature review. Methods We conducted a retrospective review of patients with epilepsy who underwent video-electroencephalogram (VEEG) monitoring at the Epilepsy Center of West China Hospital, Sichuan University, between January 2021 and October 2024. For those patients who meet the 2017 International League Against Epilepsy (ILAE) diagnostic criteria for epilepsy, we will have their history data reviewed to look for the presence of piloerection[3]. Cases exhibiting pilomotor seizures were identified based on synchronized video documentation or clinical confirmation of ictal manifestations through direct observation by the medical team or family members, or via patient self-report. For all enrolled patients, we collected demographic data, semiology characteristics, and disease progression profiles. These clinical parameters were integrated with multimodal neuroimaging and neurophysiological findings, followed by a comprehensive evaluation of the epileptogenic zone. Results Among 8,482 patients diagnosed with epilepsy, seventeen patients presented with piloerection as the ictal semiology. Four of them were excluded because of incomplete clinical data. In total, the data of the remaining 13 right - handed patients (6 males, 7 females) were analyzed. The mean age was 36.7 ± 10.9 years. The mean age at onset was 32.2 ± 12.7 years. Ten patients experienced seizures during VEEG monitoring. Semiology In all 13 cases, piloerection manifested as an integral component with other clinical presentation. Each patient demonstrated autonomic manifestations, including tachycardia, epigastric distress, nausea/vomiting, sweating, or olfactory hallucinations, déjà vu, limb paresthesia, altered consciousness, automatisms, or progression to generalized tonic-clonic seizures. The topographic progression of piloerection was shown in Table 1. EEG and imaging findings Interictal epileptiform discharges (IEDs) were identified in 11 out of 13 patients (84.6%). The temporal region was the predominant localization (8 cases: 4 right, 1 left, and 3 bilateral). The remaining cases exhibited IEDs in the middle line (1 case), the left frontotemporal region (1 case), or bilateral temporoparietal areas (1 case). Ictal EEG recordings were successfully obtained in 10 patients. Temporal lobe onset was documented in 7 cases (3 left-sided, 3 right-sided, and 1 bilateral). Extra-temporal origin included the left frontotemporal region (2 cases) and the left frontal lobe (1 case). MRI revealed temporal lobe or hippocampal abnormalities in 9 patients, while 4 patients demonstrated normal imaging findings. Etiology Structural changes were identified in 9 patients via brain MRI, including 8 with temporal lobe/hippocampal abnormalities (2 potentially autoimmune-related) and 1 with frontal vascular malformation. Autoimmune testing in 6 cases found 1 LGI1 antibody-positive case. The remaining 5 patients had undetermined etiologies despite comprehensive evaluation. Treatment response Nine patients achieved significant seizure control with anti-seizure medications (ASMs). One patient discontinued medication voluntarily but remained seizure-free during 1 year follow-up. Case 4 underwent left temporal epileptogenic focus resection with selective hippocampectomy and has been seizure-free for nine months postoperatively. Three patients showed a poor therapeutic response. Case 6 continues to experience 3-4 monthly seizures despite treatment with four ASMs. Table 1. Demographic and clinical characteristics of patients with pilomotor seizures. Case Num. Age Sex First seizure Pilo onset region Spreading to Semiology IEDs EEG onset MRI PET SPECT CSF autoantibodies Etilology ASMs Relevent medical history 1 36 M 35 RUL whole body déjà vu, pilo, R limbs numbness, olfactory hallucinations R T: sharp waves R T: 1-2 Hz slow wave→4-5 Hz rhythmic R T hypermetabolic in the right portion of the clivus NA negative unclear good response to LCM nasopharyngeal carcinoma 2 46 F 45 R or L limbs whole body increased heart rate, pilo, swallowing L T: sharp waves L F T: 2-3 Hz rhythmic slow wave L T NA NA NA L T: cavernous angioma poor response to LEV, VPA 3 33 F 32 LUL left limbs L limbs numbness, pilo R T: sharp waves R or L T: 4-5 Hz rhythmic→2-3 Hz rhythmic negative NA NA NA unclear NA, seizure free NA 4 25 F 16 R limbs bilateral limbs chill, palpitation, pilo→swallowing/chewing, leftward gaze→asymmetric tonic posturing→GTCS middle line: SWC L F T: 2-3 Hz rhythmic slow wave L HS L HS; hypometabolic in L T; L FCD hyperperfusion in L T NA L: HS good response to L T H operation and LEV, ZNS NA 5 34 F 32 RUL whole body increased heart rate, auditory hallucinations, pilo→sweating L F T: sharp waves L T: 2-3 Hz slow waves→2-4 Hz SWC nodule in R T, probable cystic lesion NA NA negative unclear good response to PER 6 36 M 25 R limbs whole body tachycardia, laughter, head deviation to R, LOC→RUL flexion, RLL extension, L limbs hyperkinetic movements→lips pursing, left-hand automatisms→postictal aphasia bi T: sharp waves L F: rhythmic sharp waves negative L F NA negative L F: vascular malformation poor response to OXC, VPA, PER, LEV 7 53 F 47 LUL whole body precordial tightness, pilo R T: sharp waves R T: 3-4 Hz rhythmic slow wave→2-3 Hz SWC→2-3 Hz rhythmic slow waves bi H and amygdala hypermetabolic in bi H and amygdala; hypometabolic in bi F hyperperfusion in the R T H, insula, basal ganglia region, thalamus and parieto-occipital junction region LGI1 autoimmune encephalitis poor response to LEV 8 27 M 25 L face no spreading LOC, pilo bi T and bi P: spikes and sharp waves R T: 2-3 Hz SWC L H smaller than contralateral, normal signal NA NA negative lupus encephalitis? good response to LEV metabolic encephalopathy at 14; diagnosed with SLE at 20 9 44 M 43 bi face and bi upper limbs no spreading optical hallucination, increased heart rate, pilo no IEDs L T: 6-7 Hz slow waves→L F T:4-5 Hz slow waves negative NA NA NA viral encephalitis OXC 10 25 M 22 RUL bilateral limbs olfactory hallucinations,pilo, déjà vu, GTCS no IEDs no ictal EEG R T NA NA negative lupus encephalitis good response to LEV, LCM diagnosed with SLE at 23 11 34 F 23 bilateral whole body fear, pilo bi T: sharp waves no ictal EEG negative NA NA NA unclear good response to VPA, LCM 12 25 F 16 unclear whole body fear, palpitations, chills, pilo, and rising epigastric sensation→repeated swallowing, tachycardia, tachypnea bi T: sharp waves and spike L T: 7-8 Hz rhythmic→3-5 Hz rhythmic bi HS bi HS NA negative bi HS good response to VPA, LCM, ZNS, LEV diagnosed with viral encephalitis at 16 13 59 M 57 unclear face fear, pilo, GTCS R T: sharp waves no ictal EEG R T NA NA NA unclear good response to LCM, LEV craniotomy for sellar meningioma at 56 Pilo: piloerection; IEDs: interictal epileptiform discharges; MRI: magnetic resonance imaging; PET: positron emission tomography; SPECT: single-photon emission computed tomography; CSF: cerebrospinal fluid; ASMs: anti-seizure medications; M: male; F: female; R: right; L: left; UL: upper limb; LL: lower limb; T: temporal; LCM: lacosamide; F: frontal; LEV: levetiracetam; VPA: valproic acid; GTCS: generalized tonic-clonic seizures; SWC: spike and wave complex; H: hippocampus; S: sclerosis; FCD: focal cortical dysplasia; ZNS: zonisamide; PER: perampanel; LOC: loss of consciousness; OXC: oxcarbazepine; SLE: systemic lupus erythematosu Discussion The pilomotor seizure is a rare autonomic symptom of focal epileptic seizures, which may be overlooked during diagnosis. We reported 13 cases of pilomotor seizures to explore the origin and related networks. In the skin, the sympathetic nervous system, the arrector pili muscle (APM; of mesenchymal origin), and the hair follicle (HF; of epithelial origin) form a functionally integrated tri-lineage unit. The APM is anchored to the bulge region of the hair follicle and receives direct sympathetic innervation, enabling coordinated piloerection[5]. The neural circuit of piloerection is triggered by temperature or emotional stimuli and involves multi-level integration of the central and autonomic nervous systems[6]. The temperature-triggered pathway begins with cutaneous cold receptors (e.g., TRPM8), which are activated by low temperatures and transmit signals via Aδ/C fibers to the spinal dorsal horn. These signals then ascend through the spinothalamic tract to the parabrachial nucleus in the brainstem, which further activates neurons in the hypothalamic preoptic area[7]. The emotion-triggered pathway originates in the amygdala, which receives emotional signals (e.g., fearful or moving), and relays them to the hypothalamic paraventricular nucleus (PVN) for integration[8]. Both pathways ultimately converge as hypothalamic signals descend through the brainstem to the spinal intermediolateral column (IML). Postganglionic sympathetic fibers release norepinephrine, which acts on α1-adrenergic receptors in the arrector pili muscles to induce piloerection[9]. This neural activity is also modulated by higher cortical centers, including the prefrontal cortex (PFC) and anterior cingulate cortex (ACC)[10,11]. The ictal piloerection observed in pilomotor seizures may result from pathological hyperactivation of the sympathetic-cutaneous circuitry, the thalamus or amygdala, by epileptogenic networks. In our case series, pilomotor seizures predominantly affected adults. Among 13 cases, the mean age of the first seizure was 32.2 years (range: 16-57), with 11 cases occurring at adulthood and 2 cases at 16 years. This age distribution may be caused by the predominantly adult population treated at our epilepsy center. The literature review of 104 cases revealed that among 64 patients with documented age of onset, the mean age was 40.4 years (range: 1-82), with 56 cases occurring in adulthood. The underreporting of "goosebumps" by pediatric patients may be attributed to the phenomenon. A few studies reported piloerection in pediatric epilepsy patients [12,13]. In a retrospective study, it was found that while 60 children exhibited autonomic symptoms, none demonstrated piloerection[14]. These findings suggest that pilomotor seizures may be associated with neurological development and maturation. This may also be attributed to the underreporting of piloerection by pediatric patients, which necessitates more careful observation by caregivers and more detailed inquiry during history-taking. Pilomotor seizures exhibit a strong predilection for temporal lobe origin. In our case series, 11 of 13 patients demonstrated temporal lobe origin. This finding aligns with our literature review of 60 well-localized cases, which identified temporal lobe onset in 55 patients, consistent with established reports[15,16]. It suggests approximately 10% of pilomotor seizures originate from extra-temporal regions, with frontal and parietal lobes being the most frequently involved[17]. Ictal EEG recordings in 7 out of 9 temporal lobe cases revealed distinctive rhythmic delta activity (1-4Hz). Given that the characteristic theta rhythm is typically observed in mesial temporal lobe epilepsy[18], this potentially indicated unique pathophysiological mechanisms and precise localizing value in pilomotor seizures. The lateralizing value of pilomotor seizures is not fully understood. In our series of 13 cases, 9 clearly exhibited unilateral onset of piloerection. Among these, 2 patients showed strictly ipsilateral propagation, while 7 cases exhibited contralateral spread. The initial side of piloerection was contralateral to the epileptogenic zone in 6 cases, with only 1 case showing ipsilateral correspondence. Previous studies have primarily focused on documenting the presence or distribution of piloerection, while systematic characterization of its initial localization and propagation patterns has been lacking. We emphasize the importance of recording both the originating side and spreading characteristics of pilomotor manifestations, which may provide valuable lateralizing information for the epileptogenic zone. Given that epilepsy is a network disease, localizing the epileptogenic zone based solely on piloerection requires caution. However, the localizing value of this stereotyped clinical manifestation occurring at seizure onset should not be underestimated. Pilomotor seizures may demonstrate significant associations with specific etiologies, particularly autoimmune encephalitis and nervous system tumors. In our series of 13 cases, one tested positive for LGI1 antibodies, while two others had comorbid systemic lupus erythematosus. A systematic literature review of 104 cases identified 30 patients with confirmed autoimmune encephalitis. And approximately 25% of pilomotor seizure cases were associated with gliomas or limbic encephalitis[15]. Pilomotor seizures occur in about 0.65% of patients with refractory temporal lobe epilepsy [19], whereas the prevalence rises to 13.3%-14% in limbic encephalitis populations [20–22]. These suggest that pilomotor seizure may possess distinct pathophysiological underpinnings linked to immune-mediated neuroinflammatory processes. The majority of patients with pilomotor seizures demonstrate favorable responses to anti-seizure medications (ASMs), achieving adequate seizure control through standardized treatment protocols. In cases where the underlying etiology is identifiable, a multimodal therapeutic approach is indicated. Conclusion Our study demonstrates a strong predilection for temporal lobe origin. These seizures are characterized by specific ictal EEG patterns, notably rhythmic delta activity, and are almost invariably accompanied by other autonomic or psychic symptoms. And detailed documentation of the piloerection's onset region and spreading pattern may provide valuable lateralizing information. While pilomotor seizures are often overlooked or misdiagnosed, enhanced recognition and systematic characterization of this semiological feature are crucial for accurate diagnosis, localization, and targeted management of epilepsies. Declarations Acknowledgements Non- applicable. Authors’ contributions Z.L. and B.L. wrote the main manuscript text and collected the data. H.Z., Y.C., and R.Y. contributed to data analysis and interpretation. D.Z., J.C., and X.W. supervised the project and revised the manuscript. All authors reviewed and approved the final manuscript. Funding This study is supported by the National Key R&D Program of China (No.2021YFC2401204, 2022YFC2503805). Data availability The datasets generated for this study are available upon request from the corresponding author. Ethics approval and consent to participate Ethics approval and consent to participate Informed consent was obtained from patients or their families. The study was approved by the Ethics Committee Biomedical Research, West China Hospital of Sichuan University. Consent for publication The publication of Case1 arm piloerection photo has obtained the patient's informed consent. Competing interests All authors declare that they have no competing interests. References Benedek M, Kaernbach C. Physiological correlates and emotional specificity of human piloerection. Biol Psychol 2011;86:320–9. https://doi.org/10.1016/j.biopsycho.2010.12.012. Heathers JAJ, Fayn K, Silvia PJ, Tiliopoulos N, Goodwin MS. The voluntary control of piloerection. PeerJ 2018;6:e5292. https://doi.org/10.7717/peerj.5292. Beniczky S, Trinka E, Wirrell E, et al. Updated classification of epileptic seizures: Position paper of the International League Against Epilepsy. Epilepsia. 2025;66(6):1804-1823. doi:10.1111/epi.18338 Lam EM, Worrell GA, Laughlin RS. Semiology of the rare seizure subtype piloerection. Arch Neurol 2010;67:1524–7. https://doi.org/10.1001/archneurol.2010.304. Shwartz Y, Gonzalez-Celeiro M, Chen C-L, Pasolli HA, Sheu S-H, Fan SM-Y, et al. Cell types promoting goosebumps form a niche to regulate hair follicle stem cells. Cell 2020;182:578-593.e19. https://doi.org/10.1016/j.cell.2020.06.031. McKemy DD, Neuhausser WM, Julius D. Identification of a cold receptor reveals a general role for TRP channels in thermosensation. Nature 2002;416:52–8. https://doi.org/10.1038/nature719. Nakamura K, Morrison SF. A thermosensory pathway mediating heat-defense responses. Proc Natl Acad Sci U S A 2010;107:8848–53. https://doi.org/10.1073/pnas.0913358107. LeDoux JE. Emotion circuits in the brain. Annu Rev Neurosci 2000;23:155–84. https://doi.org/10.1146/annurev.neuro.23.1.155. Roosterman D, Goerge T, Schneider SW, Bunnett NW, Steinhoff M. Neuronal control of skin function: The skin as a neuroimmunoendocrine organ. Physiol Rev 2006;86:1309–79. https://doi.org/10.1152/physrev.00026.2005. Critchley H, Daly E, Phillips M, Brammer M, Bullmore E, Williams S, et al. Explicit and implicit neural mechanisms for processing of social information from facial expressions: A functional magnetic resonance imaging study. Hum Brain Mapp 2000;9:93–105. https://doi.org/10.1002/(SICI)1097-0193(200002)9:23.0.CO;2-Z. Critchley HD, Mathias CJ, Josephs O, O’Doherty J, Zanini S, Dewar B-K, et al. Human cingulate cortex and autonomic control: Converging neuroimaging and clinical evidence. Brain J Neurol 2003;126:2139–52. https://doi.org/10.1093/brain/awg216. VanDongen-Trimmer H, Sannagowdara K, Balakrishnan B, Farias-Moeller R. A case of HIV seroconversion presenting similarly to anti-N-methyl-D-aspartate receptor encephalitis. Neurocrit Care 2019;31:423–7. https://doi.org/10.1007/s12028-019-00805-5. Seeck M, Zaim S, Chaves-Vischer V, Blanke O, Maeder-Ingvar M, Weissert M, et al. Ictal bradycardia in a young child with focal cortical dysplasia in the right insular cortex. Eur J Paediatr Neurol EJPN Off J Eur Paediatr Neurol Soc 2003;7:177–81. https://doi.org/10.1016/s1090-3798(03)00051-5. Koutroumanidis M. Autonomic symptoms during childhood partial epileptic seizures. Epilepsia 2007;48:1216–7; author reply 1217-1218. https://doi.org/10.1111/j.1528-1167.2007.01155_2.x. Tényi D, Bóné B, Horváth R, Komoly S, Illés Z, Beier CP, et al. Ictal piloerection is associated with high-grade glioma and autoimmune encephalitis-results from a systematic review. Seizure 2019;64:1–5. https://doi.org/10.1016/j.seizure.2018.11.009. Loddenkemper T, Kellinghaus C, Gandjour J, Nair DR, Najm IM, Bingaman W, et al. Localising and lateralising value of ictal piloerection. J Neurol Neurosurg Psychiatry 2004;75:879–83. https://doi.org/10.1136/jnnp.2003.023333. Roze E, Oubary P, Chédru F. Status-like recurrent pilomotor seizures: Case report and review of the literature. J Neurol Neurosurg Psychiatry 2000;68:647–9. https://doi.org/10.1136/jnnp.68.5.647. Tatum WO 4th. Mesial temporal lobe epilepsy. J Clin Neurophysiol Off Publ Am Electroencephalogr Soc 2012;29:356–65. https://doi.org/10.1097/WNP.0b013e31826b3ab7. Rocamora R, Becerra JL, Fossas P, Gomez M, Vivanco-Hidalgo RM, Mauri JA, et al. Pilomotor seizures: An autonomic semiology of limbic encephalitis? Seizure 2014;23:670–3. https://doi.org/10.1016/j.seizure.2014.04.013. McGinty RN, Handel A, Moloney T, Ramesh A, Fower A, Torzillo E, et al. Clinical features which predict neuronal surface autoantibodies in new-onset focal epilepsy: Implications for immunotherapies. J Neurol Neurosurg Psychiatry 2021;92:291–4. https://doi.org/10.1136/jnnp-2020-325011. Finke C, Prüss H, Heine J, Reuter S, Kopp UA, Wegner F, et al. Evaluation of cognitive deficits and structural hippocampal damage in encephalitis with leucine-rich, glioma-inactivated 1 antibodies. JAMA Neurol 2017;74:50–9. https://doi.org/10.1001/jamaneurol.2016.4226. Pondrelli F, Giannoccaro MP, Bisulli F, Ferri L, Menghi V, Mostacci B, et al. Pilomotor seizures in autoimmune limbic encephalitis: Description of two GAD65 antibodies- related cases and literature review. Seizure 2022;98:71–8. https://doi.org/10.1016/j.seizure.2022.03.025. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 28 Apr, 2026 Read the published version in Acta Epileptologica → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9071232","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":605279268,"identity":"81022232-59ca-4049-9b0d-66323511945f","order_by":0,"name":"Zhijun Le","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Zhijun","middleName":"","lastName":"Le","suffix":""},{"id":605279269,"identity":"d4eb397f-c4ce-490f-8c10-ce1516d5ad11","order_by":1,"name":"Bingqian Li","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Bingqian","middleName":"","lastName":"Li","suffix":""},{"id":605279270,"identity":"3e9ddd31-5be5-4b23-ac63-345eabcbbfcf","order_by":2,"name":"Hesheng Zhang","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Hesheng","middleName":"","lastName":"Zhang","suffix":""},{"id":605279272,"identity":"b793fdab-4e21-4690-8bad-942494311cbf","order_by":3,"name":"Yujie Chen","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Yujie","middleName":"","lastName":"Chen","suffix":""},{"id":605279273,"identity":"25eebdb9-4746-460b-9ec6-a8ef0c87aca9","order_by":4,"name":"Raowei Yan","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Raowei","middleName":"","lastName":"Yan","suffix":""},{"id":605279275,"identity":"5fe65058-c43d-4995-9d65-327e3e13d2db","order_by":5,"name":"Dong Zhou","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Dong","middleName":"","lastName":"Zhou","suffix":""},{"id":605279277,"identity":"3fb0b7f3-6e83-4228-a70b-e4dbd6096ba7","order_by":6,"name":"Jiani Chen","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Jiani","middleName":"","lastName":"Chen","suffix":""},{"id":605279279,"identity":"1462612b-9003-4046-8ed8-0271e28635a4","order_by":7,"name":"Xintong Wu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAtklEQVRIiWNgGAWjYBACefbm4x8/VNTI8ROtxbDnWBqzxJljxpINROu54WPGwNvGnLjhALE6GGewpT2QOMOWuPl48gaGHxXbCGthl24+blBQIWO87cyzAsaeM7eJsGXOsQQJoC2y227kGDAzthGhhQGoUgLoF8bNM0jQYgbSorhBglgtwEBONgYFsgTQLweJ8gswKg8+BEdle/LGBz8qiHEYAiQYHCBJPVgLqTpGwSgYBaNghAAAsg1BcIj9O3sAAAAASUVORK5CYII=","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":true,"prefix":"","firstName":"Xintong","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2026-03-09 09:39:58","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9071232/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9071232/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s42494-026-00260-8","type":"published","date":"2026-04-28T15:57:49+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":104668699,"identity":"d08dc9d0-bb82-4bdf-9c60-03df6a4c5971","added_by":"auto","created_at":"2026-03-15 16:54:39","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1356240,"visible":true,"origin":"","legend":"\u003cp\u003eIctal EEG Patterns and Piloerection in Patients During Seizure Monitoring. (A) Scalp ictal EEG in Case 4 demonstrated 2–3 Hz rhythmic slow-wave activity, a pattern also observed in Cases 1, 3, 5, 7, and 8. (B) In Case 12, the ictal EEG began as rhythmic 7–8 Hz activity, which subsequently evolved into 3–5 Hz discharges. (C) Case 6 exhibited seizure onset with EEG activity originating from the frontocentral region. (D) Piloerection was observed in Case 1 during the seizure episode.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9071232/v1/0377fc4493b7b3049e36949f.png"},{"id":108437630,"identity":"78456a49-d9f3-42e4-9c89-e62b895e3ad9","added_by":"auto","created_at":"2026-05-04 16:00:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1616388,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9071232/v1/88a32d7d-af3d-44af-8e35-6ae503279e4f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical and electroencephalogram characteristics of pilomotor seizures","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePiloerection, often referred to\u0026nbsp;\u0026ldquo;goose bumps\u0026rdquo;, is a physiological phenomenon characterized by contraction of the arrector pili muscles in response to cold exposure or emotional stimuli[1]. Autonomic control of choriocapillaris movements was reported in a very small number of cases[2]. It suggests that this response is primarily mediated by autonomic nervous system, with the hypothalamus, limbic system, and frontal cortex involved in key regulatory roles.\u003c/p\u003e\n\u003cp\u003ePiloerection is defined as an autonomic phenomenon descriptor in the ILAE 2025 position paper on the classification of epileptic seizures[3]. In clinical practice, pilomotor seizures are often misdiagnosed as anxiety or depression if accompanied by emotional symptoms such as fear or other autonomic manifestations[4].\u003c/p\u003e\n\u003cp\u003eWe summarized in detail the clinical features and epileptogenic zones of 13 cases of pilomotor seizures and provided a literature review.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe conducted a retrospective review of patients with epilepsy who underwent video-electroencephalogram (VEEG) monitoring at the Epilepsy Center of West China Hospital, Sichuan University, between January 2021 and October 2024. For those patients who meet the 2017 International League Against Epilepsy (ILAE) diagnostic criteria for epilepsy, we will have their history data reviewed to look for the presence of piloerection[3]. Cases exhibiting pilomotor seizures were identified based on synchronized video documentation or clinical confirmation of ictal manifestations through direct observation by the medical team or family members, or via patient self-report.\u003c/p\u003e\n\u003cp\u003eFor all enrolled patients, we collected demographic data, semiology characteristics, and disease progression profiles. These clinical parameters were integrated with multimodal neuroimaging and neurophysiological findings, followed by a comprehensive evaluation of the epileptogenic zone.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eAmong 8,482 patients diagnosed with epilepsy, seventeen patients presented with piloerection as the ictal semiology. Four of them were excluded because of incomplete clinical data. In total, the data of the remaining 13 right - handed patients (6 males, 7 females) were analyzed. The mean age was 36.7 \u0026plusmn; 10.9 years. The mean age at onset was 32.2 \u0026plusmn; 12.7 years. Ten patients experienced seizures during VEEG monitoring.\u003c/p\u003e\n\u003cp\u003eSemiology\u003c/p\u003e\n\u003cp\u003eIn all 13 cases, piloerection manifested as an integral component with other clinical presentation. Each patient demonstrated autonomic manifestations, including tachycardia, epigastric distress, nausea/vomiting, sweating, or olfactory hallucinations, d\u0026eacute;j\u0026agrave; vu, limb paresthesia, altered consciousness, automatisms, or progression to generalized tonic-clonic seizures. The topographic progression of piloerection was shown in Table 1.\u003c/p\u003e\n\u003cp\u003eEEG and imaging findings\u003c/p\u003e\n\u003cp\u003eInterictal epileptiform discharges (IEDs) were identified in 11 out of 13 patients (84.6%). The temporal region was the predominant localization (8 cases: 4 right, 1 left, and 3 bilateral). The remaining cases exhibited IEDs in the middle line (1 case), the left frontotemporal region (1 case), or bilateral temporoparietal areas (1 case). Ictal EEG recordings were successfully obtained in 10 patients. Temporal lobe onset was documented in 7 cases (3 left-sided, 3 right-sided, and 1 bilateral). Extra-temporal origin included the left frontotemporal region (2 cases) and the left frontal lobe (1 case). MRI revealed temporal lobe or hippocampal abnormalities in 9 patients, while 4 patients demonstrated normal imaging findings.\u003c/p\u003e\n\u003cp\u003eEtiology\u003c/p\u003e\n\u003cp\u003eStructural changes were identified in 9 patients via brain MRI, including 8 with temporal lobe/hippocampal abnormalities (2 potentially autoimmune-related) and 1 with frontal vascular malformation. Autoimmune testing in 6 cases found 1 LGI1 antibody-positive case. The remaining 5 patients had undetermined etiologies despite comprehensive evaluation.\u003c/p\u003e\n\u003cp\u003eTreatment response\u003c/p\u003e\n\u003cp\u003eNine patients achieved significant seizure control with anti-seizure medications (ASMs). One patient discontinued medication voluntarily but remained seizure-free during 1 year follow-up. Case 4 underwent left temporal epileptogenic focus resection with selective hippocampectomy and has been seizure-free for nine months postoperatively. Three patients showed a poor therapeutic response. Case 6 continues to experience 3-4 monthly seizures despite treatment with four ASMs.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 1. Demographic and clinical characteristics of patients with pilomotor seizures.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCase Num.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eFirst seizure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePilo onset region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSpreading to\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSemiology\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eIEDs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eEEG onset\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMRI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePET\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eSPECT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCSF autoantibodies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eEtilology\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eASMs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eRelevent medical history\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRUL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ed\u0026eacute;j\u0026agrave; vu, pilo, R limbs numbness, olfactory hallucinations\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: 1-2 Hz slow wave\u0026rarr;4-5 Hz rhythmic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ehypermetabolic in the right portion of the clivus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to LCM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003enasopharyngeal carcinoma\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR or L limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eincreased heart rate, pilo, swallowing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F T: 2-3 Hz rhythmic slow wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T: cavernous angioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003epoor response to LEV, VPA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLUL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eleft limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL limbs numbness, pilo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR or L T: 4-5 Hz rhythmic\u0026rarr;2-3 Hz rhythmic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA, seizure free\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebilateral limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003echill, palpitation, pilo\u0026rarr;swallowing/chewing, leftward gaze\u0026rarr;asymmetric tonic posturing\u0026rarr;GTCS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003emiddle line: SWC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F T: 2-3 Hz rhythmic slow wave\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL HS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL HS; hypometabolic in L T; L FCD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ehyperperfusion in L T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL: HS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to L T H operation and LEV, ZNS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRUL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eincreased heart rate, auditory hallucinations, pilo\u0026rarr;sweating\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T: 2-3 Hz slow waves\u0026rarr;2-4 Hz SWC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enodule in R T, probable cystic lesion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to PER\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003etachycardia, laughter, head deviation to R, LOC\u0026rarr;RUL flexion, RLL extension, L limbs hyperkinetic movements\u0026rarr;lips pursing, left-hand automatisms\u0026rarr;postictal aphasia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F: rhythmic sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL F: vascular malformation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003epoor response to OXC, VPA, PER, LEV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLUL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eprecordial tightness, pilo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: 3-4 Hz rhythmic slow wave\u0026rarr;2-3 Hz SWC\u0026rarr;2-3 Hz rhythmic slow waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi H and amygdala\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ehypermetabolic in bi H and amygdala; hypometabolic in bi F\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ehyperperfusion in the R T H, insula, basal ganglia region, thalamus and parieto-occipital junction region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLGI1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eautoimmune encephalitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003epoor response to LEV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL face\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno spreading\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLOC, pilo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi T and bi P: spikes and sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: 2-3 Hz SWC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL H smaller than contralateral, normal signal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elupus encephalitis?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to LEV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;metabolic encephalopathy at 14; diagnosed with SLE at 20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi face and bi upper limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno spreading\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eoptical hallucination, increased heart rate, pilo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno IEDs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T: 6-7 Hz slow waves\u0026rarr;L F T:4-5 Hz slow waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eviral encephalitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eOXC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eRUL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebilateral limbs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eolfactory hallucinations,pilo, d\u0026eacute;j\u0026agrave; vu, GTCS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno IEDs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno ictal EEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003elupus encephalitis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to LEV, LCM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ediagnosed with SLE at 23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebilateral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003efear, pilo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno ictal EEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to VPA, LCM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ewhole body\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003efear, palpitations, chills, pilo, and rising epigastric sensation\u0026rarr;repeated swallowing, tachycardia, tachypnea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi T: sharp waves and spike\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eL T: 7-8 Hz rhythmic\u0026rarr;3-5 Hz rhythmic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi HS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi HS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003enegative\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ebi HS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to VPA, LCM, ZNS, LEV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ediagnosed with viral encephalitis at 16\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eface\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003efear, pilo, GTCS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T: sharp waves\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eno ictal EEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eR T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eunclear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003egood response to LCM, LEV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ecraniotomy for sellar meningioma at 56\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ePilo: piloerection; IEDs: interictal epileptiform discharges; MRI: magnetic resonance imaging; PET: positron emission tomography; SPECT: single-photon emission computed tomography; CSF: cerebrospinal fluid; ASMs: anti-seizure medications; M: male; F: female; R: right; L: left; UL: upper limb; LL: lower limb; T: temporal; LCM: lacosamide; F: frontal; LEV: levetiracetam; VPA: valproic acid; GTCS: generalized tonic-clonic seizures; SWC: spike and wave complex; H: hippocampus; S: sclerosis; FCD: focal cortical dysplasia; ZNS: zonisamide; PER: perampanel; LOC: loss of consciousness; OXC: oxcarbazepine; SLE: systemic lupus erythematosu\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe pilomotor seizure is a rare autonomic symptom of focal epileptic seizures, which may be overlooked during diagnosis. We reported 13 cases of pilomotor seizures to explore the origin and related networks.\u003c/p\u003e\n\u003cp\u003eIn the skin, the sympathetic nervous system, the arrector pili muscle (APM; of mesenchymal origin), and the hair follicle (HF; of epithelial origin) form a functionally integrated tri-lineage unit. The APM is anchored to the bulge region of the hair follicle and receives direct sympathetic innervation, enabling coordinated piloerection[5]. The neural circuit of piloerection is triggered by temperature or emotional stimuli and involves multi-level integration of the central and autonomic nervous systems[6]. The temperature-triggered pathway begins with cutaneous cold receptors (e.g., TRPM8), which are activated by low temperatures and transmit signals via A\u0026delta;/C fibers to the spinal dorsal horn. These signals then ascend through the spinothalamic tract to the parabrachial nucleus in the brainstem, which further activates neurons in the hypothalamic preoptic area[7]. The emotion-triggered pathway originates in the amygdala, which receives emotional signals (e.g., fearful or moving), and relays them to the hypothalamic paraventricular nucleus (PVN) for integration[8]. Both pathways ultimately converge as hypothalamic signals descend through the brainstem to the spinal intermediolateral column (IML). Postganglionic sympathetic fibers release norepinephrine, which acts on \u0026alpha;1-adrenergic receptors in the arrector pili muscles to induce piloerection[9]. This neural activity is also modulated by higher cortical centers, including the prefrontal cortex (PFC) and anterior cingulate cortex (ACC)[10,11]. The ictal piloerection observed in pilomotor seizures may result from pathological hyperactivation of the sympathetic-cutaneous circuitry, the thalamus or amygdala, by epileptogenic networks.\u003c/p\u003e\n\u003cp\u003eIn our case series, pilomotor seizures predominantly affected adults. Among 13 cases, the mean age of the first seizure was 32.2 years (range: 16-57), with 11 cases occurring at adulthood and 2 cases at 16 years. This age distribution may be caused by the predominantly adult population treated at our epilepsy center. The literature review of 104 cases revealed that among 64 patients with documented age of onset, the mean age was 40.4 years (range: 1-82), with 56 cases occurring in adulthood. The underreporting of \u0026quot;goosebumps\u0026quot; by pediatric patients may be attributed to the phenomenon. A few studies reported piloerection in pediatric epilepsy patients [12,13]. In a retrospective study, it was found that while 60 children exhibited autonomic symptoms, none demonstrated piloerection[14]. These findings suggest that pilomotor seizures may be associated with neurological development and maturation. This may also be attributed to the underreporting of piloerection by pediatric patients, which necessitates more careful observation by caregivers and more detailed inquiry during history-taking.\u003c/p\u003e\n\u003cp\u003ePilomotor seizures exhibit a strong predilection for temporal lobe origin. In our case series, 11 of 13 patients demonstrated temporal lobe origin. This finding aligns with our literature review of 60 well-localized cases, which identified temporal lobe onset in 55 patients, consistent with established reports[15,16]. It suggests approximately 10% of pilomotor seizures originate from extra-temporal regions, with frontal and parietal lobes being the most frequently involved[17].\u003c/p\u003e\n\u003cp\u003eIctal EEG recordings in 7 out of 9 temporal lobe cases revealed distinctive rhythmic delta activity (1-4Hz). Given that the characteristic theta rhythm is typically observed in mesial temporal lobe epilepsy[18], this potentially indicated unique pathophysiological mechanisms and precise localizing value in pilomotor seizures.\u003c/p\u003e\n\u003cp\u003eThe lateralizing value of pilomotor seizures is not fully understood. In our series of 13 cases, 9 clearly exhibited unilateral onset of piloerection. Among these, 2 patients showed strictly ipsilateral propagation, while 7 cases exhibited contralateral spread. The initial side of piloerection was contralateral to the epileptogenic zone in 6 cases, with only 1 case showing ipsilateral correspondence. Previous studies have primarily focused on documenting the presence or distribution of piloerection, while systematic characterization of its initial localization and propagation patterns has been lacking. We emphasize the importance of recording both the originating side and spreading characteristics of pilomotor manifestations, which may provide valuable lateralizing information for the epileptogenic zone.\u0026nbsp;Given that epilepsy is a network disease, localizing the epileptogenic zone based solely on piloerection requires caution.\u0026nbsp;However, the localizing value of this stereotyped clinical manifestation occurring at seizure onset should not be underestimated.\u003c/p\u003e\n\u003cp\u003ePilomotor seizures may demonstrate significant associations with specific etiologies, particularly autoimmune encephalitis and nervous system tumors. In our series of 13 cases, one tested positive for LGI1 antibodies, while two others had comorbid systemic lupus erythematosus. A systematic literature review of 104 cases identified 30 patients with confirmed autoimmune encephalitis. And approximately 25% of pilomotor seizure cases were associated with gliomas or limbic encephalitis[15]. Pilomotor seizures occur in about 0.65% of patients with refractory temporal lobe epilepsy [19], whereas the prevalence rises to 13.3%-14% in limbic encephalitis populations [20\u0026ndash;22]. These suggest that pilomotor seizure may possess distinct pathophysiological underpinnings linked to immune-mediated neuroinflammatory processes.\u003c/p\u003e\n\u003cp\u003eThe majority of patients with pilomotor seizures demonstrate favorable responses to anti-seizure medications (ASMs), achieving adequate seizure control through standardized treatment protocols. In cases where the underlying etiology is identifiable, a multimodal therapeutic approach is indicated.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur study demonstrates a strong predilection for temporal lobe origin. These seizures are characterized by specific ictal EEG patterns, notably rhythmic delta activity, and are almost invariably accompanied by other autonomic or psychic symptoms.\u003c/p\u003e \u003cp\u003eAnd detailed documentation of the piloerection's onset region and spreading pattern may provide valuable lateralizing information. While pilomotor seizures are often overlooked or misdiagnosed, enhanced recognition and systematic characterization of this semiological feature are crucial for accurate diagnosis, localization, and targeted management of epilepsies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eNon- applicable.\u003c/p\u003e\n\u003cp\u003eAuthors\u0026rsquo; contributions\u003c/p\u003e\n\u003cp\u003eZ.L. and B.L. wrote the main manuscript text and collected the data. H.Z., Y.C., and R.Y. contributed to data analysis and interpretation. D.Z., J.C., and X.W. supervised the project and revised the manuscript. All authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis study is supported by the National Key R\u0026amp;D Program of China (No.2021YFC2401204, 2022YFC2503805).\u003c/p\u003e\n\u003cp\u003eData availability\u003c/p\u003e\n\u003cp\u003eThe datasets generated for this study are available upon request from the corresponding author.\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from patients or their families. The study was approved by the Ethics Committee Biomedical Research, West China Hospital of Sichuan University.\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eThe publication of Case1 arm piloerection photo has obtained the patient\u0026apos;s informed consent.\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003eAll authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBenedek M, Kaernbach C. Physiological correlates and emotional specificity of human piloerection. Biol Psychol 2011;86:320\u0026ndash;9. https://doi.org/10.1016/j.biopsycho.2010.12.012.\u003c/li\u003e\n\u003cli\u003eHeathers JAJ, Fayn K, Silvia PJ, Tiliopoulos N, Goodwin MS. The voluntary control of piloerection. PeerJ 2018;6:e5292. https://doi.org/10.7717/peerj.5292.\u003c/li\u003e\n\u003cli\u003eBeniczky S, Trinka E, Wirrell E, et al. Updated classification of epileptic seizures: Position paper of the International League Against Epilepsy. Epilepsia. 2025;66(6):1804-1823. doi:10.1111/epi.18338\u003c/li\u003e\n\u003cli\u003eLam EM, Worrell GA, Laughlin RS. Semiology of the rare seizure subtype piloerection. Arch Neurol 2010;67:1524\u0026ndash;7. https://doi.org/10.1001/archneurol.2010.304.\u003c/li\u003e\n\u003cli\u003eShwartz Y, Gonzalez-Celeiro M, Chen C-L, Pasolli HA, Sheu S-H, Fan SM-Y, et al. Cell types promoting goosebumps form a niche to regulate hair follicle stem cells. Cell 2020;182:578-593.e19. https://doi.org/10.1016/j.cell.2020.06.031.\u003c/li\u003e\n\u003cli\u003eMcKemy DD, Neuhausser WM, Julius D. Identification of a cold receptor reveals a general role for TRP channels in thermosensation. Nature 2002;416:52\u0026ndash;8. https://doi.org/10.1038/nature719.\u003c/li\u003e\n\u003cli\u003eNakamura K, Morrison SF. A thermosensory pathway mediating heat-defense responses. Proc Natl Acad Sci U S A 2010;107:8848\u0026ndash;53. https://doi.org/10.1073/pnas.0913358107.\u003c/li\u003e\n\u003cli\u003eLeDoux JE. Emotion circuits in the brain. Annu Rev Neurosci 2000;23:155\u0026ndash;84. https://doi.org/10.1146/annurev.neuro.23.1.155.\u003c/li\u003e\n\u003cli\u003eRoosterman D, Goerge T, Schneider SW, Bunnett NW, Steinhoff M. Neuronal control of skin function: The skin as a neuroimmunoendocrine organ. Physiol Rev 2006;86:1309\u0026ndash;79. https://doi.org/10.1152/physrev.00026.2005.\u003c/li\u003e\n\u003cli\u003eCritchley H, Daly E, Phillips M, Brammer M, Bullmore E, Williams S, et al. Explicit and implicit neural mechanisms for processing of social information from facial expressions: A functional magnetic resonance imaging study. Hum Brain Mapp 2000;9:93\u0026ndash;105. https://doi.org/10.1002/(SICI)1097-0193(200002)9:2\u0026amp;#x0003c;93::AID-HBM4\u0026amp;#x0003e;3.0.CO;2-Z.\u003c/li\u003e\n\u003cli\u003eCritchley HD, Mathias CJ, Josephs O, O\u0026rsquo;Doherty J, Zanini S, Dewar B-K, et al. Human cingulate cortex and autonomic control: Converging neuroimaging and clinical evidence. Brain J Neurol 2003;126:2139\u0026ndash;52. https://doi.org/10.1093/brain/awg216.\u003c/li\u003e\n\u003cli\u003eVanDongen-Trimmer H, Sannagowdara K, Balakrishnan B, Farias-Moeller R. A case of HIV seroconversion presenting similarly to anti-N-methyl-D-aspartate receptor encephalitis. Neurocrit Care 2019;31:423\u0026ndash;7. https://doi.org/10.1007/s12028-019-00805-5.\u003c/li\u003e\n\u003cli\u003eSeeck M, Zaim S, Chaves-Vischer V, Blanke O, Maeder-Ingvar M, Weissert M, et al. Ictal bradycardia in a young child with focal cortical dysplasia in the right insular cortex. Eur J Paediatr Neurol EJPN Off J Eur Paediatr Neurol Soc 2003;7:177\u0026ndash;81. https://doi.org/10.1016/s1090-3798(03)00051-5.\u003c/li\u003e\n\u003cli\u003eKoutroumanidis M. Autonomic symptoms during childhood partial epileptic seizures. Epilepsia 2007;48:1216\u0026ndash;7; author reply 1217-1218. https://doi.org/10.1111/j.1528-1167.2007.01155_2.x.\u003c/li\u003e\n\u003cli\u003eT\u0026eacute;nyi D, B\u0026oacute;n\u0026eacute; B, Horv\u0026aacute;th R, Komoly S, Ill\u0026eacute;s Z, Beier CP, et al. Ictal piloerection is associated with high-grade glioma and autoimmune encephalitis-results from a systematic review. Seizure 2019;64:1\u0026ndash;5. https://doi.org/10.1016/j.seizure.2018.11.009.\u003c/li\u003e\n\u003cli\u003eLoddenkemper T, Kellinghaus C, Gandjour J, Nair DR, Najm IM, Bingaman W, et al. Localising and lateralising value of ictal piloerection. J Neurol Neurosurg Psychiatry 2004;75:879\u0026ndash;83. https://doi.org/10.1136/jnnp.2003.023333.\u003c/li\u003e\n\u003cli\u003eRoze E, Oubary P, Ch\u0026eacute;dru F. Status-like recurrent pilomotor seizures: Case report and review of the literature. J Neurol Neurosurg Psychiatry 2000;68:647\u0026ndash;9. https://doi.org/10.1136/jnnp.68.5.647.\u003c/li\u003e\n\u003cli\u003eTatum WO 4th. Mesial temporal lobe epilepsy. J Clin Neurophysiol Off Publ Am Electroencephalogr Soc 2012;29:356\u0026ndash;65. https://doi.org/10.1097/WNP.0b013e31826b3ab7.\u003c/li\u003e\n\u003cli\u003eRocamora R, Becerra JL, Fossas P, Gomez M, Vivanco-Hidalgo RM, Mauri JA, et al. Pilomotor seizures: An autonomic semiology of limbic encephalitis? Seizure 2014;23:670\u0026ndash;3. https://doi.org/10.1016/j.seizure.2014.04.013.\u003c/li\u003e\n\u003cli\u003eMcGinty RN, Handel A, Moloney T, Ramesh A, Fower A, Torzillo E, et al. Clinical features which predict neuronal surface autoantibodies in new-onset focal epilepsy: Implications for immunotherapies. J Neurol Neurosurg Psychiatry 2021;92:291\u0026ndash;4. https://doi.org/10.1136/jnnp-2020-325011.\u003c/li\u003e\n\u003cli\u003eFinke C, Pr\u0026uuml;ss H, Heine J, Reuter S, Kopp UA, Wegner F, et al. Evaluation of cognitive deficits and structural hippocampal damage in encephalitis with leucine-rich, glioma-inactivated 1 antibodies. JAMA Neurol 2017;74:50\u0026ndash;9. https://doi.org/10.1001/jamaneurol.2016.4226.\u003c/li\u003e\n\u003cli\u003ePondrelli F, Giannoccaro MP, Bisulli F, Ferri L, Menghi V, Mostacci B, et al. Pilomotor seizures in autoimmune limbic encephalitis: Description of two GAD65 antibodies- related cases and literature review. Seizure 2022;98:71\u0026ndash;8. https://doi.org/10.1016/j.seizure.2022.03.025.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-9071232/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9071232/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003ePiloerection, a physiological response to cold or emotional stimuli, is a rare autonomic manifestation of epileptic seizures. The literature on pilomotor seizures remains limited, with its anatomical correlates and electrophysiological mechanisms poorly understood.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective analysis of 13 patients with pilomotor seizures identified from 8,482 individuals monitored at Epilepsy Center of West China Hospital. Demographic data, seizure characteristics, neuroimaging, and neurophysiological findings were analyzed to determine the epileptogenic zone and associated etiologies.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eOur case series revealed a strong predilection for temporal lobe origin (11/13 patients), with distinctive ictal EEG patterns including rhythmic delta activity. Piloerection was consistently accompanied by other autonomic or psychic symptoms. Most patients responded favorably to anti-seizure medications.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003ePilomotor seizures are associated with temporal lobe epilepsy and are characterized by distinctive ictal EEG patterns, particularly rhythmic delta activity, and are frequently associated with specific etiologies such as autoimmune encephalitis.\u003c/p\u003e","manuscriptTitle":"Clinical and electroencephalogram characteristics of pilomotor seizures","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-15 16:54:27","doi":"10.21203/rs.3.rs-9071232/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2ef9f168-21fc-4c3e-a031-32e35ca3ee62","owner":[],"postedDate":"March 15th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T15:59:57+00:00","versionOfRecord":{"articleIdentity":"rs-9071232","link":"https://doi.org/10.1186/s42494-026-00260-8","journal":{"identity":"acta-epileptologica","isVorOnly":false,"title":"Acta Epileptologica"},"publishedOn":"2026-04-28 15:57:49","publishedOnDateReadable":"April 28th, 2026"},"versionCreatedAt":"2026-03-15 16:54:27","video":"","vorDoi":"10.1186/s42494-026-00260-8","vorDoiUrl":"https://doi.org/10.1186/s42494-026-00260-8","workflowStages":[]},"version":"v1","identity":"rs-9071232","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9071232","identity":"rs-9071232","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}