{"paper_id":"43ce983e-b9fa-42e5-b513-61dbfb9c4d17","body_text":"Contralateral cerebellar atrophy in Rasmussen’s syndrome: a case report | 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 Case Report Contralateral cerebellar atrophy in Rasmussen’s syndrome: a case report Roger Guy Pilo Ndibo, Fabrice Zobel Lekeumo Cheuyem, Orel Kelvin Ndouandju Saha, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7810897/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction Rasmussen's syndrome is a rare and devastating chronic progressive encephalitis, characterized by unilateral brain inflammation, pharmaco-resistant focal epilepsy, and progressive neurological deficit. This case report describes the magnetic resonance imaging (MRI) findings in a 12-year-old child with Rasmussen's syndrome, illustrating the rare feature of contralateral cerebellar atrophy. Case presentation The patient presented with status epilepticus and progressive hemiparesis. Cerebral MRI demonstrated the characteristic lesions of the disease: right hemispheric atrophy, FLAIR hyperintensities of the subcortical white matter, and ipsilateral ventricular enlargement. The notable element was the discovery of left cerebellar atrophy. The diagnosis of Rasmussen's syndrome was established based on the clinical evolution and radiological data. Conclusion This study contributes to medical literature by supporting the pathophysiological hypothesis of trans-synaptic degeneration along the crossed cortico-ponto-cerebellar pathways, secondary to the progressive destruction of the cerebral hemisphere. This case highlights that contralateral cerebellar atrophy should be recognized as a possible manifestation in the advanced evolution of this encephalitis, thus enriching the spectrum of its MRI manifestations and assisting in differentiating the disease from other entities responsible for unilateral cerebral atrophy. Nuclear Medicine & Medical Imaging Rasmussen's syndrome cerebellar atrophy trans-synaptic degeneration cerebral MRI focal epilepsy Figures Figure 1 Figure 2 Figure 3 Introduction Rasmussen's syndrome is a rare and devastating chronic progressive encephalitis, characterized by unilateral brain inflammation, pharmaco-resistant focal epilepsy, and progressive neurological deficit [ 1 ]. The disease primarily affects children, with a median age of onset around six years, and leads to irreversible cortical hemispheric atrophy [ 2 , 3 ]. Diagnosis relies on suggestive clinical presentation, electroencephalographic data, and characteristic findings on magnetic resonance imaging (MRI), which typically progress from focal cortical edema to marked hemispheric atrophy with T2/FLAIR hyperintensities of the subcortical white matter [ 1 , 4 ]. While atrophy of the affected cerebral hemisphere is a cardinal feature of the syndrome, the observation of contralateral cerebellar atrophy is much rarer and less described in the literature. A few reported cases suggest that this involvement may result from a phenomenon of trans-synaptic degeneration of the crossed cortico-ponto-cerebellar pathways, following prolonged destruction of the contralateral cerebral cortex [ 2 , 5 ]. Documentation of this specific manifestation through sequential imaging remains exceptional. We report the case of a 12-year-old child presenting with status epilepticus, revealing typical Rasmussen's syndrome of the right hemisphere, associated with progressive contralateral left cerebellar atrophy, evidenced by MRI. This case offers an opportunity to describe this poorly understood phenomenon and support the pathophysiological hypothesis of retrograde trans-synaptic degeneration. Our objective is to underscore the importance of this atypical radiological entity, which can complicate the clinical picture and broaden the differential diagnosis. Case presentation Patient information The patient was a 12-year-old female who had been presenting for several months with drug-refractory focal epilepsy and progressive motor impairment. Her medical history included chronic recurrent bilateral parotitis. Clinical findings Neurological examination revealed a moderate (3/5) proportional left hemiparesis, as well as balance disturbances. A complementary imaging workup, specifically a cerebral MRI with gadolinium injection, was recommended. Diagnostic approach MRI demonstrated atrophy of the right cerebral hemisphere with moderate ex vacuo enlargement of the ipsilateral ventricular system and widening of the cortical sulci (Fig. 1 ). Furthermore, diffuse FLAIR hyperintensities were observed in the right subcortical white matter (Fig. 2 ). Additionally, left cerebellar atrophy was identified (Fig. 3 ). Diagnosis The MRI presentation was highly suggestive of chronic hemispheric encephalitis within the framework of Rasmussen's syndrome, characterized by typical unilateral right cortico-subcortical atrophy and associated inflammatory involvement of the white matter, without tumor or vascular features (gliosis). The particularity of this case resided in the associated contralateral cerebellar atrophy, consistent with secondary trans-synaptic degeneration. Follow-up The patient was referred to a neurologist for better management and is currently awaiting definitive seizure treatment (hemispherectomy). Discussion Rasmussen's syndrome is a chronic progressive encephalitis that typically affects only one cerebral hemisphere [ 6 , 7 ]. Contralateral cerebellar atrophy is not classic, but it is increasingly recognized as a possible complication in advanced stages of the disease. The scientific literature proposes two main mechanisms to explain it. This includes first, the trans-synaptic degeneration (or \"crossed cerebellar diaschisis\") which is the most frequently cited mechanism. In this pattern, the nerve fibers connecting the cerebral cortex to the cerebellum form crossed cortico-ponto-cerebellar pathways. A long-lasting, unilateral brain lesion leads to a disconnection of these pathways, ultimately causing secondary atrophy of the contralateral cerebellum [ 5 , 8 ]. Secondly, The primary inflammatory involvement which was described in a recent and larger study suggested that the characteristic inflammation of Rasmussen’s syndrome could, in certain cases, directly extend and primarily affect the ipsilateral cerebellum (on the same side as the cerebral lesion), particularly when FLAIR hyperintensities are observed there [ 5 ]. In a cohort study including 57 patients conducted in 2021, cerebellar involvement was observed in numerous patients [ 5 ]. Two profiles were identified namely the contralateral and ipsilateral atrophies. The mechanism proposed for contralateral atrophy was that of trans-synaptic degeneration of the crossed cortico-ponto-cerebellar pathways. As for ipsilateral atrophy, the mechanism evoked was primary cerebellar inflammation. In a study conducted in 2021, the case of a 26-year-old patient who had been ill since age 8, demonstrated marked left cerebral atrophy, associated with ipsilateral brainstem atrophy and contralateral right cerebellar atrophy. He explained this by the long duration of the disease, specifically contralateral atrophy due to interruption of the cortico-ponto-cerebellar fibers (diaschisis) and brainstem atrophy due to Wallerian degeneration [ 8 ]. In earlier studies, including case reports and small series, contralateral cerebellar atrophy has been occasionally reported, consistent with the concept of crossed cerebellar diaschisis [ 5 ]. The management of Rasmussen’s syndrome aims to control epilepsy and slow the inflammatory process [ 9 ]. The prognosis is severe, but functional surgery can transform the evolution of the disease [ 5 ]. Conclusion Contralateral cerebellar atrophy, although rare, should be recognized as a possible manifestation of Rasmussen's syndrome in advanced stages, thereby enriching the spectrum of its MRI findings beyond the classic unilateral hemispheric atrophy. This observation supports the pathophysiological hypothesis of trans-synaptic degeneration along the crossed cortico-ponto-cerebellar pathways and underscores the value of imaging for documenting the progression of this encephalitis, while also broadening the differential diagnosis in the face of asymmetric cerebral atrophy associated with contralateral cerebellar involvement. Abbreviations MRI Magnetic resonance imaging Declarations Ethical Approval Statement Informed consent was obtained in writing from the patient's legal guardian. Consent for Publication Informed consent was obtained in writing from the patient's legal guardian to publish this case report and any accompanying images. Competing interests All authors declare no conflict of interest. Funding Source This research did not receive any specific grant from funding agencies in the public, commercial, or non-profit sectors. Author Contribution All authors equally contributed to this manuscript. They read and approved its final version. Availability of data and materials Data sharing does not apply to this article as no dataset was generated or analyzed during the current study. References Yahya EH, Khadija L, Nourrelhouda B, Nazik A, Latifa C, Siham EH (2023) A Case Report of Rasmussen Encephalitis and its Stages: The Important Role of Imaging. Glob Pediatr Health 10:2333794X231214084 Vimal J, Nagarajan R, Sriram D (2015) Rasmussen’s encephalitis: A case report. Australas Med J 8(3):80–84 Klaa H, Ben Younes T, Benrhouma H, Nagi S, Rouissi A, Kraoua I et al (2020) Rasmussen’s Encephalitis: A Report of a Tunisian Pediatric Case and Literature Review. Case Rep Neurol Med. ; 2020:6810237 Tien RD, Ashdown BC, Lewis DV, Atkins MR, Burger PC (1992) Rasmussen’s encephalitis: neuroimaging findings in four patients. Am J Roentgenol 158(6):1329–1332 Reiter JT, David B, Enders S, Prillwitz CC, Bauer T, Atalay D et al (2021) Infratentorial MRI Findings in Rasmussen Encephalitis Suggest Primary Cerebellar Involvement. Neurol Neuroimmunol Neuroinflammation 8(6):e1058 Fornari Caprara AL, Rissardo JP, Nagele EP (2024) Rasmussen Encephalitis: Clinical Features, Pathophysiology, and Management Strategies—A Comprehensive Literature Review. Med (Mex) 60(11):1858 Varadkar S, Bien CG, Kruse CA, Jensen FE, Bauer J, Pardo CA et al (2014) Rasmussen’s encephalitis: clinical features, pathobiology, and treatment advances. Lancet Neurol 13(2):195–205 Agarwal A, Garg K, Gulati A, Gulati P (2021) Rasmussen Encephalitis with Ipsilateral Brain Stem and Contralateral Cerebellar Atrophy. Neurol India 69(4):1140 Peeke J, Tang-Wai R, Robison A, Achiriloaie A (2024) Rasmussen’s encephalitis in a pediatric patient with subtle early MRI changes: A case report. Radiol Case Rep 19(11):5496–5500 Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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14:41:59\",\"extension\":\"jpeg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":44642,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eAxial T1 MRI slice showing right hemispheric atrophy\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage1.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7810897/v1/feae5b904cebd7c12f88f2bb.jpeg\"},{\"id\":93343199,\"identity\":\"248f30f6-9efd-4411-803c-c8eecea8cf25\",\"added_by\":\"auto\",\"created_at\":\"2025-10-12 14:49:59\",\"extension\":\"jpeg\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":59877,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eAxial FLAIR MRI slice showing FLAIR hyperintensities of the subcortical white matter\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage2.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7810897/v1/d70ab3ebe500d9f432adb62b.jpeg\"},{\"id\":93342155,\"identity\":\"3aaac4e6-cb26-410f-82d7-673b8459a5c8\",\"added_by\":\"auto\",\"created_at\":\"2025-10-12 14:41:59\",\"extension\":\"jpeg\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":51967,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCoronal T2 MRI slice showing contralateral cerebellar atrophy\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage3.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7810897/v1/88d255649b3cac9ef914d7f2.jpeg\"},{\"id\":93343939,\"identity\":\"c95c6726-1d8c-47fa-b189-6a1ca97f07be\",\"added_by\":\"auto\",\"created_at\":\"2025-10-12 14:58:03\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":551440,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-7810897/v1/71553d9e-c546-406b-a96e-c0f9f889ffb0.pdf\"}],\"financialInterests\":\"The authors declare no competing interests.\",\"formattedTitle\":\"\\u003cp\\u003e\\u003cstrong\\u003eContralateral cerebellar atrophy in Rasmussen’s syndrome: a case report\\u003c/strong\\u003e\\u003c/p\\u003e\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eRasmussen's syndrome is a rare and devastating chronic progressive encephalitis, characterized by unilateral brain inflammation, pharmaco-resistant focal epilepsy, and progressive neurological deficit [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e]. The disease primarily affects children, with a median age of onset around six years, and leads to irreversible cortical hemispheric atrophy [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e]. Diagnosis relies on suggestive clinical presentation, electroencephalographic data, and characteristic findings on magnetic resonance imaging (MRI), which typically progress from focal cortical edema to marked hemispheric atrophy with T2/FLAIR hyperintensities of the subcortical white matter [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eWhile atrophy of the affected cerebral hemisphere is a cardinal feature of the syndrome, the observation of contralateral cerebellar atrophy is much rarer and less described in the literature. A few reported cases suggest that this involvement may result from a phenomenon of trans-synaptic degeneration of the crossed cortico-ponto-cerebellar pathways, following prolonged destruction of the contralateral cerebral cortex [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Documentation of this specific manifestation through sequential imaging remains exceptional.\\u003c/p\\u003e\\u003cp\\u003eWe report the case of a 12-year-old child presenting with status epilepticus, revealing typical Rasmussen's syndrome of the right hemisphere, associated with progressive contralateral left cerebellar atrophy, evidenced by MRI. This case offers an opportunity to describe this poorly understood phenomenon and support the pathophysiological hypothesis of retrograde trans-synaptic degeneration. Our objective is to underscore the importance of this atypical radiological entity, which can complicate the clinical picture and broaden the differential diagnosis.\\u003c/p\\u003e\"},{\"header\":\"Case presentation\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e\\u003ch2\\u003ePatient information\\u003c/h2\\u003e\\u003cp\\u003eThe patient was a 12-year-old female who had been presenting for several months with drug-refractory focal epilepsy and progressive motor impairment. Her medical history included chronic recurrent bilateral parotitis.\\u003c/p\\u003e\\u003c/div\\u003e\\n\\u003ch3\\u003eClinical findings\\u003c/h3\\u003e\\n\\u003cp\\u003eNeurological examination revealed a moderate (3/5) proportional left hemiparesis, as well as balance disturbances. A complementary imaging workup, specifically a cerebral MRI with gadolinium injection, was recommended.\\u003c/p\\u003e\\n\\u003ch3\\u003eDiagnostic approach\\u003c/h3\\u003e\\n\\u003cp\\u003eMRI demonstrated atrophy of the right cerebral hemisphere with moderate ex vacuo enlargement of the ipsilateral ventricular system and widening of the cortical sulci (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e). Furthermore, diffuse FLAIR hyperintensities were observed in the right subcortical white matter (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e). Additionally, left cerebellar atrophy was identified (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e).\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\u003cp\\u003e\\u003c/p\\u003e\\n\\u003ch3\\u003eDiagnosis\\u003c/h3\\u003e\\n\\u003cp\\u003eThe MRI presentation was highly suggestive of chronic hemispheric encephalitis within the framework of Rasmussen's syndrome, characterized by typical unilateral right cortico-subcortical atrophy and associated inflammatory involvement of the white matter, without tumor or vascular features (gliosis). The particularity of this case resided in the associated contralateral cerebellar atrophy, consistent with secondary trans-synaptic degeneration.\\u003c/p\\u003e\\n\\u003ch3\\u003eFollow-up\\u003c/h3\\u003e\\n\\u003cp\\u003eThe patient was referred to a neurologist for better management and is currently awaiting definitive seizure treatment (hemispherectomy).\\u003c/p\\u003e\"},{\"header\":\"Discussion\",\"content\":\"\\u003cp\\u003eRasmussen's syndrome is a chronic progressive encephalitis that typically affects only one cerebral hemisphere [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. Contralateral cerebellar atrophy is not classic, but it is increasingly recognized as a possible complication in advanced stages of the disease. The scientific literature proposes two main mechanisms to explain it. This includes first, the trans-synaptic degeneration (or \\\"crossed cerebellar diaschisis\\\") which is the most frequently cited mechanism. In this pattern, the nerve fibers connecting the cerebral cortex to the cerebellum form crossed cortico-ponto-cerebellar pathways. A long-lasting, unilateral brain lesion leads to a disconnection of these pathways, ultimately causing secondary atrophy of the contralateral cerebellum [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e]. Secondly, The primary inflammatory involvement which was described in a recent and larger study suggested that the characteristic inflammation of Rasmussen\\u0026rsquo;s syndrome could, in certain cases, directly extend and primarily affect the ipsilateral cerebellum (on the same side as the cerebral lesion), particularly when FLAIR hyperintensities are observed there [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eIn a cohort study including 57 patients conducted in 2021, cerebellar involvement was observed in numerous patients [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e]. Two profiles were identified namely the contralateral and ipsilateral atrophies. The mechanism proposed for contralateral atrophy was that of trans-synaptic degeneration of the crossed cortico-ponto-cerebellar pathways. As for ipsilateral atrophy, the mechanism evoked was primary cerebellar inflammation.\\u003c/p\\u003e\\u003cp\\u003eIn a study conducted in 2021, the case of a 26-year-old patient who had been ill since age 8, demonstrated marked left cerebral atrophy, associated with ipsilateral brainstem atrophy and contralateral right cerebellar atrophy. He explained this by the long duration of the disease, specifically contralateral atrophy due to interruption of the cortico-ponto-cerebellar fibers (diaschisis) and brainstem atrophy due to Wallerian degeneration [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e]. In earlier studies, including case reports and small series, contralateral cerebellar atrophy has been occasionally reported, consistent with the concept of crossed cerebellar diaschisis [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e].\\u003c/p\\u003e\\u003cp\\u003eThe management of Rasmussen\\u0026rsquo;s syndrome aims to control epilepsy and slow the inflammatory process [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. The prognosis is severe, but functional surgery can transform the evolution of the disease [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e].\\u003c/p\\u003e\"},{\"header\":\"Conclusion\",\"content\":\"\\u003cp\\u003eContralateral cerebellar atrophy, although rare, should be recognized as a possible manifestation of Rasmussen's syndrome in advanced stages, thereby enriching the spectrum of its MRI findings beyond the classic unilateral hemispheric atrophy. This observation supports the pathophysiological hypothesis of trans-synaptic degeneration along the crossed cortico-ponto-cerebellar pathways and underscores the value of imaging for documenting the progression of this encephalitis, while also broadening the differential diagnosis in the face of asymmetric cerebral atrophy associated with contralateral cerebellar involvement.\\u003c/p\\u003e\"},{\"header\":\"Abbreviations\",\"content\":\"\\u003cdiv class=\\\"DefinitionList\\\"\\u003e\\u003cdiv class=\\\"DefinitionListEntry\\\"\\u003e\\u003cdiv class=\\\"Term\\\"\\u003eMRI\\u003c/div\\u003e\\u003cdiv class=\\\"Description\\\"\\u003e\\u003cp\\u003eMagnetic resonance imaging\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/div\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cb\\u003eEthical Approval Statement\\u003c/b\\u003e\\u003c/p\\u003e\\u003cp\\u003eInformed consent was obtained in writing from the patient's legal guardian.\\u003c/p\\u003e\\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eConsent for Publication\\u003c/strong\\u003e\\u003cp\\u003e Informed consent was obtained in writing from the patient's legal guardian to publish this case report and any accompanying images.\\u003c/p\\u003e\\u003c/p\\u003e\\u003cp\\u003e\\u003ch2\\u003eCompeting interests\\u003c/h2\\u003e\\u003cp\\u003eAll authors declare no conflict of interest.\\u003c/p\\u003e\\u003c/p\\u003e\\u003ch2\\u003eFunding Source\\u003c/h2\\u003e\\u003cp\\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or non-profit sectors.\\u003c/p\\u003e\\u003ch2\\u003eAuthor Contribution\\u003c/h2\\u003e\\u003cp\\u003eAll authors equally contributed to this manuscript. They read and approved its final version.\\u003c/p\\u003e\\u003ch2\\u003eAvailability of data and materials\\u003c/h2\\u003e\\u003cp\\u003eData sharing does not apply to this article as no dataset was generated or analyzed during the current study.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003eYahya EH, Khadija L, Nourrelhouda B, Nazik A, Latifa C, Siham EH (2023) A Case Report of Rasmussen Encephalitis and its Stages: The Important Role of Imaging. Glob Pediatr Health 10:2333794X231214084\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eVimal J, Nagarajan R, Sriram D (2015) Rasmussen\\u0026rsquo;s encephalitis: A case report. Australas Med J 8(3):80\\u0026ndash;84\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eKlaa H, Ben Younes T, Benrhouma H, Nagi S, Rouissi A, Kraoua I et al (2020) Rasmussen\\u0026rsquo;s Encephalitis: A Report of a Tunisian Pediatric Case and Literature Review. \\u003cem\\u003eCase Rep Neurol Med.\\u003c/em\\u003e ; 2020:6810237\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eTien RD, Ashdown BC, Lewis DV, Atkins MR, Burger PC (1992) Rasmussen\\u0026rsquo;s encephalitis: neuroimaging findings in four patients. Am J Roentgenol 158(6):1329\\u0026ndash;1332\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eReiter JT, David B, Enders S, Prillwitz CC, Bauer T, Atalay D et al (2021) Infratentorial MRI Findings in Rasmussen Encephalitis Suggest Primary Cerebellar Involvement. Neurol Neuroimmunol Neuroinflammation 8(6):e1058\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eFornari Caprara AL, Rissardo JP, Nagele EP (2024) Rasmussen Encephalitis: Clinical Features, Pathophysiology, and Management Strategies\\u0026mdash;A Comprehensive Literature Review. Med (Mex) 60(11):1858\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eVaradkar S, Bien CG, Kruse CA, Jensen FE, Bauer J, Pardo CA et al (2014) Rasmussen\\u0026rsquo;s encephalitis: clinical features, pathobiology, and treatment advances. Lancet Neurol 13(2):195\\u0026ndash;205\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003eAgarwal A, Garg K, Gulati A, Gulati P (2021) Rasmussen Encephalitis with Ipsilateral Brain Stem and Contralateral Cerebellar Atrophy. Neurol India 69(4):1140\\u003c/span\\u003e\\u003c/li\\u003e\\u003cli\\u003e\\u003cspan\\u003ePeeke J, Tang-Wai R, Robison A, Achiriloaie A (2024) Rasmussen\\u0026rsquo;s encephalitis in a pediatric patient with subtle early MRI changes: A case report. Radiol Case Rep 19(11):5496\\u0026ndash;5500\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":true,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"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\":\"Rasmussen's syndrome, cerebellar atrophy, trans-synaptic degeneration, cerebral MRI, focal epilepsy\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-7810897/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-7810897/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003ch2\\u003eIntroduction\\u003c/h2\\u003e\\u003cp\\u003eRasmussen's syndrome is a rare and devastating chronic progressive encephalitis, characterized by unilateral brain inflammation, pharmaco-resistant focal epilepsy, and progressive neurological deficit. This case report describes the magnetic resonance imaging (MRI) findings in a 12-year-old child with Rasmussen's syndrome, illustrating the rare feature of contralateral cerebellar atrophy.\\u003c/p\\u003e\\u003ch2\\u003eCase presentation\\u003c/h2\\u003e\\u003cp\\u003eThe patient presented with status epilepticus and progressive hemiparesis. Cerebral MRI demonstrated the characteristic lesions of the disease: right hemispheric atrophy, FLAIR hyperintensities of the subcortical white matter, and ipsilateral ventricular enlargement. The notable element was the discovery of left cerebellar atrophy. The diagnosis of Rasmussen's syndrome was established based on the clinical evolution and radiological data.\\u003c/p\\u003e\\u003ch2\\u003eConclusion\\u003c/h2\\u003e\\u003cp\\u003eThis study contributes to medical literature by supporting the pathophysiological hypothesis of trans-synaptic degeneration along the crossed cortico-ponto-cerebellar pathways, secondary to the progressive destruction of the cerebral hemisphere. This case highlights that contralateral cerebellar atrophy should be recognized as a possible manifestation in the advanced evolution of this encephalitis, thus enriching the spectrum of its MRI manifestations and assisting in differentiating the disease from other entities responsible for unilateral cerebral atrophy.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Contralateral cerebellar atrophy in Rasmussen’s syndrome: a case report\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-10-12 14:41:54\",\"doi\":\"10.21203/rs.3.rs-7810897/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"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\":\"19627bf4-180e-420e-b8a4-5c56b946215d\",\"owner\":[],\"postedDate\":\"October 12th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[{\"id\":55985871,\"name\":\"Nuclear Medicine \\u0026 Medical Imaging\"}],\"tags\":[],\"updatedAt\":\"2025-10-12T14:41:54+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-10-12 14:41:54\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7810897\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7810897\",\"identity\":\"rs-7810897\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}