Dark cerebellum on Apparent Diffusion Coefficient maps—an early indicator of fulminant cerebellitis

Dark cerebellum on Apparent Diffusion Coefficient maps—an early indicator of fulminant cerebellitis | 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 Dark cerebellum on Apparent Diffusion Coefficient maps—an early indicator of fulminant cerebellitis Akshata Angadi, Mahesh Kamate, Virupaxi Hattiholi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7585769/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 13 You are reading this latest preprint version Abstract Fulminant cerebellitis is an important cause of acute severe encephalopathy with raised intracranial pressure in an otherwise healthy child. If the diagnosis is delayed or missed, this can be fatal. Magnetic resonance imaging of the brain helps in early diagnosis. Though signal changes on T2 and fluid attenuation and inversion recovery sequences in fulminant cerebellitis have been described, the findings on diffusion weighted imaging and apparent diffusion coefficient maps have been rarely described in the literature. While the diffusion weighted image shows a bright signal, the apparent deficient coefficient map shows a dark cerebellum. There can be brainstem compression and cerebellar tonsillar herniation. Here we report a young boy with acute onset of coma who had a dark cerebellum on apparent deficient coefficient maps that prompted early treatment with resultant good outcome. Clinical trial number: This study is not a clinical trial. Hence, ‘Clinical trial number: not applicable.’ Fulminant cerebellitis raised intracranial pressure diffusion weighted imaging apparent diffusion coefficient maps coma Figures Figure 1 Introduction Fulminant cerebellitis is a rare neuroinflammatory disease characterized by swelling of the cerebellum that can lead to brainstem compression and can be fatal if not treated promptly. 1 It occurs in otherwise healthy children with an acute onset of increased intracranial pressure and presents as vomiting, altered sensorium, decerebrate posturing, and abnormal breathing patterns. Early and rapid diagnosis enables interventions to control neuroinflammation, such as pulse steroids or intravenous immunoglobulin, along with measures to reduce intracranial pressure. Many children may also need a decompressive craniectomy 2 . This highlights the importance of considering this condition in any child with sudden, severe encephalopathy and underscores the need for early diagnosis. Magnetic resonance imaging (MRI) of the brain provides key diagnostic clues. Here, we report a child who presented with sudden coma, where a dark cerebellum on apparent diffusion coefficient (ADC) maps of MRI suggested fulminant cerebellitis, and prompt medical treatment led to complete recovery. Case report A previously healthy 11-year-old boy presented with a fever associated with an upper respiratory tract infection. On day-2 of illness, he developed vomiting, abnormal posturing of limbs, and altered sensorium. On examination, the child was comatose with decerebrate posturing and neurogenic hyperventilation, suggesting brainstem dysfunction. The fundus examination was normal. Serum biochemistry other than hyponatremia (112meq/L) was normal. T1, T2/fluid-attenuated inversion recovery (FLAIR) MRI brain axial and sagittal sequences showed brainstem compression and mild cerebellar tonsillar herniation (Fig-1a-d). The supratentorial compartment was normal, with no space-occupying lesions or hydrocephalus. The clue to the cause of brainstem compression came from the diffusion weighted imaging (DWI), which showed restricted diffusion of the entire cerebellum, and the corresponding ADC map revealed a dark cerebellum, suggesting cytotoxic edema (Fig-1e-f). This imaging finding was suggestive of fulminant cerebellitis with brainstem compression. In view of raised intracranial pressure, lumbar puncture was deferred. Immediately, pulse methylprednisolone (30mg/kg/dose) was started, and measures to reduce raised intracranial pressure, such as head-end elevation, 3% saline, and fluid restriction, were instituted. The child stabilized over the next 12 hours, and hence, decompressive craniectomy was deferred. On the third day, his sensorium improved, and 5 days later, he was discharged with mild gait ataxia on day 7 of illness. Discussion Acute cerebellitis is a rare inflammatory condition that affects the cerebellum, with a wide range of severity, from a self-limiting illness to a fulminant disease. It is characterized by an acute onset of encephalopathy, accompanied by headache, vomiting, and MRI abnormalities in the cerebellum 1 , 2 . The presence of MRI abnormalities differentiates acute cerebellitis from the common post-infectious acute cerebellar ataxia 3 . Typical MRI features in acute cerebellitis include T2/FLAIR signal changes in cerebellar white matter, grey matter, and cerebellar peduncles 2 . While it could be due to the actual involvement of the cerebellum by the infecting agent, many cases of acute cerebellitis are caused by an autoimmune phenomenon, such as acute disseminated encephalomyelitis or myelin oligodendrocyte glycoprotein-associated disease. Cerebellar inflammation due to any cause can lead to compression of the brainstem, as the posterior fossa is a constrained space. It may result in altered levels of consciousness that can obscure the initial signs of cerebellar involvement 4 . Patients may even present with coma and autonomic dysfunction. This presentation, characterized by symptoms of increased intracranial pressure overshadowing cerebellar signs and associated with significant inflammation, is known as fulminant acute cerebellitis. It should be considered as a differential diagnosis in any child with a sudden onset of raised intracranial pressure. This condition carries a higher risk of lasting sequelae and even death 5 . In our case, there were no cerebellar symptoms at presentation. This often leads clinicians to omit mention of cerebellar involvement in the neuroimaging requisition. Since routine sequences like T1, T2, and FLAIR are usually normal, cerebellitis can be easily missed by the radiologist if subtle signs of brainstem compression are overlooked. At discharge, the patient exhibited mild ataxia. Routine sequences, such as T1, T2, and FLAIR, may show brainstem compression with cerebellar tonsillar herniation, without significant changes in the cerebellum. DWI, which shows restricted diffusion, and the corresponding ADC maps, which display a reversal of signal changes, are critical in suggesting fulminant cerebellitis as a cause of brainstem compression 6 . In the case of fulminant cerebellitis, diffuse cerebellar edema that sets in acutely over a period of a few hours can cause tonsillar herniation, brainstem compression, and effacement of the aqueduct or third ventricle, leading to obstructive hydrocephalus 6 . This could be due to an inappropriate innate immune response to an infectious trigger. There could be a cytokine storm limited to the cerebellum. This can be similar to acute necrotizing encephalitis (ANEC), where there is localized cytokine storm limited to the basal ganglia and sometimes involves the brainstem and cerebellum 7 , 8 . Evidence for this fact can be seen in the case reported by Shelar SS et al, where the child had fulminant cerebellitis with diffusion restriction and reversal on ADC maps, and the white matter in the MRI also showed restricted diffusion, giving the characteristic bright tree appearance, which is typical of acute leukoencephalopathy with restricted diffusion (ALERD) 6 , 9 . ALERD is another condition characterized by a cytokine storm in the brain and predominantly affects the white matter. We can envisage that conditions like acute necrotizing encephalitis, fulminant cerebellitis, and ALERD are disorders characterized by localized cytokine storms affecting the basal ganglia, cerebellum, and white matter. Overlaps can occur, such as ALERD with fulminant cerebellitis, as seen in a case reported by Shellar S et al., and involvement of the cerebellum and basal ganglia, as happens in ANEC 6 , 7 . These predominant changes on DWI and ADC maps help differentiate fulminant cerebellitis from post-infectious acute cerebellitis, which is due to autoimmune response and mainly shows changes on T2/FLAIR sequences of MRI. This also opens the therapeutic option of using drugs like the interleukin-6 inhibitor tocilizumab in fulminant cerebellitis. Tocilizumab plays a role in treating both ANEC and ALERD and has been shown to reduce mortality and morbidity associated with these conditions. More studies are needed to explore the role of drugs like tocilizumab in fulminant cerebellitis. Therefore, the finding of a dark cerebellum on ADC maps should suggest the possibility of fulminant cerebellitis and prompt aggressive immunomodulatory therapy, which can be followed by decompressive craniectomy if medical treatment fails. Declarations Consent to publish declaration: Informed written consent was obtained from parents to publish the findings. Funding: None. Competing interests: The authors declare no competing interests Author Contribution MK diagnosed and was involved in management of patients. He conceptualised the study and will act as guarantor of the study. AA did the literature review and drafted the article. VH read the neuroimages. The final manuscript was approved by all the authors. References Kamate M, Chetal V, Hattiholi V. Fulminant Cerebellitis: A Fatal, Clinically Isolated Syndrome. Pediatr Neurol. 2009;41:220–2. Lancella L, Esposito S, Galli ML, Bozzola E, Labalestra V, Boccuzzi E, et al. Acute cerebellitis in children: an eleven-year retrospective multicentric study in Italy. Ital J Pediatr. 2017;43:54. Orman G, Kralik SF, Desai NK, Meoded A, Sangi-Haghpeykar H, Jallo G, et al. Can MRI Differentiate between Infectious and Immune-Related Acute Cerebellitis? A Retrospective Imaging Study. American Journal of Neuroradiology. 2021;42:2231–7. Molina Corbacho M, Martín Birlanga F, Sarrión Sos N, Gargallo Tatay P, Tomás Vila M. Fulminant acute cerebellitis: An under-diagnosed condition? An Pediatr (Engl Ed). 2019;90:188-190. Levy EI, Harris AE, Omalu BI, Hamilton RL, Branstetter BF 4th, Pollack IF. Sudden death from fulminant acute cerebellitis. Pediatr Neurosurg. 2001;35:24-8. Shelar SS, Kashikar SV, Parihar P, Bhoyar MP, Dhande R, Thaker N. Acute Fulminant Viral Cerebellitis with Hypoxic-Ischemic Encephalopathy in a Male Child. Cureus. 2024 14;16:e69408. Kansagra SM, Gallentine WB. Cytokine storm of acute necrotizing encephalopathy. Pediatr Neurol. 2011;45:400-2. Wang S, Wang D, Wang X, Chen M, Wang Y, Zhou H, Zhou Y, Lv Y, Wei H. Cytokine Storm Related to CD4 + T Cells in Influenza Virus-Associated Acute Necrotizing Encephalopathy. Immune Netw. 2024;24(2):e18. Kamate M. Acute Leukoencephalopathy with Restricted Diffusion. Indian J Crit Care Med. 2018;22:519-523. Jaiswal A, Patel S, Khare S, Passi GR. Tocilizumab in a Child with Acute Leukoencephalopathy with Restricted Diffusion. Ann Indian Acad Neurol. 2023;26:95-96. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 03 Nov, 2025 Reviews received at journal 22 Oct, 2025 Reviews received at journal 11 Oct, 2025 Reviews received at journal 24 Sep, 2025 Reviewers agreed at journal 23 Sep, 2025 Reviewers agreed at journal 22 Sep, 2025 Reviews received at journal 21 Sep, 2025 Reviewers agreed at journal 21 Sep, 2025 Reviewers agreed at journal 21 Sep, 2025 Reviewers invited by journal 20 Sep, 2025 Editor assigned by journal 11 Sep, 2025 Submission checks completed at journal 11 Sep, 2025 First submitted to journal 10 Sep, 2025 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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10:10:27","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":30182,"visible":true,"origin":"","legend":"","description":"","filename":"1867a5d85ffb4623adcb66d320ccab971structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7585769/v1/bda3e225197efc2c2bb9f8aa.xml"},{"id":92584356,"identity":"04d0933c-11e1-4356-bcf7-43136e4ada14","added_by":"auto","created_at":"2025-10-01 10:10:27","extension":"html","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":38087,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7585769/v1/7b787a39044f7dfcc506453f.html"},{"id":92584875,"identity":"4c5b21a6-6582-46cc-83f3-bcd76de05a3f","added_by":"auto","created_at":"2025-10-01 10:18:27","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":164049,"visible":true,"origin":"","legend":"\u003cp\u003eAxial T1 (a), T2 (b) weighted, and FLAIR (c) images reveal a normal signal in the cerebellum and compression of the pons and mid-brain, which is evidenced by the distortion of the brainstem and obliteration of the cisternal space. T1 (d) sagittal image also shows flattening of the pontine belly, suggesting brainstem compression. DWI (e) sequence shows hyperintensities in the cerebellum, indicating restricted diffusion, and the corresponding ADC map (e) shows reversal of the signal seen on DWI (the dark cerebellum).\u003c/p\u003e","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7585769/v1/71d055080fd21061a7c44712.jpg"},{"id":92584877,"identity":"7a27d94c-b83e-4968-a4e2-a04a3e141eb3","added_by":"auto","created_at":"2025-10-01 10:18:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":425646,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7585769/v1/21b8fcce-92f9-41ff-a563-fcc99b3dfed6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Dark cerebellum on Apparent Diffusion Coefficient maps—an early indicator of fulminant cerebellitis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eFulminant cerebellitis is a rare neuroinflammatory disease characterized by swelling of the cerebellum that can lead to brainstem compression and can be fatal if not treated promptly.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e It occurs in otherwise healthy children with an acute onset of increased intracranial pressure and presents as vomiting, altered sensorium, decerebrate posturing, and abnormal breathing patterns. Early and rapid diagnosis enables interventions to control neuroinflammation, such as pulse steroids or intravenous immunoglobulin, along with measures to reduce intracranial pressure. Many children may also need a decompressive craniectomy\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. This highlights the importance of considering this condition in any child with sudden, severe encephalopathy and underscores the need for early diagnosis. Magnetic resonance imaging (MRI) of the brain provides key diagnostic clues. Here, we report a child who presented with sudden coma, where a dark cerebellum on apparent diffusion coefficient (ADC) maps of MRI suggested fulminant cerebellitis, and prompt medical treatment led to complete recovery.\u003c/p\u003e"},{"header":"Case report","content":"\u003cp\u003eA previously healthy 11-year-old boy presented with a fever associated with an upper respiratory tract infection. On day-2 of illness, he developed vomiting, abnormal posturing of limbs, and altered sensorium. On examination, the child was comatose with decerebrate posturing and neurogenic hyperventilation, suggesting brainstem dysfunction. The fundus examination was normal. Serum biochemistry other than hyponatremia (112meq/L) was normal. T1, T2/fluid-attenuated inversion recovery (FLAIR) MRI brain axial and sagittal sequences showed brainstem compression and mild cerebellar tonsillar herniation (Fig-1a-d). The supratentorial compartment was normal, with no space-occupying lesions or hydrocephalus. The clue to the cause of brainstem compression came from the diffusion weighted imaging (DWI), which showed restricted diffusion of the entire cerebellum, and the corresponding ADC map revealed a dark cerebellum, suggesting cytotoxic edema (Fig-1e-f). This imaging finding was suggestive of fulminant cerebellitis with brainstem compression. In view of raised intracranial pressure, lumbar puncture was deferred. Immediately, pulse methylprednisolone (30mg/kg/dose) was started, and measures to reduce raised intracranial pressure, such as head-end elevation, 3% saline, and fluid restriction, were instituted. The child stabilized over the next 12 hours, and hence, decompressive craniectomy was deferred. On the third day, his sensorium improved, and 5 days later, he was discharged with mild gait ataxia on day 7 of illness.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAcute cerebellitis is a rare inflammatory condition that affects the cerebellum, with a wide range of severity, from a self-limiting illness to a fulminant disease. It is characterized by an acute onset of encephalopathy, accompanied by headache, vomiting, and MRI abnormalities in the cerebellum\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The presence of MRI abnormalities differentiates acute cerebellitis from the common post-infectious acute cerebellar ataxia\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eTypical MRI features in acute cerebellitis include T2/FLAIR signal changes in cerebellar white matter, grey matter, and cerebellar peduncles\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. While it could be due to the actual involvement of the cerebellum by the infecting agent, many cases of acute cerebellitis are caused by an autoimmune phenomenon, such as acute disseminated encephalomyelitis or myelin oligodendrocyte glycoprotein-associated disease.\u003c/p\u003e\u003cp\u003eCerebellar inflammation due to any cause can lead to compression of the brainstem, as the posterior fossa is a constrained space. It may result in altered levels of consciousness that can obscure the initial signs of cerebellar involvement\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Patients may even present with coma and autonomic dysfunction. This presentation, characterized by symptoms of increased intracranial pressure overshadowing cerebellar signs and associated with significant inflammation, is known as fulminant acute cerebellitis. It should be considered as a differential diagnosis in any child with a sudden onset of raised intracranial pressure. This condition carries a higher risk of lasting sequelae and even death\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. In our case, there were no cerebellar symptoms at presentation. This often leads clinicians to omit mention of cerebellar involvement in the neuroimaging requisition. Since routine sequences like T1, T2, and FLAIR are usually normal, cerebellitis can be easily missed by the radiologist if subtle signs of brainstem compression are overlooked. At discharge, the patient exhibited mild ataxia.\u003c/p\u003e\u003cp\u003eRoutine sequences, such as T1, T2, and FLAIR, may show brainstem compression with cerebellar tonsillar herniation, without significant changes in the cerebellum. DWI, which shows restricted diffusion, and the corresponding ADC maps, which display a reversal of signal changes, are critical in suggesting fulminant cerebellitis as a cause of brainstem compression\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. In the case of fulminant cerebellitis, diffuse cerebellar edema that sets in acutely over a period of a few hours can cause tonsillar herniation, brainstem compression, and effacement of the aqueduct or third ventricle, leading to obstructive hydrocephalus\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. This could be due to an inappropriate innate immune response to an infectious trigger. There could be a cytokine storm limited to the cerebellum. This can be similar to acute necrotizing encephalitis (ANEC), where there is localized cytokine storm limited to the basal ganglia and sometimes involves the brainstem and cerebellum\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Evidence for this fact can be seen in the case reported by Shelar SS et al, where the child had fulminant cerebellitis with diffusion restriction and reversal on ADC maps, and the white matter in the MRI also showed restricted diffusion, giving the characteristic bright tree appearance, which is typical of acute leukoencephalopathy with restricted diffusion (ALERD)\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. ALERD is another condition characterized by a cytokine storm in the brain and predominantly affects the white matter.\u003c/p\u003e\u003cp\u003eWe can envisage that conditions like acute necrotizing encephalitis, fulminant cerebellitis, and ALERD are disorders characterized by localized cytokine storms affecting the basal ganglia, cerebellum, and white matter. Overlaps can occur, such as ALERD with fulminant cerebellitis, as seen in a case reported by Shellar S et al., and involvement of the cerebellum and basal ganglia, as happens in ANEC\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. These predominant changes on DWI and ADC maps help differentiate fulminant cerebellitis from post-infectious acute cerebellitis, which is due to autoimmune response and mainly shows changes on T2/FLAIR sequences of MRI. This also opens the therapeutic option of using drugs like the interleukin-6 inhibitor tocilizumab in fulminant cerebellitis. Tocilizumab plays a role in treating both ANEC and ALERD and has been shown to reduce mortality and morbidity associated with these conditions. More studies are needed to explore the role of drugs like tocilizumab in fulminant cerebellitis.\u003c/p\u003e\u003cp\u003eTherefore, the finding of a dark cerebellum on ADC maps should suggest the possibility of fulminant cerebellitis and prompt aggressive immunomodulatory therapy, which can be followed by decompressive craniectomy if medical treatment fails.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConsent to publish declaration:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed written consent was obtained from parents to publish the findings.\u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e\u003cp\u003eNone.\u003c/p\u003e\u003cp\u003eCompeting interests: The authors declare no competing interests\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eMK diagnosed and was involved in management of patients. He conceptualised the study and will act as guarantor of the study. AA did the literature review and drafted the article. VH read the neuroimages. The final manuscript was approved by all the authors.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eKamate M, Chetal V, Hattiholi V. Fulminant Cerebellitis: A Fatal, Clinically Isolated Syndrome. Pediatr Neurol. 2009;41:220\u0026ndash;2. \u003c/li\u003e\n\u003cli\u003eLancella L, Esposito S, Galli ML, Bozzola E, Labalestra V, Boccuzzi E, et al. Acute cerebellitis in children: an eleven-year retrospective multicentric study in Italy. Ital J Pediatr. 2017;43:54. \u003c/li\u003e\n\u003cli\u003eOrman G, Kralik SF, Desai NK, Meoded A, Sangi-Haghpeykar H, Jallo G, et al. Can MRI Differentiate between Infectious and Immune-Related Acute Cerebellitis? A Retrospective Imaging Study. American Journal of Neuroradiology. 2021;42:2231\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eMolina Corbacho M, Mart\u0026iacute;n Birlanga F, Sarri\u0026oacute;n Sos N, Gargallo Tatay P, Tom\u0026aacute;s Vila M. Fulminant acute cerebellitis: An under-diagnosed condition? An Pediatr (Engl Ed). 2019;90:188-190.\u003c/li\u003e\n\u003cli\u003eLevy EI, Harris AE, Omalu BI, Hamilton RL, Branstetter BF 4th, Pollack IF. Sudden death from fulminant acute cerebellitis. Pediatr Neurosurg. 2001;35:24-8. \u003c/li\u003e\n\u003cli\u003eShelar SS, Kashikar SV, Parihar P, Bhoyar MP, Dhande R, Thaker N. Acute Fulminant Viral Cerebellitis with Hypoxic-Ischemic Encephalopathy in a Male Child. Cureus. 2024 14;16:e69408.\u003c/li\u003e\n\u003cli\u003eKansagra SM, Gallentine WB. Cytokine storm of acute necrotizing encephalopathy. Pediatr Neurol. 2011;45:400-2. \u003c/li\u003e\n\u003cli\u003eWang S, Wang D, Wang X, Chen M, Wang Y, Zhou H, Zhou Y, Lv Y, Wei H. Cytokine Storm Related to CD4\u003csup\u003e+\u003c/sup\u003e T Cells in Influenza Virus-Associated Acute Necrotizing Encephalopathy. Immune Netw. 2024;24(2):e18.\u003c/li\u003e\n\u003cli\u003eKamate M. Acute Leukoencephalopathy with Restricted Diffusion. Indian J Crit Care Med. 2018;22:519-523. \u003c/li\u003e\n\u003cli\u003eJaiswal A, Patel S, Khare S, Passi GR. Tocilizumab in a Child with Acute Leukoencephalopathy with Restricted Diffusion. Ann Indian Acad Neurol. 2023;26:95-96.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-cerebellum","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cere","sideBox":"Learn more about [The Cerebellum](http://link.springer.com/journal/12311)","snPcode":"12311","submissionUrl":"https://submission.nature.com/new-submission/12311/3","title":"The Cerebellum","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Fulminant cerebellitis, raised intracranial pressure, diffusion weighted imaging, apparent diffusion coefficient maps, coma","lastPublishedDoi":"10.21203/rs.3.rs-7585769/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7585769/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFulminant cerebellitis is an important cause of acute severe encephalopathy with raised intracranial pressure in an otherwise healthy child. If the diagnosis is delayed or missed, this can be fatal. Magnetic resonance imaging of the brain helps in early diagnosis. Though signal changes on T2 and fluid attenuation and inversion recovery sequences in fulminant cerebellitis have been described, the findings on diffusion weighted imaging and apparent diffusion coefficient maps have been rarely described in the literature. While the diffusion weighted image shows a bright signal, the apparent deficient coefficient map shows a dark cerebellum. There can be brainstem compression and cerebellar tonsillar herniation. Here we report a young boy with acute onset of coma who had a dark cerebellum on apparent deficient coefficient maps that prompted early treatment with resultant good outcome.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is not a clinical trial. Hence, ‘Clinical trial number: not applicable.’\u003c/p\u003e","manuscriptTitle":"Dark cerebellum on Apparent Diffusion Coefficient maps—an early indicator of fulminant cerebellitis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-01 10:10:23","doi":"10.21203/rs.3.rs-7585769/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-03T17:15:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-22T18:01:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-12T03:14:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-24T16:37:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"295586186511422702911509616705041849273","date":"2025-09-23T13:11:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"213422042382432810059591139043320383330","date":"2025-09-22T19:12:49+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-21T18:38:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"238061118376869398106209918557640368681","date":"2025-09-21T15:51:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"1118794631073216246014787744096432771","date":"2025-09-21T07:24:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-20T21:05:28+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-12T03:57:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-12T03:56:05+00:00","index":"","fulltext":""},{"type":"submitted","content":"The Cerebellum","date":"2025-09-10T19:35:02+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-cerebellum","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cere","sideBox":"Learn more about [The Cerebellum](http://link.springer.com/journal/12311)","snPcode":"12311","submissionUrl":"https://submission.nature.com/new-submission/12311/3","title":"The Cerebellum","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"cf89f1a8-0df2-4b51-83ec-30cf51aa0d76","owner":[],"postedDate":"October 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-01-13T19:38:11+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-01 10:10:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7585769","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7585769","identity":"rs-7585769","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}