Acute Cerebellitis in Children: A Variable Clinical Entity

Etiologies and clinical characteristics of acute ataxia in a single national children's medical center

OBJECTIVE

To analyze etiologic factors of pediatric acute ataxia and to identify the severity of its underlying causes for urgent medical intervention.

METHODS

Clinical data of children diagnosed with acute ataxia between December 2015 and December 2021 from one national medical center were analyzed retrospectively.

RESULTS

A total of 99 children (59 boys, 40 girls), median age at disease onset 55 (range: 12-168) months, were enrolled. The median follow period was 46 (range 6-78) months. Eighty-six (86.9 %) children were diagnosed with immune-associated acute ataxia, among which acute post-infectious cerebellar ataxia (APCA) was the most common diagnosis (50.5 %), followed by demyelinating diseases of the central nervous system (18.2 %) and Guillain-Barré syndrome (9.1 %). On cerebrospinal fluid (CSF) examination, 35/73 (47.9 %) patients had pleocytosis (>5 cells/mm3), and 18/73 (24.7 %) had elevated protein levels. Thirty-one patients (31.3 %) had an abnormal cerebral MRI. Children with other immune-associated acute cerebellar ataxia had more extracerebellar symptoms, intracranial MRI lesions, abnormal CSF results, longer hospital stay, higher recurrence rates and incidence of neurological sequelae than children with APCA.

CONCLUSION

Immune-associated acute ataxia is the main cause of pediatric acute ataxia, among which APCA is the most common phenotype. However, some immune-associated diseases, especially autoantibody-mediated disease, which has a higher recurrence rate and neurological sequelae account for an increasing proportion of pediatric acute ataxia. When children present with extracerebellar symptoms, abnormal cranial MRI or CSF results, and without prodromal infection, prudent differential diagnosis is recommended.

Autoantibody status, neuroradiological and clinical findings in children with acute cerebellitis

BACKGROUND

Acute cerebellitis (AC) in children and adolescents is an inflammatory disease of the cerebellum due to viral or bacterial infections but also autoimmune-mediated processes.

OBJECTIVE

To investigate the frequency of autoantibodies in serum and CSF as well as the neuroradiological features in children with AC.

MATERIAL AND METHODS

Children presenting with symptoms suggestive of AC defined as acute/subacute onset of cerebellar symptoms and MRI evidence of cerebellar inflammation or additional CSF pleocytosis, positive oligoclonal bands (OCBs), and/or presence of autoantibodies in case of negative cerebellar MRI. Children fulfilling the above-mentioned criteria and a complete data set including clinical presentation, CSF studies, testing for neuronal/cerebellar and MOG antibodies as well as MRI scans performed at disease onset were eligible for this retrospective multicenter study.

RESULTS

36 patients fulfilled the inclusion criteria for AC (f:m = 14:22, median age 5.5 years). Ataxia was the most common cerebellar symptom present in 30/36 (83 %) in addition to dysmetria (15/36) or dysarthria (13/36). A substantial number of children (21/36) also had signs of encephalitis such as somnolence or seizures. In 10/36 (28 %) children the following autoantibodies (abs) were found: MOG-abs (n = 5) in serum, GFAPα-abs (n = 1) in CSF, GlyR-abs (n = 1) in CSF, mGluR1-abs (n = 1) in CSF and serum. In two further children, antibodies were detected only in serum (GlyR-abs, n = 1; GFAPα-abs, n = 1). MRI signal alterations in cerebellum were found in 30/36 children (83 %). Additional supra- and/or infratentorial lesions were present in 12/36 children, including all five children with MOG-abs. Outcome after a median follow-up of 3 months (range: 1 a 75) was favorable with an mRS ≤2 in 24/36 (67 %) after therapy. Antibody (ab)-positive children were significantly more likely to have a better outcome than ab-negative children (p = .022).

CONCLUSION

In nearly 30 % of children in our study with AC, a range of abs was found, underscoring that autoantibody testing in serum and CSF should be included in the work-up of a child with suspected AC. The detection of MOG-abs in AC does expand the MOGAD spectrum.

A Novel Radiological Score System to Assess the Clinical Severity in Patients with Acute Cerebellitis

To develop a radiological score system to assess the severity of acute cerebellitis (AC) and to compare radiological severity score at the onset to cerebellar atrophy at follow-up. Clinical and MRI findings were recorded in 16 patients with AC. Radiological severity score considering topographic patterns, gray/white matter involvement, enhancement, tonsillar herniation or hydrocephalus development and clinical severity score taking into account clinical symptoms were assessed for each patient at the onset of the symptoms. Radiological and neurological sequelae were assessed at follow-up. At symptoms onset, clinical severity scale ranged from mild to severe and radiological severity score ranged from 3 to 7 with higher scores indicating a greater severity. The cut-off value of 5 for radiological score well segregated severe patients defined by clinical scale. A significant correlation between clinical scale and radiological severity scores (p < 0.001, r = 0.75) was found. At follow-up visit, all children developed cerebellar atrophy and 5 children showed neurologic sequelae while adults showed complete resolution without atrophy. Patients in whom atrophy was not observed had both older ages (p < 0.001) and a focal cerebellar involvement (p = 0.03). In patients with AC, radiological severity score may be a useful tool in evaluating clinical severity, but it is not capable to predict neither neurological sequelae nor evolution towards atrophy. Cerebellar atrophy, observed in children with AC, may be caused by several factors such as the age of patient and the extension of cerebellar involvement and it may be counterbalanced by neuronal restoring processes due to neuroplasticity.

Case report and literature analysis: Autoimmune cerebellar ataxia associated with homer-3 antibodies

Objective

We present a case of autoimmune cerebellar ataxia (ACA) associated with Homer protein homolog 3 (Homer-3) antibodies. Then, a review of the literature was conducted to summarize its clinical spectrum to improve clinicians' understanding of this rare entity.

Case presentation

A 25-year-old man suffered from the subacute onset of cerebellar ataxia and psychiatric symptoms with abnormalities in the cerebellum on initial brain MRI and Homer-3 antibodies titers of 1:100 in the serum. His neurological symptoms did not improve after intravenous methylprednisolone but significantly improved following plasma exchange with a modified Rankin Scale (mRS) score of 1. However, 5 months later, he experienced relapse during oral prednisone tapering with enhanced cerebellar lesions and obvious cerebellar atrophy on repeated MRI. Various immunomodulatory approaches, including corticosteroids and plasma exchange, were utilized with no improvement. Then rituximab was given for the first time to treat Homer-3 autoimmunity with partial improvement of symptoms. However, the patient remained profoundly disabled with an mRS score of 4.

Conclusion

ACA associated with Homer-3 antibodies may have a suboptimal response to corticosteroid therapy. More intense immunotherapy such as rituximab may contribute to the improvement of cerebellar syndrome. Relapsing courses and presentation of cerebellar atrophy may suggest a poor prognosis in this entity.

Diagnostic approach and update on encephalitis

PURPOSE OF REVIEW

The present article gives an update and outlines the fundamental principles of clinical reasoning and a diagnostic approach to a patient suspected to have acute encephalitis.

RECENT FINDINGS

Encephalitis remains to be associated with significant mortality and neurological morbidity. Unfortunately, the etiologic diagnosis remains elusive for the majority of the patients with encephalitis preventing targeted therapies. Clinicians could utilize clues such as duration of symptoms, exposure history, cerebrospinal fluid profile, neuroimaging findings and locations, and entertain certain opportunistic infections in immunosuppressed individuals. A comprehensive diagnostic for the most common viral and autoimmune etiologies should be systematically done and prompt empiric antiviral therapy should be started. Evaluation and therapy for autoimmune etiologies should be done for patients with a negative viral work up. Brain biopsy and metagenomic sequencing should be considered for patients with unknown etiologies that are clinically worsening.

SUMMARY

Encephalitis remains with unacceptable mortality and morbidity with the most common etiologies being idiopathic. A comprehensive diagnostic work up and prompt antiviral and autoimmune therapies are of paramount importance to improve the outcomes of this devastating disease.

Postinfectious Acute Cerebellar Syndromes in Children: A Nationally Ascertained Case Series From Australia 2013-2018

INTRODUCTION

Postinfectious acute cerebellar syndromes show a wide spectrum of acute severity and can occur with acute febrile illness or vaccine receipt. Varicella has historically been the most common cause, associated with up to 25% of cases in large cohorts. This study aimed to describe the spectrum of syndromes in a setting with high varicella vaccine coverage.

METHOD

Data were collected on children initially identified as "suspected encephalitis" subsequently designated "not-encephalitis" at participating children's hospitals in the Paediatric Active Enhanced Disease Surveillance (PAEDS) network, Australia, as part of the Acute Childhood Encephalitis study. A comprehensive descriptive analysis was undertaken on prospectively identified, national series of children with postinfectious acute cerebellar syndromes from 2013 to 2018. Cases were classified using a previously validated severity score, and the outcome was assessed at 12 months using the Liverpool Outcome Scale score.

RESULTS

A total of 20 cases (65% were vaccinated for varicella) were included, of which 70% were subcategorized as acute cerebellar ataxia (ACA), 20% acute cerebellitis (AC), and 10% acute fulminant cerebellitis (AFC). An acute febrile illness was noted in 55% and none were related to varicella or were temporally related to varicella vaccination or other childhood vaccines. A subset (total of 7 children) followed up at 12 months all showed reduced Liverpool Outcome Scale scores.

DISCUSSION

The study provides an overall description of this uncommon spectrum of neurologic syndromes and shows the infrequency of varicella zoster virus as a cause in a vaccinated population.

Acute Cerebellar Inflammation and Related Ataxia: Mechanisms and Pathophysiology

The cerebellum governs motor coordination and motor learning. Infection with external microorganisms, such as viruses, bacteria, and fungi, induces the release and production of inflammatory mediators, which drive acute cerebellar inflammation. The clinical observation of acute cerebellitis is associated with the emergence of cerebellar ataxia. In our animal model of the acute inflammation of the cerebellar cortex, animals did not show any ataxia but hyperexcitability in the cerebellar cortex and depression-like behaviors. In contrast, animal models with neurodegeneration of the cerebellar Purkinje cells and hypoexcitability of the neurons show cerebellar ataxia. The suppression of the Ca²⁺-activated K⁺ channels in vivo is associated with a type of ataxia. Therefore, there is a gap in our interpretation between the very early phase of cerebellar inflammation and the emergence of cerebellar ataxia. In this review, we discuss the hypothesized scenario concerning the emergence of cerebellar ataxia. First, compared with genetically induced cerebellar ataxias, we introduce infection and inflammation in the cerebellum via aberrant immunity and glial responses. Especially, we focus on infections with cytomegalovirus, influenza virus, dengue virus, and SARS-CoV-2, potential relevance to mitochondrial DNA, and autoimmunity in infection. Second, we review neurophysiological modulation (intrinsic excitability, excitatory, and inhibitory synaptic transmission) by inflammatory mediators and aberrant immunity. Next, we discuss the cerebellar circuit dysfunction (presumably, via maintaining the homeostatic property). Lastly, we propose the mechanism of the cerebellar ataxia and possible treatments for the ataxia in the cerebellar inflammation.

Acute Cerebellar Ataxia Associated with COVID-19 Infection in a 5-Year-Old Boy

Background:Neurologic manifestations can occur in many adult patients with COVID-19 but are less frequently described in the literature than the respiratory or inflammatory effects of the disease. There are even fewer reports of the neurologic manifestations of the disease in children. Case Report: A 5-year-old boy with type 1 diabetes mellitus had minimal symptoms from COVID-19 infection. Eight days later, he developed acute ataxia, double vision, tremor, and dysmetria. Cerebrospinal fluid (CSF) and imaging were unremarkable. He was treated with supportive care and discharged home after 4 days. Neurologic symptoms gradually improved and resolved at 2 month follow up. Conclusion: Providers should be aware of acute cerebellar ataxia as a possible complication in pediatric patients recovering from COVID-19.

Can MRI Differentiate between Infectious and Immune-Related Acute Cerebellitis? A Retrospective Imaging Study

BACKGROUND AND PURPOSE

Acute cerebellitis is an acute neurologic condition attributable to a recent or concurrent infection or a recent vaccination or ingestion of medication, with MR imaging evidence of cerebellar edema. MR imaging can confirm an anatomic abnormality and may allow the radiologist to establish a differential diagnosis. The purpose of this research was to evaluate the MR imaging findings in children with acute cerebellitis due to infectious versus immune-related conditions, in particular whether MR imaging findings allow differentiation.

MATERIALS AND METHODS

Electronic medical records were reviewed between 2003 and 2020 in our quaternary children's hospital. Data included demographics and clinical records: presentation/symptoms, final diagnosis including acute cerebellitis and immune-related acute cerebellitis, length of stay, treatment, condition at discharge, and laboratory findings. Retrospective independent review of all brain MR imaging studies was performed.

RESULTS

Forty-three patients (male/female ratio, 28:15) were included in this study. Average age at presentation was 7.08 years (range, 0.05-17.52 years). Thirty-five children had infectious and 8 children had immune-related acute cerebellitis. Significant differences in neuroimaging were the following: 1) T2-FLAIR hyperintense signal in the brainstem (37.50% versus 2.85%, P = .016); 2) T2-FLAIR hyperintense signal in the supratentorial brain higher in the immune-related group (37.50% versus 0.00%, P = .004); and 3) downward herniation, higher in the infectious acute cerebellitis group (42.85% versus 0.00%, P = .03).

CONCLUSIONS

Acute cerebellitis is a rare condition, and MR imaging is helpful in the differential diagnosis. T2-FLAIR hyperintense signal in the brainstem and supratentorial brain may be indicative of immune-related acute cerebellitis, and downward herniation may be indicative of infectious acute cerebellitis.

Encephalitis with Autoantibodies against the Glutamate Kainate Receptors GluK2

OBJECTIVE

The objective of this study was to report the identification of antibodies against the glutamate kainate receptor subunit 2 (GluK2-abs) in patients with autoimmune encephalitis, and describe the clinical-immunological features and antibody effects.

METHODS

Two sera from 8 patients with similar rat brain immunostaining were used to precipitate the antigen from neuronal cultures. A cell-based assay (CBA) with GluK2-expressing HEK293 cells was used to assess 596 patients with different neurological disorders, and 23 healthy controls. GluK2-ab effects were determined by confocal microscopy in cultured neurons and electrophysiology in GluK2-expressing HEK293 cells.

RESULTS

Patients' antibodies precipitated GluK2. GluK2 antibody-specificity was confirmed by CBA, immunoprecipitation, GluK2-immunoabsorption, and GluK2 knockout brain immunohistochemistry. In 2 of 8 samples, antibodies reacted with additional GluK2 epitopes present in GluK1 or GluK3; in both, the reactivity was abrogated after GluK2 immuno-absorption. Six of 8 patients developed acute encephalitis and clinical or magnetic resonance imaging (MRI) features of predominant cerebellar involvement (4 presenting as cerebellitis, which in 2 patients caused obstructive hydrocephalus), and 2 patients had other syndromes (1 with cerebellar symptoms). One of the samples showed mild reactivity with non-kainate receptors (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors [AMPAR] and N-methyl-D-aspartate receptors [NMDAR]) leading to identify 6 additional cases with GluK2-abs among patients with anti-AMPAR (5/71) or anti-NMDAR encephalitis (1/73). GluK2-abs internalized GluK2 in HEK293 cells and neurons; these antibody-effects were reversible in neurons. A significant reduction of GluK2-mediated currents was observed in cells treated with patients' GluK2 serum following the time frame of antibody-mediated GluK2 internalization.

INTERPRETATION

GluK2-abs associate with an encephalitis with prominent clinicoradiological cerebellar involvement. The antibody effects are predominantly mediated by internalization of GluK2. ANN NEUROL 2021;90:107-123.

A Case of Influenza Virus-Induced Acute Cerebellitis Treated with Steroid Pulse Therapy

Acute cerebellitis (AC) is characterized by acute onset cerebellar ataxia brain magnetic resonance imaging (MRI) abnormalities of the cerebellum. The most common cause of AC is viral infection, and some patients with AC experience neurological sequelae. AC associated with influenza virus is extremely rare, and its prognosis and treatment are unknown. We present the case of a 2-year-old boy with influenza virus-induced AC who was treated with pulse steroid therapy. The patient presented with fever, anorexia, vomiting, malaise, altered consciousness, truncal ataxia, dysmetria, and dysarthria. He was diagnosed with influenza using a nasopharyngeal antigen test. Brain MRI showed hyperintense T2 and diffusion-weighted signal abnormalities in the cerebellar white matter and dentate nuclei bilaterally. The patient was treated with two courses of pulse methylprednisolone therapy and recovered completely in 2 months after the onset. The prognosis of AC is poorer than that of acute cerebellar ataxia, which shows similar symptoms to AC with normal brain MRI. The type of virus might also be associated with the prognosis of AC. Literature review showed that one of the five cases (including the present case, 20%) reported with influenza-associated AC was noted to have neurological sequelae, which might be more severe than those of varicella-zoster-related AC. Given that the pathogenesis of AC is assumed to be immune-mediated, pulse methylprednisolone therapy might be a good option for the treatment of influenza virus-induced AC.

Pediatric Fulminant Cerebellitis Is Still a Fatal Disease that We Know Little About! Two Case Reports and a Literature Review

Case series

Patients: Male, 13-year-old • Female, 14-year-old

Final Diagnosis: Fulminant cerebellitis • obstructive hydrocephalus

Symptoms: Headache • unconsciousness

Medication: —

Clinical Procedure: V-P Shunt for congenital hedrocephalus

Specialty: Critical Care Medicine • Immunology • Infectious Diseases • Pediatrics and Neonatology • Radiology

Cerebellitis as a neurosurgical disease in pediatrics

The diagnostic evaluation and role of neurosurgery in the treatment of cerebellitis is unclear. We explore the diagnostic evaluation and subsequent role of neurosurgical intervention in pediatric cerebellitis in a case series, highlighting the diagnostic work up and treatments applied. A retrospective review was conducted of all pediatricpatients diagnosed with cerebellitis for whom neurosurgery was consulted at a single center from June 2008 to February 2019. Nine patients, four males (44.4%) and five females (55.6%) were identified. Common presenting symptoms were headache (n = 6, 66.7%), emesis (n = 5, 55.6%), and altered mental status (n = 4, 44.4%). Six (66.7%) had associated infections. Imaging abnormalities included tonsillar ectopia (n = 8, 88.9%), bilateral cerebellar T2 hyperintensity (n = 6, 66.7%), and obstructive hydrocephalus (n = 6, 66.7%). Management included antibiotics, antivirals, corticosteroids, mannitol, and hypertonic saline. Four (44.4%) required external ventricular drain (EVD) placement for a mean 11 days (SD 6.8, range 4-20) for hydrocephalus; none required additional neurosurgical interventions. Seven patients (77.8%) required ICU care for a mean 11.7 days (SD 14.0 range 1-42). At follow-up (mean 20.8 months, SD 28.7, range 0.6-64.9), two patients (n = 2, 22.2%) recovered completely, and six (66.7%) were functionally dependent (mRS > 2); the most common residual deficit was cognitive impairment (n = 5, 55.6%). Neurosurgical consultation should be considered in pediatric patients with cerebellitis. In our experience, temporary CSF diversion via an EVD is employed nearly half of the time. The presence of hydrocephalus requiring neurosurgical intervention may be a predictor of severe disease and poor outcome.

Acute Cerebellar Ataxia in COVID-19 Infection: A Case Report

Background

The outbreak of coronavirus disease 2019 (COVID-19) has been widely reported to cause symptoms such as fever, cough, sore throat, fatigue, and shortness of breath. Neurologic complications have not been widely reported without associated respiratory symptoms. These neurologic manifestations have been found mostly in the elderly. There has been no report of ataxia or COVID-19 cerebellitis in the young adult population without associated respiratory symptoms.

Case Report

Here we report the case of a 30-year-old patient who presented with isolated cerebellar symptoms and was diagnosed with COVID-19 cerebellitis.

Why Should an Emergency Physician Be Aware of This?

It is important for emergency physicians to know that COVID-19 can have many clinical manifestations and to have a high level of suspicion with acute neurologic symptoms.

Acute Cerebellitis or Postinfectious Cerebellar Ataxia? Clinical and Imaging Features in Acute Cerebellitis

Acute cerebellitis is a rare condition often considered within the group of acute postinfectious cerebellar ataxia despite its distinctive clinical and imaging features. We retrieved clinical, laboratory, and follow-up data of 15 children diagnosed with acute cerebellitis in our department between 2011 and 2019. There were 10 boys and 5 girls aged 3-15 years, median 9.5 years. The most common first symptoms were ataxia, vomiting, and headache. Magnetic resonance imaging (MRI) generally showed bilateral symmetrical T2 hyperintense changes with moderate swelling in the cerebellar cortex. Tonsillar herniation was present in 73.3% and obstructive hydrocephalus in 26.6%. Etiologic workup for infectious pathogens revealed Mycoplasma pneumoniae, influenza A virus, cytomegalovirus, and varicella zoster virus in 1 case each. Fourteen of 15 patients were treated with intravenous and/or oral steroids and 8 cases with intravenous immunoglobulin. No patient required surgical decompression. Neurologic examination median 12 months later revealed ataxia and dysmetria in 4 cases (27%), accompanied by memory difficulties, dysarthria or tremor. Follow-up magnetic resonance imaging (MRI; n = 12) showed diffuse cerebellar cortical T2-hyperintense signal changes in 11 cases and cerebellar atrophy in 9. The diagnosis of acute cerebellitis rather than acute postinfectious cerebellar ataxia should be considered when headache and vomiting accompany ataxia in a child. Acute cerebellitis heals with sequelae in about one-third of cases. The absence of fatalities in our series suggests early diagnosis, and steroid treatment can increase the chance of recovery. MRI results were not found to be predictive of outcome.

Nonparaneoplastic autoimmune cerebellar ataxias

PURPOSE OF REVIEW

The current review develops the clinical presentations of nonparaneoplastic autoimmune cerebellar ataxia (ACA) and analyzes the association with autoantibodies.

RECENT FINDINGS

Emerging evidence suggests that autoimmunity is involved in a significant proportion of sporadic ataxia cases. Moreover, numerous autoantibodies have recently been described in association with sporadic cerebellar ataxia, improving diagnosis and patient categorization.

SUMMARY

Nonparaneoplastic ACA encompasses postinfectious acute cerebellar ataxia, opsoclonus-myoclonus-ataxia syndrome, and pure cerebellar ataxia with or without autoantibodies. There is still confusion about how to diagnose and classify the patients, and retrospective data suggest that these very rare entities are in fact largely underrecognized. Numerous autoantibodies have been found associated with sporadic ataxia, improving diagnosis accuracy, and patient categorization. However, although anti-glutamate decarboxylase isotype 65 (GAD65), anti-contactin-associated protein 2 (CASPR2), and anti metabotropic glutamate receptor (mGluR1) antibodies are well recognized biomarkers, many other autoantibodies have been described in very small numbers of patients and their specificity is unknown. Efficient biomarkers for ACA are still lacking and in many cases the diagnosis has to rely on a body of converging evidence.

Acute Cerebellitis as a Rare Treatable Cause of Obstructive Hydrocephalus

Acute cerebellitis commonly presents as acute ataxia in children. Rarely, it can result in obstructive hydrocephalus. We report a 10-year-old boy with Mycoplasma infection–associated acute cerebellitis and obstructive hydrocephalus that responded well to conservative management with no residual neurological deficit. Wide recognition of this treatable clinical entity among neurologist would avert unnecessary investigations and ensure rationale management.

Herpes simplex virus-1 as a rare etiology of isolated acute cerebellitis: case report and literature review

Acute cerebellitis is one of the most common cerebellar disorders and occurs due to para-infectious, post-infectious, or post-vaccination cerebellar inflammation. Herpes simplex virus-1 (HSV-1) is known as a common infectious cause of sporadic encephalitis. Cerebellar involvement of HSV-1 is rare and almost always associated with meningoencephalitis. To date, HSV-1 has been identified as the cause of acute isolated cerebellitis in only two patients. Here we report another case of isolated acute cerebellitis caused by HSV-1 in a 20-month-old boy.

Rhinovirus-associated acute encephalitis/encephalopathy and cerebellitis

BACKGROUND

Rhinovirus is a common respiratory pathogen for children throughout the year; nevertheless, its central nervous system involvement is extremely rare, and only two cases have been reported to date: meningitis and sepsis-like illness.

PATIENT

A previously healthy 2-year-old Japanese boy developed fever, followed by seizures and lethargy. His cerebrospinal fluid cell count and protein level were slightly increased; brain magnetic resonance imaging showed abnormal intensities in the bilateral cerebellar dentate nuclei, which were prominent in diffusion-weighted images. After his consciousness disturbance improved, cerebellar dysfunction became apparent. He was treated symptomatically, without steroids or any other immunosuppressants. He almost recovered within a few months; however, cerebellar atrophy became evident on brain magnetic resonance imaging. Using acute specimens, human rhinovirus A was detected in his throat swab and cerebrospinal fluid.

DISCUSSION

Acute cerebellitis, in which cerebellar inflammation is predominant, is occasionally accompanied by cerebral symptoms, such as consciousness disturbance and seizures. As a causative pathogen, rotavirus is the most common; however, rhinovirus-associated acute encephalitis/encephalopathy and concurrent cerebellitis have not been reported before. Further research, using recent molecular techniques to detect various central nervous system pathogens, including rhinovirus, is needed to delineate the underlying pathophysiology.