Hemicerebellitis: Report of three paediatric cases and review of the literature

Pseudotumoral hemicerebellitis in a young male sailor with complete recovery after steroid therapy

Pseudotumoral hemicerebellitis is a rare presentation of acute cerebellitis, which involves the inflammation of a single cerebellar hemisphere and most commonly affects children. It mimics a tumor on imaging, hence given the name. In this report, we present a case of pseudotumoral hemicerebellitis in a 30-year-old male who presented to the emergency room (ER) with complaints of vertigo, vomiting, and a headache.

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.

Postinfectious coronavirus disease 2019 hemorrhagic cerebellitis: illustrative case

BACKGROUND

Conditions that can mimic posterior fossa tumors are rare. Their identification is crucial to avoid unnecessary surgical intervention, especially when prompt initiation of medical therapy is critical.

OBSERVATIONS

The authors presented a case of pseudotumoral hemorrhagic cerebellitis in a 3-year-old boy who presented initially with headache, persistent vomiting, and decreased level of consciousness 9 weeks after severe acute respiratory syndrome coronavirus 2 infection. Magnetic resonance imaging showed a left cerebellar hemorrhagic mass–like lesion with edema and mild hydrocephalus. The patient responded to high-dose steroids and was discharged 2 weeks later with complete recovery.

LESSONS

When evaluating patients with possible tumor syndromes, it is important to also consider rarer inflammatory syndromes that can masquerade as neoplasms. Postinfectious hemorrhagic cerebellitis is one such syndrome.

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.

Lyme neuroborreliosis causing unilateral cerebellitis presenting as horizontal nystagmus in a 7-year-old: an unusual presentation to an ophthalmology service

Acute cerebellitis is a rare condition with a highly heterogenous clinical course, ranging from self-limiting mild symptoms to a fulminant presentation. Symptoms include headache, vomiting, fever, ataxia, dysarthria, intention tremor, meningism, seizures, and altered level of consciousness. It warrants a high level of suspicion because of the risk of intracranial hypertension and acute hydrocephalus due to compression of the posterior fossa. We present the case of a 7-year-old boy who presented emergently with new-onset left head turn and horizontal nystagmus. Acute inflammation of a single cerebellar hemisphere (hemicerebellitis) in childhood is extremely rare, diagnosed in this case with magnetic resonance imaging. Symmetrical, diffuse cerebellar hemisphere involvement is more typical of cerebellitis. Our patient was unusual in that he presented initially with predominantly ophthalmological signs, with an otherwise normal neurological assessment. Subsequent positive serological Borrelia burgdorferi antibodies led to a diagnosis of Lyme neuroborreliosis.

Acute cerebellitis following SARS-CoV-2 infection: A case report and review of the literature

Novel coronavirus disease (COVID‐19) first described in Wuhan, China in December 2019, has rapidly spread across the world and become a global public health emergency. Literature on the neurological manifestations of COVID‐19 is limited. We report a 24‐year‐old male, who presented with vertigo, dysarthria, and bradyphrenia 3 weeks after being diagnosed with COVID‐19 on nasopharyngeal reverse transcription polymerase chain reaction. The patient was diagnosed with acute cerebellitis based on magnetic resonance imaging features and showed improvement posttreatment with intravenous methylprednisone for 5 days. The scope of this article is to highlight the importance of early identification of neurological symptoms and timely management as the outcomes may be catastrophic.

Effects of systemic corticosteroid treatment on pseudotumoral hemicerebellitis: a case report and literature review

PURPOSE

Pseudotumoral hemicerebellitis is an acute, unilateral inflammation of the cerebellum that typically affects the pediatric population. The purpose of this paper is to review cases of pseudotumoral hemicerebellitis in the literature and evaluate if treatment with systemic corticosteroids reduces length of time to symptomatic recovery.

METHODS

We present a case report of a 12-year-old male with pseudotumoral hemicerebellitis and unilateral cerebellar dysfunction. Additionally, we review the thirty-five reported cases of pseudotumoral hemicerebellitis with respect to length of time to symptomatic recovery with or without systemic corticosteroid treatment.

RESULTS

Thirty cases reported length of time to symptomatic recovery. Including our case, the mean time to recovery for those treated with systemic corticosteroids (n = 20) was 48.05 days (SE = 16.3). The mean time to recovery for those treated without (n = 10) was 86.7 days (SE = 29.3).

CONCLUSIONS

Treatment with systemic corticosteroids was associated with a faster time to symptomatic recovery compared to without. Regardless of etiology, reducing inflammation and mass effect involved in pseudotumoral hemicerebellitis may be integral to a more rapid return to neurological baseline.

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 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.

Acute Cerebellitis in Children: A Variable Clinical Entity

Acute cerebellar ataxia is the most common cause of acute ataxia in children and it usually runs a self-limiting and ultimately benign clinical course. A small proportion of children have evidence of inflammatory swelling in the cerebellum. Many of these children suffer more severe and potentially life-threatening forms of cerebellar ataxia and may need more intensive treatments including urgent neurosurgical treatments. This more severe form of acute cerebellar ataxia is often termed acute cerebellitis. Many children with acute cerebellitis have long-term neurological sequela and evidence of structural cerebellar changes on follow-up imaging. Several patterns of cerebellar inflammation have been described. The authors describe the variabilities in the clinical and radiological patterns of disease in the cases that have been described in the literature.

Hemicerebellitis can drive handedness shift

Background

Hemicerebellitisis a rare acquired condition, typical of the pediatric age. A residual switched handedness may develop after remission of acute cerebellar symptoms.

Case presentation

Herein we describe a motor functional MRI studyperformed in a 35-year old girl who had switched to left-handedness after acute right hemicerebellitis in childhood. During left hand tapping, we observed activation in the right primary sensori-motor cortex, right supplementary motor area and left superior cerebellum. During right hand tapping bilateral activations of primary sensori-motorcortex and superior cerebellum including the vermis and activation of the right supplementary motor area were observed. We speculate that during right hand tapping both the ipsilateral and contralateralpre-central gyri and the ipsilateral cerebellum would be engaged in order to recover the tapping internal model of action. From this perspective the ipsilateral pre-central gyrus might serve as are transmission station of information from the healthy cerebellum to the contralateral pre-central gyrus.

Conclusion

Selective damage of the right half of the cerebellum due to hemicerebellitis in childhood can drive shift of lateralized hand functions in the cerebrum.

Pseudotumoral acute cerebellitis associated with mumps infection in a child

Pseudotumoral cerebellitis in childhood is an uncommon presentation of cerebellitis mimicking a brain tumor. It often follows an inflammatory or infectious event, particularly due to varicella virus. Patients could have a wide clinical spectrum on presentation. Some patients may be asymptomatic or present at most with mild cerebellar signs, whereas others may suffer severe forms with brainstem involvement and severe intracranial hypertension mimicking tumor warranting surgical intervention. Imaging techniques especially multimodal magnetic resonance imaging represent an interesting tool to differentiate between posterior fossa tumors and acute cerebellitis. We describe a case of pseudotumoral cerebellitis in a 6-year-old girl consequent to mumps infection and review the literature on this rare association.

Acute cerebellitis in paediatric patients: Our experience

INTRODUCTION

Acute cerebellitis is a rare inflammatory disease with a highly variable clinical course that ranges from benign self-limiting symptoms to a fulminant presentation associated with a high risk of death due to compression of the posterior fossa, acute hydrocephalus, and intracranial hypertension.

METHODS

We reviewed clinical, laboratory, and radiological findings from children diagnosed with acute cerebellitis between May 2007 and November 2016. We analysed treatments and clinical and radiological progression.

RESULTS

Nine children met the diagnostic criteria for cerebellitis. Headache, vomiting, and drowsiness were the most frequent initial symptoms; ataxia, dysarthria, and dysmetria were the most common cerebellar signs. Cerebellitis was diagnosed with magnetic resonance imaging, which revealed cerebellar involvement (unilateral or bilateral); computerised tomography images either were normal or showed indirect signs such as triventricular hydrocephalus due to extrinsic compression of the aqueduct of Sylvius. Corticosteroids were the most commonly used treatment (6 patients). One patient required surgery due to triventricular hydrocephalus. Eight patients recovered completely, whereas the ninth displayed neurological sequelae.

CONCLUSIONS

Cerebellitis is a medical and surgical emergency; diagnosis requires a high level of suspicion and an emergency brain magnetic resonance imaging study. It is a clinical-radiological syndrome characterised by acute or subacute encephalopathy with intracranial hypertension and cerebellar syndrome associated with T2-weighted and FLAIR hyperintensities in the cerebellar cortex (unilaterally or bilaterally) and possible triventricular dilatation. Treatment is based on high-dose corticosteroids and may require external ventricular drain placement and decompressive surgery.

Acute Cerebellitis in Children: A Many-Faceted Disease

Acute cerebellitis is a rare inflammatory condition. It may have a benign, self-limiting course or present as a fulminant disease resulting in severe cerebellar damage or even sudden death. We present the clinical, laboratory, and radiologic data in 9 children diagnosed with acute cerebellitis, who were identified by database search in our pediatric medical center from January 2000 to November 2014. The main presenting symptom was headache, and the main presenting sign was ataxia. Bilateral diffuse hemispheric involvement was the most common imaging finding at presentation. Mycoplasma pneumoniae was the most common infectious pathogen found. Treatment included steroids in all cases, antibiotics in 4, and intravenous immunoglobulins in 6. Six patients had a full recovery, and 3 had residual neurologic complications. Magnetic resonance imaging (MRI) is the modality of choice for diagnosis. The course of acute cerebellitis varies from a commonly benign and self-limiting disease to an occasionally fulminant disease, resulting in severe cerebellar damage or sudden death.

Pseudotumoral hemicerebellitis as a mimicker of Lhermitte-Duclos disease in children: does neuroimaging help to differentiate them?

The clinical presentation and neuroimaging findings of children with pseudotumoral hemicerebellitis (PTHC) and Lhermitte-Duclos disease (LDD) may be very similar. The differentiation between these entities, however, is important because their management and prognosis are different. We report on three children with PTHC. For all three children, in the acute situation, the differentiation between PTHC and LDD was challenging. A review of the literature shows that a detailed evaluation of conventional and neuroimaging data may help to differentiate between these two entities. A striated folial pattern, brainstem involvement, and prominent veins surrounding the thickened cerebellar foliae on susceptibility weighted imaging favor LDD, while post-contrast enhancement and an increased choline peak on (1)H-Magnetic resonance spectroscopy suggest PTHC.

Acute hemicerebellitis in a young adult: a case report and literature review

Acute hemicerebellitis, marked by headache with or without cerebellar signs, is a rare clinical entity involving a unilateral cerebellar hemisphere. The pathogenesis of acute hemicerebellitis remains unclear, and the disease rarely occurs in adults. Here, we report an 18-year-old woman who presented with a lack of coordination of the right hand and leg lasting longer than one week, following a pulsatile headache. A neurological examination disclosed ocular dysmetria, right-sided limb ataxia and slight truncal ataxia. Cerebrospinal fluid analysis showed mononuclear pleocytosis. The serology and autoimmune studies were unremarkable. Brain magnetic resonance imaging (MRI) revealed a focal signal change in the right cerebellar hemisphere and vermis. Acute hemicerebellitis was diagnosed, and the patient was treated with intravenous methylprednisolone sodium succinate and acyclovir. Subsequently, the headache resolved, and the cerebellar signs were markedly improved. Twenty days after admission, she became asymptomatic and brain MRI showed resolution of cerebellar hyperintensity on the right side. In conclusion, we identified only 6 additional patients with adult-onset acute hemicerebellitis from previous reports, highlighting the importance of recognizing this rare clinical entity. Its clinical outcome is usually favorable, but in the acute phase, attention should be directed toward clinical symptoms that are suggestive of increased intracranial pressure.