+H-proton-magnetic resonance spectroscopic findings in a patient with acute hemicerebellitis presenting without localized signs: a case report

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.

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 pseudotumoral hemicerebellitis in a child: a rare and distinct entity?

A pseudotumoral presentation of acute hemicerebellitis is rare in pediatric age. The authors report a new single case study of a 7-year-old child with pseudotumoral unilateral cerebellitis mimicking an intracranial tumor, which clinically presented itself with signs of intracranial hypertension and mild contralateral hemiparesis, completely recovered after anti-inflammatory therapy. Brain magnetic resonance imaging (MRI) was essential for the differential diagnosis between inflammatory and neoplastic processes. The literature highlighting specific clues about pseudotumoral hemicerebellitis as a distinct clinical and radiological entity is reviewed.

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.

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

Acute inflammation of a single cerebellar hemisphere (hemicerebellitis) is a rare disorder of unknown origin. The clinical presentation is mainly characterized by headache, ataxia, dysmetria, and vomiting. In addition, some children may develop severe intracranial hypertension. The neuroimaging of hemicerebellitis raises a challenging differential diagnosis, particularly with posterior fossa tumours. Although there is no standard treatment for hemicerebellitis, its outcome is usually favourable. However, ipsilateral hemicerebellar atrophy develops in up to half of cases, and a minority of children may show persisting fine motor and/or neurocognitive sequelae. In this article, we contribute with three new reports and review a total of 35 cases of hemicerebellitis.

Acute hemicerebellitis in children: case report and review of literature

Acute hemicerebellitis in childhood is an extremely rare unilateral presentation of cerebellitis mimicking a tumour. Its aetiology is unknown, although an inflammatory or postinfectious origin is presumed. Its clinical outcome is generally good and a self-limited evolution, in the absence of specific treatment, is usually expected. MRI findings can be misunderstood leading to erroneous diagnosis and invasive treatments. Clinical improvement and regression of the pathological findings in serial MRI will help differentiate acute hemicerebellitis from a neoplastic process. Surgical procedures should be performed only in case of clinical deterioration. We present a case of pseudotumoral hemicerebellitis in an eight-year-old girl, presenting with severe headache. This paper provides a review on hemicerebellitis and highlights the clinical, diagnostic, therapeutic features and outcome of this entity.

Pseudotumoral acute hemicerebellitis in a child

Acute cerebellitis is an inflammatory disorder usually involving both sides of the cerebellum and presenting with localized signs such as ataxia. Hemicerebellitis is extremely rare in children and may clinically and radiologically resemble a tumor. There are very few reports of hemicerebellitis needing decompressive surgery. We report a case of hemicerebellitis in a 15 year old child presenting with severe headache but no cerebellar symptoms whose brain CT revealed an ill-defined mass compressing the fourth ventricle (pseudotumoral). MRI of the posterior fossa revealed a swollen left cerebellar hemisphere, supra-tentorial hydrocephalus and tonsil herniation, without any cerebral or brain stem lesions. Due to worsening symptoms she required a decompressive craniectomy, and the biopsy revealed an inflammatory process, possibly viral. At follow-up she was asymptomatic and the MRI revealed only slight cerebellar atrophy. This case had an atypical clinical presentation and illustrates that though a self-limited evolution is expected, surgical intervention may be needed in acute cerebellitis.

Acute cerebellar ataxia, acute cerebellitis, and opsoclonus-myoclonus syndrome

Acute cerebellar ataxia and acute cerebellitis represent a process characterized by parainfectious, postinfectious, or postvaccination cerebellar inflammation. There is considerable overlap between these entities. The mildest cases of acute cerebellar ataxia represent a benign condition that is characterized by acute truncal and gait ataxia, variably with appendicular ataxia, nystagmus, dysarthria, and hypotonia. It occurs mostly in young children, presents abruptly, and recovers over weeks. Neuroimaging is normal. Severe cases of cerebellitis represent the other end of the spectrum, presenting with acute cerebellar signs often overshadowed by alteration of consciousness, focal neurological deficits, raised intracranial pressure, hydrocephalus, and even herniation. Neuroimaging is abnormal and the prognosis is less favorable than in acute cerebellar ataxia. Acute disseminated encephalomyelitis may be confused with acute cerebellitis when the clinical findings are predominantly cerebellar, but lesions on neuroimaging are usually widespread. Paraneoplastic opsoclonus-myoclonus syndrome is often initially misdiagnosed as acute cerebellar ataxia, but has very specific features, course, and etiopathogensis.

Acute hemicerebellitis in a pediatric patient: a case report of a serial MR spectroscopy study

The changes in the signals for brain metabolites in the left cerebellum of a 14-year-old boy with acute hemicerebellitis were monitored using proton magnetic resonance spectroscopy (MRS). From the onset of disease treatment to long-term follow-up, MRS data were serially acquired from the left and right cerebella, basal ganglia (BG), and centrum semiovale (CS). Large fluctuations in his MRS signals were observed in the left cerebellum. At onset (first day), his glutamate/glutamine complex signals were increased (>mean ± 2 standard deviations [SD] of the control), and those for N-acetylaspartate/N-acetylaspartylglutamate and myo-inositol were decreased (<2SD). By the 25th day, these signals had recovered to normal levels, while those for choline (Cho) were increased. In other locations, the signals for mIns in the BG and Cho in the CS were decreased on the seventh day. By the 201st day, the levels of all metabolites in all locations had recovered to within ± 2SD of the control levels. In vivo proton MRS monitoring demonstrated reversible metabolite changes associated with acute hemicerebellitis, which should contribute to its differential diagnosis from brain tumors.

Acute cerebellitis presenting as tonsillar herniation and hydrocephalus

Acute cerebellitis is a rare inflammatory syndrome, often characterized by cerebellar dysfunction of rapid onset. We describe two children, a girl aged 5 years and a boy aged 11 years, with acute cerebellitis. Both manifested tonsillar herniation and hydrocephalus. The cause was Mycoplasma pneumoniae infection in the first patient, and unknown in the second. The girl was treated conservatively with steroids and diuretics, as well as vibramycin, and the boy required insertion of a ventriculostomy. Both presented a good prognosis and full recovery.

Pseudotumoural Hemicerebellitis: Conventional MR Imaging and MR Spectroscopy Evolution

Acute cerebellitis is an inflammatory process commonly involving both cerebellar hemispheres. Bilateral cerebellar hemispheres involvement is the most common finding. It typically occurs as a primary infectious, post-infectious or post-vaccination disorder, but is also a disease entity with heterogeneous pathogenesis including paraneoplasia. Acute cerebellitis is usually a benign, self-limiting and rarely fatal disease. Typically, cerebellar atrophy is a late consequence of the syndrome. We describe the radiological features of a case of pseudotumoural hemicerebellitis with emphasis on MRI and spectroscopy findings as non-invasive diagnostic tools to avoid unnecessary surgical procedures.

Differential diagnosis of cerebellar atrophy in childhood

Starting from the imaging appearance of cerebellar atrophy (CA) we provide checklists for various groups of CA: hereditary CA, postnatally acquired CA, and unilateral CA. We also include a list of disorders with ataxia as symptom, but no evidence of CA on imaging. These checklists may be helpful in the evaluation of differential diagnosis and planning of additional investigations. However, the complete constellation of clinical (including history and neurological examination), imaging, and other information have to be considered. On the basis of a single study distinction between prenatal onset atrophy, postnatal onset atrophy, and cerebellar hypoplasia is not always possible. Apart from rare exceptions, neuroimaging findings of CA are nonspecific. A pattern-recognition approach is suggested, considering isolated (pure) CA, CA and hypomyelination, CA and progressive white matter abnormalities, CA and basal ganglia involvement, and cerebellar cortex hyperintensity.

Recurrent pseudotumoral hemicerebellitis: neuroimaging findings

We present the case of a 13-year-old girl with pseudotumoral hemicerebellitis that recurred 22 months after the first episode together with conventional MR imaging findings and diffusion-weighted imaging and MR spectroscopy findings. A mirror pattern of involvement was present with the contralateral hemisphere affected in the second episode. Recurrent hemicerebellitis is unique and recognition of the radiological findings allows accurate diagnosis that can be a challenge clinically.