[Acute cerebellitis in children: regarding different etiologies]. / Cerebelite aguda na criança--a propósito de diferentes etiologias.

UNLABELLED: Acute cerebellitis is usually infectious, post-infectious or post-vaccination. Rarer causes include toxic ones. The clinical presentation is usually benign, however, severe cases with brainstem compression may present as coma. Regarding three pediatric clinical cases, the authors make a brief review on this entity, with particular emphasis on its causes and imaging findings. CASE REPORTS: Three cases of pediatric acute cerebellitis are presented- post-viral, after acute intoxication with carbon monoxide and after accidental ingestion of methadone. DISCUSSION: The etiopathogenic mechanisms underlying the imaging changes found in each of the three cases presented are discussed. CONCLUSION: An imaging examination confirms the diagnosis of cerebellitis and is important to monitor severe cases. MR is more sensitive than CT in the evaluation of the cerebellar parenchyma.

[MRI findings in Rasmussen's encephalitis]. / Achados em ressonância magnética na encefalite de Rasmussen.

INTRODUCTION: Rasmussen's encephalitis is a chronic inflammatory encephalitis of unknown etiology. Clinical, imaging and electroencephalographic characteristic findings allow its diagnosis. Serial brain MRI evaluation of these patients has a characteristic pattern of temporal evolution. Regarding a clinical case, the authors make a brief review of this pathology, with particular emphasis on the MRI findings. CASE REPORT: Female child, seven years old, who started a drug-resistant focal epilepsy at the age of four. The video-EEG revealed a left fronto-temporal epileptogenic focus. The serial MRI evaluation showed a left fronto-temporal and insular lesion with variation of its imaging features over time. After thorough investigation, the diagnosis of exclusion was that of Rasmussen's encephalitis. CONCLUSION: MRI plays an important role in the diagnosis and monitoring of Rasmussen's encephalitis. Regarding a clinical case, we review this pathology, specially its MRI findings.

[Adult cerebellar medulloblastoma: imaging findings in eight cases]. / Meduloblastomas no adulto: aspectos imagiológicos em oito casos.

Medulloblastoma is a brain tumor of neuroepithelial origin, frequent in children but rare in adults. The imaging pattern is well studied in the pediatric group thought there is controversy about the imaging characteristics in adults. We report CT and MRI imaging findings of 8 adult patients with cerebellar medulloblastoma. The mean age was 29.6 years (16-65 years). The male: female rate was 5:3. Most were lateral, located in the cerebellar hemisphere (63%). They were hyperdense on CT (67%). On the MRI they were all hypointense on T1, hyperintense on T2, with gadolinium enhancement of variable pattern. In 7 cases there were cysts/intratumoral necrosis. It was seen calcifications in 2 cases. Four patients presented hydrocephalus. In 2 cases there was no perilesional edema. All had well defined margins and superficial extension. Dural involvement was seen in 7, one of which with lateral venous sinus compromise, and brainstem invasion was seen in 1 case. The imaging findings of medulloblastomas in adults are unspecific and different from those in child. They should be considered in the differential diagnosis of cerebellar tumor in adults, especially if they are hyperdense on CT, with well defined margins, with superficial extension and with dural involvement.

[Spontaneous intracranial hypotension syndrome]. / Síndrome de hipotensão espontânea do líquor.

Spontaneous Intracranial Hypotension is a rare syndrome, characterized by orthostatic headaches, low CSF pressure and characteristic aspects on MRI. The authors describe a clinical case of Spontaneous Intracranial Hypotension, in which the MRI investigation revealed a low position of the cerebellar tonsils, a diffuse and symmetric dural enhancement and an engorgement of the cervical epidural venous plexus. The authors make a review of the physiopathology, clinical and radiological aspects related to this syndrome.