No abstract

Temporal lobe abnormalities on brain imaging have been described as strong evidence for herpes simplex encephalitis (HSE) in appropriate clinical settings. Extra temporal abnormalities are less well described in these patients. We retrospectively reviewed 20 patients of HSE and found extra temporal involvement in 11 (55%) patients. Three patients (15 %) had pure extra temporal abnormalities. Twelve patients (60%) had temporal lobe involvement, four patients (20%) had pure temporal lobe involvement and five patients (25%) had normal CT/MRI scans. Our study suggests that extra temporal involvement on brain imaging is common in HSE and in a significant minority of the patients this can even be the sole abnormality.

This 7-year-old boy presented with a 2-week history of headache, nausea, vomiting, anorexia, lethargy, and unsteadiness of gait. Brain magnetic resonance imaging (MRI) revealed a cystic mass within the vermis of the cerebellum. A suboccipital craniectomy was performed to remove a tumor that contained primitive neuroectodermal cells with florid skeletal muscle differentiation. Immunohistochemical studies and electron microscopy confirmed the presence of both a primitive neuroectodermal component and rhabdomyoblastic differentiation, consistent with the diagnosis of medullomyoblastoma. This exceedingly rare tumor of the cerebellar vermis of children is characterized by two components: primitive neuroectodermal tumor cells and skeletal muscle. Although the histogenesis remains uncertain, advances in immunohistochemistry and electron microscopy suggest the origin of this tumor from a multipotential stem cell precursor.

Acute cerebral venous strokes may contain cytotoxic edema and/or vasogenic edema on DWI scans. DWI may be helpful in diagnosing cerebral venous thrombosis in cases with cryptic presentations.

Acute cerebral venous strokes may contain cytotoxic edema and/or vasogenic edema on DWI scans. DWI may be helpful in diagnosing cerebral venous thrombosis in cases with cryptic presentations.