Herpes simplex type 1 encephalitis restricted to the brainstem in a pediatric patient

Abstract

Herpes simplex encephalitis is a potentially fatal infection of central nervous system that typically involves frontal and temporal lobes. Occasionally, it presents an extratemporal involvement and in rarer cases, it is limited to the brainstem. We describe a case of an adolescent who presented with fever, sore throat, and vertigo. Clinical picture evolved to lethargy, tetraparesis, consciousness impairment, and respiratory failure. MRI showed lesions restricted to the brainstem. PCR of CSF was positive for herpes simplex type 1.

Figure 1

Axial fluid attenuation recovery (FLAIR) MR images show symmetric abnormal hyperintensity in the cerebellar tonsils and inferior, middle, and superior cerebellar peduncles.

Figure 2

(a) Axial diffusion-weighted MR images show marked hyperintensity in some areas of the inferior and middle cerebellar peduncles. (b) On the apparent diffusion coefficient (ADC) maps, they are distinctly hypointense.