A girl with acute encephalitis followed by acute cerebellitis/cerebellopathy.

OBJECTIVE The purpose of this study is to bring attention to a case of acute encephalitis not concurrent with acute cerebellitis. CASE PRESENTATION Five days after onset of common cold symptoms, a 17-months-old girl suffered convulsions, vomiting and respiratory arrest. On exam, she had pharyngeal inflammation, brisk deep tendon reflexes, respiratory acidosis, leukocytosis, negative rapid antigen tests, and segmental pneumonia. Brain CT and MRI/MRA were negative, and EEG was consistent with acute encephalitis. Following hypothermic therapy, methylprednisolone pulse therapy and cefotaxime, she recovered. Four days after discharge, she sustained limb and truncal ataxia associated with normal EEG, followed by bilateral intention tremor. Blood and CSF chemistry and cell counts were normal. Brain MRI revealed high intensity signals in the dentate nuclei and enhancement in the cerebellar white matter, suggestive of acute cerebellitis/cerebellopathy. SPECT imaging showed reduced blood flow in the cerebellum, right thalamus and brain stem. Following short-term administration of g-globulin and prednisolone, she regained her ability to sit and, eventually, to walk. Four months after initial presentation, her brain MRI was normal. No relapse has occurred in 5 years. CONCLUSIONS The uncommon sequential development of acute encephalitis followed by acute cerebellitis suggests an immune-mediated cerebellar ataxia.