Juvenile global tremor: a clinicopathologic syndrome mimicking polymyoclonia.

Olivary nucleus degeneration is one of the pathologic characteristics of infantile olivopontocerebellar atrophy. It has also been described in premature neonates and infants with severe perinatal asphyxia and is thought to represent retrograde transsynaptic changes from cerebellar hemisphere lesions. A 2-year-old boy developed global tremor after a respiratory infection with remission after corticosteroid therapy, and recurrence of the tremor during gradual withdrawal of steroids. Neuropathologic examination revealed neuronal loss and gliosis in the lateral portions of both inferior olivary nuclei without associated abnormalities in the cerebellum. This appears to be a unique case, both clinically and neuropathologically.