Asymptomatic cerebellar atrophy after acute enteroviral encephalitis.

We report on a 13-year-old male who had acute enteroviral encephalitis causing cerebellar symptoms at the age of 10 years. Magnetic resonance imaging (MRI) showed no abnormalities. Clinically he appeared to be recovered completely after 6 months. Twenty-three months after the recovery, MRI was performed because he presented with slight lower-limb and truncal ataxia experienced as lack of foot coordination while playing football or riding a bicycle. MRI demonstrated severe cerebellar atrophy. Clinically he recovered completely in 10 days. Only sophisticated electrophysiological methods revealed cerebellar dysfunction. The case provides evidence for the plasticity of cerebellar regulatory structures involved in the coordination of fine movements. It seems that in childhood the slow, isolated disintegration of cerebellar systems can be compensated for by upper thalamic or telencephalic connections, in a similar way to a congenital deficit of the cerebellum.