Prolonged P3 latency and decreased brain perfusion in cerebellar degeneration.

OBJECTIVES

To clarify the underlying mechanism of cognitive impairments in patients with cerebellar degeneration using event-related potentials (ERPs) and regional brain perfusion measurement.

MATERIALS AND

METHODS

The P3 latency of ERPs was measured during a visual discrimination task in 15 patients with idiopathic late-onset cerebellar ataxia (ILOCA) and 10 age-matched control subjects. Regional brain perfusion was measured by single photon emission computed tomography using N-isopropyl-p[123I] iodoamphetamine.

RESULTS

The mean P3 latency was longer in the patients than in controls. The patients showed lower perfusion in the frontal cortex and in the cerebellum than control subjects. There was a significant correlation between perfusion of the frontal cortex and cerebellum.

CONCLUSIONS

The results indicate that patients with ILOCA exhibit slowing of cognitive information processing and suggest that its cognitive slowing may be due to a disruption of neural circuits between the cerebellum and the frontal cortex.