[Analysis of cerebellar functions in spinocerebellar degeneration using positron emission tomography (PET)]

We quantitatively evaluated the cerebellar functions of 23 patients with spinocerebellar degeneration (SCD) and 10 normal controls using positron emission tomography (PET). Statistical analysis was performed using the Student's test. Regional cerebral blood flow (CBF) and regional cerebral metabolic rate (CMR) of the cerebellar hemisphere and cerebellar vermis were significantly lower in patients with SCD than in normal subjects (p less than 0.001). However, no significant difference between the both groups was seen in the CBFs and the CMRs of the occipital cortex and frontal cortex. Even in the patients with SCD who had not apparent cerebellar atrophy on CT, their CBFs and CMRs of the cerebellum were significantly low, and with advance of cerebellar atrophy, they tended to fall. In the patients with SCD, the fall of CMR was more prominent than that of CBF. Neither CBF, nor CMR of the cerebellum showed correlation to the duration of the illness. The present investigation suggested that PETs were valuable for the early diagnosis and the research on the pathogenesis of SCD.