Midbrain hypometabolism as early diagnostic sign for progressive supranuclear palsy.

OBJECTIVE: Progressive supranuclear palsy (PSP) is often misdiagnosed in early phase. The purpose of this study is to investigate the feature of [(18)F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography images for the early diagnosis of PSP.

METHODS: We studied 15 patients with PSP and 16 normal subjects. Using SPM99 and analysis of covariance to eliminate the effect of aging, the differences between PSP and normals were displayed as a statistical map. In the PSP, we also investigated the correlation with duration and with the subscores of Unified Parkinson's Disease Rating Scale.

RESULTS: The glucose metabolism of midbrain was significantly lower in PSP than in normals. However, correlation was not found between the metabolism of midbrain and clinical deterioration.

CONCLUSIONS: The statistical map clearly demonstrated the hypometabolism of midbrain in PSP, which is independent of the clinical deterioration. The hypometabolism of midbrain is one of the most promising sign for early diagnosis of PSP.