Putaminal Hypometabolism Exceeding Caudate Abnormalities on 18F-FDG PET in Huntington Disease

Abstract

An 18F-FDG PET scan performed on a patient suspected of having early Huntington disease (HD) showed marked hypometabolism in bilateral putamen that was significantly worse than the hypometabolism in caudate. While HD could not be completely excluded, the scan finding was felt to be somewhat atypical for HD because of a lesser degree of caudate involvement. Genetic testing eventually confirmed the diagnosis of HD. This case shows that diagnosis of HD should still be considered even when putaminal hypometabolism exceeds caudate changes on 18F-FDG PET imaging.