Decrease in Cerebral and Cerebellar Gray Matter in Essential Tremor: A Voxel-Based Morphometric Analysis under 3T MRI

BACKGROUND AND PURPOSE Though routine neuroimaging is usually normal in essential tremor (ET) there is clinical evidence of widespread involvement of central nervous system. This study aimed at determining morphological changes in brain of patients with ET using voxel-based morphometry (VBM) analysis and also compare the subtypes of ET. METHODS Clinical and imaging data of 20 patients (5 women, 15 men; mean age 38.2 +/- 16.5 years) of ET were collected prospectively. To determine areas of gray matter (GM) atrophy, T1W volumetric MRI data of patients were compared with 17 matched control subjects using VBM analysis with Statistical Parametric Mapping 5. RESULTS Compared to controls, patients showed scattered areas of cerebral and cerebellar atrophy. Voxel-wise analysis of patients with and without head tremor showed widespread areas of GM atrophy in cerebral hemispheres of patients with head tremor. No difference was observed between the familial and nonfamilial subgroups of ET. Multiple regression analysis revealed relationship between GM atrophy and tremor severity score. CONCLUSIONS Patients with ET showed widespread areas of atrophy in both cerebellum and cerebral GM, which supports the current concept of the progressive and diffuse nature of ET. Patients with additional head tremor may represent a distinct subgroup of ET.