Structural changes in cerebellar outflow tracts after thalamotomy in essential tremor

Background This study set out to determine whether structural changes are present outside the thalamus after thalamotomy in patients with essential tremor (ET), specifically in the cerebellorubrothalamic tracts. We hypothesized that diffusion tensor imaging (DTI) would detect these changes. Methods We collected DTI scans and analyzed differences in Fractional Anisotropy (FA) and Mean Diffusivity (MD) between the left and right superior and middle cerebellar peduncle in ET patients that have undergone unilateral, left, thalamotomy and ET patients that did not undergo thalamotomy (control group). We used classical ROI-based statistics to determine whether changes are present. Results We found decreased FA and increased MD values in the right superior cerebellar peduncle leading to the left, lesioned thalamus, only in the thalamotomy group. Conclusions Our study suggests long-term structural changes in the cerebellorubrothalamic tract after thalamotomy. This contributes to further understanding of the biological mechanism following surgical lesions in the basal ganglia.