Striatal volume loss in HD as measured by MRI and the influence of CAG repeat

Background: Hunting-ton's disease (HD) is an autosomal dominant neurodegene rative disease that results from the expansion of a trinucleotide (CAG) rep eat on chromosome 4. Progressive degeneration of the striatum is the pathol ogic hallmark of the disease. Little is known about the regional selectivit y of the neurodegeneration and its relationship to the genetic expansion. M ethods: The authors used high-resolution MRI to determine the relationship between the genetic expansion and the degree of striatal degeneration. Morp hometric analyses of the striatum from high-resolution MR images from 27 su bjects with HD were compared with those of 24 healthy control subjects. Res ults and conclusions: Striatal volumes were reduced in subjects with HD as compared with control subjects, in agreement with previously published repo rts. Left-sided volumes were smaller than right-sided volumes in subjects w ith HD; in healthy subjects, right-sided volumes were smaller. Finally, vol ume loss was significantly correlated with CAG repeat number. These results have potential implications for the design and assessment of therapeutic a gents in the future.