HUNTINGTON'S disease is an autosomal dominant disease characterized by slowly progressive personality changes, dementia, and movement disorders.^{1 , 2} The average age at onset is 30 to 40 years, and the disease lasts for an average of 15 to 20 years. Analysis with restriction-fragmentlength polymorphisms (RFLPs) has localized the Huntington's disease gene close to the telomere of the short arm of chromosome 4.^{1 2 3} Prominent striatal atrophy with loss of striatal neurons and relative sparing of fibers of passage and afferent axons is the pathological hallmark of Huntington's disease.⁴ Recent studies have demonstrated a distinct pattern of vulnerability of striatal neurons in Huntington's . . .