Thin-section computed tomographic (CT) scans of 1.5 mm thickness were obtained in the study of 44 consecutive patients with Huntington's disease (HD) and six patients with sporadic progressive chorea and dementia. Mild to moderate midbrain and pontine atrophy, a dilated third ventricle, and enlarged quadrigeminal plate cisterns were observed in most cases suggesting that brainstem atrophy is common in HD. Brainstem atrophy preceding caudate atrophy in two cases and pontine or midbrain atrophy to a similar degree as caudate atrophy in eight cases suggest that brainstem atrophy may occasionally precede or appear at the same time as caudate atrophy. The CT scan brainstem findings and their neuropathologic confirmation suggests a more important role for the brainstem in the pathophysiology of HD.
