Juvenile Huntington disease: CT and MR features.

PURPOSE To describe the clinical and radiologic manifestations of juvenile Huntington disease and to determine whether adult imaging criteria for Huntington disease are helpful for pediatric patients. METHODS Six patients (3 to 18 years of age; mean age, 9.8 +/- 5.6 years; 3 female, 3 male) with juvenile Huntington disease were studied with CT (n = 6) and/or MR (n = 3). CT and MR studies were evaluated for frontal horn distance/intercaudate distance and bicaudate ratios, which were compared with those of 24 age-matched healthy children and 12 age-matched patients with Leigh (n = 9) or Wilson (n = 3) disease. RESULTS Atrophy of the caudate nuclei was identified in all Huntington patients. The frontal horn distance/intercaudate distance (1.64 +/- 0.39) and bicaudate (0.205 +/- 0.060) ratios of the patients with juvenile Huntington disease were found to be significantly different from those of healthy children and that of those patients with Leigh/Wilson disease. The 3 patients with Huntington disease who underwent MR evaluation were noted to have increased proton density- and T2-weighted signal in the caudate nuclei and putamina. CONCLUSION As in adult patients, the use of frontal horn distance/intercaudate distance and bicaudate ratios are helpful for the diagnosis of Huntington disease in pediatric patients. On MR, increased proton density- and T2-weighted signal in the atrophic caudate nuclei and putamina are additional features of juvenile Huntington disease.