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.