INVOLVEMENT OF THE PONTOMEDULLARY CORTICOSPINAL TRACTS - A USEFUL FINDING IN THE DIAGNOSIS OF X-LINKED ADRENOLEUKODYSTROPHY

PURPOSE: To determine whether pontomedullary corticospinal tract invol vement is a common and specific finding of adrenoleukodystrophy on MR images. METHODS: MR images of 10 patients with biochemically proved ad renoleukodystrophy who were examined during the last 6 years were revi ewed retrospectively to determine the frequency of corticospinal tract involvement in the medulla, pens, mesencephalon, internal capsules, a nd corona radiata. MR images of 10 patients with other leukodystrophie s (three with Krabbe disease, two with Alexander disease, two with met achromatic leukodystrophy, two with Pelizaeus-Merzbacher disease, and one with Canavan disease) were reviewed with specific attention to the pontomedullary corticospinal tracts. RESULTS: Medullary and pontine c orticospinal tract involvement was present in eight of the 10 patients with adrenoleukodystrophy. Mesencephalic and internal capsular involv ement was present in three patients. The corona radiata portion of the corticospinal tracts was not involved in any of the 10 patients. No p ontomedullary corticospinal tract involvement was identified in any of the 10 patients with other leukodystrophies. The difference in the fr equency of pontomedullary corticospinal tract involvement between the two groups was highly significant, CONCLUSION: Pontomedullary corticos pinal tract involvement is a common finding in adrenoleukodystrophy an d is unusual in other leukodystrophies. Awareness of this finding can facilitate the radiologic diagnosis of this disease and may expedite m anagement of affected patients.