Subcortical band heterotopia (MRIs)

(A) and (B) Axial T1-weighted images from a single patient with subcortical band heterotopia. (A) is more caudal than (B) and demonstrates an approximately 1 cm-thick band in the subcortical white matter. In (B), due to an averaging artifact, the band is somewhat more distinct at this more rostral level. (C) Coronal image from a member of a subcortical band heterotopia pedigree, demonstrating a distinct band and an essentially normal-appearing cerebellum. This patient appears to have two layers of heterotopic band, as has been reported by Barkovich and colleagues (Barkovich AJ, Guerrini R, Battaglia G, et al. Band heterotopia: correlation of outcome with magnetic resonance imaging parameters. Ann Neurol 1994;36:609-17.) (D) Axial image from a sporadic patient with subcortical band heterotopia, demonstrating that the band may be indistinct from the overlying cortex. The band is more distinct posteriorly. Also note mild ventricular dilatation in all patients. Asterisk=outer cortex, arrow=band. (Contributed by Dr. Joseph Gleeson.)