MR imaging of incomplete band heterotopia.

In 1989, Barkovich et al. [1] described a new neuronal migration anomaly referred to thereafter as band heterotopia. Similar findings were also reported by Livingston and Aicardi [2] in describing two children with mild epilepsy and learning behavior problems. In band heterotopia, a continuous band of heterotopic neurons is interposed between the lateral ventricles and the cerebral cortex. The layers of ectopic gray matter are described as bilateral and symmetric. This distribution is one of the main reasons why CT and MR imaging often fail to identify it. A case of atypical band heterotopia, characterized by an asymmetric distribution, is described in the present report.