DISTRIBUTION OF LEPTOMENINGEAL GLIONEURONAL HETEROTOPIA IN ALOBAR HOLOPROSENCEPHALY

Objective: To clarify the pathogenetic significance of the topographic distribution of leptomeningeal glioneuronal heterotopia, a common fin ding in holoprosencephaly. Design: Gross, histological, and immunohist ochemical observations of alobar holoprosencephaly in brain specimens taken at autopsy. Setting: Referral center. Materials: Brains removed at autopsy from five consecutive patients with alobar holoprosencephal y. Main Outcome Measures: Immunoperoxidase staining for glial fibrilla ry acidic protein. Results: In all brains, leptomeningeal glioneuronal heterotopia showed an identical distribution, ranging from the basal prosencephalon to the pens, with the thickest distribution occurring i n the basal prosencephalon. Conclusion: The constant localization impl icates leptomeningeal glioneuronal heterotopia in severe dysgenesis of midline prosencephalon, the basic pathogenesis of the anomaly.