Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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April 12, 2010
Band Heterotopia
- Heterotopia is the name given to focal or diffuse collections of ectopic neurons in the cerebral hemispheres, a neuronal migrational anomaly. It can be broadly classified into the subependymal, subcortical and band types of heterotopias.
- In general, band heterotopia is seen largely in women. Men with a mutation of the related gene (called XLIS or DCX) usually die in utero or have a much more severe brain anomaly.
- Diffuse band heterotopia (double cortex) consists of smooth layers of gray matter that often follow the curvature of overlying cortex. They are not convoluted nor are they contiguous with the overlying cortex. They do not contain blood vessels or CSF.
- On MRI, it shows the characteristic 3-layers (double cortex), with a thin layer of white matter between the cortex and the heterotopic band. The cortex may be relatively normal or pachygyric.
- Symptoms can vary from normal to severe developmental delay or mental retardation. Severity of clinical symptoms is related to the area of the cortex involved and the thickness of the band heterotopia.