Malformations of Cortical Development

Abnormal cortical development represents a major cause of epilepsy. Most such abnormalities may now be detected using magnetic resonance imaging (MRI), although some remain undetectable even with the best imaging techniques. The largest malformation groups express different perturbations of developmental stages and carry a variable propensity to epileptogenesis, preservation or reorganization of cortical function and for atypical cortical organization. Some patients have obvious neurological impairment, whereas others show unexpected deficits that are detectable only by screening. Drug-resistant epilepsy is frequent but might be amenable to surgical treatment in some patients. Surgical planning should be based on assessments of structural, and if possible functional imaging, as well as clinical and electrographic features. Most malformations of cortical development are caused by genetic defects and brain imaging has been instrumental to the identification of causative genes. Nowadays many patients with epilepsy due to malformations of cortical development can be offeredgenetic counseling.