Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Abstract

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.

Role of Magnetic Resonance Imaging in Paediatric Epilepsy

“…Brodtkorb et al 15 1992 studied 303 patients with epileptic seizures referred for MRI and found 4.3% malformations of cortical development.…”

Patient Mutations in Doublecortin Define a Repeated Tubulin-binding Domain

“…Mutations in DCX lead to the human disorder double cortex and X-linked lissencephaly (1,2), which appears to be due to a primary defect in cortical neuronal migration (3), resulting in epilepsy and mental retardation (4). In lissencephaly (lissos means smooth) the normally gyrated six-layered cortex is replaced by a smooth four-layered cortex, whereas in double cortex there is a normal-appearing outer cortex and a second layer of cortical neurons in the subcortical white matter.…”

Clinical Features of a Series of Non-Surgical Patients with Focal Cortical Dysplasia and Epilepsy

“…Most of them have FCD in the frontal lobe. As mentioned by other authors [5,6,22,26], FCD is associated with a wide range of clinical presentations. There is no particular seizure semiology that characterizes patients with FCD compared with other surgical series of epilepsy patients [16][17][18].…”

“…MCD are considered the second most common cause of medically resistant focal epilepsy in adults after hippocampal sclerosis [3]. In patients with resistant epilepsy, the MCD have been observed in 8-12% of cases [4] and in up to 14% of children with resistant epilepsy and mental retardation [5,6].…”