Malignant migrating partial seizures in infancy

Abstract

The syndrome of malignant migrating partial seizures in infancy (MMPSI) was first reported in 1995, and is now included among the childhood epileptic syndromes in the revision proposal of the ILAE Commission on classification and terminology. The main clinical features are seizure onset in the first 6 months of life, occurrence of almost continuous migrating polymorphous focal seizures, associated with multifocal ictal EEG discharges, progressive deterioration of psychomotor development combined with frequent evolution of acquired microcephaly, and lack of a significant familial and etiological context. Eventually, children develop major axial hypotonia, pyramidal and extrapyramidal signs with athetotic movements and strabismus. Neuroradiological, biochemical, and genetic investigations thus far have note contributed to our knowledge about this syndrome. Etiology is still unknown, though it appears reasonable to suspect a genetic etiology for MMPSI; a channelopathy may be responsible for the age-dependent cortical neuronal hyperexcitability. Seizures are markedly drug resistant and outcome is generally severe. However, some patients may respond favourably to bromide, stiripentol associated with clonazepam, and, more recently, to levetiracetam. Vagus nerve stimulation and a ketogenic diet have been tried also but with poor or inconclusive results. Based on age at onset, MMPEI may be placed between early epileptic encephalopthies and infantile spasms.