Clinical and electroencephalographic polymorphism of malignant migrating partial seizures in infancy

Abstract

Malignant migrating partial seizures in infancy (MMPSI) are a rare epileptic syndrome that occurs in the first 6 months of life and is characterized by multiple continuous electroencephalographic and electroclinical focal ictal patterns with involvement of different independent areas of both hemispheres and with arrested psychomotor development. Is proposed the definition of this epileptic syndrome as: «malignant epilepsy of infancy with migrating multifocal seizures» or «Coppola-Dulac syndrome». The paper describes an observation of 19 MMPSI patients examined and treated at Departament of Psychoneurology №2, Russian Children Clinical Hospital. Video-EEG monitoring showed that all the patients had very frequent and polymorphous seizures — at least 5 types in every child with ictal patterns originating from different areas of both hemispheres. The infants with MMPSI were found to have 4 subtypes of the syndrome: (1) a classicform with drug-resistant migrating status epilepticus (SE) of migrating multifocal seizures and with absolutely poor prognosis (n = 7); (2) a severe mixed form (MMPSI + early myoclonic encephalopathy (EME) with a combination of electroclinical characteristics of MMPSI with migrating multifocal SE and EME with chaotic erratic myoclonus and a suppression-burst pattern with diffuse polyspikewaves on EEG (n = 5); (3) a moderate type with reverse evolution to monofocal or multifocal epilepsy with a decrease in seizure frequency and better prognosis of life and psychomotor development (n = 5); (4) a subtle form manifesting itself as slightly identified minimal motor and inhibitory seizures, subclinical migrating multifocal SE pattern on EEG, multiple partial awakenings during sleep due to ictal patterns, and as severely delayed psychomotor development (n = 2). MMPSI is a severe form of SE in infancy with high drug resistance. At the same time, only the injection form of valproate (convulex) could stabilize progressive worsening and reduce seizure frequency in 3 cases of benzo-diazepine-resistant SE in MMPSI. Intravenous convulex is a rational alternative to benzodiazepines in SE in infancy, especially in cases of bulbar innervation disturbances and at high risk for depressed respiratory and cardiac functions.

Keywords

• malignant migrating partial seizures in infancy
• status epilepticus in infancy
• injection forms of valproate