PSEUDO-LENNOX SYNDROME: CLINICAL AND ELECTROENCEPHALOGRAPHIC CHARACTERISTICS

Abstract

Pseudo-Lennox syndrome (PLS), or atypical benign partial epilepsy of childhood, is a disease from a group of age-related epileptic encephalopathies with a phenomenon of continuous spike-wave activity during slow sleep, which manifests itself as frequent polymorphic focal motor and pseudogeneralized seizures, cognitive impairments, as well as regional and diffuse epileptiform activity on electroencephalogram (EEG) by the morphology identical to that of benign epileptiform patterns of childhood. The disease was first described by J. Aicardi and J. J. Chevrie in 1982, based on a study of 7 cases. Its diagnostic complexity is the polymorphism of both epileptic seizures and EEG data, as well as low awareness of the syndrome among physicians and its absence in the international classification of epilepsies. The typical triad of seizures, which occurs in nearly 100 % of patients, encompasses focal motor paroxysms (identical to those as observed in Rolandic epilepsy), atypical absences, and atonic seizures. Seizures in PLS in its active period (generally up to 7–8 years) are highly resistant to antiepileptic drugs. Only a few agents have been proven to be effective in PLS; these include valproates, succinimides, benzodiazepines, topiramate, and sulthiame. The frequency of seizures are noted to increase in patients with PLS treated with drugs, such as vigabatrin, gabapentin, lamotrigine, phenobarbital, or phenytoin. The author considers in detail the history of studies of the disease, clinical manifestations, diagnostic criteria, therapeutic approaches, and prognosis.