Atypical “Benign” Partial Epilepsy of Childhood or Pseudo-Lennox Syndrome. Part II: Family Study

Abstract

Atypical benign partial epilepsy of childhood (ABPE = Pseudo-Lennox syndrome) shows semiologic parallels to Lennox-Gastaut syndrome, however--besides the lack of tonic seizures--it has an entirely different etiology and prognosis. Recently Hahn et al [17] investigated the long-term evolution of 43 cases with ABPE. Symptomatology, EEG findings, and course were found to overlap with Rolandic epilepsy, Landau-Kleffner syndrome and ESES. The incidence of seizures in relatives was determined in the whole series investigated by Hahn et al [17]. Five of 56 siblings suffered from seizures (3 Rolandic seizures; one febrile convulsions; one unclassified). Three fathers reported grand mal. In 29 families of the series of Hahn et al EEG recordings were performed: 22 brothers, 19 sisters and 16 pairs of parents. In 29% of the siblings a sharp wave focus was demonstrable. The rate rose to 40% when only siblings investigated at the age of maximum expression (3 to 10 years) were considered. Sharp wave foci were mostly multifocal and indistinguishable from those observed in siblings of children with Rolandic epilepsy. Photoparoxysmal response and generalized spikes and waves during rest and hyperventilation were also found to be significantly elevated (26% and 13% respectively). We conclude that ABPE is a subgroup of idiopathic partial epilepsy of childhood (representing a less benign part of a spectrum) that has to be ranked in a continuum with Rolandic epilepsy. The different clinical phenotype might be caused by a higher expressivity of the identical genetic trait, possibly facilitated by other genetic or acquired factors. Genetic heterogeneity represents another possibility.

Genome-Wide Copy Number Variation in Epilepsy: Novel Susceptibility Loci in Idiopathic Generalized and Focal Epilepsies

“…Fifteen of the events we detected involve a single gene. Two genes were altered in two patients each: AUTS2 deletions were identified in one proband with juvenile myoclonic epilepsy (JME) and one proband with unclassified non-lesional epilepsy with features of atypical benign partial epilepsy (ABPE) [39]. Deletions involving CTYSB ( SPECC1 ) were identified in two probands with IGE.…”

“…Therefore, we included probands with common idiopathic focal epilepsies and non-lesional, idiopathic epilepsies. Some of our probands were diagnosed with specific epilepsy syndromes, including myoclonic astatic epilepsy (Doose Syndrome), atypical benign partial epilepsy [39], Landau-Kleffner syndrome, idiopathic West syndrome, severe idiopathic generalized epilepsy of infancy [59] and benign neonatal or infantile seizures. These particular epilepsy syndromes are usually associated with normal MRI results.…”

Rolando-Epilepsie

“…Pseudo-Lennox-Syndrom davon ausgegangen werden, dass die Epilepsie in der überwiegen-den Zahl der Fälle während der Pubertät ausheilt oder sich zumindest deutlich bessert. Da die Epilepsie bis dahin aber oft nur schwer behandelbar ist, behalten rund 50% der Patienten deutliche mentale Defizite zurück [10,14].…”

“…Bei Geschwistern von Kindern mit atypischer benigner Partialepilepsie (AB-PE) oder Pseudo-Lennox-Syndrom liegt der Anteil positiver Befunde mit ca. 40% deutlich höher [10]. In unselektierten Kohorten findet sich das EEG-Merkmal des CTS hingegen nur bei 1,5% der Kinder im Alter von 5 bis 13 Jahren [11].…”

“…Die Autoren schlossen hieraus, dass die genetischen Einflüsse bei der RE eine geringere Rolle als bei der viel selteneren atypischen Form spielen. Diese Interpretation stimmt auch mit den Ergebnissen der Geschwisteruntersuchungen von Doose et al [10] überein.…”