The National General Practice Study of Epilepsy. The syndromic classification of the International League Against Epilepsy applied to epilepsy in a general population
M. Manford, Y. M. Hart, J. W. Sander and S. D. Shorvon
Chalfont Centre for Epilepsy, Buckinghamshire, England.
In this prospective, population-based study of 594 cases of newly diagnosed
epilepsy, proportions in categories as defined by the International League
Against Epilepsy (ILAE) were as follows: (1) localization-related
epilepsies: 1.1* idiopathic, 1.2%; 1.2* symptomatic, 16.2%; and 1.3
cryptogenic, 24.6%; (2) generalized epilepsies: 2.1* idiopathic (idiopathic
generalized epilepsy) with 3-Hz spike and wave: absence epilepsy, 2.2%;
juvenile myoclonic epilepsy, 1.5%; and nonspecific idiopathic generalized
epilepsy, 5.6%; 2.3.1* symptomatic generalized epilepsies, 1.5%; 2.3.2*
specific syndromes with generalized epilepsy, 0.3%; 3.2 seizures without
unequivocal focal or generalized features, 32%; 4.1 situation-related
syndromes, isolated seizures, 9.9%; seizures due to acute toxic or
metabolic cause,* 4.5%. Only 33.6% were in diagnostic ILAE categories
(asterisks) and many rare syndromes were not represented. The remainder
(66.4%) were in various nonspecific categories. Only 24% of
localization-related epilepsies could be clinically localized to a single
ILAE-proposed site of origin and of these best localized cases, 14% had
strongly discordant imaging or electroencephalograms. These major problems
in applying the ILAE classification to epilepsy in the general population
and its underemphasis of modern imaging techniques are discussed.
