Cryptogenic localization-related epilepsy with childhood onset: The problem of definition and prognosis.
BACKGROUND
Up to one-third of children with epilepsy are diagnosed with cryptogenic localization-related epilepsy (CLRE). CLRE is a large nonspecific category within the ILAE classification. For this population no unequivocal prognosis exists.


METHODS
Twenty-five articles describing aspects of CLRE were included in this review.


RESULTS
As a result of the progress in epilepsy research, as well as more advanced investigation in individual cases, the population with CLRE constantly changes. Also, disagreement on interpretation of the classification has resulted in striking differences between the populations described. High remission rates are reported, but relapse occurs frequently, leaving the long-term prognosis unforeseeable. This is reflected in academic and psychosocial prognosis, which is described to be problematic in CLRE specifically. Possible prognostic factors of CLRE in children have been identified: age at onset, seizure semiology, seizure frequency, intractability, interictal epileptiform activity on EEG, and premorbid IQ. These factors are explored to define subgroups within the CLRE population.


CONCLUSIONS
Prospective studies on well-defined CLRE cohorts are needed to identify factors that distinguish various prognostic subgroups. Specific attention should be focused on course of the epilepsy, scholastic achievement, and psychosocial outcome.
Reijs
Rianne P
RP
Department of Research and Development, Epilepsy Centre Kempenhaeghe, Heeze, The Netherlands. ReijsR@kempenhaeghe.nl
van Mil
Saskia G M
SG
van Hall
Mariette H J A
MH
Arends
Johan B A M
JB
Weber
Jacobiene W
JW
Renier
Wil O
WO
Aldenkamp
Albert P
AP