SUMMARYPurpose: To determine the frequency and determinants of subnormal global cognitive function in a representative, community-based sample of children prospectively identified at the time of initial diagnosis of epilepsy. Methods: In children enrolled with newly diagnosed epilepsy and followed a median of 10.5 years, level of cognitive function (within normal, borderline, mild, moderate to severe mental retardation (MR), neurologically devastated, and impaired but not further classified (NFC)) was determined based upon neurologists' and school records, repeated parental interviews, and, in over half the participants, standardized neuropsychological testing. For multivariable analyses, subnormal cognitive function was designated as consistent with a full scale IQ < 80. Results: Global cognitive function was considered within normal, N = 451 (73.6%), borderline, N = 31 (5.1%), mild MR, N = 21 (3.4%), more severe MR, N = 45 (7.3%), devastated, N = 29 (4.7%), and impaired-NFC, N = 36 (5.9%). Age at onset <5 years, symptomatic etiology, epileptic encephalopathy, remission status and current AED treatment were each strongly associated with level of cognitive function (all p-values <0.0001). In a multivariable logistic regression model, all variables except remission status independently contributed to subnormal global cognitive function. Discussion: Evidence of subnormal global cognitive function is apparent in approximately one of four children with epilepsy. Young age at onset, symptomatic cause, epileptic encephalopathy, and continued treatment, despite their strong intercorrelations, are independently associated with this outcome. KEY WORDS: Cognition, Neuropsychology, Children, Epilepsy.Epilepsy is associated with significant cognitive comorbidity (Lhatoo & Sander, 2001) although the frequency of such comorbidity in people with epilepsy in the general population is often hard to determine. This association between epilepsy and cognitive comorbidity is due to a number of factors including the underlying causes of and risk factors for epilepsy which themselves may be associated (Hack et al., 1996;Pinto-Martin et al., 1999;Wood et al., 2000). The association between mental retardation (MR) and epilepsy has been well described in the literature (Curatolo et al., 1995;Eriksson et al., 1998). The effects of chronic seizures on brain development, structure and function (Holmes, 2001;Fuerst et al., 2003;Hermann et al., 2006); the medication used to treat seizures (Meador, 1994(Meador, , 2006; and possibly an independent effect of the physiological disturbances that predispose the brain to seizures in the first place (Berg et al., 2005) may all contribute to cognitive morbidity in people with epilepsy. Many of these factors are strongly intercorrelated. The overall burden of cognitive co-morbidity in people with epilepsy and the independent contribution of 608 609 Cognitive Function in Epilepsy each of these factors to abnormal cognitive function have not, to our knowledge, been clearly delineated.In the context of l...
