COGNITIVE DYSFUNCTION AND THE DISTRIBUTION OF SPIKE ACTIVITY IN BECTS

Objectives: Benign epilepsy with centro-temporal spikes (BECTS) is characterised by focal epileptic discharges (spikes) in the absence of apparent structural pathology or frequent seizures. Children with BECTS also experience cognitive dysfunction, but the relationship between this problem and the distribution of the spike activity is unknown. As a first step towards understanding this issue, the present study addressed the question: is the spike activity in BECTS associated with a regionally specific or a diffuse cognitive impairment?

Methods: Twelve children with BECTS (Mean age 9.78±1.5, range 7–12 years; 11 males) and twelve age- and sex- matched controls participated in the study. The participants completed a battery of neuropsychological tests assessing intelligence, receptive and expressive language, primary memory, new learning, academic attainment, and executive function.

Results: The performance of the BECTS children was not significantly different from that of the controls on measures of intelligence (VIQ t=1.35, p=0.20), receptive language (t=1.77, p=0.11), new learning (t=0.65, p=0.53), academic achievement (reading t=1.47, p=0.17; spelling t=1.75, p=0.11; mathematical ability t=1.52, p=0.16), or executive function (t=0.65, p=0.53). The BECTS children, however, were selectively impaired on expressive language (t=2.34, p=0.04) and primary memory capacity (t=2.63, p=0.03).

Conclusions: BECTS is associated with a circumscribed impairment of language and primary memory function. These functions are highly dependent on the ventrolateral frontal cortex, a brain region with close proximity to the seizure focus in BECTS. This finding lends support to the notion that cognitive dysfunction in BECTS is closely related to the distribution of spike activity.