Effects of interictal discharges on cognition and behaviour in children with well-controlled epilepsy
Objective: There is evidence that in patients with epilepsy interictal discharges can
be accompanied by transitory cognitive impairment (TCI). However, it is not kno\vn
whether interictal discharges and TCI impair day to day psychosocial functioning,
and if so whether drug treatment to suppress discharges is effective in the absence of
Aims of study: (1) Effect of lamotrigine on interictal discharges, behaviour and
cognition in children with epilepsy. (2) Effect of interictal discharges on behaviour
and cognition in children with epilepsy. (3) Effect of suppression of discharges
behaviour in children with epilepsy.
Method: In a randomised, double-blind, placebo-controlled, cross-over study with
lamotrigine ambulatory EEG, cognitive test battery and behavioural scores were
measured in 61 patients at baseline, placebo and lamotrigine phase.
Interictal discharges are common in children with epilepsy even if seizures are well
controlled. Lamotrigine reduced the duration of discharges per hour, but not the total
number per hour in this group of patients. Lamotrigine had no significant negative or
positive effect on cognitive performance in children with epilepsy. Tel was found in
over 500/0 of patients with sufficient discharges for analysis. There was a significant
correlation of side of discharges to the type of test (spatial or verbal), when
correcting for dominant hemisphere. Interictal discharges were associated with
impaired cognitive performance (working memory). During treatment with
lamotrigine global rating of behaviour significantly improved in patients with a
reduction in discharges rate, but not in patients with without a change in discharge
rate. This was independent of randomization or presence of seizures.
Conclusion: lnterictal discharges are common even in children with well-controlled
epilepsy and associated with cognitive impairment particularly affecting \\orking
memory. Our data suggest that suppressing interictal discharges can improve
behaviour in children with behavioural problems and epilepsy.