Abstracts

Sleep abnormalities in children with primary generalized epilepsy have not been well defined and methodological problems; especially lack of normative controls is evident in published investigations. We here report the results of a small controlled pilot study that revealed abnormal sleep architecture in children with primary generalized epilepsy, an abnormality that appears to have daytime cognitive consequences.
Two groups of children ages 5-18 were recruited for this investigation 1) children with primary generalized epilepsy (juvenile myoclonic or absence epilepsy) treated with non-barbiturate and non-benzodiazepine anticonvulsant medications, and 2) age and sex matched controls were recruited for investigation. All subjects underwent two consecutive nights of nocturnal polysomnography with extended electroencephalography and were then administered Connor[rsquo]s Continuous Performance Test to assess daytime attentional function. Wilcoxan signed-rank order tests were used to examine group differences across the sleep measures. Spearman correlations were used to examine the relationship between sleep variables and attentional function. This investigation was reviewed and approved by the IRB of the University of Wisconsin.
Nine patients (5 male and 4 female) and 7 controls (4 male and 3 female) were studied. Mean age was 14 for patients and 14.4 for controls, and mean duration of epilepsy for patients was 5.5 years. All patients with epilepsy were treated with Depakote either alone (n= 7) or in combination with Zarontin(n=2). The control subjects were on no medications. Mean REM latency (143.41[plusmn]70.59 vs. 122.8[plusmn]39.22 p[gt]0.02), mean stage 1 sleep percent total sleep time (%TST) (7.9[plusmn]3.76 vs. 4.86[plusmn]2.16 p[gt] 0.0015), and wakefulness after sleep onset (WASO) (42.83[plusmn]34.40 vs. 22.71[plusmn] 17.81 p[gt] 0.01) were significantly higher for patients compared to controls. There were no significant group differences on measures of sleep efficiency (88% vs. 90%), mean stage 2 sleep %TST (46.5 vs. 49), mean slow wave sleep %TST (17.9 VS. 17.1) or respiratory disturbance index (2.98 vs. 2.8). One patient had 3 electrographic seizures, but no patients had clinical seizures during the two nights of the study. Overall attentional performance was significantly worse in patients compared to controls (10.5[plusmn]7.1 vs. 4.56[plusmn]3.7 p[gt] 0.01). There was a significant correlation between increased REM latency, increased WASO and abnormal daytime attention function in patients (r = 0.70; r =0.60 respectively).
This controlled pilot study, involving a modest sample size, demonstrates disturbed sleep architecture among children with idiopathic generalized epilepsy compared to healthy controls. Disturbed sleep architecture appears to be of clinical consequence given its relationship to significantly poorer daytime attentional function.
[Supported by: Clinical Research Fellowship Grant: Epilepsy Foundation
UW GCRC Grant: 2M 01 RR03186-18]