Interrelationship of sleep and juvenile myoclonic epilepsy (JME): a sleep questionnaire-, EEG-, and polysomnography (PSG)-based prospective case-control study.

We studied the effects of 'epilepsy on sleep and its architecture' and 'sleep on the occurrence and distribution of interictal epileptiform discharges (ED)' using 'sleep questionnaires', 'EEG', and 'PSG' in patients with JME. Forty patients with JME [20 on valproate (Group I - 20.8±4.0 years; M: F=9:11) and 20 drug-naïve (Group II - 24.4±6.7 years; M: F=9:11)] and 20 controls (M: F=9:11; age: 23.5±4.7 years) underwent assessment with Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), overnight PSG, and scalp-EEG. Epileptiform discharges (EDs) were quantified in different sleep stages. The 'ED Index' was derived as number of EDs/min per stage. Statistical Package for the Social Sciences (SPSS) vs. 11 was used for statistical analysis. A 'p' <0.05 was considered as statistically significant. There was poor sleep quality in patients compared to controls (p=0.02), while there was no significant difference in ESS scores between the groups. The PSG parameters were comparable in both groups. Routine EEG revealed EDs in 22/40 (Group I: 7 and Group II: 15) patients. Thirty-five patients had EDs in various sleep stages during PSG (Group I: 17 and Group II: 18): N1 - Group I: 9 and Group II: 14, N2 - Group I: 14 and Group II: 14, N3 - Group I: 14 and Group II: 10, and REM - Group I: 9 and Group II: 11. The ED Index was higher during N2/N3 in Group I and N1/REM in Group II. The epileptiform discharges were frequently associated with arousals in N1/REM and K-complexes in N2. There was no other significant difference between Groups I and II. In conclusion, there was poor sleep quality in patients with JME compared to controls, especially those on valproate who had altered sleep architecture. Epileptiform activity was observed more often in sleep than wakefulness. Sleep stages had variable effect on epileptiform discharges with light sleep having a facilitatory effect in the drug-naïve group and slow wave sleep having a facilitatory effect in the valproate group.