Abstracts

Rationale: Purpose: To determine if cognitively normal children with intractable epilepsy have a higher rate sleep abnormalities measured on polysomnogram (PSG) than their non-epileptic siblings. Methods: Cognitively normal children aged 6-18 years with intractable epilepsy (seizures >q3monthly despite trials of >2 AEDs), who had a sibling without epilepsy in the same age range were prospectively identified from the epilepsy clinic of the Alberta Children’s Hospital over a 14 month period. Eligible children and their sibling underwent an overnight PSG where the following parameters were measured: Apnea-Hypopnea Index, Lowest and Mean Oxygen Saturation, Highest and Mean CO2 Level, Total Sleep Time, Sleep Efficiency, Proportion of REM, Slow-Wave Sleep and Stage 1 Sleep of Total Sleep Time, Number of Spontaneous Arousals and Number of Periodic Limb Movements. Children with epilepsy also had continuous EEG monitoring during the PSG. Results: Thirteen of 18 eligible children with epilepsy underwent PSG. Twelve siblings were also studied (one sibling was unable to be accommodated for the PSG study). Mean age was 11.2 yrs (7.1-16.6, SD 2.9) for cases and 10.5 yrs (6.0-15.0, SD 3.1) for siblings. Gender ratio was 6M:7F for cases and 4M:8F for controls. Epilepsy syndrome was idiopathic generalized in 2, idiopathic partial in 1, cryptogenic partial in 7 and symptomatic partial in 3. Current mean AED number 1.8 (range 1-3, SD 0.6) and children had failed a mean of 2.9 (range 0-8, SD 2.7) AEDs in the past. Apnea-Hypopnea Index was abnormal (>1.5) in 4/13 cases and 4/12 controls (p=0.89), but significantly abnormal (>5.0) in only 1/13 cases (p=0.33). Sleep efficiency tended to be lower in children with epilepsy than siblings (p=0.09) and was abnormal (<85%) in 5/13 cases and 2/12 controls (p=0.23). While children with epilepsy who were overweight tended to have a higher Apnea-Hypopnea Index (p=0.20), neither seizure type (partial vs generalized), epilepsy etiology nor number of current AEDs were predictive of either greater sleep disordered breathing or poorer sleep efficiency.