Abstracts

Rationale: Survey-based studies suggest that sleep disorders affect over 38% of patients with epilepsy and over 58% of patients with tuberous sclerosis complex (TSC). In TSC, the high prevalence of sleep abnormalities is likely linked to the rate of epilepsy in this group, but additional factors such as psychiatric comorbidities and underlying brain pathology may also contribute. In this investigation, we set out to describe sleep abnormalities present in patients with epilepsy, both with and without TSC, and to explore potential differences in their prevalence among these groups. Methods: We conducted a retrospective chart review of patients followed at the Herscot Center for TSC and at the Pediatric Epilepsy Program at MGH to identify patients with previously diagnosed sleep disorders. We evaluated associations among aspects of seizure severity and sleep pathology in patients with epilepsy and TSC (+TSC) and in those with epilepsy without TSC (-TSC). Additionally, we conducted a prospective questionnaire study of patients aged 3-18 in both these clinics. Over 400 patients meeting our inclusion criteria were mailed descriptive and diagnostic questionnaires to assess epilepsy severity, sleep pathology, and behavioral disorders. Results: 12 of 268 (4.5%) patients with TSC carried a sleep disorder diagnosis, compared to 48 of 903 (5.3%) patients with epilepsy without TSC (p=0.52). The groups did not differ in baseline seizure characteristics, as there was no significant difference in age at seizure onset (p=0.23), number of previous anti-epileptic medications (p=0.54), or number of prior seizure types (p=0.77). Also, the groups did not differ in the prevalence of patients taking a daily sleep medication (p=0.27). There appeared to be a more patients in the +TSC group with a sleep disorder and psychiatric comorbidity (8 of 12, 67%) than in the -TSC group (14 of 48, 29%), though multivariate analyses to confirm the significance of this association were deferred given our small sample size. Among patients from either group with a sleep disorder diagnosis (n=60), 45 (75%) had a likely insomnia, 12 (20%) an obstructive sleep apnea, and 3 (5%) a parasomnia. The results of the prospective questionnaire portion of the study will be presented. Conclusions: There was no difference in the prevalence of formal sleep disorder diagnoses among patients with epilepsy with or without TSC, however few in either group met these criteria. Consistent with previous reports, fewer patients received formal diagnoses of sleep disorders by clinicians than what is predicted in survey-studies. This may indicate that sleep abnormalities are “under-diagnosed” in our clinic population. Interestingly, our findings suggest there may be a higher prevalence of psychiatric comorbidities in our patients with sleep disorders and TSC versus epilepsy, however larger samples our needed to confirm this. We will corroborate these findings with the results of our questionnaire-based investigation to further examine the prevalence of sleep disturbances among these groups and examine the contributions of seizure severity and psychiatric comorbidities in sleep pathology.