Abstracts

Rationale: Non-Epileptic events (NEE) in patients with developmental delay/ intellectual disability (DD/ID) represent a considerable challenge. Our goal is to determine whether we can identify factors that can prospectively aide clinical identification of NEE in the DD/ID population. This study represents our initial results on the etiology of NEE in patients who are typically developing (TD) compared to those with DD/ID. Methods: A retrospective review of data in 2009 at the Pediatric Epilepsy Monitoring Unit (PEMU) at our institution. For all patients, the admitting diagnosis was spells of unknown origin. The referring physician s clinical history was reviewed. Episodes were classified as either epileptic seizures (ES), behavioral/psychogenic non-epileptic events (PNEE) or physiologic non-epileptic events (PhysNEE). The clinical characteristics and semiology of the NEE were compared in TD vs DD/ID patients Results: Of the 348 patients admitted to the PEMU, 165(47%) were admitted secondary to a diagnosis of unknown origin. NEE was confirmed in 93 (56.3%) patients. 44 were females (47.3%), age range was 1month - 19 years, (mean 8.4 years). Of the 93 confirmed NEE patients, 31 (33.3%) had physiologic etiology and 64 (66.7%) had behavioral/psychogenic etiology. 2 patients (2.1%) had events with both etiologies. Comparing the 2 groups, in the 58 (62.4%) TD patients, the diagnosis of NEE consisted of: 20 (34.4) physiologic NEE, 39 (67.2%) behavioral/psychogenic NEE, and 1 both. In the 35 (37.6%) patients with DD/ID, the diagnosis of NEE consisted of: 11 (31.4%) physiologic NEE, 25 (71.4%) behavioral/psychogenic NEE and 1 had both. 40 patients with NEE (43%) had a concurrent diagnosis of epilepsy. Comparing the 2 groups, 21 (36.2%) TD patients had epilepsy vs. 19 (54.2 %) with DD/ID. Of the 21 TD patients with epilepsy, 17 (81%) had PNEE and 4 (19%) had PhysNEE. Of the 19 patients with epilepsy and DD/ID, 16 (84.2%) had PNEE and 3 (15.8%) had PhysNEE. Of the 53 (57%) NEE patients without epilepsy, 37 (63.7%) with NCF did not have epilepsy vs. 16 (45.7%) with DD/CI. In the 37 TD patients w/o epilepsy, 22 (59%) had PNEE and 15 (41%) had PhysNEE compared to 16 patients with DD/ID w/o epilepsy in whom 9/16 (56%) had PNEE and 7/16 (44%) had PhysNEE Conclusions: Caregivers and physicians, have difficulty distinguishing NEE in patients with DD/ID. In both TD and DD/ID patients, the majority of NEE is secondary to behavioral/psychogenic causes, and in children with comorbid epilepsy, there is an even higher proportion of NEE secondary to PNEE. Therefore, etiology alone does not distinguish the two groups, and other guidelines will be needed to aid the recognition of NEE in DD/ID patients.