0653 WORSENING PSYCHOMOTOR VIGILANCE AFTER BRIEF NAPS IN HYPERSOMNOLENT PATIENTS: MSLT NAP CORRELATES

Abstract Introduction: Physiologic sleep inertia is operationalized as cognitive impairments upon awakening. Markedly pronounced sleep inertia, or sleep drunkenness, is common in idiopathic hypersomnia and may exist on a continuum with physiologic sleep inertia or may represent a distinct entity. Previous work has demonstrated significant worsening of vigilance on Psychomotor Vigilance Task (PVT) lapses (reaction times >500ms) and reciprocal of reaction time (RRT) following brief naps among hypersomnolent patients, but the MSLT correlates of these changes in vigilance are unknown. Methods: Patients undergoing PSG/MSLT (N=118; Age=37.38 ± 14.39; 62.71% women), with diagnoses of Idiopathic hypersomnia (n=37), Obstructive Sleep Apnea (n=29), Narcolepsy Type 1 (n=8) and Type 2 (n=6), and subjective sleepiness with normal MSLT (n=30), were administered PVT before and after MSLT naps 2 and 4. PVT performance was analyzed with paired t-tests, mixed-effects, and general linear models. Results: For nap 2, lapses and RRT demonstrated significant worsening post-nap relative to pre-nap, (10.31 ± 18.56 [pre] vs 13.42 ± 20.65 [post]; t= -2.98, p=0.0035 and 3.24 ± 0.87[pre] vs 3.05 ± 0.91[post]; t=5.06, p=