Narcolepsy

Abstract

Serial measurements of regional cerebral blood flow were made by the ¹³³Xe inhalation method during the early stages of sleep and wakefulness in eight normal volunteers and 12 patients with narcolepsy. Electroencephalogram, electro-oculogram, and submental electromyogram were recorded simultaneously. In normals, mean hemispheric gray matter blood flow (Fg) during stages I and II sleep was significantly less (−9.2 percent) than waking values (84.3 ± 13 ml per 100 gm brain per minute). Maximum regional blood flow decreases during sleep occurred in the brainstem-cerebellar (−25.1 percent), right inferior temporal (−23.1 percent) and bilateral frontal (−18.9 percent) regions (p < 0.05). In patients with narcolepsy, mean hemispheric Fg while awake was 80.5 ± 13 ml per 100 gm brain per minute. During REM sleep (n =2), mean hemispheric Fg increased by 9.8 percent concurrently with large increases (+34.6 percent) in brainstem-cerebellar region flow. During stages I and II sleep without REM (n=6), there were significant increases in mean hemispheric Fg of ±20.2 percent (p < 0.01) and brainstem-cerebellar Fg of 38.0 percent (p < 0.01), just the opposite of changes in normals. In narcolepsy, there appears to be a reversal of normal cerebral deactivation patterns, particularly involving the brainstem, during stages I and II sleep.