Sleep electroencephalogram changes in acute hemispheric stroke

Background/objective: Since reports of the effects of cerebral hemispheric stroke on sleep architecture are rare and contradictory, we prospectively studied 24 patients with first acute supratentorial, extra-thalamic stroke.Methods: We assessed stroke severity, topography, and volume (on brain MRI). Sleep electroencephalogram recordings were performed a mean of 12 days after stroke onset, and scored for sleep stages over the healthy hemisphere. Sleep spindles and sawtooth waves were analyzed over both hemispheres. Data were compared with those of 17 age and gender-matched patients with normal brain imaging.Results: Compared to controls, stroke patients had lower total sleep time (P<0.01), lower sleep efficiency (P=0.02), and reduced amounts of NREM sleep stages 2-4 (P=0.02). Sleep spindles and sawtooth waves were often bilaterally reduced in patients with stroke volumes >25 ml. Abnormalities of REM sleep were more common in sleep studies performed within 3 days after stroke onset. Compared to patients with poor outcome, those with good outcome had higher sleep efficiency (P<0.01), more sleep time (P=0.02), and more NREM sleep stage 2 (P<0.01).Conclusion: Acute hemispheric stroke is accompanied by sleep EEG changes over the healthy hemisphere that correlate with stroke severity. These findings support the hypothesis that the cerebral hemispheres participate in the control of sleep.