Marta Pace1,2, Millene R Camilo3,4, Andrea Seiler3, Simone B Duss3, Johannes Mathis3, Mauro Manconi3,5, Claudio L Bassetti1,3. 1. Center for Experimental Neurology (ZEN), Department of Neurology, University Hospital (Inselspital), Bern, Switzerland. 2. Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Genova, Italy. 3. Department of Neurology, University Hospital-Inselspital, Bern, Switzerland. 4. Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil. 5. Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland.
Abstract
Study Objectives: Sleep disturbances are common in acute stroke patients and are linked with a negative stroke outcome. However, it is also unclear which and how such changes may be related to stroke outcome. To explore this link, we performed a sleep electroencephalogram (EEG) study in animals and humans after ischemic stroke. Methods: (1) Animal study: 12 male rats were assigned to two groups: ischemia (IS) and sham surgery (Sham). In both groups, sleep architecture was investigated 24 h before surgery and for the following 3 days. (2) Human study: 153 patients with ischemic stroke participating in the SAS-CARE prospective, multicenter cohort study had a polysomnography within 9 days after stroke onset. Functional stroke outcome was assessed by the modified Rankin Scale (mRS) at hospital discharge (short-term outcome) and at a 3-month follow-up (long-term outcome). Results: (1) Animal study: rapid eye movement (REM) sleep was significantly reduced in the IS group compared to the Sham group. (2) Human study: patients with poor short-term functional outcome had a reduction of REM sleep and prolonged REM latency during the acute phase of stroke. REM latency was the only sleep EEG variable found to be significantly related to short- and long-term functional impairment in a multiple linear regression analysis. Conclusions: Acute ischemic stroke is followed by a significant reduction of REM sleep in animals and humans. In humans, this reduction was linked with a bad stroke outcome; in addition, REM latency was found to be an independent predictor of stroke evolution. Potential explanations for this role of REM sleep in stroke are discussed. Clinical Trial Registration: http://clinicaltrials.gov. Unique identifier: NCT01097967.
Study Objectives: Sleep disturbances are common in acute strokepatients and are linked with a negative stroke outcome. However, it is also unclear which and how such changes may be related to stroke outcome. To explore this link, we performed a sleep electroencephalogram (EEG) study in animals and humans after ischemic stroke. Methods: (1) Animal study: 12 male rats were assigned to two groups: ischemia (IS) and sham surgery (Sham). In both groups, sleep architecture was investigated 24 h before surgery and for the following 3 days. (2) Human study: 153 patients with ischemic stroke participating in the SAS-CARE prospective, multicenter cohort study had a polysomnography within 9 days after stroke onset. Functional stroke outcome was assessed by the modified Rankin Scale (mRS) at hospital discharge (short-term outcome) and at a 3-month follow-up (long-term outcome). Results: (1) Animal study: rapid eye movement (REM) sleep was significantly reduced in the IS group compared to the Sham group. (2) Human study: patients with poor short-term functional outcome had a reduction of REM sleep and prolonged REM latency during the acute phase of stroke. REM latency was the only sleep EEG variable found to be significantly related to short- and long-term functional impairment in a multiple linear regression analysis. Conclusions: Acute ischemic stroke is followed by a significant reduction of REM sleep in animals and humans. In humans, this reduction was linked with a bad stroke outcome; in addition, REM latency was found to be an independent predictor of stroke evolution. Potential explanations for this role of REM sleep in stroke are discussed. Clinical Trial Registration: http://clinicaltrials.gov. Unique identifier: NCT01097967.