Visual and Spectral Analysis of Sleep EEG in Acute Hemispheric Stroke

Abstract

Background: Reports on the effects of focal hemispheric damage on sleep EEG are rare and contradictory. Patients and Methods: Twenty patients (mean age ± SD 53 ± 14 years) with a first acute hemispheric stroke and no sleep apnea were studied. Stroke severity [National Institute of Health Stroke Scale (NIHSS)], volume (diffusion-weighted brain MRI), and short-term outcome (Rankin score) were assessed. Within the first 8 days after stroke onset, 1–3 sleep EEG recordings per patient were performed. Sleep scoring and spectral analysis were based on the central derivation of the healthy hemisphere. Data were compared with those of 10 age-matched and gender-matched hospitalized controls with no brain damage and no sleep apnea. Results: Stroke patients had higher amounts of wakefulness after sleep onset (112 ± 53 min vs. 60 ± 38 min, p < 0.05) and a lower sleep efficiency (76 ± 10% vs. 86 ± 8%, p < 0.05) than controls. Time spent in slow-wave sleep (SWS) and rapid eye movement (REM) sleep and total sleep time were lower in stroke patients, but differences were not significant. A positive correlation was found between the amount of SWS and stroke volume (r = 0.79). The slow-wave activity (SWA) ratio NREM sleep/wakefulness was lower in patients than in controls (p < 0.05), and correlated with NIHSS (r = –0.47). Conclusion: Acute hemispheric stroke is accompanied by alterations of sleep EEG over the healthy hemisphere that correlate with stroke volume and outcome. The increased SWA during wakefulness and SWS over the healthy hemisphere contralaterally to large strokes may reflect neuronal hypometabolism induced transhemispherically (diaschisis).

Correlation between sleep and cognitive functions after hemispheric ischaemic stroke

“…Muller et al found a lower sleep efficiency, as well as lower amounts of SWS and REM sleep in patients with acute hemispheric stroke 17 . Gottselig et al 18 documented a reduced spindle activity on the side of the lesion in patients with extra-thalamic stroke.…”

“…Changes in sleep EEG patterns after hemispheric stroke have been documented in studies of the last three decades [12][13][14][15][16][17][18][19] . Muller et al found a lower sleep efficiency, as well as lower amounts of SWS and REM sleep in patients with acute hemispheric stroke 17 .…”

Sleep Architecture in Stroke and Relation to Outcome

“…Most studies report a reduction in sleep efficiency and increased wakefulness after sleep onset [3,4,5,6,7], with [3] or without [8] a reduction in total sleep time. Stage II is found to be reduced [3, 6] or even increased [8, 9], and similar results are reported for slow wave sleep (SWS) [3, 6,9,10,11,12].…”

“…Similarly, there is no evidence for the relation of stroke severity to sleep architecture. Regarding the outcome, certain sleep features have been associated with poor prognosis, namely reduced sleep efficiency and total sleep time, increased 24-hour sleep and reduced sleep spindles, K complexes and sleep stages II, REM and SWS [3, 5, 8, 15]. …”

Detection of Infarct Lesions From Single MRI Modality Using Inconsistency Between Voxel Intensity and Spatial Location—A 3-D Automatic Approach

“…This usually results in an infarct in the brain, which comprises dead tissues due to the stroke. The detailed information about the location and volume of the infarcts is crucial to a number of stroke-related research questions, such as predicting prognosis, Manuscript identifying chronic functional deficits [3]- [7], or investigating sleep problems of stroke patients [8], [9]. In addition, the availability of a lesion mask may also be beneficial to analyses of functional MRI [10] and diffusion tensor imaging.…”