Stroke and Behavior

Sleep-wake disturbances in supra-and infratentorial stroke: an analysis of post-acute sleep architecture and apnea

BACKGROUND AND PURPOSE

Sleep-wake disturbances (SWD) are common following stroke, and often extend into the post-acute to chronic periods of recovery. Of particular interest to recovery is a reduction in rapid eye movement (REM) sleep, as we know REM sleep to be important for learning and memory. While there is a breadth of evidence linking SWD and stroke, much less work has been done to identify and determine if differences in sleep architecture and apnea severity are dependent on stroke infarct topographies.

METHODS

A retrospective chart review was conducted of 48 ischemic stroke patients having underwent a full, overnight polysomnography (PSG). All patients were over 30 days post-injury (post-acute) at the time of the PSG. Patients were divided into supra- and infratentorial infarct topography groups based on available medical and imaging records. In addition to sleep study record review, cognitive and outcome measures were examined.

RESULTS

Results showed that patients with infratentorial stroke had poorer sleep efficiency, decreased REM sleep, and higher apnea hypopnea index (AHI) than those with supratentorial injuries. Longer continuous REM periods were correlated with higher verbal learning/memory scores, higher levels of positive affect, and lower levels of emotional/behavioral dyscontrol. Neither age nor AHI were significantly correlated with the amount or duration of REM. Slow-wave sleep was significantly reduced across both injury topographies.

CONCLUSIONS

Infratentorial ischemic stroke patients display significant disruptions in sleep architecture and may require close monitoring for SWDs in the post-acute period to maximize outcome potential. REM sleep is particularly affected when compared to supratentorial ischemic stroke.

Does cognition improve following LVAD implantation?

BACKGROUND

Studies of cognition after LVAD surgery have produced mixed results. To explore whether cognition would improve, decline, or remain stable after LVAD surgery, we examined cognition before and 1- and 3-months after LVAD surgery. Patients with post-surgical stroke were excluded.

METHODS

28 subjects (mean age = 54.31 ± 12 years) comprised an observational case series from the DuraHeart LVAS device® trial. Cognitive testing was performed at baseline, 1-month, and 3-month post-surgery, and included tests of attention, memory, language, visualmotor speed (TMT) and visualconstruction.

RESULTS

No difference in cognition was found between baseline and 1-month exams (means z score improvement = 0.06, p = 0.43) but cognition improved significantly between baseline and 3-month exams (mean z score improvement = 0.34, p < 0.00001). Examination of individual test scores found, after correction for multiple comparisons, only the TMT variable was significantly different at the 3-month exam.

CONCLUSIONS

We found significantly improved cognition 3 months after LVAD surgery in a subset of patients without post-surgical stroke. The reasons for the lack of cognitive improvement at the 1-month post-surgical assessment may include ongoing medical and physiological disruptions in the immediate post-operative period. Further research into the sources of delayed improvement is warranted. Cognitive assessments performed immediately after surgery should be interpreted with caution because the results may not reflect longer term cognitive outcomes. LVAD patients may require additional support to successfully manage their health in the weeks immediately following surgery but assistance needs may decrease over time.

C-Phycocyanin and Phycocyanobilin as Remyelination Therapies for Enhancing Recovery in Multiple Sclerosis and Ischemic Stroke: A Preclinical Perspective

Myelin loss has a crucial impact on behavior disabilities associated to Multiple Sclerosis (MS) and Ischemic Stroke (IS). Although several MS therapies are approved, none of them promote remyelination in patients, limiting their ability for chronic recovery. With no available therapeutic options, enhanced demyelination in stroke survivors is correlated with a poorer behavioral recovery. Here, we show the experimental findings of our group and others supporting the remyelinating effects of C-Phycocyanin (C-PC), the main biliprotein of Spirulina platensis and its linked tetrapyrrole Phycocyanobilin (PCB), in models of these illnesses. C-PC promoted white matter regeneration in rats and mice affected by experimental autoimmune encephalomyelitis. Electron microscopy analysis in cerebral cortex from ischemic rats revealed a potent remyelinating action of PCB treatment after stroke. Among others biological processes, we discussed the role of regulatory T cell induction, the control of oxidative stress and pro-inflammatory mediators, gene expression modulation and COX-2 inhibition as potential mechanisms involved in the C-PC and PCB effects on the recruitment, differentiation and maturation of oligodendrocyte precursor cells in demyelinated lesions. The assembled evidence supports the implementation of clinical trials to demonstrate the recovery effects of C-PC and PCB in these diseases.