Nocturnal deterioration after ischemic stroke and autonomic dysfunction: hypothesis and implications.

Background: A significant number of patients admitted to hospital after acute ischemic stroke deteriorate clinically. Deterioration is generally noted within the first 48 h after stroke onset. The mechanisms leading to this deterioration are not fully understood. Summary: One potential cause of this deterioration may be altered or impaired autonomic function. We expect the hemodynamic changes regulated by the autonomic nervous system that are dysregulated after stroke to be exaggerated during sleep, resulting in arrhythmia and blood pressure fluctuations in these patients. Such physiological changes could result in worsening the overall outcome of the ischemic stroke patient or in sudden death. Therefore, it is necessary to summarize yet unrelated observations and hypothesize on their individual effects and interactions as they relate to poststroke deterioration. Key Messages: If the hypothesis is correct that dysautonomia occurs to the degree that it affects clinical outcomes negatively, this would have important implications for the prevention of neurological deterioration and sudden death after ischemic stroke.