The effect of whole‐body skin cooling on dynamic cerebral autoregulation

Abstract

The incidence of cerebrovascular accident is elevated during the winter season. Increases in blood pressure associated with an enhanced vasoconstricted state during cold exposure may contribute to this risk. We hypothesized that whole‐body skin cooling would impair dynamic cerebral autoregulation, perhaps due to both systemic and cerebral vasoconstriction. Supine resting data from fifteen young healthy participants were obtained before and during whole‐body skin cooling. In addition, subjects performed a simple cognitive task (Go/No‐go tasks) in each condition. Subjects also performed a separate time control trial while remaining in thermoneutral conditions. Dynamic cerebral autoregulation was assessed by transfer function analysis (TFA) of middle cerebral artery blood velocity and mean arterial pressure. Whole‐body cooling decreased mean skin temperature (P<0.001), while ear canal temperature and respiratory variables were maintained. The cold stress increased mean arterial blood pressure (P<0.01) while heart rate decreased (P<0.05). Vascular conductance of both the internal and external carotid arteries (Doppler ultrasound) decreased during cooling, indicating cerebral and systemic vasoconstriction, respectively. The TFA‐derived low frequency gain increased during the cold stress (P<0.05), indicative of reduced dynamic cerebral autoregulation. The Go/No‐go task did not alter the TFA‐derived gain during cooling. None of these variables were altered during the thermoneutral time control trial. These findings suggest that whole‐body skin cooling impairs dynamic cerebral autoregulation.Support or Funding InformationJapan Society for the Promotion of Science 18H03166