Serial Changes in Static and Dynamic Cerebral Autoregulation after Acute Ischaemic Stroke

Abstract

Background: The longitudinal changes in static and dynamic cerebral autoregulation (CA) following acute ischaemic stroke are unknown and were assessed in this study. Methods: Fifty-four ischaemic stroke patients were studied within 96 h of ischaemic stroke and again 7–14 days later, using transcranial Doppler techniques to measure CA. Results were compared to an age-, sex- and blood pressure (BP)-matched control group. Static BP pressor stimulus was produced by thigh cuff inflation and dynamic stimulus by rapid thigh cuff release. Results: Dynamic, but not static, CA was globally impaired at initial (mean dynamic CA index 3.9 ± 3.1 vs. 6.2 ± 2.3, p < 0.005) and follow-up studies (dynamic CA 3.9 ± 2.8 vs. 6.2 ± 2.3, p < 0.01) in stroke patients compared to controls. Static CA was similar in stroke patients and controls and was unchanged during follow-up. Conclusions: Dynamic, but not static, CA is impaired after acute ischaemic stroke and remains abnormal for at least 1–2 weeks post ictus. These changes are present in both the affected and non-affected hemispheres and are unrelated to previous antihypertensive treatment, baseline BP levels or BP changes after stroke, age or stroke type.

Disassociation of static and dynamic cerebral autoregulatory performance in healthy volunteers after lipopolysaccharide infusion and in patients with sepsis

“…Thus, low-dose isoflurane impairs dynamic performance, as evaluated by step-induced changes in MAP by thigh cuff deflation, whereas static autoregulation is unaffected (35). Similar findings have been made in patients with acute ischemic stroke, where dynamic but not static autoregulation was found to be attenuated (10), a pattern that was evident up to 2 wk after the ictus (11). Thus, dynamic autoregulation may be relatively sensitive, and static autoregulation may be more robust to various physiological and pathophysiological events, which could imply that the response time of the cerebral circulation may be affected before its actual ability to respond adequately to steady-state changes in MAP.…”

Fast blood flow monitoring in deep tissues with real-time software correlators

“…healthy) brain maintains relatively constant cerebral blood flow (CBF) despite fluctuations in mean arterial blood pressure (MAP) [55]. Importantly, CVAR is often impaired after brain injury; in this scenario, CBF can vary in response to MAP variation [56,57]. Moreover, the degree of CVAR impairment correlates with the initial severity of brain injury and is an independent predictor of outcome [41,56,58].…”

Republished: Society for Neuroscience in Anesthesiology and Critical Care Expert Consensus Statement: Anesthetic Management of Endovascular Treatment for Acute Ischemic Stroke*

“…55,57 Treatment of acute stroke induced-hypertension with antihypertensive medications does not significantly improve patient outcome. 58 …”