Dynamic cerebral autoregulation changes during sub-maximal handgrip maneuver

• Published in: PloS one 2013-08, Vol.8 (8), p.e70821-e70821
• Main Authors: Nogueira, Ricardo C, Bor-Seng-Shu, Edson, Santos, Marcelo R, Negrão, Carlos E, Teixeira, Manoel J, Panerai, Ronney B
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Autoregressive moving average; Biology; Blood; Blood flow; Blood pressure; Brain - physiology; Brain research; Carbon dioxide; Cerebral blood flow; Circulatory system; Contraction; Exercise; Female; Flow velocity; Hand - physiology; Hand Strength - physiology; Heart; Hemodynamics; Hospitals; Humans; Male; Medicine; Metabolism; Middle Aged; Neurosurgery; Physical education; Physics; Physiology; Regulatory mechanisms (biology); Stroke; Time Factors; Vasoconstriction; Vasodilation; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0070821

We investigated the effect of handgrip (HG) maneuver on time-varying estimates of dynamic cerebral autoregulation (CA) using the autoregressive moving average technique. Twelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO₂ pressure (PETCO₂), and noninvasive arterial blood pressure (ABP) were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP), resistance area-product (RAP), and time-varying autoregulation index (ARI) were obtained. PETCO₂ did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p