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Reduced Cerebrovascular Response to CO 2 Rebreathing in Spinal Cord Injury
Author(s) -
Hamner J.W.,
Taylor J Andrew,
Tan Can
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.833.4
Subject(s) - medicine , transcranial doppler , spinal cord injury , cardiology , cerebral blood flow , anesthesia , stroke (engine) , arterial blood , hemodynamics , blood pressure , spinal cord , mechanical engineering , psychiatry , engineering
Individuals with spinal cord injury (SCI) are at increased risk for an array of health problems during the chronic stages of injury. Among these is a greater risk of stroke. One potential culprit is impairment in cerebrovascular responses to changes in arterial blood gases. In able‐bodied individuals, the cerebral vasculature dilates in response to elevated arterial carbon dioxide (i.e. cerebrovascular reactivity), and impairment in cerebrovascular reactivity has been linked to increased risk of stroke. Therefore we examined the cerebral blood flow response to progressive increases in arterial CO 2 via rebreathing in individuals with SCI (n = 7, from C5 to T8) and able‐bodied individuals (n = 6). We measured end‐tidal CO 2 , cerebral blood flow velocity (Doppler ultrasound), arterial pressure (photoplethysmography) and derived cerebrovascular reactivity as the slope between end‐tidal CO 2 and cerebrovascular conductance. We found a significantly reduced cerebrovascular reactivity in subjects with SCI (0.0791±0.0276 vs. 0.217±0.04 cm s ‐1 mmHg ‐1 %CO 2 ‐1 , p < 0.05). This suggests that individuals with SCI are less sensitive to changes in arterial CO 2 than able‐bodied, which may play a role in the exacerbated incidence of stroke in SCI. Supported by NIH grant R01 HL117037.