TY - JOUR
T1 - Changes in cerebral oxygenation and blood flow during LBNP in spinal cord-injured individuals
AU - Houtman, Sibrand
AU - Serrador, Jorge M.
AU - Colier, Willy N.J.M.
AU - Strijbos, Derek W.
AU - Shoemaker, Kevin
AU - Hopman, Maria T.E.
PY - 2001
Y1 - 2001
N2 - Spinal cord-injured (SCI) individuals, having a sympathetic nervous system lesion, experience hypotension during sitting and standing. Surprisingly, they experience few syncopal events. This suggests adaptations in cerebrovascular regulation. Therefore, changes in systemic circulation, cerebral blood flow, and oxygenation in eight SCI individuals were compared with eight able-bodied (AB) individuals. Systemic circulation was manipulated by lower body negative pressure at several levels down to -60 mmHg. At each level, we measured steady-state blood pressure, changes in cerebral blood velocity with transcranial Doppler, and cerebral oxygenation using near-infrared spectroscopy. We found that mean arterial pressure decreased significantly in SCI but not in AB individuals, in accordance with the sympathetic impairment in the SCI group. Cerebral blood flow velocity decreased during orthostatic stress in both groups, but this decrease was significantly greater in SCI individuals. Cerebral oxygenation decreased in both groups, with a tendency to a greater decrease in SCI individuals. Thus present data do not support an advantageous mechanism during orthostatic stress in the cerebrovascular regulation of SCI individuals.
AB - Spinal cord-injured (SCI) individuals, having a sympathetic nervous system lesion, experience hypotension during sitting and standing. Surprisingly, they experience few syncopal events. This suggests adaptations in cerebrovascular regulation. Therefore, changes in systemic circulation, cerebral blood flow, and oxygenation in eight SCI individuals were compared with eight able-bodied (AB) individuals. Systemic circulation was manipulated by lower body negative pressure at several levels down to -60 mmHg. At each level, we measured steady-state blood pressure, changes in cerebral blood velocity with transcranial Doppler, and cerebral oxygenation using near-infrared spectroscopy. We found that mean arterial pressure decreased significantly in SCI but not in AB individuals, in accordance with the sympathetic impairment in the SCI group. Cerebral blood flow velocity decreased during orthostatic stress in both groups, but this decrease was significantly greater in SCI individuals. Cerebral oxygenation decreased in both groups, with a tendency to a greater decrease in SCI individuals. Thus present data do not support an advantageous mechanism during orthostatic stress in the cerebrovascular regulation of SCI individuals.
KW - Lower body negative pressure
KW - Postural syncope
KW - Tetraplegia
UR - http://www.scopus.com/inward/record.url?scp=0034748965&partnerID=8YFLogxK
U2 - 10.1152/jappl.2001.91.5.2199
DO - 10.1152/jappl.2001.91.5.2199
M3 - Article
C2 - 11641362
AN - SCOPUS:0034748965
SN - 8750-7587
VL - 91
SP - 2199
EP - 2204
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 5
ER -