TY - JOUR
T1 - Hemoglobin oxygen saturation as a marker of cerebral hemodynamics in carotid artery occlusion
T2 - An integrated transcranial doppler and near-infrared spectroscopy study
AU - Vernieri, Fabrizio
AU - Silvestrini, Mauro
AU - Tibuzzi, Francesco
AU - Pasqualetti, Patrizio
AU - Altamura, Claudia
AU - Passarelli, Francesco
AU - Matteis, Maria
AU - Rossini, Paolo Maria
PY - 2006/11
Y1 - 2006/11
N2 - Cerebral hemodynamics play a pivotal role in stroke pathogenesis. Transcranial Doppler (TCD) studies demonstrated the importance of cerebral vasomotor reactivity (VMR) on the outcome of carotid artery occlusion (CAO). So far, positron emission tomography represents the best technique for detecting both hemodynamic and metabolic aspects of cerebral perfusion adaptive processes in cerebrovascular patients. Near-infrared spectroscopy (NIRS) is a new method allowing for a non-invasive assessment of cerebral blood flow and hemoglobin (Hb) oxygenation parameters. A recent TCD and NIRS study demonstrated that patients with symptomatic CAO had lower VMR values measured by TCD and lower oxygen saturation (oxygen%) increases detected by NIRS than asymptomatic ones. The parameters were obtained simultaneously after CO2 inhalation. The present study aims to investigate if Hb oxygen % could represent also at rest a marker of hemodynamic status in carotid disease. Thirty-five symptomatic and 17 asymptomatic patients with CAO underwent a simultaneous examination by means of TCD and NIRS at rest condition and during CO2 reactivity test. Symptomatic patients presented with oxygen% values at rest higher (p = 0.001) and VMR values lower (p <0.001) than asymptomatic subjects. According to a logistic model, for each unitary VMR increase, the odds of being symptomatic decreases of about 10% (OR = 0.9, p = 0.001); for each unitary increase of oxygen% at baseline, this odd increases of about 23% (OR = 1.23, p = 0.031). In addition to TCD VMR values, oxygen hemoglobin saturation at rest detected by NIRS can discriminate symptomatic from asymptomatic patients with CAO. NIRS can add an important contribution to explain pathophysiological mechanisms of stroke occurrence.
AB - Cerebral hemodynamics play a pivotal role in stroke pathogenesis. Transcranial Doppler (TCD) studies demonstrated the importance of cerebral vasomotor reactivity (VMR) on the outcome of carotid artery occlusion (CAO). So far, positron emission tomography represents the best technique for detecting both hemodynamic and metabolic aspects of cerebral perfusion adaptive processes in cerebrovascular patients. Near-infrared spectroscopy (NIRS) is a new method allowing for a non-invasive assessment of cerebral blood flow and hemoglobin (Hb) oxygenation parameters. A recent TCD and NIRS study demonstrated that patients with symptomatic CAO had lower VMR values measured by TCD and lower oxygen saturation (oxygen%) increases detected by NIRS than asymptomatic ones. The parameters were obtained simultaneously after CO2 inhalation. The present study aims to investigate if Hb oxygen % could represent also at rest a marker of hemodynamic status in carotid disease. Thirty-five symptomatic and 17 asymptomatic patients with CAO underwent a simultaneous examination by means of TCD and NIRS at rest condition and during CO2 reactivity test. Symptomatic patients presented with oxygen% values at rest higher (p = 0.001) and VMR values lower (p <0.001) than asymptomatic subjects. According to a logistic model, for each unitary VMR increase, the odds of being symptomatic decreases of about 10% (OR = 0.9, p = 0.001); for each unitary increase of oxygen% at baseline, this odd increases of about 23% (OR = 1.23, p = 0.031). In addition to TCD VMR values, oxygen hemoglobin saturation at rest detected by NIRS can discriminate symptomatic from asymptomatic patients with CAO. NIRS can add an important contribution to explain pathophysiological mechanisms of stroke occurrence.
KW - Carotid artery occlusion
KW - Cerebral hemodynamics
KW - Doppler, transcranial
KW - Spectroscopy, near-infrared
KW - Stroke
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U2 - 10.1007/s00415-006-0244-6
DO - 10.1007/s00415-006-0244-6
M3 - Article
C2 - 16786210
AN - SCOPUS:33845632922
VL - 253
SP - 1459
EP - 1465
JO - Journal of Neurology
JF - Journal of Neurology
SN - 0340-5354
IS - 11
ER -