Reliability and reactivity of the prefrontal hemodynamic responses in essential hypertension: a functional near infrared spectroscopy study.
Prefrontal (PFC) cerebral vasoreactivity may be altered in hypertension but has not been studied during postural change and carbon dioxide (CO2) rebreathing. In this study, a dual procedure of 5% CO2 rebreathing with positional change (standing to supine and reverse) was performed on normotensive (N = 24) and essential hypertensive males (N = 16) (18-55 years) to assess reliability of PFC responses using functional near infrared spectroscopy. The groups (matched on age levels, N = 13) were also compared on their hemodynamic reactivity (change of oxyhemoglobin or total hemoglobin as a function of change in end tidal CO2). Test-retest reliability within one session and 7 days later was moderate to high (intraclass correlation coefficient = .63-.901) in both normotensive and hypertensive groups for all hemodynamic measures; whereas reliability of reactivity measures for oxyhemoglobin and total hemoglobin was moderate (intraclass correlation coefficient = .68-.762). Functional near infrared spectroscopy-measured PFC hemodynamic responses are highly reproducible in normotensive and adult essential hypertensive males.
Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada. Electronic address: hercules@ualberta.ca.
Hercules
H
Grant
Department of Occupational Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Yagesh
Y
Bhambhani
Department of Psychology, University of Alberta, Edmonton, Alberta, Canada.
Anthony
A
Singhal
Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Robert
R
Haennel
Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Sharon
S
Warren
D000293:Adolescent; D000328:Adult; D001784:Blood Gas Analysis / Q000379:methods; D019296:Capnography / Q000379:methods; D002560:Cerebrovascular Circulation; D000075222:Essential Hypertension; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000032:analysis; D017397:Prefrontal Cortex / Q000098:blood supply*; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D016683:Supine Position; D055815:Young Adult
D010108:Oxyhemoglobins
Carbon dioxide rebreathing; high blood pressure; orthostatic stress; vascular reactivity