Cerebral autoregulation assessed by near-infrared spectroscopy: validation using transcranial Doppler in patients with controlled hypertension, cognitive impairment and controls

Abstract

Purpose Cerebral autoregulation (CA) aims to attenuate the effects of blood pressure variation on cerebral blood flow. This study assessed the criterion validity of CA derived from near-infrared spectroscopy (NIRS) as an alternative for Transcranial Doppler (TCD). Methods Measurements of continuous blood pressure (BP), oxygenated hemoglobin (O2Hb) using NIRS and cerebral blood flow velocity (CBFV) using TCD (gold standard) were performed in 82 controls, 27 patients with hypertension and 94 cognitively impaired patients during supine rest (all individuals) and repeated sit to stand transitions (cognitively impaired patients). The BP-CBFV and BP-O2Hb transfer function phase shifts (TFφ) were computed as CA measures. Spearman correlations (ρ) and Bland Altman limits of agreement (BAloa) between NIRS- and TCD-derived CA measures were computed. BAloa separation < 50° was considered a high absolute agreement. Results NIRS- and TCD-derived CA estimates were significantly correlated during supine rest (ρ = 0.22–0.30, N = 111–120) and repeated sit-to-stand transitions (ρ = 0.46–0.61, N = 19–32). BAloa separation ranged between 87° and 112° (supine rest) and 65°–77° (repeated sit to stand transitions). Conclusion Criterion validity of NIRS-derived CA measures allows for comparison between groups but was insufficient for clinical application in individuals.

Determinants of orthostatic cerebral oxygenation assessed using near-infrared spectroscopy

“…Cerebral perfusion is influenced by cerebral autoregulation (aiming to attenuate cerebral blood flow and cerebral oxygenation fluctuations during orthostatic BP drops) and may for clinical purposes be derived from near-infrared spectroscopy (NIRS) measurements. NIRS measurements reflect changes of cerebral oxygenated and deoxygenated hemoglobin concentrations in the brain, and are less dependent on operator training and temporal bone anatomy compared to transcranial Doppler measurements (Mol et al, 2020b;Mol et al, 2019a;Kainerstorfer et al, 2015;Mol et al, 2021). Orthostatic cerebral oxygenation changes measured with NIRS may depend on age, sex, type of postural change (i.e., standing up from sitting versus supine position), BP and baroreflex sensitivity (BRS, defined as change in inter beat interval divided by change in BP) (Mol et al, 2020b;Mol et al, 2018b;Mol et al, 2020a;Tzeng et al, 2010).…”

Cerebral Autoregulation Assessment Using the Near Infrared Spectroscopy ‘NIRS-Only’ High Frequency Methodology in Critically Ill Patients: A Prospective Cross-Sectional Study

“…A NIRS model using a slightly different HF-range correction for serial time trends was previously studied in awake patients with (mild) cognitive and in healthy subjects. They studied the relationship between ABP and oxyHb [ 24 ]. It might be interesting to compare our results with those retrieved from ABP—oxyHb calculations.…”

Correlation of Obesity and Overweight with Cervical Vascular Function Among Healthy Populations

“…6 Numerous investigations evaluating neck vasculature in patients with diabetes, hypertension, and coronary artery disease utilizing CAU and TCD have demonstrated good sensitivity and specificity in disease prediction. [7][8][9][10] Studies have revealed that TCD has an 88% specificity and a 91% sensitivity for the diagnosis of ischemic stroke. 11 Therefore, the use of CAU and TCD for the detection of vascular function in the neck can lead to early detection of vascular dysfunction, which can lead to interventional treatment and reduce the possibility of serious disease.…”