Increased Pulsatility of the Intracranial Blood Flow Spectral Waveform on Transcranial Doppler Does Not Point to Peripheral Arterial Disease in Stroke Patients

Abstract

Background Peripheral arterial disease (PAD) is common in patients with acute cerebral ischemia. Indexes of resistance derived from the systolic and diastolic velocities are routinely used in diagnostic transcranial Doppler (TCD) to detect intracranial arterial disease. We sought to explore whether these indexes can predict the presence of PAD in acute cerebral ischemia. Methods We prospectively evaluated consecutive patients with acute cerebral ischemia. On TCD, peak-systolic and end-diastolic velocities in both middle cerebral and basilar arteries were manually measured to calculate pulsatility index (PI) and resistance index (RI). Increased resistance was defined as PI equal to 1.2 or more and RI equal to .75 or more. Ankle–brachial index (ABI) measurements were performed and an ABI equal to .9 or more was considered predictive of definite PAD. Results We included 95 patients (45 male, 50 female) aged 66 ± 9 years with a median National Institutes Health Stroke Scale score of 3 (interquartile range, 8) points. The ABI was abnormal and consistent with definite PAD in 24 of 95 (25.3%; 95% confidence interval [CI], 16.4–34.2) patients. Increased PI did not differ among patients with and without PAD (20.8% vs. 28.2%, P = .60). Only 1 patient with PAD had increased RI as opposed to 4 patients without PAD (4.2% vs. 5.6%, P = 1.0). Increased PI was not found to be an independent predictor of PAD (odds ratio [OR], .68; 95% CI, .22–2.12; P = .51). Increases in both PI and RI independently predicted arterial hypertension (OR, 1.62; 95% CI, 1.19–2.21; P = .002 and OR, 3.20; 95% CI, 1.51–6.77; P = .002, respectively). Conclusions Our findings indicate that PAD cannot be inferred from intracranial flow parameters predictive of arterial disease and risk factors such as hypertension among patients with acute cerebral ischemia.

Transcranial Doppler study in acute spontaneous intracerebral hemorrhage: The role of pulsatility index

“…Therefore, CBF pulsatility is likely to be primarily determined by wave reflections reflected from other vessel beds with high resistance. Thus, it was hypothesized that while CBF decreases, PI increases due to the elevation of cerebral artery stiffness, pressure pulsatility, and wave reflection [ 4 , 7 , 8 , 22 , 25 , 26 , 28 ].…”

Transcranial Color-Coded Doppler Cerebral Hemodynamics Following Aerobic Exercise Training: Outcomes From a Pilot Randomized Clinical Trial

“…The peak systolic velocity, end diastolic velocity, resistive index, PI, and systolic to diastolic ratio were obtained from the Doppler waveforms on both the right and left sides (Figure 1). The MFV and PI were calculated as described by Barlinn et al 11 and are presented in equations 1 and 2. A temporal average peak velocity of >120 cm/s was used as a threshold for vasospasm.…”

Comparison of Transcranial Doppler Ultrasound with Computational Fluid Dynamics: Responses to Physiological Stimuli

“…TCD has been used to measure blood flow velocity and derived metrics of arterial pulsatility and resistance in patients with cerebrovascular diseases 4, 13, 18 , as well as being used in estimating cerebral blood flow (CBF) to different regions of the brain 24 . It has also been used to assess prognosis and diagnosis of life-threating conditions such as sickle cell anemia, stenosis, hemorrhage and ischemia across a spectrum of patient ages 25, 29 .…”