The Relationship between Changes in Systemic Blood Viscosity and Transcranial Doppler Pulsatility in Lacunar Stroke

Abstract

Background:We hypothesized that changes in blood viscosity (BV) would influence cerebral vessel viscosity, which is related to the transcranial Doppler (TCD) pulsatility index (PI). Using serial BV and TCD examinations, we sought to evaluate the relationship between changes in BV and TCD PI in lacunar stroke patients. Methods: Patients (aged ≥50 years) who developed lacunar stroke within 7 days of symptom onset were enrolled. Laboratory tests and TCD examinations were conducted at admission and 180 (±30) days after the onset of stroke. Patients were categorized into the decreased BV and increased BV groups. Decreased BV suggested that the BV value in the baseline study minus the 180-day study was positive, and vice-versa. Results: A total of 128 patients who had experienced classic lacunar syndromes were enrolled and 67 (52%) were included in the final analysis. At the end of the 180-day study, changes in systolic BV (SBV) were not associated with PI changes. Regarding diastolic BV (DBV), hematocrit (Hct) adjusted partial correlation analysis showed no significant relationship between changes in DBV and PI (r=0.25, p=0.068). The correlation analysis showed that changes in hemoglobin and Hct were positively associated with SBV and DBV changes (r>0.488, p<0.0001 and r>0.461, p<0.0001), confirming that Hct was the major determinant factor of BV. Conclusion: This study did not show a relationship between changes in BV and cerebral arterial pulsatility in patients with lacunar stroke. The changes in BV were positively associated with changes in Hct.

Relationship between hypertension and pulsatility index in acute ischemic stroke patients

“…Long-term increase in blood lipids can also cause damage to the artery walls, which correlates viscosity with atherosclerosis. In this study, the hematocrit at the time of examination was not analyzed so that it might also affect the results of the PI indirectly (Kim et al, 2020).…”

“…The microangiopathic process also releases several inflammatory cytokines, such as endothelin and prostacyclin, and interferes with autoregulation of cerebral blood flow, which impairs blood flow to distal areas. Vicenzini et al have found that an increase in PI is associated with a decrease in end-diastolic volume (EDV), which indicates the development of vasoconstriction in the distal vessels (Kim et al, 2020).…”

Progression in Lacunar Stroke is Related to Elevated Blood Viscosity

“…BV is elevated in the acute phase of ischemic stroke and gradually improves in the chronic phass, 7 and appears to be significantly higher in LS than in other stroke subtypes. 9,11 When the blood passes through the stenotic cerebral perforating arteries, increased BV can aggravate the flow disturbance and cause vascular endothelial remodeling and luminal occlusion. These hemorheological changes can be related to thrombus propagation or arterial reocclusion in progressive LS.…”

“…9,10 It has been postulated that when the blood passes the cerebral small arteries, increased BV can aggravate the flow disturbance and cause luminal occlusion. 9,11 Considering the underlying pathomechanisms of ND in LS, we hypothesized that increased BV could influence cerebral vessel viscosity, which is related to thrombus propagation and collateral blood flow circulation. Hence, this study aimed to determine the relationship between ND and BV in patients with LS.…”

Microfluidic Platform for Stroke Risk Prediction: Evaluation of Blood Viscosity by Shear Rate Variations

“…High BV increases accordingly thromboembolic risk and is a correlation factor for cardiovascular disease. Those studies exhibit the associations between BV and ischemic stroke (Grotemeyer, Kaiser, Grotemeyer, & Husstedt, 2014; Han et al, 2019; T. Kim et al, 2020). There are many comprehensive factors to effective BV, such as blood sugar, erythrocyte amounts and thrombus (Baeckström, Folkow, Kendrick, Löfving, & ÖBerg, 1971; Cadroy, Horbett, & Hanson, 1989;Somer & Meiselman, 1993;Tamariz et al, 2008).…”