Ultrasonographic Changes in Brain Hemodynamics in Patients with Parkinson's Disease and Risk Factors for Cerebrovascular Disease: A Pilot Study

Recent epidemiological studies have revealed a correlation between atypical features and worse functional outcomes in Parkinson's disease (PD) patients with cerebrovascular disease (CVD). We aimed to evaluate the brain hemodynamics of PD patients with risk factors for CVD using Doppler ultrasonography. In this prospective pilot study, we randomly included 27 outpatients diagnosed with PD. Transcranial color-coded sonography (TCCS) examinations were performed, obtaining measurements of middle cerebral artery mean flow velocities (Vm), the resistance index (RI), and the pulsatility index (PI). The breath-holding index (BHI) was used to assess cerebrovascular reactivity (cVR). Standardized functional scales (UPDRS III, Hoehn & Yahr scale, and MoCA) were administered. The patients were divided into two groups: those with two or more vascular risk factors (PDvasc) and those with fewer than two vascular risk factors (PDnvasc). Patients in the PDvasc group showed higher PI (1.00 vs. 0.85; p=0.020), RI (0.59 vs. 0.5; p=0.05), H&Y mean (2.4 vs. 1.4; p=0.036), higher frequency of altered cVR (90.9% vs. 25.0%; p=0.001), and lower BHI (0.46 vs. 1.01; p=0.027). We also divided the patients in other two groups: one with patients with classical and another with akinetic-rigid PD clinical type. Patients with the akinetic-rigid type of PD had significantly higher RI (0.60 vs. 0.51; p=0.03), PI (0.99 vs. 0.77; p=0.03), higher frequency of altered cVR (80% vs. 35%; p=0.02), and lower BHI (0.48 vs. 0.96; p=0.05) than patients with classic-type PD. We concluded that TCCS displays impaired cerebrovascular reactivity and a more severe disease pattern in Parkinsonian patients with two or more risk factors for CVD and in the akinetic-rigid type. Doppler ultrasonography may be a useful tool in a clinical setting to investigate PD patients.