Background: Parkinson’s disease (PD) is one of the most common movement disorders. Some studies have reported cerebral hemodynamic abnormalities in patients with Parkinson’s disease. This study aimed to measure cerebrovascular reactivity in patients with Parkinson’s disease and to examine its relationship with the Unified Parkinson's Disease Rating Scale scores.
Methods: In this case-control study was conducted on 36 patients with Parkinson’s disease and 36 age- and gender-matched healthy individuals as the control group in 2022. Sampling was performed with the convenience method. Transcranial Doppler was performed to measure the mean flow velocity of the middle cerebral artery at rest and after the apnea test. The Unified Parkinson's Disease Rating Scale was administered to patients, and the results were statistically analyzed.
Results: The Breath-Holding Index (BHI) was 1.02 ± 0.19 and 0.714 ± 0.14 in the control and patient groups, respectively, indicating a statistically significant difference (P<0.001)  . Also, BHI showed a statistically significant relationship with all questionnaire items and the questionnaire's total score.
Conclusion: Cerebrovascular reactivity decreased in patients with PD, and this decrease was correlated with clinical findings.