BACKGROUND: The aim of this study was to investigate the relationship between plasma α-synuclein (α-syn) levels and cerebral blood flow in patients with Parkinson disease (PD) with freezing of gait (FOG). METHODS: A total of 120 cases of PD patients were selected, and FOG was evaluated according to the FOG questionnaire, with a score of >
3 classified as FOG. Based on the evaluation results, the patients were divided into the PD-FOG group (58 cases) and the PD-NFOG group (62 cases). Cerebral blood flow parameters including cerebral blood flow velocity (CBFV) of the middle cerebral artery, posterior cerebral artery, and basilar artery, phase difference, and gain were monitored, and plasma α-syn levels were measured by enzyme-linked immunosorbent assay. Multifactorial logistic regression analysis was performed to explore the influencing factors of patients with Parkinson's with FOG. RESULTS: FOG occurred in 58 out of 120 cases of PD patients, and the prevalence rate amounted to 48.3%. CBFV of the middle cerebral artery, posterior cerebral artery, and basilar artery were slower, phase difference was smaller, and plasma α-syn level was higher in the PD-FOG group. CBFV of the middle cerebral artery, posterior cerebral artery, and basilar artery, phase difference, and plasma α-syn level were independent influences on FOG in PD patients. CONCLUSIONS: Decreased cerebrovascular reserve function and increased plasma α-synuclein level increase the risk of FOG in PD patients.