To analyze the clinical features of transcranial sonography (TCS)on patients with Parkinson's disease (PD), and to explore the protective and risk factors associated with the substantia nigra hyperecho to provide the basis for the diagnosis and prevention of PD.

A total of 214 patients diagnosed with PD as outpatients and inpatients in the Department of Neurology of the Second Affiliated Hospital of Soochow University between August 2009 and December 2013 consented to participate in the study. These patients were classified into two groups: the patients with transcranial sonography substantia nigra hyperecho (TCS⁺ ) and the patients with normal echo (TCS^-). Then the gender, age of onset, onset forms, and the third part of the Unified Parkinson's Disease Rating Scale (UPDRS Ⅲ) score between the TCS⁺ and TCS^- groups were compared. Logistic regression analysis was used to analyze the factors which might influence the substantia nigra echo, including gender, age of onset, onset forms, duration, blood uric acid and UPDRS Ⅲ scores.

(1) The TCS⁺ positive rate among 214 patients with PD was 58.88%(126/214). The positive rate of male patients was 69.29%(88/127), of female patients was 43.68%(38/87). Substantia nigra echo sort was sorted by positive rate as follows: group of older onset men 76.39%(55/72), group of middle-aged onset men 60.00%(33/55), group of older onset women 48.00%(24/50), group of middle-aged onset women 37.84%(14/37). (2) TCS⁺ positive rate of male patients was higher than female patients (χ²=13.990, P=0.000), especially in the older aged group, TCS⁺ positive rate of male patients was dramatically higher (χ²=12.774, P<0.001). The positive rate of older onset group was higher than middle-aged onset group (χ²=4.046, P=0.044). In the male patient group, the TCS⁺ positive rate of the older onset group was higher than middle-aged onset group (χ²=3.936, P=0.047), but in the female patient group, there was no statistically significant difference between them. In middle-aged onset group and older onset group, the positive rate of TCS⁺ in male patients was significantly higher than the female patients. (3) In TCS⁺ group, the main form of onset was rigidity, while that in TCS^- group was tremor. TCS⁺ in rigidity group was higher than that in tremor-rigidity group (χ²=5.968, P=0.015). (4) There was no statistically significant difference between TCS⁺ group and TCS^- group in UPDRS Ⅲ score. (5) Multivariate regression analysis showed that independent protective factors of TCS⁺ included gender (OR=0.273, 95% CI 0.141-0.529, P<0.01) and blood uric acid (OR=0.994, 95% CI 0.990-0.999, P=0.017); independent risk factors included the age of onset (OR=2.253, 95% CI 1.194-4.252, P=0.012) and duration of disease (OR=1.128, 95% CI 1.026-1.241, P=0.013).

Later age of onset, longer duration of disease, lower blood uric acid level and male PD patients have higher incidence of TCS⁺. Onset forms and the severity of motor signs have no statistically significant difference between the TCS⁺ group and the TCS^- group.

Parkinson disease; Substantia nigra; Ultrasonography, Doppler, transcranial; Factor analysis, statistical; Risk factors