Is hyperhomocysteinemia associated with the structural changes of the substantia nigra in Parkinson's disease? A two-year follow-up study

Abstract

Objective: It was recently found that structural changes in the substantia nigra (SN) and motor symptoms become more prominent in Parkinson's disease (PD) patients with striatal silent lacunar infarction (SSLI) than in those without SSLI. Hyperhomocysteinemia (HHCY) was an independent risk factor for SSLI in PD patients. In this follow-up study, we investigated the relationship between HHCY and structural changes of the SN in PD patients.

Methods: A total of 72 untreated early PD patients without SSLI, divided into control and HHCY groups, were enrolled in this study. All participants underwent conventional MRI and diffusion kurtosis imaging (DKI) twice; at baseline and at the 2-year visit. The differences of the following variables between the two groups were analyzed: mean kurtosis (MK) values of the SN, the severity of disease, daily dosage of levodopa, and the variation of these indexes from baseline to 2-year visit. Logistic regression analysis was used to identify the relationship between HHCY and structural changes of the SN in PD patients.

Results: 1.All variables mentioned above showed significant differences between the two groups. 2. The variation in MK values of the SN were positively correlated with the variation in the severity of disease. 3. HHCY was an independent risk factor for the variation in MK values of the SN in PD patients.

Conclusion: HHCY is associated with the structural changes of the SN in PD patients. As PD progresses, motor symptoms become aggravated with increased structural changes to the SN, especially in patients with HHCY.

Keywords: Diffusion kurtosis imaging; Hyperhomocysteinemia; Motor symptoms; Parkinson's disease; Substantia nigra.