White matter hyperintensities and the progression from mild parkinsonian signs to parkinsonism and Parkinson's disease.

This study investigated the impact of white matter hyperintensities (WMHs) on the progression from mild parkinsonian signs (MPS) to parkinsonism and Parkinson's disease (PD). Participants with MPS completed 5 years of follow-up. WMHs were divided into periventricular WMHs and deep WMHs according to magnetic resonance imaging scans. The diagnosis of MPS, parkinsonism, and PD was based on the motor portion of the Unified Parkinson's Disease Rating Scale. Cox proportional hazard models were used to identify the association between WMHs and MPS progression. Of the 636 participants, 166 (26.1%) with MPS developed parkinsonism and PD after follow-up. After adjusting for potential factors, severe WMHs were associated with an increased risk of MPS progression, moderate and severe periventricular WMHs and severe deep WMHs were associated with the risk of MPS progression, and severe WMHs were associated with the progression of gait/balance impairment, bradykinesia, and rigidity. Additionally, participants treated for vascular risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia had a lower risk of MPS progression.