Determinants of Levodopa Responsiveness in Patients with Vascular Parkinsonism

Vascular Parkinsonism (VaP) is characterized by symmetric, predominantly lower limb bradykinesia and rigidity and no significant improvement with levodopa. We aimed to describe the clinical and radiological features of patients with VaP and the factors that determine levodopa responsiveness.

This is a retrospective chart review of patients with VaP. The study included 44 patients (36 men) with VaP. The diagnosis was based on Zijlman's criteria. Demographic and clinical details were recorded from the case files. MRI data were available for all the patients. However, the motor severity scores assessed in the OFF and ON states using the unified Parkinson's disease rating scale (UPDRS) part III were available for 17 patients only. Based on the Magnetic Resonance Imaging (MRI) finds, patients were categorized into isolated periventricular ischemic (PVI) changes, isolated basal ganglia (BG)/thalamic infarcts, and both combined.

The mean age at the diagnosis was 65.2 ± 7.4 years. Further, the age at the onset of symptoms was 61.8 ± 8.1 years and the total disease duration was 3.5 ± 2.5 years. Hypertension was the most common risk factor and was observed in 88.6% of patients. Symmetrical lower body parkinsonism was observed in 88.6%. The mean UPDRS part III OFF score was 33.76 ± 12.7 and ON score was 30 ± 13.98. PVI changes were the most common MRI abnormality detected. Patients with isolated BG/thalamic infarcts had better mini-mental status examination scores and better levodopa responsiveness compared to other groups.

Hypertension was the most common risk factor seen in patients with VaP. Those with isolated BG/thalamus infarcts demonstrated better levodopa responsiveness.