Vascular Parkinsonism: Clinical and Imaging Patterns in Diagnostic Definition

Abstract

Background: Vascular parkinsonism (VaP) is a heterogeneous clinical entity characterised by parkinsonian features attributed to cerebrovascular disease, typically identified through neuroimaging. In recent years, the validity of the term "vascular parkinsonism" has been increasingly debated by leading experts in neurodegenerative disorders. Differentiating it from other conditions, particularly idiopathic Parkinson's disease (IPD), remains clinically challenging due to overlapping manifestations and the absence of disease-specific biomarkers. Accurate diagnostic distinction is essential to guide appropriate treatment strategies and align therapeutic interventions with the underlying aetiology. Objective: This study aims to characterise and compare the clinical and neuroradiological features of patients with VaP and IPD, with particular emphasis on the topography and extent of cerebrovascular lesions. Methods: A cross-sectional study was conducted involving 14 patients with VaP and 58 with IPD, all followed at a tertiary movement disorders centre. Demographic and clinical data were retrospectively extracted from electronic medical records. Neuroimaging exams were independently reviewed by a neuroradiologist blinded to clinical diagnosis. Statistical analyses were subsequently performed to compare groups. Results: VP patients were significantly older (p<0.001) and had a higher prevalence of vascular risk factors (p=0.05). Clinically, they showed a predominance of lower-limb parkinsonism (p<0.001), postural instability (p=0.003), falls (p<0.001), freezing of gait (p=0.002), and corticospinal (p=0.006) or pseudobulbar signs (p=0.036). Levodopa responsiveness was minimal or absent in 71.4% of VP cases, in contrast to 89.7% of patients with IPD who demonstrated a robust therapeutic response (p<0.001). Neuroimaging revealed moderate-to-severe white matter hyperintensities (Fazekas grades 2-3) in 71.4% of VaP patients, compared with only 3.4% in the IPD group (p<0.001). Strategic infarcts were exclusively identified in patients with VP (p<0.001). Conclusions: These findings reinforce the clinicoradiological distinction between VaP and IPD. Hallmark features of VP include predominant lower-body involvement, postural instability, poor dopaminergic responsiveness, and a substantial cerebrovascular burden on neuroimaging. While no single feature is pathognomonic, the integration of clinical and radiological data remains essential for accurate diagnosis. Future research should aim to validate diagnostic criteria and explore biomarker-based approaches.