White matter lesions in Parkinson disease

Abstract

Pure vascular parkinsonism without evidence of nigral Lewy body pathology may occur as a distinct clinicopathological entity, but a much more frequent occurrence is the comorbid presence of age-associated white matter lesions (WMLs) in idiopathic Parkinson disease (PD). WMLs are associated with motor and cognitive symptoms in otherwise normal elderly individuals. Comorbid WMLs are, therefore, expected to contribute to clinical symptoms in PD. Studies of WMLs in PD differ with regard to methods of assessment of WML burden and the patient populations selected for analysis, but converging evidence suggests that postural stability and gait motor functions are predominantly affected. WMLs are described to contribute to dementia in Alzheimer disease, and emerging but inconclusive evidence indicates similar effects in PD. In this article, we review the literature addressing the occurrence and impact of WMLs in PD, and suggest that WMLs may exacerbate or contribute to some motor and cognitive deficits associated with PD. We review existing and emerging methods for studying white matter pathology in vivo, and propose future research directions.

Visual deprivation elicits subclinical postural inflexibilities in early Parkinson's disease

“…that may alter posturographic variables. However, MRI of the brain was not performed in all subjects in order to exclude the possibility of white matter lesions that may contribute to PI [42]. We tried to minimize this possibility by performing detailed neurological examinations on individual subjects and excluded them if focal neurological deficits were present.…”

Clinicoradiological comparison between vascular parkinsonism and Parkinson’s disease

“…Infarctions in basal ganglia and deep white matter occur very frequently in the elderly who do not have parkinsonism, and patients with pathologically confirmed PD may present with vascular lesions as incidental findings. Nevertheless, 30–55% of patients with PD have white matter changes on brain scans that may prompt physicians to incorrectly diagnose VP 36 40. This issue is further complicated by observations that apparently similar vascular lesions noted on brain imaging may be associated with parkinsonism in some patients but not in others 40 41.…”

Parkinson's disease motor subtypes and mood

“…White matter damage is a significant predictor of gait problems and falls in the elderly [53] and is also strongly associated with depression and cognitive impairment. [54] In PD, microstructural white matters changes are similarly associated with both axial motor and cognitive symptoms [55] while recent in vivo studies report increased white matter changes in cortico-limbic and medial thalamic areas in depressed patients. [6;56] In contrast to the evidence relating motor subtype to depression in PD, there is limited and inconsistent evidence for an association with anxiety.…”