The severity of leukoaraiosis correlates with the clinical phenotype of Parkinson's disease.

The impact of leukoaraiosis on Parkinson's disease (PD) has not been completely explained. We evaluated 141 patients with PD to assess the role of leukoaraiosis and determined its influence on the clinical phenotype of PD. Clinical assessments during off medication and leukoaraiosis grading were performed according to the atherosclerosis risk in communities (ARIC) study. Patients were grouped into two phenotypes, tremor or postural instability and gait difficulty (PIGD)-dominant groups. Associations between the age at onset, gender, disease duration, cardiovascular risk factors, leukoaraiosis grade and the disease phenotype were analyzed. In addition, the role of the leukoaraiosis grade in relationship to the parkinsonian motor handicaps was evaluated. The leukoaraiosis correlated with the severity of the clinical symptoms of PD as measured by the United Parkinson's disease rating scale (UPDRS) scores and the Hoehn and Yahr (H + Y) stage. There were significant correlations observed between the leukoaraiosis grade and specific motor handicaps especially those with axial symptoms. Multivariate logistic regression analysis showed that the leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD. The leukoaraiosis grade was independently associated with the PIGD motor phenotype of PD; this might be explained by the affects on nondopaminergic subcortical pathways. These results have implications for clinical management of PD with regard to the control of vascular risk factors.