White matter hyperintensities in Parkinson's disease. Clinical correlations.

OBJECTIVES: To verify recent preliminary data indicating that white matter hyperintensities on magnetic resonance imaging are more abundant in patients with Parkinson's disease (PD) than in healthy subjects and to examine possible correlation between these abnormalities and clinical features of PD. DESIGN: Magnetic resonance imaging data on patients with PD and normal subjects were compared as to frequency, extent, and topographic location of white matter hyperintensities; moreover, in the PD group, we studied the possible correlation of white matter hyperintensities with clinical features such as severity, disease duration, and therapy. SETTING: The outpatient clinic of the Institute of Clinical Neurology and the Neuroradiology Unit of the University of Pisa (Italy). PATIENTS: We studied 102 nondemented patients with idiopathic PD and 68 sex- and age-matched healthy controls, all screened for absence of cerebrovascular risk factors. OUTCOME MEASURES: White matter hyperintensities were classified as periventricular hyperintensities and deep hyperintensities. Frequency, extent, and topographic location of both periventricular and deep hyperintensities were evaluated. The clinical parameters examined were disease duration, treatment type, and disease severity (using Hoehn and Yahr staging and the Unified Parkinson's Disease Rating Scale), as well as disease progression index (ratio between Hoehn and Yahr stage and disease duration). RESULTS: The frequency and the extent of periventricular hyperintensities were significantly higher in patients with PD than in healthy subjects. Moreover, within the PD group, the patients who had periventricular hyperintensities had significantly shorter disease duration and greater disease severity, ie, a higher disease progression index, than those who did not. CONCLUSION: These data suggest that periventricular hyperintensities may represent a marker for a clinical subtype of PD characterized by a more rapid neurodegenerative process.