Association of blood pressure variability with white matter hyperintensities and nigrostriatal dopaminergic deficits in drug-naïve Parkinson's disease.

Blood pressure variability, white matter brain lesions and degeneration of nigrostriatal dopaminergic neurons may be associated with each other in patients with Parkinson's disease (PD). We examined the coefficient of variation of systolic blood pressure (CV-sBP) in 122 drug-naïve patients with newly diagnosed PD. The association of CV-sBP with degree of white matter hyperintensities and striatal specific binding ratio (SBR) of I-2 carbomethoxy-3-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (I-FP-CIT) were examined taking cardiovascular risk factors into account. The results showed that patients with higher CV-sBP were older (r = 0.362, p < 0.001) and had severer periventricular hyperintensities (PVH) (r = 0.261, p = 0.002), deep and subcortical white matter hyperintensities (DSWMH) (r = 0.237, p = 0.004) and lower striatal SBR (right SBR: r = - 0.269, p = 0.002, left SBR: r = - 0.341, p < 0.001). Patients with severer PVH or DSWMH had lower striatal SBR (PVH: r = - 0.317, p < 0.001, DSWMH: r = - 0.350, p < 0.001). CV-sBP was significantly associated with left striatal SBR (β =-0.264, p = 0.008), especially left caudate SBR (β = - 0.181, p = 0.044) after controlling for age, sex, motor severity, hypertension, diabetes, and DSWMH grade. In conclusion, higher blood pressure variability was associated with greater dopaminergic degeneration in the left striatum, independently of white matter hyperintensity grade. Whether this association reflects dopaminergic neuronal loss or structural alterations in the striatum remains unclear.