Association between nigrosome-1 appearance on MRI and fine motor function in healthy adults and people living with Parkinson’s disease
摘要
One proposed MRI biomarker for Parkinson’s disease (PD) is the loss of hyperintense signal in nigrosome-1, a subregion of the dorsolateral substantia nigra pars compacta. However, little is known about the functional correlates of nigrosome-1 appearance on susceptibility-weighted MRI. This exploratory study investigated whether the area of the nigrosome-1 hyperintense signal is associated with fine motor performance in healthy adults and people living with PD. The cross-sectional study involved 95 healthy adults (aged 21–79 years) and 34 adults living with PD (aged 51–80 years). Participants completed an MRI, object grip and lift task, grooved pegboard test, maximal pinch grip voluntary contraction, maximal finger tapping, and tremor assessments. Predictors of fine motor performance were investigated with multilevel mixed-effects linear regression analysis. Area of nigrosome-1 hyperintense signal significantly predicted contralateral grooved pegboard performance (p = 0.001) in the healthy group, and contralateral maximum rate of change in grip force (object grip and lift task; p = 0.040) and ipsilateral tremor amplitude in the 3.9–6.6 Hz frequency range during a postural task (p = 0.050) in the PD group. Only one of these effects (grooved pegboard) survived correction for multiple comparisons. Expected between-group differences in area of nigrosome-1 hyperintense signal and fine motor performance were observed for participants aged 51–80 years (p ≤ 0.05). These findings suggest that area of nigrosome-1 hyperintense signal is associated with performance of some fine motor tasks in healthy adults and adults living with PD. The results of the current study inform interpretation of nigrosome-1 MRI findings in clinical settings.