Longitudinal changes of iron in the substantia nigra of early-stage Parkinson's disease.

BACKGROUND

Higher iron occurs in the substantia nigra in Parkinson's disease (PD), but its behavior over time is poorly understood.

OBJECTIVE

To determine if nigral iron measured by quantitative susceptibility MRI can track progression of early stages of PD.

METHODS

Thirty-four early-stage PD patients (disease duration < 4 yrs) and 35 matched controls were recruited. Iron content in the substantia nigra and related regions was obtained using quantitative susceptibility mapping with zero-referencing at both baseline and one-year follow-up, along with clinical metrics.

RESULTS

Of five clinic metrics and five regional iron measures, only MDS-UPDRS II (p = 0.046) and SNc iron (p = 0.004) showed significant changes for PD subjects in the one-year epoch. The changes of SNc iron also were correlated with changes of MDS-UPDRS II (p = 0.005).

CONCLUSION

Nigral iron content measured by zero-referencing is sensitive for tracking disease progression in early-stage PD.