Different iron deposition patterns in akinetic/rigid-dominant and tremor-dominant Parkinson's disease

The loss of dopaminergic cells and excessive iron deposition in some deep brain nuclei are associated with the pathophysiology of PD, and different clinical subtypes may indicate different pathological processes. This study was designed to investigate the relationships between regional iron in the cardinal subcortical nuclei and different clinical subtypes.

Nine Arkinetic/Rigid-dominant Parkinson's disease (PDAR) patients, eight Tremor-dominant (PDTD)patients and 10 matched healthy controls were recruited for this study. The iron content in 8 cardinal subcortical nuclei was measured through SWI sequence scanning (3.0 T), and different patterns of iron deposition were analyzed not only between the PD patients and HC groups but also between the different clinical subtypes.

Compared with the healthy controls, the iron content in the substantia nigra pars compacta(SNc), substantia nigra pars reticulata(SNr) from both the severe and milder side in PD groups were significantly increased (P < 0.01 and P < 0.02 for SNc; both P < 0.01 for SNr), and the iron content in the GP of both the severe and milder side of the PDAR patients was significantly increased compared with the PDTD patients (P < 0.01 and P = 0.02, respectively) CONCLUSION: SWI is a very good technique for the in vivo assessment of subcortical nucleus iron content, and abnormal deposition of iron in the SNc and SNr is an obvious characteristic in PD patients. Furthermore, our data indicates that PDAR patients have higher iron content in the GP than PDTD patients and HCs, indicating that abnormal iron deposition in GP is related to the phenotype of Akinetic/Rigid in PD patients.