Neuromelanin is a dark pigment that locates within certain catecholamine neurons of the human brain, such as the dopaminergic neurons of the substantia nigra pars compacta (SNc) and the noradrenergic neurons of the locus ceruleus (LC).1 It is thought to be formed as a by-product of the catecholamine metabolism cascade via enzymatic and/or oxidative polymerization.1,2 Parkinson’s disease (PD) is characterized by the progressive loss of dopaminergic neurons that contain neuromelanin in the SNc and of noradrenergic neurons in the LC. Several pathological studies have shown...

Patients We investigated patients who were initially suspected of PD and were finally confirmed PD or AD between December 2008 and April 2012. Both MR imaging and MIBG scintigraphy performed within 1 year thereafter were retrospectively evaluated. Probable PD and AD were diagnosed according to the criteria of the United Kingdom Brain Bank and National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association, respectively. Patients with PD were assigned to groups with either early-PD or late-PD based...

The signal intensity of the lateral SNc on NmMRI was reduced in early-PD and late-PD and that of the medial SNc was gradually and stage-dependently reduced in PD. The signal intensity of LC was obviously reduced in late-PD. Signal reduction was not significant in the SNc and LC of patients with AD (Figure 1a). The heart-to-mediastinum ratio on MIBG scintigrams was stage-dependently reduced in PD and normal in AD (Figure 1b). Quantitative NmMRI revealed smaller contrast ratios in the lateral SNc of patients with early-PD...

NmMRI~SNc~ We found that the contrast ratio of the lateral SNc was significantly decreased in early-PD and late-PD and that of the medial SNc gradually and stage-dependently decreased in PD, which corresponded to the pathological lesions. These findings indicate that SNc lesions extend from the lateral to the medial regions as PD progresses. Tanaka et al. reported that a reduction in neuromelanin contrast started ventrolaterally and advanced medially in the substantia nigra based on a visual assessment of NmMR images18.However, the present study is the...

1. Fedorow H, Tribl F, Halliday G, et al. Neuromelanin in human dopamine neurons;　comparison with peripheral melanins and relevance to Parkinson’s disease. ProgNeurobiol 2005;75:109-24. 2. Zecca L, Tampellini D, Gerlach M, et al. Substantia nigra neuromelanin: structure, synthesis, and molecular behavior. Mol Pathol 2001;54:414-8. 3. Damier P, Hirsch EC, Agid Y, et al. The substantia nigra of the human brain. II.Patterns of loss of dopamine-containing neurons in Parkinson’s disease. Brain1999;122:1437-48. 4. Fearnley JM, Lees AJ. Aging and Parkinson’s disease: substantia nigra regional　selectivity. Brain...

Fuminori Miyoshi, Department of Radiology, Tottori University, Yonago, Japan [email protected] Shinichiro Kitao, Department of Radiology, Tottori University, Yonago, Japan [email protected] Marie Takasugi, Department of Radiology, Tottori University, Yonago, Japan [email protected] Yuki Shinohara, Department of Radiology, Tottori University, Yonago, Japan [email protected] Yoshiko Kanasaki, Department of Radiology, Tottori University, Yonago, Japan [email protected] Shinya Fujii, Department of Radiology, Tottori University, Yonago, Japan [email protected] Toshio Kaminou, Department of Radiology, Tottori University, Yonago, Japan [email protected] Toshihide Ogawa, Department of Radiology, Tottori University, Yonago, Japan [email protected]