Rinsho Shinkeigaku (Clinical Neurology)

Original Article

Neuromelanin-related contrast in the substantia nigra semiquantitatively evaluated by magnetic resonance imaging at 3T: comparison between normal aging and Parkinson disease

Makoto Tanaka, M.D.1)2), Yuko Aihara, M.D.1)2), Sachie Ikeda, M.D.1)2) and Yoshiaki Aihara, M.D.1)

1)Shinozuka Hospital
2)Kitakanto Neurological Disorders Research Center

Fast spin-echo (FSE) T1-weighted magnetic resonance imaging (MRI) at 3T, which was optimized to detect neuromelanin-related contrast (NRC), was applied to quantitative estimation of signal alterations in the substantia nigra pars compacta (SNc) of 72 normal volunteers and 59 patients with Parkinson disease (PD). We examined relationship between NRC in SNc and clinical parameters. The NRC showed significant positive correlation with normal aging and was slightly but significantly higher in women than in men. Significant reduction in the NRC was found in PD as compared with 59 age- and sex-matched normal volunteers. The NRC in PD was negatively and significantly correlated with duration of illness and disease severity assessed by UPDRS and Hoehn & Yahr stage. Significant reduction of the NRC was demonstrated in patients with visual hallucinations as compare with patients without the symptoms. REM sleep behavior disorder also contributed reduction of NRC although it did more mildly than visual hallucination. Anosmia or hyposmia had no statistical relationship with the amount of NRC in PD. The overall visual inspection indicated that the reduction of the NRC in PD should start at the ventrolateral portion of SNc and advance medially. Additionally, we studied dementia with Lewy body disease (DLB). The NRC was reduced more significantly in DLB patients with PD symptoms than in those without them who also showed a significant reduction compared with normal controls. Quantification and distribution of the NRC obtained by 3T MRI was well correlated with pathological findings reported previously and clinical parameters in this study. Visualization and quantification of the NRC provide some parts of clinical and diagnostic information about pathologic condition of SNc.
Full Text of this Article in Japanese PDF (710K)

(CLINICA NEUROL, 51: 14|20, 2011)
key words: neuromelanin, Parkinson's disease, aging, substantia nigra, MRI

(Received: 30-Jul-10)