Differentiation of early-stage parkinsonisms using neuromelanin-sensitive magnetic resonance imaging.
OBJECTIVE
The purpose of this study was to investigate whether the signal intensity of the substantia nigra pars compacta (SNc) and locus coeruleus (LC) on neuromelanin-sensitive magnetic resonance imaging (MRI) can discriminate early-stage parkinsonism disorders, for which differential diagnosis is generally difficult.


METHODS
Neuromelanin-sensitive MRI at 3 T was performed in 53 patients with early parkinsonism and 22 healthy controls. After an observation period of >1.5 year, the patients were clinically diagnosed with Parkinson's disease (PD; n = 30), multiple system atrophy with predominant parkinsonism (MSA-P; n = 10), or progressive supranuclear palsy syndrome (PSPS; n = 13). The signal intensity of the lateral, central, and medial parts of the SNc and the LC were measured and the contrast ratios (CR) against adjacent white-matter structures was calculated.


RESULTS
The CR of the lateral SNc was lower in the PD and MSA-P groups than in the PSPS and control groups (p = 0.0001-0.05). The CR of the LC was lower in the PD group than in the other groups (p = 0.0001-0.05). Sensitivity and specificity of the CRs for discriminating PD from MSA-P was 60% and 90%, respectively, those for PD/PSPS were 63-88% and 77-92%, respectively, and those for MSA-P/PSPS were 80% and 85%, respectively. These properties were comparable or better to MIBG scintigraphy.


CONCLUSIONS
Neuromelanin-sensitive MRI can depict differences in signal intensity of the lateral SNc and the LC among the parkinsonism disorders at their early stages.
Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan. Electronic address: csato@iwate-med.ac.jp.
Chigumi
C
Ohtsuka
Institute for Biomedical Sciences, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Makoto
M
Sasaki
Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Kanako
K
Konno
Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Kanako
K
Kato
Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Junko
J
Takahashi
Institute for Biomedical Sciences, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Fumio
F
Yamashita
Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
Yasuo
Y
Terayama
D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008125:Locus Coeruleus / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008543:Melanins; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000175:diagnosis* / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism / Q000473:pathology
D008543:Melanins; C014121:neuromelanin
Differential diagnosis; MIBG scintigraphy; Magnetic resonance imaging; Neuromelanin; Parkinson's disease