Purpose
Introduction
Neuromelanin is a by-product of the synthesis of monoamine neurotransmitters such as noradrenalin and dopamine,
and is mainly expressed in neurons of the locus coeruleus (LC) and substantia nigra pars compacta (SNc) [1-3].
Neuromelanin can induce paramagnetic T1-shortening effects when combined with metals such as iron and copper [4,
5].
T1-weighted imaging has failed to depict neuromelanin-generated contrast,
presumably because of the negligible T1 difference between neuromelanin and brain tissue.
Sasaki et al.
reported neuromelanin-related contrast in the SNc and LC using a multi-slice...
Methods and Materials
We retrospectively analyzed MR brain images in three autopsy-proven cases (an 81-year-old man with normal neuropathological findings,
an 81-year-old man with DLB,
and a 68-year-old woman with PD).
After obtaining consent from the relatives,
we conducted postmortem examination of these brains.
All aspects of this retrospective study were approved by the institutional review board at our institution.
Established DLB neuropathological criteria were applied [8,
9] for neuropathological diagnosis of PD and DLB.
We checked for the presence of Lewy bodies with neuronal loss and gliosis...
Results
Postmortem NmMRI and histological correlations in the SNc
Case 1 (normal control)
Postmortem NmMRI of the midbrain showed a diffuse hyperintense areas in the SNc.
The signal intensity of the SNc was higher than that of the SC (Fig.
2A).
Myelin staining of the SNc was the same as that of the SC,
whereas strong myelin staining was seen in the red nucleus,
medial lemniscus,
and cerebral peduncle (Fig.
2B).
Diffuse ferritin deposition in the SNc was fainter than that in the red nucleus,
medial...
Conclusion
In this study,
we directly correlated postmortem NmMRI and neuropathological findings.
On the postmortem NmMRI of the midbrain,
the signal intensity of the SNc was higher than that of the SC in the normal control case,
whereas the signal intensity of the SNc was as same as that of the SC in the DLB and PD cases.
These findings are same as findings with antemortem NmMRI [6].
Also,
the correlation between postmortem NmMRI and neuropathological findings revealed that the diffuse hyperintense areas in the SNc...
References
1.
Marsden D.
Brain pigment and its relation to brain catecholamines.
Lancet 1965; 10:475-76.
2.
Graham DG.
On the origin and significance of neuromelanin.
Arch Pathol Lab Med 1979; 103:359-62.
3.
Bazelon M,
Fenichel GM,
Randall J.
Studies on neuromelanin: I.
A melanin system in the human adult brainstem.
Neurology 1967; 17:512-18.
4.
Enochs WS,
Hyslop WB,
Bennett HF,
et al.
Sources of the increased longitudinal relaxation rates observed in melanotic melanoma: an in vitro study of synthetic melanins.
Invest Radiol 1997; 24:794-804.
5.
Enochs...
Personal Information
Shinichiro Kitao,
M.D.
Division of Radiology,
Department of Pathophysiological and Therapeutic Science,
Faculty of Medicine,
Tottori University,
Yonago,Japan;
[email protected]
Eiji Matsusue,
M.D.,
Ph.D.
Department of Radiology,
Tottori Prefectual Central Hospital,
Tottori,
Japan;
[email protected]
Shinya Fujii,
M.D.,
Ph.D.
Division of Radiology,
Department of Pathophysiological and Therapeutic Science,
Faculty of Medicine,
Tottori University,
Yonago,Japan.
Fuminori Miyoshi,
M.D.
Division of Radiology,
Department of Pathophysiological and Therapeutic Science,
Faculty of Medicine,
Tottori University,
Yonago,Japan.
Toshio Kaminou,
M.D.,
Ph.D.
Division of Radiology,
Department of Pathophysiological and Therapeutic Science,
Faculty of...
