scholarly journals Substantia nigra neuromelanin magnetic resonance imaging in patients with different subtypes of Parkinson disease

2021 ◽  
Author(s):  
Lu Wang ◽  
Yayun Yan ◽  
Liyao Zhang ◽  
Yan Liu ◽  
Ruirui Luo ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Clinical Symptoms ◽  
Dopamine Neurons ◽  
Substantia Nigra Pars Compacta ◽  
Resonance Imaging ◽  
Mean Values

AbstractNeuromelanin (NM) is a dark pigment that mainly exists in neurons of the substantia nigra pars compacta (SNc). In Parkinson disease (PD) patients, NM concentration decreases gradually with degeneration and necrosis of dopamine neurons, suggesting potential use as a PD biomarker. We aimed to evaluate associations between NM concentration in in vivo SN and PD progression and different motor subtypes using NM magnetic resonance imaging (NM-MRI). Fifty-four patients with idiopathic PD were enrolled. Patients were divided into groups by subtypes with different clinical symptoms: tremor dominant (TD) group and postural instability and gait difficulty (PIGD) group. Fifteen healthy age-matched volunteers were enrolled as controls. All subjects underwent clinical assessment and NM-MRI examination. PD patients showed significantly decreased contrast-to-noise ratio (CNR) values in medial and lateral SN (P < 0.05) compared to controls. CNR values in lateral SN region decreased linearly with PD progression (P = 0.001). PIGD patients showed significant decreases in CNR mean values in lateral SN compared to TD patients (P = 0.004). Diagnostic accuracy of using lateral substantia nigra (SN) in TD and PIGD groups was 79% (sensitivity 76.5%, specificity 78.6%). NM concentration in PD patients decreases gradually during disease progression and differs significantly between PD subtypes. NM may be a reliable biomarker for PD severity and subtype identification.

New Magnetic Resonance Imaging Biomarkers Advance the Characterization of Parkinson Disease

US Neurology ◽  
2013 ◽  
Vol 09 (01) ◽  
pp. 8
Author(s):  
David A Ziegler ◽  
Suzanne Corkin ◽  
◽  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Structural Mri ◽  
Careful Examination ◽  
Imaging Biomarkers ◽  
Resonance Imaging ◽  
Current State ◽  
Magnetic Resonance Imaging Mri

The pathophysiology of idiopathic Parkinson disease (PD) is traditionally characterized as substantia nigra degeneration, but careful examination of the widespread neuropathologic changes suggests individual differences in neuronal vulnerability. A major limitation to studies of disease progression in PD has been that conventional magnetic resonance imaging (MRI) techniques provide relatively poor contrast for the structures that are affected by the disease, and thus are not typically used in experimental or clinical studies. Here, we review the current state of structural MRI as applied to the analysis of the PD brain. We also describe a new multispectral MRI method that provides improved contrast for the substantia nigra and basal forebrain, which we recently used to show that these structures display different trajectories of volume loss early in the disease.

scholarly journals Neuromelanin-Sensitive Magnetic Resonance Imaging in Schizophrenia: A Meta-Analysis of Case-Control Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Lara Wieland ◽  
Sophie Fromm ◽  
Stefan Hetzer ◽  
Florian Schlagenhauf ◽  
Jakob Kaminski
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Substantia Nigra ◽  
Meta Analysis ◽  
Case Control ◽  
Primary Study ◽  
Resonance Imaging ◽  
Case Control Studies ◽  
Significant Difference

Background: Psychiatry is in urgent need of reliable biomarkers. Novel neuromelanin-sensitive magnetic resonance imaging (NM-MRI) sequences provide a time-efficient and non-invasive way to investigate the human brain in-vivo. This gives insight into the metabolites of dopaminergic signaling and may provide further evidence for potential dopaminergic alterations in patients with schizophrenia (SCZ). The present systematic review provides a meta-analysis of case-control studies using neuromelanin-sensitive sequences in SCZ vs. healthy controls (HC).Methods: According to predefined search terms and inclusion criteria studies were extracted on PubMed. Meta-analyses with a fixed and random-effects model with inverse variance method, DerSimonian-Laird estimator for τ2, and Cohen's d were calculated. Bias was assessed using funnel plots. The primary study outcome was contrast-to-noise ratio (CNR) in the substantia nigra compared between HC and SCZ.Results: The total sample of k = 6 studies included n = 183 cases and n = 162 controls. Across all studies we found a significant elevation of CNR in the substantia nigra (d = 0.42 [0.187; 0.655], z = 3.521, p &lt; 0.001) in cases compared to controls. We found no significant difference in the control region of locus coeruleus (d = −0.07 [−0.446; 0.302], z = −0.192, p = 0.847), with CNR for the latter only reported in k = 3 studies.Conclusion: CNR in the substantia nigra were significantly elevated in cases compared to controls. Our results support neuromelanin as a candidate biomarker for dopaminergic dysfunction in schizophrenia. Further studies need to assess this candidate marker in large, longitudinal cohorts and address potential effects of disease state, medication and correlations with symptoms.

Monitoring stem cell migration in the nervous system by in vivo magnetic resonance imaging

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S692-S692
Author(s):  
Mathias Hoehn ◽  
Uwe Himmelreich ◽  
Ralph Weber ◽  
Pedro Ramos-Cabrer ◽  
Susanne Wegener ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nervous System ◽  
Stem Cell ◽  
Cell Migration ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Stem Cell Migration

Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Side Effects ◽  
Magnetic Resonance ◽  
Tobacco Mosaic Virus ◽  
Contrast Agents ◽  
Single Molecule ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

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