Multimodal MRI assessment of nigro-striatal pathway in multiple system atrophy and Parkinson disease.
BACKGROUND
Parkinson's disease (PD) and multiple system atrophy (MSA) are two neurodegenerative alpha-synucleinopathies characterized by severe impairment of the nigro-striatal pathway. Based on T1-, T2*-, and diffusion-weighted magnetic resonance imaging (MRI), macro-structural and micro-structural abnormalities in these diseases can be detected.


OBJECTIVE
This study was undertaken to compare the nigro-striatal changes that occur in patients with PD with those in patients with both variants of MSA (the parkinsonian variant, MSA-P, and the cerebellar variant, MSA-C), and to explore correlations between different MRI parameters and clinical data.


METHODS
We simultaneously measured volume, T2* relaxation rates, and mean diffusivity in nigro-striatal structures (substantia nigra, caudate nucleus, and putamen) of 26 patients with PD and 29 patients with MSA (16 with MSA-P and 13 with MSA-C).


RESULTS
Significant changes in the putamina in patients with MSA were observed compared with patients with PD. Patients with MSA-P had higher mean diffusivity values in their putamina than did patients with PD or MSA-C. The putamina of both subgroups of MSA had higher T2* relaxation rates values than PD. Remarkably, discriminant analysis showed that using two measurements of microstructural damage (T2* relaxation rates and mean diffusivity in the putamen) allowed 96% accuracy to distinguish patients with PD from those with MSA-P. Correlation analyses between MRI findings and clinical variables revealed that patients with PD showed significant correlations only at the nigra. In patients with MSA, clinical variables correlated with MRI findings in both the nigra and striatum.


CONCLUSIONS
Multimodal MRI reveals different pattern of nigro-striatal involvement in patients with PD and patients with MSA.
['Barbagallo|Gaetano|G|', 'Sierra-Peña|Maria|M|', 'Nemmi|Federico|F|', 'Traon|Anne Pavy-Le|AP|', 'Meissner|Wassilios G|WG|', 'Rascol|Olivier|O|', 'Péran|Patrice|P|']
D000328:Adult D000368:Aged D003342:Corpus Striatum D006801:Humans D008279:Magnetic Resonance Imaging D008875:Middle Aged D019578:Multiple System Atrophy D010300:Parkinson Disease D011699:Putamen
multimodal MRI nigro-striatal pathway multiple system atrophy Parkinson's disease