Koide K, Sugiyama A, Yokota H, Mukai H, Wang J, Nakamura K, Misawa S, Ito S, Kuwabara S. Nerve Hypertrophy and Altered Diffusion in Anti-Myelin-Associated Glycoprotein Neuropathy Detected by Brachial Plexus Magnetic Resonance Neurography.
Eur Neurol 2021;
85:95-103. [PMID:
34583351 DOI:
10.1159/000519128]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/14/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION
This study assessed the morphological changes and diffusion tensor imaging (DTI)-derived parameters of the brachial plexus using magnetic resonance neurography (MRN) in patients with anti-myelin-associated glycoprotein (anti-MAG) neuropathy.
METHODS
Eight patients with anti-MAG neuropathy underwent MRN of the brachial plexus with 3-dimensional (3D) short tau inversion recovery (STIR) and DTI sequences. Two neuroradiologists and a neurologist qualitatively assessed nerve hypertrophy on 3D STIR MRN. The cross-sectional area (CSA) of the nerve roots was measured. Quantitative analyses of fractional anisotropy (FA) and axial, radial, and mean diffusivity (AD, RD, and MD) were obtained after postprocessing on DTI and manual segmentation.
RESULTS
There was nerve hypertrophy in 37.5% of the patients with anti-MAG neuropathy. All patients with anti-MAG neuropathy with nerve hypertrophy were refractory to rituximab therapy. The CSA of the nerve roots was inversely correlated with FA and positively correlated with MD and RD. FA decreased in the nerve roots and inversely correlated with disease duration.
CONCLUSIONS
Nerve hypertrophy appears in the proximal portion of peripheral nerves, such as the brachial plexus, in patients with anti-MAG neuropathy. Altered diffusion in the nerve roots might be associated with the loss of myelin integrity due to the demyelination process in anti-MAG neuropathy.
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