TY - JOUR
T1 - Plexus MRI helps distinguish the immune-mediated neuropathies MADSAM and MMN
AU - Beecher, Grayson
AU - Howe, Benjamin M.
AU - Shelly, Shahar
AU - Nathan, P.
AU - Mauermann, Michelle L.
AU - Taylor, Bruce V.
AU - Spinner, Robert J.
AU - Tracy, Jennifer A.
AU - Dyck, P. James B.
AU - Klein, Christopher J.
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/10/15
Y1 - 2022/10/15
N2 - Background: Among immune-mediated neuropathies, clinical-electrophysiological overlap exists between multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) and multifocal motor neuropathy (MMN). Divergent immune pathogenesis, immunotherapy response, and prognosis exist between these two disorders. MRI reports have not shown distinction of these disorders, but biopsy confirmation is lacking in earlier reports. MADSAM nerves are hypertrophic with onion bulbs, inflammation, and edema, whereas MMN findings are limited to multifocal axonal atrophy. Objectives: To understand if plexus MRI can distinguish MADSAM from MMN among pathologically (nerve biopsy) confirmed cases. Methods: Retrospective chart review and blinded plexus MRI review of biopsy-confirmed MADSAM and MMN cases at Mayo Clinic. Results: Nine brachial plexuses (MADSAM-5, MMN-4) and 6 lumbosacral plexuses (MADSAM-4, MMN-2) had fascicular biopsies of varied nerves. Median follow-up in MADSAM was 93 months (range: 7–180) and 27 (range: 12–109) in MMN (p = 0.34). MRI hypertrophy occurred solely in MADSAM (89%, 8/9) with T2-hyperintensity in both. There was no correlation between time to imaging for hypertrophy, symptom onset age, or motor neuropathy impairments (mNIS). At last follow-up, on diverse immunotherapies mNIS improved in MADSAM (median − 4, range: −22 to 0), whereas MMN worsened (median 3, range: 0 to 6, p = 0.03) on largely IVIG. Conclusion: Nerve hypertrophy on plexus MRI helps distinguish MMN from MADSAM, where better immunotherapy treatment outcomes were observed. These findings are consistent with the immune pathogenesis seen on biopsies. Radiologic distinction is possible independent of time to imaging and extent of motor deficits, suggesting MRI is helpful in patients with uncertain clinical-electrophysiologic diagnosis, especially motor-onset MADSAM.
AB - Background: Among immune-mediated neuropathies, clinical-electrophysiological overlap exists between multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) and multifocal motor neuropathy (MMN). Divergent immune pathogenesis, immunotherapy response, and prognosis exist between these two disorders. MRI reports have not shown distinction of these disorders, but biopsy confirmation is lacking in earlier reports. MADSAM nerves are hypertrophic with onion bulbs, inflammation, and edema, whereas MMN findings are limited to multifocal axonal atrophy. Objectives: To understand if plexus MRI can distinguish MADSAM from MMN among pathologically (nerve biopsy) confirmed cases. Methods: Retrospective chart review and blinded plexus MRI review of biopsy-confirmed MADSAM and MMN cases at Mayo Clinic. Results: Nine brachial plexuses (MADSAM-5, MMN-4) and 6 lumbosacral plexuses (MADSAM-4, MMN-2) had fascicular biopsies of varied nerves. Median follow-up in MADSAM was 93 months (range: 7–180) and 27 (range: 12–109) in MMN (p = 0.34). MRI hypertrophy occurred solely in MADSAM (89%, 8/9) with T2-hyperintensity in both. There was no correlation between time to imaging for hypertrophy, symptom onset age, or motor neuropathy impairments (mNIS). At last follow-up, on diverse immunotherapies mNIS improved in MADSAM (median − 4, range: −22 to 0), whereas MMN worsened (median 3, range: 0 to 6, p = 0.03) on largely IVIG. Conclusion: Nerve hypertrophy on plexus MRI helps distinguish MMN from MADSAM, where better immunotherapy treatment outcomes were observed. These findings are consistent with the immune pathogenesis seen on biopsies. Radiologic distinction is possible independent of time to imaging and extent of motor deficits, suggesting MRI is helpful in patients with uncertain clinical-electrophysiologic diagnosis, especially motor-onset MADSAM.
KW - Brachial plexus
KW - Lumbosacral plexus
KW - MADSAM
KW - MMN
KW - MRI
KW - Nerve biopsy
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U2 - 10.1016/j.jneuroim.2022.577953
DO - 10.1016/j.jneuroim.2022.577953
M3 - Article
C2 - 36007424
AN - SCOPUS:85136319267
SN - 0165-5728
VL - 371
JO - Journal of neuroimmunology
JF - Journal of neuroimmunology
M1 - 577953
ER -