Distal acquired demyelinating symmetric neuropathy

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• Classic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) typically presents with proximal and distal weakness.
• Chronic demyelinating neuropathies exhibit diverse phenotypes beyond classic CIDP.
• Phenotypic classification aids in distinguishing these neurological disorders.

Purpose of the Study:

• To characterize a variant of acquired, symmetric, demyelinating neuropathy with distal sensory or sensorimotor features.
• To differentiate distal acquired demyelinating symmetric (DADS) neuropathy from CIDP based on clinical presentation.
• To identify predictors of treatment response in demyelinating neuropathies.

Main Methods:

• Retrospective review of 53 patients with acquired symmetric demyelinating polyneuropathies.
• Classification based on neuropathy pattern: distal (DADS) versus proximal and distal (CIDP).
• Secondary classification by presence and type of monoclonal protein (M-protein).

Main Results:

• M-proteins found in 22% of CIDP patients, with good response to immunomodulating therapy.
• Two-thirds of DADS neuropathy patients had immunoglobulin M (IgM) kappa monoclonal gammopathies.
• IgM kappa M-protein in DADS predicted poor response to therapy; 67% had anti-MAG antibodies.

Conclusions:

• Phenotypic distinction of acquired demyelinating neuropathies is clinically valuable.
• Phenotype can predict IgM kappa M-proteins and anti-myelin-associated glycoprotein (anti-MAG) antibodies.
• Predicting response to immunomodulating therapy is possible through phenotypic classification.