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CANOMAD syndrome (Chronic Ataxic Neuropathy, Ophthalmoplegia, Monoclonal IgM protein, cold Agglutinins and Disialosyl antibodies) is a rare chronic immune-mediated demyelinating polyneuropathy.
- Chronic ataxic neuropathy-ophthalmoplegia-IgM paraprotein-cold agglutinins-disialosyl antibodies syndrome
- Chronic sensory ataxic neuropathy with anti-dyalosyl IgM antibodies
- Prevalence: Unknown
- Inheritance: -
- Age of onset: Adult
- ICD-10: G61.8
- OMIM: -
- UMLS: C2931684
- MeSH: C537980
- GARD: 9778
- MedDRA: -
The exact prevalence is unknown but less than 30 cases have been reported in the literature.
The clinical picture comprises a chronic neuropathy with marked sensory ataxia and areflexia, and with relatively preserved motor function in the limbs. Motor weakness affecting the oculomotor and bulbar muscles is present as either a fixed or relapsing-remitting feature. Clinical electrophysiology and nerve biopsy show demyelinating and axonal features. The CANOMAD phenotype is associated with anti-GQ1b and anti-disialosyl antibodies.
The diagnosis is based on clinical examination, the results of electrophysical tests, and the detection of antibodies to gangliosides.
The condition resembles 'chronic Miller-Fisher syndrome' (see this term) but has a chronic course that often extends over decades. Inflammatory peripheral neuropathies should also be considered in the differential diagnosis, as they may induce demyelinating damage due to autoimmune processes.
Management and treatment
Plasma exchange and intravenous immunoglobulin have been reported with temporary benefit in some cases. Other treatments (corticosteroids, beta-interferons and cytotoxic drugs) remain to be evaluated.