In 1985, circulating IgM antibodies reacting with NeuAc(alpha2–8)NeuAc(alpha2–3)Gal-configured disialosyl gangliosides (including GD1b, GD3, GT1b, and GQ1b) were first described in a patient with chronic sensory neuropathy.1 The typical clinical picture of anti-disialosyl-associated neuropathy comprises marked sensory ataxia, areflexia, a relatively preserved motor function excepting ophtalmoplegia and a chronic or relapsing course.2 In half of the cases, IgM antibodies are also cold agglutinins, fulfilling all the conditions for the chronic ataxic neuropathy, ophthalmoplegia, monoclonal IgM protein, cold agglutinins and disialosyl antibodies (CANOMAD) syndrome. We report two patients with a chronic or relapsing sensory neuropathy and ophtalmoplegia associated with anti-disialosyl IgM antibodies who developed asymmetrical motor weakness related to multifocal persistent conduction blocks, an unusual feature in this context.

Patient 1

A 39-year-old woman presented with gait ataxia and paraesthesias in the left foot. Paraesthesias spread up to both legs, and then to both hands within a year. Over the following year, ataxia worsened, and distal weakness appeared in the lower limbs, predominating on the left side. Clinical examination showed decreased sensation to all modalities in all four extremities, gait ataxia, dorsal and plantar flexion weakness, and absent tendon reflexes in the lower limbs. Six years after disease onset, she developed right hand and proximal lower limb weakness. Three years later, she presented with a right-sided ptosis …