CANOMAD and other chronic ataxic neuropathies with disialosyl antibodies (CANDA).

Abstract

CANOMAD/CANDA are syndromes characterized by ataxic neuropathy, ophthalmoplegia, monoclonal gammopathy, cold agglutinins and disialosyl antibodies. A retrospective review of our neuromuscular autoantibody panel database was performed. Anti-GD1b seropositive patients with ataxia were included. Eleven patients were identified. Median age at onset was 56years. Median disease duration was 6years. All patients had gait disorders. Nine had ocular motility abnormalities. Most had a monoclonal protein and all had elevated serum IgM. Electrodiagnostic studies showed a mixed axonal/demyelinating pattern (6), an axonal pattern (4), or a pure demyelinating pattern (1). Ultrasounds showed nerve enlargement patterns consistent with acquired demyelination. A nerve biopsy showed near complete loss of myelinated axons with preservation of smaller axons. Rituximab was the most effective immunotherapy. CANOMAD/CANDA are rare and debilitating disorders with characteristic clinical and diagnostic findings. In our cohort, nerve ultrasound showed regional nerve enlargement and rituximab was the most effective immunomodulatory therapy.