Acute and chronic ataxic neuropathies with disialosyl antibodies: a continuous clinical spectrum and a common pathophysiological mechanism.

Acute ataxic neuropathies with disialosyl antibodies include Fisher syndrome, ataxic Guillain-Barré syndrome (GBS), and acute sensory ataxic neuropathy. Fisher syndrome and ataxic GBS are more strongly associated with IgG anti-GQ1b and anti-GT1a than with anti-GD1b antibodies, whereas the association is reversed in the case of acute sensory ataxic neuropathy. Chronic ataxic neuropathy with disialosyl antibodies is associated with IgM paraprotein to GD1b and GQ1b, which occasionally reacts with GT1a. The clinical, electrophysiological, and pathological features, along with experimental findings, suggest that acute and chronic ataxic neuropathies with disialosyl antibodies form a continuous clinical and pathophysiological spectrum characterized by a complement-mediated disruption at the nodal region and are better classified in the new category of nodo-paranodopathies.