A man in his 70s with decreased strength and sensation in his legs

Over the last decade, antibodies targeting proteins at the node of Ranvier have been described in a subgroup of patients with autoimmune neuropathies, known as nodopathies. These disorders present an important differential diagnosis to chronic inflammatory demyelinating polyneuropathy (CIDP) due to the clinical overlap and the differences in treatment needed.

A previously healthy man in his seventies presented with a two-week history of mild paresis, diffuse sensory reduction and diminished tendon reflexes in the lower limbs. Findings from an MRI scan of the spinal cord were normal, but a spinal tap revealed albuminocytological dissociation. Neurography indicated acute motor sensory axonal neuropathy (AMSAN), leading to the patient being treated with IVIG.

Para/nodopathies present important differential diagnoses to CIDP, as they do not respond to conventional treatments. Accurate diagnosis is crucial, as the treatment approach differs but is effective for both groups.