Figure 3.

Pathophysiology of neuromyotonia. (A) Schematic overview of the VGKC complex in the juxtaparanodal region of myelinated axons (modified from [144]). CASPR2, together with contactin-2 and other proteins, is fundamental for clustering Kv1 channels. CASPR2 antibodies could interfere with CASPR2-contactin-2 interaction leading to Kv expression down-regulation with consequent impairment of action potential repolarisation and excessive or prolonged release of acetylcholine. (B) This leads to prolonged EPP and repetitive nerve firing. The EMG shows myokymic discharges (doublets, triplets, and multiplets).