Hereditary continuous muscle fibre activity (Q103466)

Generalised peripheral nerve hyperexcitability are a heterogeneous group of disorders presenting as involuntary, continuous muscle overactivity. The clinical presentation can include muscle cramps, fasciculations, myokymia (undulating movements of the skin surface), and pseudomyotonia (delayed relaxation after a contraction). There are many peripheral nerve hyperexcitability syndromes, with different pathogenesis that include both genetic and acquired disorders. The most well-known is Isaacs syndrome, often called acquired neuromyotonia.