Clinical features of neuromyotonia:
(1) muscle twitching
(2) muscle cramps
(3) muscle stiffness and delayed relaxation
(4) muscle weakness
(5) transient paresthesias
(6) variable axonal polyneuropathy
Laboratory findings may include:
(1) motor nerve hyperexcitability on electrophysiologic studies with repetitive compound muscle action potentials (CMAP) afterdischarges, fasciculations and neuromyotonic discharges
(2) variable presence of antibodies to VGKC (voltage-gated potassium channel)
Tumors reported to cause a paraneoplastic neuromyotonia:
(1) lung cancer
(2) thymoma
(3) Hodgkin's disease
(4) plasmacytoma
(5) renal cell carcinoma
(6) urinary bladder carcinoma
(7) ovarian cancer
Diagnosis as a paraneoplastic syndrome:
(1) acquired disorder (not hereditary)
(2) presence of a tumor
(3) exclusion of other causes
(4) disease activity related to amount of tumor present
