Neuromyotonia, or Isaacs syndrome, is a neuromuscular disorder characterized by peripheral nerve hyperexcitability.1,–,3 It may be hereditary or acquired. Clinical features include muscle twitching, cramps, stiffness, delayed muscle relaxation, and transient paresthesias. Electrophysiologic studies show motor nerve hyperexcitability, including myokymic or neuromyotonic discharges, fasciculations, and repetitive compound muscle action potential (CMAP) afterdischarges. An associated axonal polyneuropathy is present in a few cases. About 40% of patients with acquired neuromyotonia demonstrate antibodies to the voltage-gated potassium channel (VGKC). Symptoms may respond to anticonvulsants or immunosuppression. Acquired neuromyotonia is a recognized paraneoplastic syndrome commonly associated with chest tumors (thymoma, lung cancer, Hodgkin lymphoma), with rare reports of plasmacytoma and renal cell and bladder carcinoma.1,2 We report a patient presenting with acquired neuromyotonia attributed to ovarian cancer, whose diagnosis was delayed due to the atypical location of her cancer. ### Case reports. A 59-year-old woman with a history of migraine headaches and systemic lupus erythematosus (SLE), quiescent since 1980, presented with 1 year of intermittent twitching of her face, fingers, and toes, and multiple episodes of loss of muscle tone while standing or walking, in the setting of a clear sensorium; strength and tone returned …