Isaac's syndrome associated with CIDP and pregnancy

Neuromyotonia with all its synonyms is a disorder of peripheral nerve hyperexcitability characterized by regular or irregular myokymia, muscle cramps and stiffness, delayed muscle relaxation after contraction, and hyperhidrosis associated with well-described spontaneous electromyographic features. Herein, we report clinical and electrodiagnostic findings of a pregnant woman with neuromyotonia who also suffered from chronic inflammatory demyelinating polyneuropathy. We treated the patient with plasma exchange, 50 mL/kg (twice weekly, for six weeks). After two weeks of treatment, cramps and stiffness were substantially reduced. After four weeks, she looked normal with a relatively smooth gait. After eight weeks, the patient was entirely well with no cramps or stiffness. Repeat EMG showed no myokymic discharges. After four months she was in good health and the plasma exchanges continued every other week without the use of corticosteroids or cytotoxic agents. Afterwards, we discontinued the plasma exchange and only visited the patient regularly. One year later, we repeated a five-day course of plasma exchange to overcome mild recurrence of myokymia in her thighs. Now, after four years, she is healthy without any disability or problem. The patient's child has been healthy throughout without any evidence of neuromyotonia.