In addition to the 19 cases of neuromytonia syndrome previously published, one further observation by the author is presented. The symptoms for neuromyotonia are an involuntary tensing of the musculature with impairment of movement, fasciculation and myokymia as well as specific electromyographic criteria. These symptoms are causes by a functional disturbance in the peripheral nervous system. They can be considerably improved by administering phenytoin and carbamazepine.