The electromyogram is of use in the diagnosis of lesions in which the demonstration of minimal lower motor neuron disease is of importance. These lesions can often be found in no other way. It is also of value in certain neurosurgical problems not frequently encountered. Furthermore, while the electromyogram is in no sense a substitute for a complete history and a careful physical and neurological examination, it sometimes leads to an important finding previously overlooked, or indicates the need for further investigative measures, such as myelography2.