Diagnosis. Usually, the physician conducts several tests and puts down notes describing the nature of the cramps. Once he is done, the patient will be offered several methods to define and cope with myoclonus. They include the imaging exam (e.g., brain check), electroencephalogram, and electromyography. The first type of tests can identify which part of the brain causes the condition. The second group of exams allows tracking the patterns of electrical activity. The third group of tests is there to scan the muscle health and behavior.