Between August 1993 and March 1994, electrodiagnostic studies were performed on 42 patients with spinal cord injuries who were admitted to Severance Hospital, Yonsei University College of Medicine. The patients were classified into two groups: complete spinal cord injury group and incomplete spinal cord injury group. The changes of abnormal spontaneous activities and nerve conduction study findings were evaluated according to time along with spasticity grade.

In this study, it was found that both abnormal spontaneous activity occuring frequency and compound muscle action potential amplitude decreased according to time after complete spinal cord injury. For both complete and incomplete spinal cord injury, occurrence of abnormal spontaneous activity was found to be decreasing as spasticity increased.

According to this study it was found that abnormal spontaneous activities to be present in most patients with spinal cord injury even without peripheral nerve lesions, and their occurance decreased proportionally as the time after injury and the spasticity increased.