Acute effects of transcutaneous electric nerve stimulation on self-injurious behavior

The purpose of this study was to determine the acute effects of conventional mode transcutaneous electric nerve stimulation (TENS) on the rate of selfinjurious behaviors (SIB) in two young multiply handicapped persons with mental retardation. The first individual exhibited high rates of severe selfbiting. In an alternating treatments design the TENS unit was randomly switched on or off in two daily sessions. In initial open trials SIB appeared to be clearly suppressed by TENS. During blind trials, in which the observers were kept uninformed as to the TENS status, frequency of biting was still slightly lower during active TENS conditions as compared to TENS-off conditions. The rate of a second maladaptive behavior (finger gouging) was not affected by TENS. The second individual exhibited high frequency of head banging. Two sessions, consisting of two conditions each, were scheduled daily throughout the study. During baseline periods the TENS unit was switched off. During the alternating treatments phases the unit was alternatively switched on or off in a random and predetermined fashion. The data indicate that head hitting rates were reduced by TENS, and that four concurrently recorded behaviors were unaffected by the TENS. It was concluded that TENS had selective effects on SIB in both individuals without achieving clinically significant results. TENS effects were found to continue for some time after the unit was switched off. The data are discussed as to their scientific and clinical implications.