Effects of sham feedback following successful SMR training in an epileptic: follow-up study.

After 1 year of SMR biofeedback training of a severe epileptic teenage male, incidence of atonic seizures decreased from 8/hr to less than 1/3 hr. SMR increased from 10% to 70%. Epileptiform discharges decreased from 45% to 15%. Unknown to the patient, his family, or certain members of our research staff, noncontingent feedback was introduced on 7/22/74, ending 9/11/74. A significant decrease occurred for SMR (down 8%), and a significant increase for epileptiform discharges (up 4%). Rate of seizures increased, but was not statistically significant over preceding months of contingent feedback. Incidence of seizures associated with urine loss increased from approximately 6/month to 23/month during noncontingent feedback, a significant increase. Urine-loss results suggest that although seizures did not become more frequent, those the patient did experience were "harder," i.e., more severe. Contingent feedback was reinstituted following the 7-wk sham, and recovery of all variables to their former levels (prior to sham) occurred.