Effects of Central Cortical EEG Feedback Training on Incidence of Poorly Controlled Seizures

Abstract

The clinical effects of central cortical EEG feedback training were examined in 8 patients with poorly controlled seizures. After base-line recordings, patients were trained in the laboratory and then initiated on a double or triple crossover design using portable equipment at home, with bimonthly laboratory test sessions. Performance at home was monitored by a strip chart recorder with the portable unit. Training was based on the simultaneous detection of 2 central cortical (C3-T3) EEG frequency bands (6-9 Hz and either 12-15 or 18-23 Hz), with reward provided for the occurrence of one in the absence of the other. The design consisted of successive 3-mo. periods of training, with reward contingencies reversed after each period without the subject''s knowledge. Seizure incidence records were compared statistically before, during and after the design. Of the 8 patients, 6 reported significant and sustained seizure reductions, which averaged 74%, following reward for either 12-15 or 18-23 Hz in the absence of 6-9 Hz. Response to positive reward for 12-15 Hz was specific, with seizure rates returning to base line when reinforcement contingenicies were reversed. Reduced seizure rates following positive reward for 18-23 Hz were not altered with contingency reversals. A nonspecific interpretation of these effects is rejected in favor of an EEG normalizing hypothesis.