Evaluation of a sLORETA Neurofeedback Protocol for Treating Chronic Tinnitus

Alpha/delta neurofeedback has been shown to be a potential treatment option for chronic tinnitus. Traditional neurofeedback approaches working with a handful of surface electrodes have been criticized, however, due to their low spatial specificity. The purpose of this study was to evaluate a tomographic neurofeedback protocol that combines activity measured across the whole scalp with sLORETA source estimation.Method Forty-eight chronic tinnitus patients participated in 15 weekly neurofeedback training sessions and extensive pre, post, as well as follow-up testing. Patients were randomly assigned to a tomographic (ToNF) or a traditional electrode-based neurofeedback (NTNF) group. The main outcome measures of this study consisted of tinnitus distress, loudness, and pre- and post-training EEG activity in trained frequency bands on surface and source level. Results For both groups a significant reduction of tinnitus distress and loudness was found. While distress changes seemed to persist, loudness levels returned to baseline in the follow-up period. Furthermore, the trained alpha/delta ratio increased significantly during the training and remained stable in the follow-up period. No between-group differences between the two groups (ToNF or NTNF) were found, which suggests a similar contribution to symptom improvement and changes in EEG patterns. Conclusions This study shows that a tomographic alpha/delta protocol should be considered a valuable addition to tinnitus treatment with neurofeedback. More knowledge about distinct tinnitus subtypes and their manifestation in respective brain activity patterns is necessary in order to develop more individually specific eurofeedback approaches.