EEG-Based Multifocal Tomographic Neurofeedback in Older Individuals With Chronic Tinnitus Does Not Lead to Persistent...

Tinnitus is typically a chronic condition characterized by phantom hearing sensations in the absence of external sound sources. Although there is currently no commonly agreed neurobiological model of tinnitus generation and chronification, several electrophysiological parameters have been proposed as potential neural markers to objectify tinnitus symptoms. Accordingly, electroencephalography-based (EEG) neurofeedback may prove to be a promising symptom-relieving intervention to directly influence the development, maintenance, and distress of tinnitus. In the present clinical study, we examined the effects of low- and high-intensity multifocal tomographic EEG neurofeedback in two matched cohorts of older participants with chronic subjective tinnitus who learned to regulate electrical activity in three circumscribed brain regions, namely the auditory cortex, anterior insula, and dorsal anterior cingulate.

Using a crossover design in which the two groups received 1 or 2 weekly training sessions in the first month, with the same number of total training sessions after 2 months, participants attempted to increase the alpha/delta power ratio in the bilateral auditory cortex as well as the theta/beta ratio in the dorsal anterior cingulate cortex and the anterior insula. We evaluated the impact of the EEG-based neurofeedback training on self-reported tinnitus scores, psychological variables, and health-related dimensions. The effectiveness of multifocal tomographic neurofeedback and training intensity was also assessed using resting-state EEG data collected before and after 1 and 2 months of training, as well as 3 and 6 months after the last training session.

Neurofeedback protocols were generally associated with lower tinnitus distress and had a positive impact on subjective general health status in the low-intensity training group. However, contrary to our expectations, we did not find any neural effect of neurofeedback for the trained brain regions or on subjective tinnitus perception.

Taken together, these results provide a critical perspective on the relationship between multifocal tomographic neurofeedback and group-based resting-state EEG as a marker of training-dependent changes of neural activity.