A portable neurofeedback device for treating chronic subjective tinnitus: Feasibility and results of a pilot study

Background: Several clinical studies have shown that neurofeedback (NFB) has the potential to significantly improve the quality of life of patients complaining of chronic subjective tinnitus. Yet the clinical applicability of such a therapeutic approach in the everyday practice has not been tested so far. Objective: This study aims at investigating the feasibility and efficacy of a semi-automated NFB intervention by means of a portable device that eventually could be used by the patients at home on an everyday basis. The duration of setup procedures is minimized through the use of a dry electrodes electroencephalography (EEG) headset and an automated user-interface. Methods: We conducted a pilot clinical study (non-controlled, single arm, NCT03773926 ). According to a predetermined power calculation, a homogeneous population of 33 subjects with strict inclusion criteria was enrolled. After inclusion, all patients underwent 10 NFB sessions lasting 50 min each, over a period of 5 weeks and a 3-month follow-up period. According to previous studies, the NFB training aimed at increasing the alpha-band power (8–12 Hz) in the EEG power spectrum on the averaged signal of leads FC1, FC2, F3 and F4. Tinnitus handicap inventory (THI) was used as a primary outcome measure. Secondary outcome measures were the visual analog scales (VAS) and the change of the alpha-band power within sessions and across training. Time points of assessment were before intervention (T1), after intervention (T2) and at the 3-month follow-up (T3). Results: Patient exhibited a clinically significant decrease of the THI score, with a 23% decrease (N = 28) on average between T1 and T2 and a 31% decrease (N = 25) between T1 and T3. A significant increase of the alpha-band power within sessions was observed. No significant increase of the alpha-band power across sessions was observed. For the 19 subjects where sufficient data were exploitable, a significant correlation was found between the evolution of the alpha-band training across sessions and the evolution of the THI between T1 and T2. The sessions were well tolerated and no adverse effect was reported. Conclusion: This study suggests that neurofeedback has potential to suit everyday clinical practice with the goal to significantly reduce tinnitus intrusiveness. The merits and limitations of this NFB procedure are discussed, especially with respect to the choice of EEG electrodes to ensure a good signal quality.