Modulierung anormaler Gehirnaktivität bei Menschen mit chronischem Tinnitus : Entwicklung eines Neurofeedbacktrainings
2007, Dohrmann, Katalin
Tinnitus, the perception of sound without the presence of a physical stimulus persistent longer than 6 months, is a widespread condition. It may take various forms of distressing impairment related to the auditory system. To date, multiple treatments have been suggested; however, none can be considered as a validated cure. These approaches had been developed heuristically rather than on a neuroscientific understanding of the phenomenon. Based on findings of abnormal oscillatory brain activity in tinnitus sufferers (Weisz et al., 2005), I introduce its specific operant modification as a remedy for tinnitus symptoms. The particular remodeling of brain circuits producing this abnormal oscillatory activity can be achieved by neurofeedback techniques. Normalization of pathological activity is achieved mainly through an enhancement of alpha activity, i.e. oscillatory activity produced in perisylvian regions within the alpha range (8 12 Hz) and concomitant reduction in the delta power range (0.5 4 Hz). Twenty-one participants with chronic tinnitus and slight tinnitus-related distress (range from 6 to 69 points on the Tinnitus Questionnaire (Goebel & Hiller, 1998), mean of 26.5) took part in ten sessions of neurofeedback training distributed over four weeks. Both tinnitus loudness and distress could be reduced during training with Cohens d = 0.663 for tinnitus loudenss and d = 0.47 for distress. Participants who successfully modified their oscillatory pattern profited from the treatment to the extent that the tinnitus sensation became completely abolished (in two participants). Overall neurofeedback training proved to be significantly more successful in reducing tinnitus-related distress than a frequency discrimination training. As this form of neurofeedback training is a pilot project, I will come forward with suggestions for improvement and implementation of the training in clinical practice but also in further research.