Auditory Processing During Sleep: A Clinical Application in Tinnitus

Abstract

It is known that changes in neuronal activity occur during the sleep-wake cycle along the entire auditory pathway. Subjective tinnitus is an anomalous auditory perception resulting from dysfunction of neuronal plasticity. A therapeutic strategy using acoustic stimulation with sound mimicking tinnitus during sleep was developed, resulting in decrease in the reported intensity of tinnitus and improvement in the patients’ quality of life. Since each stage of sleep has different roles in the memory consolidation process, the impact on the intensity of tinnitus with acoustic stimulation at different stages of sleep was analyzed separately. All patients stimulated at stage N2 (stage with spindles) showed significant decrement in the tinnitus intensity the day after stimulation, while nobody stimulated at the stage N3 (slow wave sleep) showed changes in tinnitus intensity. The results show that brain dynamics associated with N2 sleep stage is likely to be characterized by the possibility of establishing interactions with the auditory processing networks, thus resulting in a reduction of tinnitus intensity. These results are in agreement with other previous results showing more changes in power spectra and coherence in electroencephalographic waves in N2 sleep stage when there is sound stimulation.