Somatic tinnitus (review). A consequence of plasticity and bimodal integration in the dorsal cochlear nucleus

: Somatic tinnitus is a peculiar tinnitus type that can be defined as a tinnitus that can be modulated in intensity and/or pitch by manipulating some regions of the head and neck but also as tinnitus associated with facial pain or dysesthesis in the same area. Those areas are innervated by the trigeminal nerve and the cervical plexus. This can be explained by functional connections between the trigeminal system and the auditory brainstem and mid-brain. A literature overview shows how different messages coming from the head and neck are able to modulate the hearing information. Tinnitus is generated by an increase of the spontaneous discharges of the dorsal cochlear nucleus neurons, tonotopic reorganisation and an increase of the neural synchronism in the auditory cortex. Trigeminal stimulations have an influence on the activity of the dorsal cochlear nucleus especially in case of an associated hearing loss.