Surgical brain modulation for tinnitus : the past, present and future
Faculty of Medicine and Health Sciences
Journal of neurosurgical sciences. - Milano
, p. 323-340
University of Antwerp
Tinnitus treatment has traditionally been restricted to ENT surgeons, audiologists, psychologists and psychiatrists. Recently, both basic and clinical research has focused on the brain's involvement in the generation of tinnitus, opening the tinnitus field up to neurologists and neurosurgeons specialized in the field of tinnitus. Non-pulsatile tinnitus can be considered an auditory phantom phenomenon, analogous to phantom pain, both with regards to pathophysiological mechanisms, clinical characteristics, and treatment approaches Thus the understanding of tinnitus has benefited a lot from translating available knowledge of the somatosensory (pain) system to the auditory system. A literature review of neuromodulatory approaches to tinnitus is integrated in a single center's experience with invasive neuromodulation treatments for tinnitus. This is compared to findings from neuromodulatory treatment of chronic pain syndromes. The past, present and future options for functional neurosurgical approaches are outlined. In the past only destructive approaches were used, consisting of nerve lesions and frontal lobotomies. Presently neurostimulation trials are ongoing evaluating the effect of auditory cortex stimulation, frontal cortex stimulation, thalamic (VIM) and caudate stimulation as well as amygdalohippocampal stimulation, yielding suppression rates between 10 and 70%. Further potentially promising targets include the anterior cingulate, the medial geniculate bodies (MGB), the periaqueductal gray/ tectal longitudinal column (PAG/TLC), the dorsal cochlear nucleus, as well as the C2 and trigeminal nerve. Understanding tinnitus and its potential neuromodulation treatments is relatively simple for a neurosurgeon specialized in pain or a pain physician, based on the pathophysiological and clinical analogies. Similarly to pain a multi-disciplinary approach can be advocated, and in view of the epidemiology and amount of suffering associated with this enigmatic symptom further investment in possible neuromodulation treatments is warranted.