De Ridder Dirk, De Mulder Gert, Walsh Vincent, Muggleton Neil, Sunaert Stefan, Møller Aage
Department of Neurosurgery, University Hospital Antwerp, Edegem, Belgium.
J Neurosurg. 2004 Mar;100(3):560-4. doi: 10.3171/jns.2004.100.3.0560.
Tinnitus is a distressing symptom that affects up to 15% of the population for whom no satisfactory treatment exists. The authors present a novel surgical approach for the treatment of intractable tinnitus, based on cortical stimulation of the auditory cortex. Tinnitus can be considered an auditory phantom phenomenon similar to deafferentation pain, which is observed in the somatosensory system. Tinnitus is accompanied by a change in the tonotopic map of the auditory cortex. Furthermore, there is a highly positive association between the subjective intensity of the tinnitus and the amount of shift in tinnitus frequency in the auditory cortex, that is, the amount of cortical reorganization. This cortical reorganization can be demonstrated by functional magnetic resonance (fMR) imaging. Transcranial magnetic stimulation (TMS) is a noninvasive method of activating or deactivating focal areas of the human brain. Linked to a navigation system that is guided by fMR images of the auditory system, TMS can suppress areas of cortical plasticity. If it is successful in suppressing a patient's tinnitus, this focal and temporary effect can be perpetualized by implanting a cortical electrode. A neuronavigation-based auditory fMR imaging-guided TMS session was performed in a patient who suffered from tinnitus due to a cochlear nerve lesion. Complete suppression of the tinnitus was obtained. At a later time an extradural electrode was implanted with the guidance of auditory fMR imaging navigation. Postoperatively, the patient's tinnitus disappeared and remains absent 10 months later. Focal extradural electrical stimulation of the primary auditory cortex at the area of cortical plasticity is capable of suppressing contralateral tinnitus completely. Transcranial magnetic stimulation may be an ideal method for noninvasive studies of surgical candidates in whom stimulating electrodes might be implanted for tinnitus suppression.
耳鸣是一种令人苦恼的症状，影响着高达15%的人群，目前尚无令人满意的治疗方法。作者提出了一种基于听觉皮层刺激治疗顽固性耳鸣的新型手术方法。耳鸣可被视为一种类似于去传入性疼痛的听觉幻像现象，这种现象在躯体感觉系统中也有观察到。耳鸣伴随着听觉皮层音调定位图的变化。此外，耳鸣的主观强度与听觉皮层中耳鸣频率的变化量之间存在高度正相关，即皮层重组的量。这种皮层重组可以通过功能磁共振成像（fMR）来证实。经颅磁刺激（TMS）是一种激活或失活人脑局部区域的非侵入性方法。与由听觉系统的fMR图像引导的导航系统相连，TMS可以抑制皮层可塑性区域。如果它成功地抑制了患者的耳鸣，这种局部和暂时的效果可以通过植入皮层电极来永久化。在一名因耳蜗神经病变而患有耳鸣的患者中进行了基于神经导航的听觉fMR成像引导的TMS治疗。耳鸣得到了完全抑制。随后，在听觉fMR成像导航的引导下植入了硬膜外电极。术后，患者的耳鸣消失，10个月后仍未复发。在皮层可塑性区域对初级听觉皮层进行局部硬膜外电刺激能够完全抑制对侧耳鸣。经颅磁刺激可能是对可能植入刺激电极以抑制耳鸣的手术候选者进行非侵入性研究的理想方法。
