耳鸣相关脑区的正电子发射断层成像

目的　探讨与耳鸣相关的脑区并观察听力损失、耳鸣侧别、优势半球等因素的影响。方法　用正电子发射断层成像 (positronemissiontomograph ,PET)研究 17例耳鸣患者的脑葡萄糖代谢活动 ,并与 15例无耳鸣者作对照。示踪剂为18F标记的去葡萄糖。按有无听力损失将所有受试者分为 4组 ,第 1组耳鸣伴听力损失 ,13例 ;第 2组耳呜但听力正常 ,4例 ;第 3组无耳呜有听力损失 ,2例 ;第 4组无耳呜且听力正常 ,13例。用专门统计分析软件Statisticalparametersmapping(SPM)进行统计分析 ,按照Talairach坐标确定与耳呜相关脑区的解剖部位 (brodmannarea ,BA)。结果　耳呜相关脑区位于左侧颞横回 (BA41)、左侧颞上回 (BA42、2 2 )、左侧颞中回前部 (BA38)和左侧海马 ,这一结果不依赖于耳呜的侧别 ,而且与优势关球无关。听力损失相关的脑区主要是双侧颞上回后部 (BA42、2 2 )、颞中回中部 (BA2 1)、联合听区 (BA39)、左侧额中回 (BA8、9)、左侧额下回 (BA45 )等。结论　PET为主观耳呜提供了客观证据 ,有望成为耳呜的客观检测方法。

Positron emission tomography of tinnitus-related brain areas

Objective To map the tinnitus specific central activity and foci site in brain and to investigate the effect of hearing loss,tinnitus side, right or left handed on foci site. Methods Glucose metabolic activity of brain was studied wity positron emission tomography(PET)using 18 F-FDG as radiotracer. Seventeen patients with severe tinnitus and fifteen control subjects participated in this study.All subjects were felled into four groups according to their hearing levels.There were 13 tinnitus patients wity hearing loss in Group one,4 tinnitus patients without hearing loss in Group two,2 control subjects with hearing loss in Group three and 13 control subjects without hearing loss in Group four.Statistical parameters mapping (SPM) was used to analyze the PET data and to determine the Brodman area (BA) according to Talairach coordinate system. Results Increase of neuronal activity caused by tinnitus occurred predominately in the left hemisphere wity significant foci in the transverse temporal gyrus (BA41) ,superior temporal gyrus(BA42,22),anterior middle temporal gyrus (BA38) and hippocampus.Bilateral hemispheres were concerned wity the neurona activity caused by hearing loss while foci site were located at the posterior superior temporal gyrus (BA42,22),medial portion of middle temporal gyrus(BA21),combined auditory area(BA39).Left middle frontal gyrus(BA8,9) as well as left inferior frontal gyrus(BA45) were also link up wity hearing loss.Conclusion As a new path in research,PET has provided an objective evidence for tinntius and may be used as a potential tool in objectively measuring tinnitus.Tinnitus-related brain areas and their influence factors were discussed.