Objective: To investigate abnormal directional functional connectivity of the nucleus accumbens (NAc) in chronic tinnitus patients using resting-state functional magnetic resonance imaging (fMRI), and to determine the relationship between the degree of this connectivity and tinnitus characteristics. Methods: The resting-state fMRI data of 40 patients with bilateral chronic tinnitus (12 males and 28 females, aged from 26 to 63(50.6±11.6) years) and 40 healthy controls with normal hearing (16 males and 24 females, aged from 26 to 70(45.9±12.4)years) were retrospectively enrolled from the Department of Otolaryngology, Nanjing First Hospital from January 2017 to January 2020. The bilateral NAc were selected as seeds to detect the directional functional connectivity with the whole brain, then the effective connectivity values between the two groups were compared using Granger Causality Analysis (GCA), and the correlation between the effective connectivity and the characteristics of tinnitus was calculated. Results: Compared with healthy controls, the effective connectivity from the left NAc to left middle frontal gyrus in patients with bilateral chronic tinnitus was increased [(1.0±0.2)vs(0.6±0.3)], the effective connectivity from the right NAc to left inferior frontal gyrus was enhanced [(0.9±0.3)vs(0.6±0.4)], the effective connectivity from the right middle temporal gyrus to left NAc was enhanced [(1.0±0.2)vs(0.5±0.3)], the effective connectivity from the right middle frontal gyrus to right NAc was also enhanced[(1.0±0.2)vs(0.5±0.3)](all P<0.05). After adjusting for age, gender, education level, and gray matter volume, positive correlations was observed between the Tinnitus Handicap Questionnaire (THQ) scores and increased effective connectivity values from the left NAc to the left middle frontal gyrus (r=0.386, P=0.020). Additionally, enhanced effective connectivity values from the right middle frontal gyrus to the right NAc was also positively associated with tinnitus duration (r=0.390, P=0.019). Conclusion: The directional functional connectivity between the NAc and prefrontal cortex in patients with chronic tinnitus is enhanced.
目的： 利用静息态功能磁共振（fMRI）技术探讨慢性耳鸣患者大脑伏隔核（NAc）的异常定向功能连接，并确定这种连接程度与耳鸣临床特征之间的关系。 方法： 回顾性收集2017年1月至2020年1月在南京市第一医院耳鼻喉科就诊的40例慢性双侧耳鸣患者［男12例，女28例，年龄26~63（50.6±11.6）岁］以及同期体检的40名听力正常的健康志愿者［男16例，女24例，年龄26~70（45.9±12.4）岁］的静息态fMRI数据，采用格兰杰因果分析（GCA）方法，选择双侧NAc作为种子点检测与全脑的定向功能连接，然后比较两组间的有效连接值，并计算其与耳鸣特征的相关性。 结果： 与健康对照组相比，慢性耳鸣患者左侧NAc到左侧额中回的有效连接值增强 ［（1.0±0.2）比（0.6±0.3）］，右侧NAc到左侧额下回的有效连接值增强［（0.9±0.3）比（0.6±0.4）］，右侧颞中回到左侧NAc的有效连接值增强［（1.0±0.2）比（0.5±0.3）］，右侧额中回到右侧NAc的有效连接值亦增强［（0.9±0.2）比（0.6±0.4）］（均P<0.05）。在校正年龄、性别、教育程度及灰质体积后，左侧NAc至左侧额中回增强的有效连接值与耳鸣残疾问卷得分呈正相关（r=0.386， P=0.020），右侧额中回至右侧NAc增强的有效连接值与耳鸣病程亦呈正相关（r=0.390， P=0.019）。 结论： 慢性耳鸣患者大脑NAc与前额叶皮层之间定向功能连接增强。.