Deactivation of the Parahippocampal Gyrus Preceding Auditory Hallucinations in Schizophrenia
Deactivation of the Parahippocampal Gyrus Preceding Auditory Hallucinations in Schizophrenia
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DOI：
10.1176/appi.ajp.2009.09040456
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发表时间：
2010-04-01
影响因子：
17.7
通讯作者：
Sommer, Iris E. C.
中科院分区：
文献类型：
--
作者：
Diederen, Kelly M. J.;Neggers, Sebastiaan F. W.;Sommer, Iris E. C.
目的：语言相关区域网络的激活在听觉语言幻觉中已有报道。然而，目前还不清楚这种激活是如何触发的。识别在幻听前表现出显著信号变化的大脑区域可能揭示这些幻觉的起源。方法：24名精神病患者通过挤压手持气球在3-特斯拉功能磁共振成像中指示存在听觉语言幻觉。进行了一次样本t检验，以显示GroupWise在幻觉中的激活。为了能够分析幻觉前6到0秒的大脑激活情况，进行了一种量身定制的“选择性平均”方法，而不需要任何关于血流动力学响应曲线的先验假设。为了控制与运动相关的激活，15名健康对照组受试者在匹配的时间间隔挤压气球。结果：GroupWise分析在听觉语言幻觉中发现双侧(右侧多于左侧)语言相关区域和双侧运动区的大脑激活。在出现这些幻觉之前，可以在左侧海马区旁回观察到明显的失活。此外，在左侧颞叶上回、右侧额下回和左额中回以及右侧脑岛和左侧小脑也发现有明显的先幻觉失活。在匹配的球囊挤压之前，比较对象之间没有发现明显的信号变化。结论：精神障碍患者的听觉言语幻觉始终发生在海马区旁回的失活之前。据推测，副海马体在记忆记忆中发挥中心作用，将信息从海马体发送到关联区。在产生幻听时，这一区域的功能障碍可能会导致右侧语言区域的激活不足。
Objective: Activation in a network of language-related regions has been reported during auditory verbal hallucinations. It remains unclear, however, how this activation is triggered. Identifying brain regions that show significant signal changes preceding auditory hallucinations might reveal the origin of these hallucinations.Method: Twenty-four patients with a psychotic disorder indicated the presence of auditory verbal hallucinations during 3-Tesla functional magnetic resonance imaging by squeezing a handheld balloon. A one-sample t test was performed to reveal groupwise activation during hallucinations. To enable analysis of brain activation 6 to 0 seconds preceding hallucinations, a tailored "selective averaging" method, without any a priori assumptions concerning the hemodynamic response profile, was performed. To control for motor-related activation, 15 healthy comparison subjects squeezed a balloon at matched time intervals.Results: Groupwise analysis during auditory verbal hallucinations revealed brain activation in bilateral (right more than left) language-related regions and bilateral motor regions. Prominent deactivation preceding these hallucinations was observed in the left parahippocampal gyrus. In addition, significant deactivation preceding hallucinations was found in the left superior temporal, right inferior frontal, and left middle frontal gyri as well as in the right insula and left cerebellum. No significant signal changes were revealed prior to the matched balloon squeezing among the comparison subjects.Conclusions: Auditory verbal hallucinations in patients with a psychotic disorder are consistently preceded by deactivation of the parahippocampal gyrus. The para-hippocampus has been hypothesized to play a central role in memory recollection, sending information from the hippocampus to the association areas. Dysfunction of this region could trigger inadequate activation of right language areas during auditory hallucinations.