Department of Psychiatry, Neuroscience Division, University Medical Center, Utrecht, The Netherlands.
Am J Psychiatry. 2010 Apr;167(4):427-35. doi: 10.1176/appi.ajp.2009.09040456. Epub 2010 Feb 1.
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.
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.
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.
Auditory verbal hallucinations in patients with a psychotic disorder are consistently preceded by deactivation of the parahippocampal gyrus. The parahippocampus 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.
在听觉言语幻觉期间，已报道语言相关区域网络的激活。然而，尚不清楚这种激活是如何触发的。确定在听觉幻觉之前显示出显著信号变化的脑区可能揭示这些幻觉的起源。
24 名患有精神障碍的患者在 3-Tesla 功能磁共振成像期间通过挤压手持气球来指示听觉言语幻觉的存在。进行单样本 t 检验以显示幻觉期间的组激活。为了能够在幻觉前 6 到 0 秒进行脑激活分析，采用了一种定制的“选择性平均”方法，而无需对血流动力学响应曲线进行任何先验假设。为了控制与运动相关的激活，15 名健康对照者在匹配的时间间隔内挤压气球。
听觉言语幻觉期间的组分析显示双侧（右侧多于左侧）语言相关区域和双侧运动区域的脑激活。在这些幻觉之前观察到左侧海马旁回的明显去激活。此外，在幻觉前还发现了左颞上回、右额下回和左额中回以及右岛叶和左小脑的显著去激活。在对照者中，在匹配的气球挤压之前没有发现显著的信号变化。
精神障碍患者的听觉言语幻觉始终以前海马旁回的去激活为先导。海马旁回被假设在记忆回忆中起核心作用，将信息从海马体发送到联合区域。该区域的功能障碍可能会在听觉幻觉期间触发右侧语言区域的激活不足。
