Department of Neurosurgery, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, USA.
Department of Psychiatry, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, USA.
Neuromodulation. 2020 Jun;23(4):478-488. doi: 10.1111/ner.13101. Epub 2020 Feb 5.
The P50, a positive auditory-evoked potential occurring 50 msec after an auditory click, has been characterized extensively with electroencephalography (EEG) to detect aberrant auditory electrophysiology in disorders like schizophrenia (SZ) where 61-74% have an auditory gating deficit. The P50 response occurs in primary auditory cortex and several thalamocortical regions. In rodents, the gated P50 response has been identified in the reticular thalamic nucleus (RT)-a deep brain structure traversed during deep brain stimulation (DBS) targeting of the ventral intermediate nucleus (VIM) of the thalamus to treat essential tremor (ET) allowing for interspecies comparison. The goal was to utilize the unique opportunity provided by DBS surgery for ET to map the P50 response in multiple deep brain structures in order to determine the utility of intraoperative P50 detection for facilitating DBS targeting of auditory responsive subterritories.
We developed a method to assess P50 response intraoperatively with local field potentials (LFP) using microelectrode recording during routine clinical electrophysiologic mapping for awake DBS surgery in seven ET patients. Recording sites were mapped into a common stereotactic space.
Forty significant P50 responses of 155 recordings mapped to the ventral thalamus, RT and CN head/body interface at similar rates of 22.7-26.7%. P50 response exhibited anatomic specificity based on distinct positions of centroids of positive and negative responses within brain regions and the fact that P50 response was not identified in the recordings from either the internal capsule or the dorsal thalamus.
Detection of P50 response intraoperatively may guide DBS targeting RT and subterritories within CN head/body interface-DBS targets with the potential to treat psychosis and shown to modulate schizophrenia-like aberrancies in mouse models.
P50 是一种正性听觉诱发电位，在听觉点击后 50ms 出现，已通过脑电图（EEG）广泛表征，以检测精神分裂症（SZ）等疾病中的异常听觉电生理学，其中 61-74%存在听觉门控缺陷。P50 反应发生在初级听觉皮层和几个丘脑皮质区域。在啮齿动物中，已在网状丘脑核（RT）中识别出门控 P50 反应-这是一种深部脑结构，在靶向丘脑腹侧中间核（VIM）的深部脑刺激（DBS）中穿过，以治疗原发性震颤（ET），允许种间比较。目标是利用 DBS 治疗 ET 手术提供的独特机会，在多个深部脑结构中绘制 P50 反应图，以确定术中 P50 检测对于促进听觉反应亚区的 DBS 靶向的实用性。
我们开发了一种方法，在七名 ET 患者的清醒 DBS 手术中，使用微电极记录在常规临床电生理图谱期间，通过局部场电位（LFP）在术中评估 P50 反应。记录部位被映射到共同的立体定向空间。
在映射到腹侧丘脑、RT 和 CN 头/体界面的 155 次记录中，有 40 次显著的 P50 反应，其发生率为 22.7-26.7%。P50 反应表现出基于脑区正、负反应质心位置的解剖特异性，以及在从内囊或背侧丘脑的记录中未识别出 P50 反应的事实。
术中 P50 反应的检测可能指导 DBS 靶向 RT 和 CN 头/体界面内的亚区-DBS 靶点具有治疗精神病的潜力，并已被证明可调节小鼠模型中的精神分裂症样异常。
