Ferrarelli Fabio, Sarasso Simone, Guller Yelena, Riedner Brady A, Peterson Michael J, Bellesi Michele, Massimini Marcello, Postle Bradley R, Tononi Giulio
Department of Psychiatry, University of Wisconsin-Madison, USA.
Arch Gen Psychiatry. 2012 Aug;69(8):766-74. doi: 10.1001/archgenpsychiatry.2012.147.
Converging evidence from electrophysiological studies suggests that in individuals with schizophrenia, electroencephalographic frontal fast oscillations are reduced. It is still unclear whether this reduction reflects an intrinsic deficit of underlying cortical/thalamocortical circuits and whether this deficit is specific for frontal regions. Recent electrophysiological studies in healthy individuals have established that, when perturbed, different brain regions oscillate at a specific, intrinsically generated dominant frequency, the natural frequency.
To assess the natural frequency of the posterior parietal, motor, premotor, and prefrontal cortices in patients with schizophrenia and healthy control subjects.
High-density electroencephalographic recordings during transcranial magnetic stimulation of 4 cortical areas were performed. Several transcranial magnetic stimulation–evoked electroencephalographic oscillation parameters, including synchronization, amplitude, and natural frequency, were compared across the schizophrenia and healthy control groups.
Wisconsin Psychiatric Institute and Clinic, University of Wisconsin–Madison.
Twenty patients with schizophrenia and 20 age-matched healthy control subjects.
High-density electroencephalographic measurements of transcranial magnetic stimulation–evoked activity in 4 cortical areas, scores on the Positive and Negative Syndrome Scale, and performance scores (reaction time, accuracy) on 2 computerized tasks (word memory [Penn Word Recognition Test] and facial memory [Penn Facial Memory Test]).
Patients with schizophrenia showed a slowing in the natural frequency of the frontal/prefrontal regions compared with healthy control subjects (from an average of a 2-Hz decrease for the motor area to an almost 10-Hz decrease for the prefrontal cortex). The prefrontal natural frequency of individuals with schizophrenia was slower than in any healthy comparison subject and correlated with both positive Positive and Negative Syndrome Scale scores and reaction time on the Penn Word Recognition Test.
These findings suggest that patients with schizophrenia have an intrinsic slowing in the natural frequency of frontal cortical/thalamocortical circuits, that this slowing is not present in parietal areas, and that the prefrontal natural frequency can predict some of the symptoms as well as the cognitive dysfunctions of schizophrenia.
电生理研究的汇聚证据表明，精神分裂症患者的脑电图额叶快速振荡减少。目前尚不清楚这种减少是否反映了潜在皮质/丘脑皮质回路的内在缺陷，以及这种缺陷是否特定于额叶区域。最近对健康个体的电生理研究表明，当受到干扰时，不同的脑区会以特定的、内在产生的主导频率振荡，即自然频率。
评估精神分裂症患者和健康对照者顶叶后部、运动区、运动前区和前额叶皮质的自然频率。
在对4个皮质区域进行经颅磁刺激期间进行高密度脑电图记录。比较了精神分裂症组和健康对照组的几个经颅磁刺激诱发的脑电图振荡参数，包括同步性、振幅和自然频率。
威斯康星大学麦迪逊分校威斯康星精神病学研究所和诊所。
20名精神分裂症患者和20名年龄匹配的健康对照者。
4个皮质区域经颅磁刺激诱发活动的高密度脑电图测量、阳性和阴性症状量表得分以及两项计算机任务（单词记忆[宾夕法尼亚单词识别测试]和面部记忆[宾夕法尼亚面部记忆测试]）的表现得分（反应时间、准确性）。
与健康对照者相比，精神分裂症患者额叶/前额叶区域的自然频率减慢（从运动区平均降低2赫兹到前额叶皮质几乎降低10赫兹）。精神分裂症患者的前额叶自然频率比任何健康对照者都慢，并且与阳性和阴性症状量表得分以及宾夕法尼亚单词识别测试中的反应时间相关。
这些发现表明，精神分裂症患者额叶皮质/丘脑皮质回路的自然频率存在内在减慢，这种减慢在顶叶区域不存在，并且前额叶自然频率可以预测精神分裂症的一些症状以及认知功能障碍。
