Clinical Emotion and Cognition Research Laboratory, Inje University, Goyang, Republic of Korea; Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
Clinical Emotion and Cognition Research Laboratory, Inje University, Goyang, Republic of Korea.
Neuroimage Clin. 2019;22:101732. doi: 10.1016/j.nicl.2019.101732. Epub 2019 Feb 21.
Abnormalities in the 40-Hz auditory steady-state response (ASSR) of the gamma range have been reported in schizophrenia (SZ) and are regarded as important pathophysiological features. Many of the previous studies reported diminished gamma oscillations in SZ, although some studies reported increased spontaneous gamma oscillations. Furthermore, brain morphological correlates of the gamma band ASSR deficits have rarely examined. We investigated different measures of the 40-Hz ASSR and their association with brain volumes and psychological measures of SZ.
The 40-Hz ASSR was measured for 80 dB click sounds (1 ms, 500-ms trains at 40-Hz, with 3050 to 3500 inter-train interval) using electroencephalography with 64 electrodes in 33 patients with SZ (male: 16, female: 17 (age range: 21-60)) and 30 healthy controls (HCs) (male: 13, female: 17 (age range: 23-64)). Four gamma oscillation measures (evoked power, spontaneous oscillations (baseline and total power), and inter-trial phase coherence (ITC)) were assessed. The source activities of the ASSR were also analyzed. Brain volumes were assessed using high-resolution magnetic resonance imaging and voxel-based morphometry and superior temporal gyrus (STG) volume measures were obtained.
Patients with SZ had larger total and evoked powers and higher ITC than HCs. Both groups showed significantly different association between mean evoked power and right STG volume. In HCs but not SZ, mean evoked power showed significant positive correlation with right STG volume. In addition, the two groups showed significantly different association between verbal fluency and mean evoked power. High evoked power was significantly correlated with poor verbal fluency in SZ.
The current study found increased gamma oscillation in SZ and suggests significant involvement of the STG in gamma oscillations.
研究发现精神分裂症（SZ）患者的 40Hz 听觉稳态响应（ASSR）γ频段存在异常，这被认为是重要的病理生理学特征。许多先前的研究报告称 SZ 患者的γ 振荡减少，尽管一些研究报告称其自发性γ 振荡增加。此外，γ 频段 ASSR 缺陷的脑形态学相关性很少被研究。我们研究了 40Hz ASSR 的不同测量方法及其与脑容量和 SZ 心理测量的关系。
使用 64 个电极的脑电图测量 80dB 点击声（1ms，500ms 时程，40Hz，3050-3500ms 时程间隔），共纳入 33 名 SZ 患者（男性 16 名，女性 17 名（年龄范围：21-60 岁））和 30 名健康对照者（HCs）（男性 13 名，女性 17 名（年龄范围：23-64 岁））。评估了 4 种γ 振荡测量方法（诱发功率、自发振荡（基线和总功率）和试验间相位相干性（ITC））。还分析了 ASSR 的源活动。使用高分辨率磁共振成像和基于体素的形态计量学评估脑容量，并获得颞上回（STG）体积测量值。
与 HCs 相比，SZ 患者的总功率和诱发功率更大，ITC 更高。两组的平均诱发功率与右侧 STG 体积之间均存在显著不同的相关性。在 HCs 中，但在 SZ 中没有，平均诱发功率与右侧 STG 体积呈显著正相关。此外，两组之间在言语流畅性与平均诱发功率之间存在显著不同的相关性。SZ 患者中高诱发功率与言语流畅性差显著相关。
本研究发现 SZ 患者的γ 振荡增加，并表明 STG 显著参与了γ 振荡。
