Griskova-Bulanova Inga, Voicikas Aleksandras, Dapsys Kastytis, Melynyte Sigita, Andruskevicius Sergejus, Pipinis Evaldas
Institute of Biosciences, Life Sciences Centre, Vilnius University, Saulėtekio av. 7, LT-10257 Vilnius, Lithuania.
Vilnius Republican Psychiatric Hospital, Parko str. 21, LT-11205 Vilnius, Lithuania.
Brain Sci. 2020 Dec 27;11(1):22. doi: 10.3390/brainsci11010022.
The 40 Hz auditory steady-state response (ASSR) impairment is suggested as an electrophysiological biomarker of schizophrenia; however, existing data also points to the deficiency of low and high frequency ASSR responses. In order to obtain the full picture of potential impairment in schizophrenia, it is important to test responses at different frequencies. The current study aims to evaluate a wide frequency range (1-120 Hz) in response to brief low-frequency carrier chirp-modulated tones in a group of patients with schizophrenia. The EEG-derived envelope following responses (EFRs) were obtained in a group of male patients with schizophrenia (N = 18) and matched controls (N = 18). While subjects were watching silent movies, 440 Hz carrier chirp-modulated at 1-120 Hz tones were presented. Phase-locking index and evoked amplitude in response to stimulation were assessed and compared on point-to-point basis. The peak frequency of the low gamma response was estimated. Measures were correlated with psychopathology-positive, negative, total scores of the Positive and Negative Syndrome Scale (PANSS), and hallucination subscale scores. In comparison to controls, patients showed (1) reduced power of theta-beta (4-18 Hz) responses, (2) intact but slower low gamma (30-60 Hz), and (3) reduced high gamma (95-120 Hz) responses. No correlation survived the Bonferroni correction, but a sign of positive association between low gamma phase-locking and the prevalence of hallucinations, and a sign of negative association between high gamma phase-locking and the total PANSS scores were observed. Brain networks showed impaired capabilities to generate EFRs at different frequencies in schizophrenia; moreover, even when responses of patients did not significantly differ from controls on the group level, they still showed potentially clinically relevant variability.
40赫兹听觉稳态反应（ASSR）损伤被认为是精神分裂症的一种电生理生物标志物；然而，现有数据也指出了低频和高频ASSR反应的缺陷。为了全面了解精神分裂症潜在的损伤情况，测试不同频率下的反应很重要。当前研究旨在评估一组精神分裂症患者对短暂低频载波啁啾调制音调在宽频率范围（1 - 120赫兹）内的反应。在一组男性精神分裂症患者（N = 18）和匹配的对照组（N = 18）中获取了脑电图衍生的包络跟随反应（EFRs）。当受试者观看无声电影时，呈现以1 - 120赫兹调制的440赫兹载波啁啾音调。在逐点基础上评估并比较了对刺激的锁相指数和诱发幅度。估计了低伽马反应的峰值频率。测量结果与精神病理学阳性、阴性症状量表（PANSS）的总分以及幻觉分量表得分相关。与对照组相比，患者表现出：（1）θ - β（4 - 18赫兹）反应功率降低；（2）低伽马（30 - 60赫兹）反应完整但较慢；（3）高伽马（95 - 120赫兹）反应降低。经Bonferroni校正后没有相关性存活，但观察到低伽马锁相与幻觉患病率之间存在正相关迹象，以及高伽马锁相与PANSS总分之间存在负相关迹象。大脑网络显示在精神分裂症中产生不同频率EFRs的能力受损；此外，即使患者在组水平上的反应与对照组没有显著差异，他们仍然表现出潜在的临床相关变异性。
