Republican Research and Practice Center for Mental Health, Dolginovsky Tract, 152, 220053, Minsk, Belarus.
Department of Psychiatry and Medical Psychology, Belarusian State Medical University, Dolginovsky Tract, 152, 220053, Minsk, Belarus.
BMC Psychiatry. 2019 Apr 8;19(1):110. doi: 10.1186/s12888-019-2093-8.
Oculomotor dysfunction is one of the most replicated findings in schizophrenia. However the association between saccadic abnormalities and particular clinical syndromes remains unclear. The assessment of saccadic movements in schizophrenia patients as well as in clinical high-risk state for psychosis individuals (CHR) as a part of schizophrenia continuum may be useful in validation of saccadic movements as a possible biomarker.
The study included 156 patients who met the ICD-10 criteria for schizophrenia: 42 individuals at clinical high-risk-state for psychosis and 61 healthy controls. The schizophrenia patients had three subgroups based on the sum of the global SAPS and SANS scores: (1) patients with predominantly negative symptoms (NS, n = 62); (2) patients with predominantly positive symptoms (PS, n = 54) (3) patients with predominantly disorganization symptoms (DS, n = 40). CHR subjects were characterized by the presence of one of the groups of criteria: (1) Ultra High Risk criteria, (2) Basic Symptoms criteria or (3) negative symptoms and formal thought disorders. Horizontal eye movements were recorded by using videonystagmograph. We measured peak velocity, latency and accuracy in prosaccade, antisaccade and predictive saccade tasks as well as error rates in the antisaccade task.
Schizophrenia patients performed worse than controls in predictive, reflexive and antisaccade tasks. Oculomotor parameters of NS were different from the other groups of patients. Latencies of predictive and reflexive saccades were significantly longer than in controls only in the NS group. The accuracy of predictive saccades was also different from controls only in the NS schizophrenia group. More prominent loss of accuracy of reflexive saccades was found in the DS group and it significantly differed from the one in other groups. Participants from DS group made more errors in antisaccade task compared to NS and PS groups. CHR subjects performed worse than controls as measured by the accuracy of reflexive saccades and antisaccades.
The study confirms the existence of different relations between the symptom dimensions of schizophrenia and saccades tasks performances. Saccadic abnormalities were revealed in the clinical (schizophrenia) and pre-clinical (clinical high risk) populations that provide further evidence for assessing saccadic abnormalities as a possible neurobiological marker for schizophrenia.
眼球运动功能障碍是精神分裂症中最常见的发现之一。然而，扫视异常与特定的临床综合征之间的关联仍不清楚。评估精神分裂症患者以及精神病临床高风险状态（CHR）个体（CHR）的扫视运动作为精神分裂症连续体的一部分可能有助于验证扫视运动作为一种可能的生物标志物。
这项研究包括了 156 名符合 ICD-10 精神分裂症标准的患者：42 名处于精神病临床高风险状态的个体和 61 名健康对照者。根据全球 SAPS 和 SANS 评分总和，将精神分裂症患者分为三组：（1）主要表现为阴性症状的患者（NS，n=62）；（2）主要表现为阳性症状的患者（PS，n=54）；（3）主要表现为精神错乱症状的患者（DS，n=40）。CHR 患者的特征是符合以下一组标准：（1）超高风险标准；（2）基本症状标准；（3）阴性症状和形式思维障碍。使用视频眼动仪记录水平眼球运动。我们测量了在预知性、反射性和反向性扫视任务中的峰值速度、潜伏期和准确性，以及反向性扫视任务中的错误率。
精神分裂症患者在预知性、反射性和反向性扫视任务中的表现均不如对照组。NS 的眼动参数与其他患者组不同。仅在 NS 组中，预测性和反射性扫视的潜伏期明显长于对照组。仅在 NS 精神分裂症组中，预测性扫视的准确性也与对照组不同。在 DS 组中，反射性扫视的准确性下降更为明显，与其他组相比差异显著。与 NS 和 PS 组相比，DS 组的反向性扫视任务错误更多。与对照组相比，CHR 患者在反射性和反向性扫视的准确性方面表现更差。
本研究证实了精神分裂症的症状维度与扫视任务表现之间存在不同的关系。在临床（精神分裂症）和临床前（精神病临床高风险）人群中发现了扫视异常，这进一步证明了评估扫视异常作为精神分裂症可能的神经生物学标志物的合理性。
