听觉P300电位及其法医学应用价值的研究

发布时间：2019-03-31 14:45

【摘要】： 前言认知过程是一个复杂的高级神经心理活动,涉及感知觉、注意、记忆、思维等。在法医学鉴定中,传统的CT、MRI只能提供有限的形态学信息,而各种心理学量表测定容易受到主观因素和受教育程度的影响。因此,研究脑损伤后认知功能障碍的客观评定方法具有重要意义。P300电位即受试者辨认OB刺激序列中低概率的“靶刺激”时,在头皮记录到潜伏期约为300ms的最大晚期正性波,是ERP中应用最广、与认知功能关系最为密切的成分。脑内血肿、脑挫裂伤患者P300潜伏期延长、波幅下降。脑损伤后精神障碍的患者也有类似的结果。但不同部位脑损伤与P300电位的关系研究较少,且各种高级心理活动与P300的关系尚不明确。本研究通过对正常人和脑损伤患者“主动”、“被动”听觉P300测试,研究P300波形特点及其影响因素,并分析不同部位、不同程度脑损伤患者P300潜伏期、波幅与正常人的差异及影响因素,进而为P300在评价脑损伤患者认知功能障碍程度方面寻找客观依据。试验对象与方法受试对象:正常人受试组20人,均为中国医科大学在校学生,各频率的纯音气导听阈均＜25dBHL。脑挫裂伤患者组30人,各频率的纯音气导听阈均＜25dBHL。所有患者均有明确的颅脑外伤史,脑挫裂伤的诊断由头CT及MRI片证实,检查时间距伤后6～12个月。试验方法:检查在隔音室内进行,采用国际标准规定的上升法进行纯音测听。采用NDI200—P+型多功能电生理记录仪做为描记系统,刺激信号为平台期25ms的短纯音,靶刺激频率2000Hz,出现概率20%,非靶刺激频率500Hz,出现概率80%,声音强度均为72dBHL。带通滤波设定为1～30Hz,刺激间隔1.1次/S,扫描时间为75ms,叠加50次。记录电极置于Cz点、Pz点,参考电极位于耳垂,前额正中发际下1cm处置接地电极。电极阻抗＜5kΩ,极间电阻相差＜3kΩ。试验结果 1、正常人及脑损伤患者靶刺激均可诱发出两个正相波及两个负向波,潜伏期在70～500ms之间,分别为N100、P200、N200和P300。 2、“默计数”和“踩踏板”任务状态下N200、P300波潜伏期较“被动”状态下短,波幅高。 3、Cz点、Pz点P300各波潜伏期均无显著性差异(P＞0.05)。N100、P200波幅Cz点高于Pz点(P＜0.05),N200、P300波幅Pz点略高于Cz点。 4、脑损伤患者N200、P300波潜伏期较正常人延长、波幅降低。弥漫脑挫裂伤患者N200、P300波潜伏期与其余组间具有统计学差异(P＜0.05)。 5、P300潜伏期在401ms以上的患者N200、P300波幅与300～350ms患者组间具有显著性差异(P＜0.01),注意障碍患者P300波潜伏期改变最明显。结论 1、任务类型主要影响N200、P300波幅。“被动”P300反应中N200、P300潜伏期可作为衡量受试者认知功能状态的稳定指标。 2、脑挫裂伤患者N200、P300波潜伏期延长、波幅下降,“被动”P300潜伏期可作为认知功能下降的客观敏感指标,弥漫性脑损伤患者P300波潜伏期延长最明显。 3、P300潜伏期是反映注意力、记忆及简单计算力等认知功能的综合性指标,其中,注意力与P300潜伏期联系最为密切。 4、在法医学鉴定中,“被动”P300波潜伏期是反映脑挫裂伤患者认知功能的客观指标,可作为一种客观检测手段应用于主观不配合及无法合作。
[Abstract]:foreword The cognitive process is a complex high-level neuropsychological activity, involving perception, attention, memory, thinking, In the forensic appraisal, the traditional CT and MRI can only provide limited morphological information, and the measurement of various psychological scales is easily subject to the subjective factors and the degree of education. Therefore, it is important to study the objective evaluation method of cognitive impairment after brain injury Significance. When the P300 potential is the "target stimulation" in which the subject recognizes the low probability in the OB stimulation sequence, the maximum late positive wave with a latent period of about 300 ms is recorded on the scalp, which is the most widely used in the ERP and is the most closely related to the cognitive function. Components. Intracerebral hematomas, prolonged latency of P300 in brain contusion and laceration, amplitude The number of patients with mental disorder after brain injury is similar. Results: The relationship between brain injury and P300 potential of different parts is less, and the relationship between various high-level psychological activities and P300 is not enough. In this study, the "initiative" and "passive" auditory P300 of normal and brain injury patients were tested to study the characteristics of P300 and its influencing factors, and to analyze the difference of P300 latency and amplitude of P300 in different parts and different degree of brain injury. And to find out the degree of cognitive impairment of the P300 in the evaluation of brain injury. The objective is to be found. Test object and method:20 people in the test group of the normal person, all the students of the Chinese Medical University, the pure tone of each frequency The hearing threshold is less than 25 dBHL.30 of the patients with brain contusion and laceration and the pure tone of each frequency The hearing threshold was less than 25 dBHL. All patients had a clear history of head trauma, and the diagnosis of brain contusion and laceration was confirmed by head CT and MRI. 6-12 months after the time span injury. Test method: check in the sound insulation room and use the international The standard standard is used for pure tone audiometry. The NDI200 + P + type multifunctional electrophysiology recorder is used as the plethysmographic system. The stimulation signal is a short pure tone of 25 ms in the platform period. The target stimulation frequency is 2000 Hz, the occurrence probability is 20%, the non-target stimulation frequency is 500 Hz, and the occurrence probability 80 The sound intensity is 72 dBHL. The band-pass filtering is set to 1-30 Hz, and the stimulation interval is 1.1 times/ S. The tracing time is 75 ms and the superposition is 50 times. The recording electrode is placed at the Cz point and the Pz point, and the reference electrode is located in the earlobe and the forehead. The ground electrode is disposed 1 cm below the median hairline. The electrode impedance is less than 5k惟, The difference of the inter-electrode resistance is less than 3 k惟. The results of the test show that both normal and brain injury patients can induce two negative waves with a latent period of between 70 and 500 ms, and the latency is between 70 and 500 ms. N200, P300 wave latency

for N100, P200, N200, and P300.2, "Palmer's count", and "step-on board" tasks "passive" state short, high amplitude.3, Cz point, P There was no significant difference in the latency of P300 in the z-point (P> 0.05). The amplitude Cz of the P200 in the N100 and P200 was higher than that of the Pz (P <0.05). 0.05), the amplitude Pz of the N200 and P300 is slightly higher than the Cz point.4, The latency of N200 and P300 wave in brain injury patients was prolonged and the amplitude was decreased. The patients with diffuse brain contusion and laceration were N200. The latency of P300 wave and the remaining groups had statistical difference (P <0.05). writing Difference (P <0.01), P300 wave in patients with attention disorder Conclusion 1. The type of task mainly affects the amplitude of N200 and P300. The latency of N200 and P300 in the P300 reaction can be used as a stable indicator to measure the state of the cognitive function of the subject. The latency of N200 and P300 waves in the brain contusion and laceration is prolonged, the amplitude is decreased, and the "passive" P300 The latent period of P300 wave in the patients with diffuse brain injury is the most obvious, and the latency of P300 in patients with diffuse brain injury is the most obvious. The comprehensive index of cognitive function, such as attention, memory, and simple calculation force, is most closely related to the latency of P300. In the forensic appraisal, the "passive" P300
【学位授予单位】：中国医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R741;D919

【引证文献】