精神分裂症阳性症状与脑质子波谱及事件相关电位的相关性

目的:探讨阳性症状为主型精神分裂症患者前额叶和丘脑氢质子磁共振波谱(1H-MRS)与事件相关电位的相关性。方法:78例7d内未使用抗精神病药及影响脑内乙酰胆碱神经递质药阳性症状为主型精神分裂症患者(研究组)及56名正常对照(对照组)。研究组在入组24h内采用多体素1H-MRS检测前额叶和丘脑生化代谢物N-乙酰基天门冬氨酸(NAA)、胆碱复合物(Cho)与肌酸复合物(Cr),计算NAA/Cr和Cho/Cr值;同时检测事件相关电位P300(P300)和听觉诱发电位(AEP),并与对照组进行比较。结果:研究组NAA/Cr值左侧前额叶、左侧丘脑均低于对照组,差异有统计学意义(1.40±0.35)vs(1.60±0.39),t=3.11,P<0.01;(1.48±0.33)vs(1.64±0.36),t=2.50,P<0.05]。研究组P300靶刺激P3(Cz、FPz)、非靶刺激NP3(Cz、FPz)与AEPP2(FPz)的潜伏期均高于对照组,靶刺激P3(Cz、FPz)、非靶刺激NP3(Cz、FPz)及AEPN1-P2(Cz、FPz)波幅均低于对照组,差异均有统计学意义(P<0.05或P<0.01)。研究组左侧前额叶NAA/Cr值与Cz点的P3潜伏期呈负相关(r=-0.32,P<0.05),与P3、N1-P2波幅呈正相关(r=0.32、0.34,P均<0.05);与FPz点P3、NP3、P2潜伏期呈负相关(r=-0.37、-0.40、-0.41,P均<0.01),与P3、NP3、N1-P2波幅呈正相关(r=0.33、0.33、0.35,P均<0.05)。结论:阳性症状为主型精神分裂症患者左侧前额叶NAA代谢失衡与认知功能损害有关,低水平的NAA浓度可能是认知功能损害的发病机制之一。

Relative study of proton magnetic resonance spectroscopy in brain and event-related potential in positive subtype schizophrenics

Objective:To explore the relationship between metabolic measures in prefrontal lobe and thalamus by proton magnetic resonance spectroscopy(1H-MRS) and event-related potential in positive subtype schizophrenics.Method:78 schizophrenics who met with medicine-free for at least 7 days and 56 normal controls were assessed in this study.A multi-voxel 1H-MRS was given to all the subjects on prefrontal lobe and thalamus within 24 hours they got in hospital.The NAA,Cho and Cr were measured,and the ratios of NAA/Cr,Cho/Cr were determined.They were also received event-related potential P300(P300) and auditory evoked potential(AEP).Results:Compared with controls,the patients demonstrated significantly lower NAA/Cr ratio both in left prefrontal lobe(1.40±0.35/1.60±0.39,t=3.11,P<0.01) and in left thalamus(1.48±0.33/1.64±0.36,t=2.50,P<0.05).And they also showed heightened latency of target waves P3(Cz,FPz),non-target NP3(Cz,FPz) of P300,and P2(FPz) of AEP,and shortened amplitude of target P3(Cz,FPz),non-target NP3(Cz,FPz) of P300,and N1-P2(Cz,FPz) of AEP(P<0.05).The NAA/Cr ratio in left prefrontal lobe was significantly negatively related with the latency of P3(Cz,FPz),NP3(FPz) of P300,and P2(FPz) of AEP(P<0.05),and positively related with the amplitude of P3(Cz,FPz),NP3(FPz),and N1-P2(Cz,FPz)(P<0.05).Conclusion:Abnormalities of NAA in left prefrontal lobe may be the root cause of cognition dysfunction in positive subtype schizophrenics.