Ohrmann Patricia, Siegmund Ansgar, Suslow Thomas, Pedersen Anya, Spitzberg Katharina, Kersting Anette, Rothermundt Matthias, Arolt Volker, Heindel Walter, Pfleiderer Bettina
Department of Psychiatry, University of Muenster, Albert-Schweitzer Strasse 11, D-48149 Muenster, NRW, Germany.
J Psychiatr Res. 2007 Oct;41(8):625-34. doi: 10.1016/j.jpsychires.2006.07.002. Epub 2006 Sep 1.
Involvement of the prefrontal cortex in schizophrenia has been implicated by neuropsychological, as well as neuropathological and imaging studies. Reductions of N-acetylaspartate (NAA), an in vivo marker of neuronal integrity, have repeatedly been detected in the frontal lobes of patients with schizophrenia by proton magnetic resonance spectroscopy (1H-MRS). In chronic medicated patients, a positive correlation between NAA levels of the prefrontal cortex and cognitive functioning has been observed, but to date, there have been no studies in first-episode neuroleptic-naive patients. In this study, single-voxel 1H-MRS was used to investigate neuronal function of the dorsolateral prefrontal cortex in 15 first-episode and 20 chronic schizophrenic patients. Outcomes were compared to 20 age-matched healthy controls to assess the relationship between prefrontal metabolism and neuropsychological performance. Patients with chronic schizophrenia had significant reductions of NAA, glutamate/glutamine, and choline levels compared to first-episode patients and healthy controls. Furthermore, creatine and phosphocreatine were significantly reduced in both patient groups compared to healthy controls. In the neuropsychological tests, chronic schizophrenic patients performed significantly poorer in the Auditory Verbal Learning Task (AVLT) compared to first-episode patients. In both patient groups, NAA levels of the left frontal lobe significantly correlated with performances in verbal learning and memory. These results corroborate data from recent structural and spectroscopic imaging studies of the frontal lobes in schizophrenia, in which cortical gray matter reductions after onset of symptoms as well as reduced levels of NAA in chronic, but not in first-episode schizophrenic patients have been reported.
神经心理学、神经病理学及影像学研究均表明，前额叶皮质与精神分裂症有关。通过质子磁共振波谱（1H-MRS）已反复检测到，精神分裂症患者额叶中作为神经元完整性体内标志物的N-乙酰天门冬氨酸（NAA）减少。在慢性服药患者中，已观察到前额叶皮质NAA水平与认知功能之间呈正相关，但迄今为止，尚未有针对首发未服用抗精神病药物患者的研究。在本研究中，采用单体素1H-MRS对15例首发和20例慢性精神分裂症患者的背外侧前额叶皮质神经元功能进行了研究。将结果与20名年龄匹配的健康对照者进行比较，以评估前额叶代谢与神经心理表现之间的关系。与首发患者和健康对照者相比，慢性精神分裂症患者的NAA、谷氨酸/谷氨酰胺和胆碱水平显著降低。此外，与健康对照者相比，两组患者的肌酸和磷酸肌酸均显著降低。在神经心理学测试中，与首发患者相比，慢性精神分裂症患者在听觉言语学习任务（AVLT）中的表现明显较差。在两组患者中，左额叶的NAA水平与言语学习和记忆表现均显著相关。这些结果证实了近期关于精神分裂症额叶的结构和波谱成像研究数据，其中报道了症状发作后皮质灰质减少以及慢性精神分裂症患者（而非首发患者）NAA水平降低。
