Nelson M D, Saykin A J, Flashman L A, Riordan H J
Department of Psychology, Dartmouth College, Hanover, NH, USA.
Arch Gen Psychiatry. 1998 May;55(5):433-40. doi: 10.1001/archpsyc.55.5.433.
Although many quantitative magnetic resonance imaging studies have found significant volume reductions in the hippocampi of patients with schizophrenia compared with those of normal control subjects, others have not. Therefore, the issue of hippocampal volume differences associated with schizophrenia remains in question.
Two meta-analyses were conducted to reduce the potential effects of sampling error and methodological differences in data acquisition and analysis. Eighteen studies with a total patient number of 522 and a total control number of 426 met the initial selection criteria.
Meta-analysis 1 yielded mean effect sizes of 0.37 (P<.001) for the left hippocampus and 0.39 (P<.001) for the right, corresponding to a bilateral reduction of 4%. Meta-analysis 2 indicated that the inclusion of the amygdala in the region of interest significantly increased effect sizes across studies (effect size for the left hippocampus and amygdala, 0.67; for the right, 0.72), whereas variables such as illness duration, total slice width, magnet strength, the use of the intracranial volume as a covariate, measurement reliability, and study quality did not. No laterality differences were observed in these data.
Schizophrenia is associated with a bilateral volumetric reduction of the hippocampus and probably of the amygdala as well. These findings reinforce the importance of the medial temporal region in schizophrenia and are consistent with frequently reported memory deficits in these patients. Future quantitative magnetic resonance imaging studies evaluating the hippocampal volume should measure the hippocampus and amygdala separately and compare the volumetric reduction in these structures to that observed in other gray matter areas.
尽管许多定量磁共振成像研究发现，与正常对照受试者相比，精神分裂症患者的海马体体积显著减小，但其他研究却未发现此现象。因此，与精神分裂症相关的海马体体积差异问题仍存在疑问。
进行了两项荟萃分析，以减少数据采集和分析中抽样误差及方法学差异的潜在影响。18项研究符合初始选择标准，其中患者总数为522例，对照总数为426例。
荟萃分析1得出，左侧海马体的平均效应量为0.37（P<0.001），右侧为0.39（P<0.001），相当于双侧减少4%。荟萃分析2表明，在感兴趣区域纳入杏仁核显著增加了各研究的效应量（左侧海马体和杏仁核的效应量为0.67；右侧为0.72），而病程、总切片宽度、磁体强度、使用颅内体积作为协变量、测量可靠性和研究质量等变量则未产生此影响。这些数据未观察到左右侧差异。
精神分裂症与海马体双侧体积减小有关，可能也与杏仁核体积减小有关。这些发现强化了内侧颞叶区域在精神分裂症中的重要性，并且与这些患者经常报告的记忆缺陷相一致。未来评估海马体体积的定量磁共振成像研究应分别测量海马体和杏仁核，并将这些结构的体积减小与其他灰质区域观察到的情况进行比较。
