Brand Matthias, Eggers Carsten, Reinhold Nadine, Fujiwara Esther, Kessler Josef, Heiss Wolf-Dieter, Markowitsch Hans J
Department of Physiological Psychology, University of Bielefeld, P.O. Box 100131, 33501 Bielefeld, Germany.
Psychiatry Res. 2009 Oct 30;174(1):32-9. doi: 10.1016/j.pscychresns.2009.03.008. Epub 2009 Sep 23.
Dissociative amnesia is a condition usually characterized by severely impaired retrograde memory functioning in the absence of structural brain damage. Recent case studies nevertheless found functional brain changes in patients suffering from autobiographical-episodic memory loss in the cause of dissociative amnesia. Functional changes were demonstrated in both resting state and memory retrieval conditions. In addition, some but not all cases also showed other neuropsychological impairments beyond retrograde memory deficits. However, there is no group study available that examined potential functional brain abnormalities and accompanying neuropsychological deteriorations in larger samples of patients with dissociative retrograde amnesia. We report functional imaging and neuropsychological data acquired in 14 patients with dissociative amnesia following stressful or traumatic events. All patients suffered from autobiographical memory loss. In addition, approximately half of the patients had deficits in anterograde memory and executive functioning. Accompanying functional brain changes were measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Regional glucose utilization of the patients was compared with that of 19 healthy subjects, matched for age and gender. We found significantly decreased glucose utilization in the right inferolateral prefrontal cortex in the patients. Hypometabolism in this brain region, known to be involved in retrieval of autobiographical memories and self-referential processing, may be a functional brain correlate of dissociative amnesia.
分离性遗忘症是一种通常表现为在无大脑结构损伤的情况下逆行性记忆功能严重受损的病症。然而，近期的病例研究发现，患有分离性遗忘症导致自传性情景记忆丧失的患者存在大脑功能变化。在静息状态和记忆检索状态下均证实了功能变化。此外，部分（但并非全部）病例还显示出除逆行性记忆缺陷之外的其他神经心理学损伤。然而，目前尚无针对更大样本的分离性逆行性遗忘症患者的潜在大脑功能异常及伴随的神经心理学衰退情况进行研究的群体研究。我们报告了14例经历压力或创伤事件后出现分离性遗忘症患者的功能成像和神经心理学数据。所有患者均患有自传性记忆丧失。此外，约半数患者存在顺行性记忆和执行功能缺陷。通过[18F]氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）测量伴随的大脑功能变化。将患者的区域葡萄糖利用率与19名年龄和性别匹配的健康受试者进行比较。我们发现患者右侧下外侧前额叶皮质的葡萄糖利用率显著降低。已知该脑区参与自传性记忆的检索和自我参照加工，其代谢减退可能是分离性遗忘症的大脑功能相关表现。
