Gadian D G, Aicardi J, Watkins K E, Porter D A, Mishkin M, Vargha-Khadem F
Radiology and Physics Unit, Institute of Child Health, London, UK.
Brain. 2000 Mar;123 Pt 3:499-507. doi: 10.1093/brain/123.3.499.
We recently reported on three young patients with severe impairments of episodic memory resulting from brain injury sustained early in life. These findings have led us to hypothesize that such impairments might be a previously unrecognized consequence of perinatal hypoxic-ischaemic injury. Neuropsychological and quantitative magnetic resonance investigations were carried out on five young patients, all of whom had suffered hypoxic-ischaemic episodes at or shortly after birth. All five patients showed severe impairments of episodic memory (memory for events), with relative preservation of semantic memory (memory for facts). However, none had any of the major neurological deficits that are typically associated with hypoxic-ischaemic injury, and all attended mainstream schools. Quantitative magnetic resonance investigations revealed severe bilateral hippocampal atrophy in all cases. As a group, the patients also showed bilateral reductions in grey matter in the regions of the putamen and the ventral part of the thalamus. On the basis of their clinical histories and the pattern of magnetic resonance findings, we attribute the patients' pathology and associated memory impairments primarily to hypoxic-ischaemic episodes sustained very early in life. We suggest that the degree of hypoxia-ischaemia was sufficient to produce selective damage to particularly vulnerable regions of the brain, notably the hippocampi, but was not sufficient to result in the more severe neurological and cognitive deficits that can follow hypoxic-ischaemic injury. The impairments in episodic memory may be difficult to recognize, particularly in early childhood, but this developmental amnesia can have debilitating consequences, both at home and at school, and may preclude independent life in adulthood.
我们最近报道了三名年轻患者，他们因幼年早期脑损伤而出现严重的情景记忆障碍。这些发现使我们推测，这种障碍可能是围产期缺氧缺血性损伤以前未被认识到的后果。对五名年轻患者进行了神经心理学和定量磁共振检查，他们均在出生时或出生后不久经历过缺氧缺血发作。所有五名患者均表现出严重的情景记忆障碍（对事件的记忆），而语义记忆（对事实的记忆）相对保留。然而，他们均没有通常与缺氧缺血性损伤相关的任何主要神经功能缺损，并且都就读于主流学校。定量磁共振检查显示，所有病例均存在严重的双侧海马萎缩。作为一个群体，这些患者在壳核和丘脑腹侧区域的灰质也出现双侧减少。根据他们的临床病史和磁共振检查结果模式，我们将患者的病理状况及相关的记忆障碍主要归因于生命早期发生的缺氧缺血发作。我们认为，缺氧缺血的程度足以对大脑中特别脆弱的区域，尤其是海马体造成选择性损伤，但不足以导致缺氧缺血性损伤后可能出现的更严重的神经和认知缺陷。情景记忆障碍可能难以识别，尤其是在幼儿期，但这种发育性遗忘在家庭和学校都会产生使人衰弱的后果，并且可能妨碍成年后的独立生活。
