Brown L J E, McGrory S, McLaren L, Starr J M, Deary I J, Maclullich A M J
Geriatric Medicine Unit, University of Edinburgh, Edinburgh, UK.
J Neurol Neurosurg Psychiatry. 2009 Jun;80(6):594-9. doi: 10.1136/jnnp.2008.169078. Epub 2009 Feb 22.
Delirium is a neuropsychiatric disorder characterised by severe cognitive impairment, but the specific neuropsychological profile of this condition has not yet been clearly delineated. Psychiatric symptoms of perceptual disturbance--such as hallucinations, illusions and misperceptions--are common in delirium, suggesting that patients may have deficits in the cognitive systems underlying visual perception.
Five neuropsychological tests of visual perception were administered to 17 older patients with delirium, as well as to two control groups comprising 14 patients with Alzheimer's dementia and 18 cognitively normal patients. The Mini Mental State Examination and the Consortium to Establish a Registry for Alzheimer's Disease verbal memory test were also administered to assess the specificity of any perceptual impairments.
Patients with delirium scored significantly lower than cognitively normal patients on all perceptual tasks and significantly lower than patients with dementia on three of these tasks. Mini Mental State Examination scores did not differ between the delirium and dementia groups, and patients with delirium showed significantly better verbal recognition performance than those with dementia.
Patients with delirium have specific visual perceptual deficits that cannot be accounted for by general cognitive impairment. These novel findings provide insights into the neural mechanisms underling delirium and might help to improve clinical detection and management of the disorder. The results also support previous suggestions that cognitive perceptual deficits play a causal role in eliciting psychiatric symptoms of perceptual disturbance.
谵妄是一种以严重认知障碍为特征的神经精神疾病，但这种疾病具体的神经心理学特征尚未明确界定。谵妄中常见感知觉障碍的精神症状，如幻觉、错觉和错误感知，这表明患者在视觉感知的认知系统中可能存在缺陷。
对17名老年谵妄患者以及两个对照组进行了五项视觉感知神经心理学测试，两个对照组分别包括14名阿尔茨海默病痴呆患者和18名认知正常的患者。还进行了简易精神状态检查和阿尔茨海默病注册登记协会言语记忆测试，以评估任何感知障碍的特异性。
谵妄患者在所有感知任务上的得分显著低于认知正常的患者，在其中三项任务上的得分显著低于痴呆患者。谵妄组和痴呆组的简易精神状态检查得分没有差异，且谵妄患者的言语识别表现显著优于痴呆患者。
谵妄患者存在特定的视觉感知缺陷，这不能用一般认知障碍来解释。这些新发现为谵妄的神经机制提供了见解，可能有助于改善该疾病的临床检测和管理。研究结果还支持了之前的观点，即认知感知缺陷在引发感知觉障碍的精神症状中起因果作用。
