記憶力衰退抱怨：失智症前兆？

Subjective Memory Complaint: An Early Sign of Dementia？

抱怨記憶力衰退是否反映一個人的記憶力改變，而可視為老年失智症的一種前兆呢？台北榮民總醫院一般神經內科分別以社區老人及門診就醫患者為對象，探討記憶力抱怨與其實際記憶力的關係及臨床上的意義。社區研究是以543位65歲及以上的老年人為對象。在間隔3年的兩次醫師診察外，每一位受訪者並作知能篩檢測驗（CASI）及簡式老年憂鬱量表（GDS－S）。門診研究是以709位56歲到96歲的就醫者為對象，除了醫師的診察外，並作了CASI及臨床失智嚴重度評估（CDR）。在作CDR時，家屬或照顧者也被單獨晤談。結果顯示，老年人有主觀記憶力抱怨的情況是非常普遍的，但主觀記憶力抱怨和實際認知能力關係並不一致。既使是在被診斷為正常的就醫者，仍有超過半數以上的人，有主觀記憶力抱怨。社區研究發現，主觀記憶力抱怨能反映出實際認知能力，但卻不能反映出一個人在過去三年或未來三年，實際認知減退與否，這也顯示記憶力衰退是一種緩慢的認知改變過程。臨床研究顯示，當記憶力退化達到失智症程度時，主觀記憶力抱怨無法反映出實際認知能力，甚至隨著失智症嚴重程度增加，患者的病識感愈少。家屬或照顧者對就醫者的認知能力有準確的評估，是臨床診察上非常重要的訊息來源。因此在作老年失智症的評估時，除了患者本身外，一定要與其家屬或照顧者晤談，才能確實了解患者日常功能是否有改變。有記憶力衰退抱怨者，得到疑似失智症或失智症的機會增加，顯示記憶力衰退抱怨是老年失智症的一種前兆，值得家屬與臨床醫療人員的重視。

Is subjective memory complaint (SMC) an early sign of dementia? In order to study the relationship between SMC and actual memory ability and the clinical significance of SMC, we studied the community elderly population and the patients from memory clinic. In community study, 543 subjects were visited twice in 1993 and 1996. In addition to neurologists’ examination, the subjects also took Cognitive Abilities Screening Instrument (CASI) and Geriatric Depression Scale-Simple Form (GDS-S) during each visit. In clinical study, 709 patients, self-referred or referred by family members to the memory clinic, were recruited. CASI and Clinical Dementia Rating (CDR) were administered to the patients, and family members or caregivers were interview independently during the CDR. Both studies indicate that SMC is very common in elderly population. In community population, SMC reflected the actual cognitive abilities, but did not reflect the actual cognitive decline in the subsequent or past three years. This suggests that the cognitive decline is a very slow process in normal aging. In clinical population, SMC did not reflect the actual cognitive abilities. Furthermore, as the severity of memory impairment increases, the self-awareness of memory impairment decreases. Family members had an accurate estimation of the patients’ memory impairment and became an important resource for evaluating the patients’ daily function. Subjects with SMC increase the possibilities in developing questionable dementia or dementia. SMC is an early sign for dementia and deserves family members’ or clinicians’ attention.