Memory Clinic, Department of Geriatric Psychiatry, The Affiliated Brain Hospital of Guangzhou Medical University (Guangzhou Huiai Hospital), Guangzhou, Guangdong Province, China.
Department of Geriatric Psychiatry, The Second People's Hospital of Dali Bai Autonomous Prefecture, Dali, Yunnan Province, China.
J Alzheimers Dis. 2021;79(2):585-595. doi: 10.3233/JAD-201168.
Odor identification dysfunction occurs early in Alzheimer's disease (AD) and is considered a preclinical symptom along with subjective cognitive decline (SCD). Nevertheless, whether subjects with SCD are co-symptomatic with odor identification dysfunction remains unclear.
To compare the degree of odor identification dysfunction and assess the relation between odor identification and cognitive performance in the AD spectrum (including SCD, mild cognitive impairment (MCI), and AD).
Patients (84 SCD, 129 MCI, 52 AD) and 35 controls underwent the Sniffin' Sticks Screen 16 test and comprehensive neuropsychological examination.
Odor identification scores were progressively lower moving from normal older adult to SCD, MCI, and AD. Additionally,the proportion of odor identification dysfunction were increasingly higher in the AD spectrum (p for trend <0.001), but no significant difference was found in the proportion of subjective olfactory dysfunction. No significant correlation was found between odor identification and cognition in the normal older adults and SCD subjects, but odor identification correlated with global cognition in the MCI (r = 0.199, p = 0.033) and in the AD (r = 0.300, p = 0.036) patients. Multiple linear regression showed that odor identification dysfunction was most strongly associated with memory among different cognitive subdomains and was most strongly associated with immediate verbal recall among different memory subdomains.
Odor identification dysfunction is already present with SCD and deepens with disease severity in the AD spectrum, and it may contribute to predicting cognitive decline and identifying SCD subjects who are at risk of developing AD.
嗅觉识别功能障碍在阿尔茨海默病（AD）早期发生，被认为是与主观认知下降（SCD）一起的临床前症状。然而，SCD 患者是否与嗅觉识别功能障碍共病尚不清楚。
比较嗅觉识别障碍的程度，并评估 AD 谱（包括 SCD、轻度认知障碍（MCI）和 AD）中嗅觉识别与认知表现之间的关系。
患者（84 例 SCD、129 例 MCI、52 例 AD）和 35 例对照者接受了 Sniffin' Sticks 测试 16 项测试和全面的神经心理学检查。
嗅觉识别评分从正常老年人到 SCD、MCI 和 AD 逐渐降低。此外，AD 谱中嗅觉识别障碍的比例逐渐升高（趋势 p<0.001），但主观嗅觉障碍的比例无显著差异。在正常老年人和 SCD 患者中，嗅觉识别与认知之间无显著相关性，但在 MCI（r=0.199，p=0.033）和 AD（r=0.300，p=0.036）患者中，嗅觉识别与整体认知相关。多元线性回归显示，嗅觉识别障碍与不同认知领域的记忆关系最密切，与不同记忆领域的即时言语回忆关系最密切。
嗅觉识别功能障碍在 SCD 中已经存在，并在 AD 谱中随着疾病严重程度的加深而加深，它可能有助于预测认知下降和识别有发生 AD 风险的 SCD 患者。
