阿尔茨海默病的扩瞳试验研究

Pupil dilation test for Alzheimer disease

目的 验证扩瞳试验能否用于诊断阿尔茨海默病 (AD)。方法 用非接触型双侧瞳孔红外同步记录分析仪对滴入 0 0 1%托吡卡胺后的瞳孔变化进行测定 ,并自动分析瞳孔直径扩大 (按对照侧校正 )的百分比。共测定AD患者 5 2例、血管性痴呆 (VD)患者 34例、老年精神分裂症 (S) 19例和老年健康人 (对照组 ) 5 7名。比较并找出最能明显区别AD与对照组的瞳孔扩大值 ,以此作为试验结果阳性与否的分界线。结果 AD患者的瞳孔在滴药 7～ 10min后便明显扩大 ,与VD、S或对照组的差异有非常显著性 (P <0 0 1)。如以第 18min时扩大值≥ 15 %作为分界线 ,AD、VD、S及对照组的阳性例数 /总例数分别为 :42 / 5 2、6 / 34、1/ 19和 12 / 5 7;用以诊断AD时的敏感性为 0 81,特异性为0 79～ 0 82 ,一致性Kappa值为 0 6 0～ 0 6 2。结论 扩瞳试验可以作为筛选AD的诊断标志之一 ,也可在鉴别AD与VD时作为参考。

Objective To determine whether pupil response to dilute tropicamide could be used as a diagnostic test for Alzheimer′s disease (AD) Methods Pupil diameters of both eye were measured simultaneously by an Infra red Automatic Pupil Recorder and Analyzer every 1/10 second for 30 minutes after instillation of 0 01% tropicamide to one eye and normal saline to the other Four groups of subjects were studied: 52 patients with AD, 32 patients with Vascular Dementia (VD), 19 aged patients with schizophrenia (S), and 57 aged normal controls (NC) The percent change of pupil diameter of the treated eye was comparied with control eye with the analyzer automatically After finding out the cut off point for differential diagnoes, the sensitivity, specificity and Kappa coefficient were calculated Results Mean percent change in pupil diameter of the treated eye showed a trend with faster maximzing dilation in AD group, which was significantly different from other groups at all the measurement points 10 minutes after instillation The dilation in NC group was most significant at the 18 th minute, and a percent change in pupil diameter ≥15% could be used as a cut off point for differentiation The ‘number of positive case/number of total case’ was separately: AD, 42/52; VD, 6/34; S, 1/19; and NC, 12/57 As a diagnostic tool for Alzheimer′s disease, the pupil dilation test has a sensitivity as 0 81, specificity as 0 79～0 82, and Kappa coefficient (degree of agreement) as 0 60～0 62 Conclusions Pupil dilation test might be used as a screening diagnosing tool for Alzheimer′s disease, or as a differential diagnosis tool between it and vascular dementia