Objective:Patients with early Alzheimer Disease (AD) and Mild Cognitive Impairment of the Amnestic type (MCI-A) have been reported to show large variability of tapping scores. Factors that contribute to that variability remain undetermined. This preliminary study aimed to identify predictors of finger tapping variability in older adults evaluated for a neurodegenerative memory disorder. Based on earlier research with normally functioning adults, we predicted that the number of “invalid” tapping responses (i.e. failure of the index finger to adequately lift off the tapping key once it is depressed to produce the next number on a mechanical counter) and the female gender would predict finger tapping variability, but age and educational level would not predict variability.Participants and Methods:This preliminary study included 4 groups of participants, comprised of 8 healthy controls (HC, 3 males; 73±7years); 12 persons with subjective memory complaints (SMC, 3 males; 69±5 years); 12 with MCI-A (7 males; 76±5 years) and 7 early AD (5 males; 75±6years). All participants were administered a modified version of the Halstead Finger Tapping Test (HFTT). Mean, range of tapping score (i.e. a measure of variability), and number of invalid taps across 7 trials in each hand were calculated. ANOVA was performed for the HFTT metrics with the main effect of group. Tukey HSD tests were used for post hoc comparisons between groups. Multiple regression analysis was performed to determine the degree to which the number of invalid tapping responses, sex, age, and educational level predicted finger tapping variability using all 4 groups.Results:Mean tapping score did not vary significantly across groups in the dominant [F (3, 35) = 0.633, p = 0.599] or non-dominant [F (3, 35) = 2.345, p = 0.090] hand. Range score approached a significant difference between groups in the dominant hand [F (3, 35) = 2.745, p = 0.058], with a clear significant effect of group on range score in the non-dominant hand [F (3, 35) = 4.078, p = 0.014]. Range score in the nondominant hand was significantly higher in the AD compared to SMC (p = 0.018) and HC (p = 0.024). Regression analysis revealed statistically significant findings for the dominant hand (R2 = 0.327, F (4, 34) = 4.130, p = 0.008) and for the non-dominant hand (R2 = 0.330, F (4, 34) = 4.180, p = 0.007). For both the dominant and non-dominant hands, number of invalid taps significantly predicted range score (ß = 0.453, p = 0.044, and ß = 0.498, p = 0.012, respectively). Sex, age, and education years did not predict range scores.Conclusions:Variability of finger tapping in patients evaluated for neurodegenerative memory disorders and aged matched controls is predicted by the number of invalid tapping responses (comprising over 30% of the variance), but not by demographic variables in this clinical sample. Neurodegenerative disorders may eliminate a sex effect.

中文翻译：

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评估老年人神经退行性记忆障碍手指敲击变异性的 56 个预测因素

目的：据报道，患有早期阿尔茨海默病 (AD) 和遗忘型轻度认知障碍 (MCI-A) 的患者表现出较大的敲击分数变异性。导致这种变异性的因素仍未确定。这项初步研究旨在确定老年人神经退行性记忆障碍手指敲击变异的预测因子。根据早期对正常功能成年人的研究，我们预测了“无效”敲击响应的数量（即，一旦按下敲击键以在机械计数器上产生下一个数字，食指就无法充分抬起敲击键）和女性性别可以预测手指敲击的变异性，但年龄和教育水平不能预测变异性。 参与者和方法：这项初步研究包括 4 组参与者，其中包括 8 名健康对照组（HC，3 名男性；73±7 岁）；12名有主观记忆障碍的人（SMC，3名男性；69±5岁）；12 名 MCI-A（7 名男性；76±5 岁）和 7 名早期 AD（5 名男性；75±6 岁）。所有参与者都接受了霍尔斯特德手指敲击测试（HFTT）的修改版本。计算每只手 7 次试验中的敲击分数的平均值、范围（即变异性的度量）和无效敲击次数。对 HFTT 指标进行方差分析，并以组为主效应。Tukey HSD 测试用于组间事后比较。进行多元回归分析，以确定无效敲击反应的数量、性别、年龄和教育水平预测所有 4 组的手指敲击变异性的程度。结果：在显性 [F] 中，各组之间的平均敲击分数没有显着差异。 (3, 35) = 0.633, p = 0.599] 或非优势 [F (3, 35) = 2.345, p = 0.090] 手牌。优势手的范围得分在各组之间接近显着差异 [F (3, 35) = 2.745，p = 0.058]，非优势手的群体对范围得分有明显的显着影响 [F (3, 35) = 4.078，p = 0.014]。与 SMC (p = 0.018) 和 HC (p = 0.024) 相比，AD 中非惯用手的范围得分显着更高。回归分析显示优势手 (R2 = 0.327, F (4, 34) = 4.130, p = 0.008) 和非优势手 (R2 = 0.330, F (4, 34) = 4.180, p = 0.007)。对于惯用手和非惯用手，无效敲击次数可显着预测范围得分（分别为 ß = 0.453，p = 0.044 和 ß = 0.498，p = 0.012）。性别、年龄和受教育年限不能预测范围分数。结论：接受神经退行性记忆障碍评估的患者和年龄匹配的对照患者中手指敲击的变异性是通过无效敲击反应的数量（包含超过 30% 的方差）来预测的，但是不是通过该临床样本中的人口统计变量。神经退行性疾病可能会消除性影响。