Department of Psychiatry and Behavioral Sciences and Neuroscience Program, Stanford University School of Medicine, Stanford, California 94305-5723, USA.
Alcohol Clin Exp Res. 2010 Mar 1;34(3):528-37. doi: 10.1111/j.1530-0277.2009.01118.x. Epub 2009 Dec 17.
Excessive sway during quiet standing is a common sequela of chronic alcoholism even with prolonged sobriety. Whether alcoholic men and women who have remained abstinent from alcohol for weeks to months differ from each other in the degree of residual postural instability and biomechanical control mechanisms has not been directly tested.
We used a force platform to characterize center-of-pressure biomechanical features of postural sway, with and without stabilizing conditions from touch, vision, and stance, in 34 alcoholic men, 15 alcoholic women, 22 control men, and 29 control women. Groups were matched in age (49.4 years), general intelligence, socioeconomic status, and handedness. Each alcoholic group was sober for an average of 75 days.
Analysis of postural sway when using all 3 stabilizing conditions versus none revealed diagnosis and sex differences in ability to balance. Alcoholics had significantly longer sway paths, especially in the anterior-posterior direction, than controls when maintaining erect posture without balance aids. With stabilizing conditions the sway paths of all groups shortened significantly, especially those of alcoholic men, who demonstrated a 3.1-fold improvement in sway path difference between the easiest and most challenging conditions; the remaining 3 groups, each showed a approximately 2.4-fold improvement. Application of a mechanical model to partition sway paths into open-loop and closed-loop postural control systems revealed that the sway paths of the alcoholic men but not alcoholic women were characterized by greater short-term (open-loop) diffusion coefficients without aids, often associated with muscle stiffening response. With stabilizing factors, all 4 groups showed similar long-term (closed loop) postural control. Correlations between cognitive abilities and closed-loop sway indices were more robust in alcoholic men than alcoholic women.
Reduction in sway and closed-loop activity during quiet standing with stabilizing factors shows some differential expression in men and women with histories of alcohol dependence. Nonetheless, enduring deficits in postural instability of both alcoholic men and alcoholic women suggest persisting liability for falling.
即使长期戒酒，慢性酒精中毒患者在安静站立时也会出现过度摆动，这是一种常见的后遗症。尚未直接测试已经戒断酒精数周到数月的男性和女性酗酒者在残余姿势不稳定和生物力学控制机制方面的程度是否存在差异。
我们使用力平台来描述姿势摆动的中心压力生物力学特征，包括在有和没有触觉、视觉和站立稳定条件下的特征，参与者包括 34 名男性酗酒者、15 名女性酗酒者、22 名男性对照组和 29 名女性对照组。各组在年龄（49.4 岁）、一般智力、社会经济地位和惯用手方面相匹配。每个酗酒组的清醒平均时间为 75 天。
在使用所有 3 种稳定条件与不使用任何稳定条件的情况下分析姿势摆动时，发现诊断和性别在平衡能力上存在差异。与对照组相比，在没有平衡辅助的情况下保持直立姿势时，酗酒者的摆动路径明显更长，尤其是在前-后方向。使用稳定条件后，所有组的摆动路径都显著缩短，尤其是酗酒男性，在最容易和最具挑战性的条件之间，摆动路径差异改善了 3.1 倍；其余 3 组，每组的改善幅度约为 2.4 倍。应用机械模型将摆动路径分为开环和闭环姿势控制系统，结果显示，酗酒男性的摆动路径特征是在没有辅助的情况下，短期（开环）扩散系数更大，通常与肌肉僵硬反应有关。有稳定因素时，所有 4 组都表现出相似的长期（闭环）姿势控制。认知能力与闭环摆动指数之间的相关性在酗酒男性中比酗酒女性更稳健。
在使用稳定因素的安静站立时，摆动和闭环活动的减少在有酒精依赖史的男性和女性中表现出一些不同的表达。尽管如此，男性和女性酗酒者姿势不稳定的持久缺陷表明仍然存在跌倒的倾向。
