Cutson T M, Gray S L, Hughes M A, Carson S W, Hanlon J T
Geriatric Research, Education, Clinical Center, Durham Veterans' Affairs Medical Center, North Carolina, USA.
J Am Geriatr Soc. 1997 Apr;45(4):435-40. doi: 10.1111/j.1532-5415.1997.tb05167.x.
This study examines the effect of a single dose of diazepam on a spectrum of balance measures in healthy older subjects. The measures include static (postural sway), dynamic (anterior tibialis muscle activation latency), and a complex self-initiated task of balance (functional reach) in addition to neuropsychological tests of attention.
A double-blind, two-period, cross-over trial.
The community surrounding a university hospital.
Community-dwelling, nonsmoking volunteers 65 years of age and older.
Measures included response to unexpected perturbation (platform/EMG muscle latency), self-initiated perturbation (functional reach), and a static measure of balance (postural sway). Neurocognitive tests (digital symbol substitution test, card sorting) were included to document the cognitive effect.
Twelve nonsmoking healthy subjects (average age = 70.4 years (66-76 years)) participated. The anterior tibalis muscle latency increased in response to a sudden perturbation with diazepam compared with placebo (TA latency 149 ms vs 142 ms, P < .001). Neurocognitive tests were adversely affected for 90 minutes after diazepam administration compared with placebo (P < .05). Other measures did not demonstrate significant effect of diazepam.
This is among the first reports showing that benzodiazepines affect neuromuscular processing related to balance control. Increased muscle latency to sudden perturbations may represent an effect of diazepam upon the oligosynaptic spinal reflex distinct from the sedation. Surface electromyography may be a valuable noninvasive tool for future studies of drug effect on balance and falls risk among older people.
本研究考察单剂量地西泮对健康老年受试者一系列平衡指标的影响。这些指标包括静态（姿势摆动）、动态（胫前肌激活潜伏期）以及一项复杂的自发平衡任务（功能性伸展），此外还包括注意力的神经心理学测试。
双盲、两阶段、交叉试验。
大学医院周边社区。
65岁及以上居住在社区的非吸烟志愿者。
测量指标包括对意外扰动的反应（平台/肌电图肌肉潜伏期）、自发扰动（功能性伸展）以及平衡的静态测量指标（姿势摆动）。纳入神经认知测试（数字符号替换测试、卡片分类）以记录认知效应。
12名非吸烟健康受试者（平均年龄 = 70.4岁（66 - 76岁））参与研究。与安慰剂相比，地西泮使突然扰动时胫前肌潜伏期增加（胫前肌潜伏期149毫秒对142毫秒，P < .001）。与安慰剂相比，地西泮给药后90分钟神经认知测试受到不利影响（P < .05）。其他指标未显示地西泮有显著影响。
这是首批表明苯二氮䓬类药物影响与平衡控制相关的神经肌肉处理的报告之一。对突然扰动的肌肉潜伏期增加可能代表地西泮对寡突触脊髓反射的作用，与镇静作用不同。表面肌电图可能是未来研究药物对老年人平衡和跌倒风险影响的一种有价值的非侵入性工具。
