Stevens Madelyn N, Baudhuin Jacqueline E, Hullar Timothy E
Department of Otolaryngology-Head and Neck Surgery, Washington University in St. Louis, St. Louis, Mo., USA.
Audiol Neurootol. 2014;19(6):370-7. doi: 10.1159/000363214. Epub 2014 Nov 12.
Cochlear implantation is a highly effective intervention for hearing loss, but insertion of an implant into the cochlea is often accompanied by loss of residual hearing function. Sometimes, postoperative testing also shows loss of function in the semicircular canals or otolith organs. The effect of this loss on equilibrium, particularly in the short term following surgery, and the risk of falling due to this loss is unknown. We prospectively measured balance in 16 consecutive adult cochlear implant patients before and 2 weeks after surgery. Subjects stood on a foam pad with eyes closed, feet together and arms at the side. The length of time over which this posture could be maintained was recorded up to a maximum value of 30 s indicating normal performance. Ten of 16 subjects reached a maximal time on preoperative testing. Nine of 16 subjects lost balance function after surgery. Four of the 10 subjects with normal preoperative balance function lost function. Subjects older than the age of 60 were more likely to lose balance function than younger subjects. We used previously published values relating balance performance on foam to risk of falling to calculate the fall risk among our subjects. The relative risk of falling increased after surgery by more than threefold in some patients. Imbalance after cochlear implantation may be much more common, particularly in the short term, than previously appreciated. This imbalance is accompanied by an increased risk of falling in many patients. Careful preoperative counseling before implantation and postoperative therapeutic intervention to improve comfort and reduce the chance of falling may be warranted, particularly in patients at a risk for injuries from falls (level of evidence: 2b).
人工耳蜗植入是一种治疗听力损失的高效干预手段，但将植入物插入耳蜗时往往会伴随着残余听力功能的丧失。有时，术后测试还显示半规管或耳石器官功能丧失。这种功能丧失对平衡的影响，尤其是在术后短期内，以及由此导致跌倒的风险尚不清楚。我们前瞻性地测量了16例连续成年人工耳蜗植入患者术前和术后2周的平衡能力。受试者闭目站在泡沫垫上，双脚并拢，双臂垂于身体两侧。记录能保持这种姿势的最长时间，最长30秒表示正常表现。16名受试者中有10名在术前测试中达到最长时间。16名受试者中有9名在术后失去平衡功能。术前平衡功能正常的10名受试者中有4名失去了功能。60岁以上的受试者比年轻受试者更易失去平衡功能。我们使用先前发表的关于在泡沫垫上平衡表现与跌倒风险的数值来计算我们研究对象的跌倒风险。在一些患者中，术后跌倒的相对风险增加了三倍多。人工耳蜗植入后的失衡可能比之前认为的更为常见，尤其是在短期内。这种失衡在许多患者中伴随着跌倒风险的增加。植入前进行仔细的术前咨询以及术后进行治疗干预以提高舒适度并降低跌倒几率可能是必要的，尤其是对于有跌倒受伤风险的患者（证据级别：2b）。
