平衡功能檢查和眩暈老人跌倒發生之關聯

Abstract

目的 本研究之主要目的為分析一系列前庭功能檢查與眩暈老人發生跌倒之關聯。 方法 病患來源為自2010年3月至2011年2月於耳鼻喉科眩暈特別門診就診之患者。研究之收案條件為年齡超過60歲，並能清楚回答測試者所詢問之問題。排除條件為曾接受中耳手術、罹患惡性腫瘤、神經系統疾病及頭部外傷(近半年內)者，同時未能完成重心動搖檢查者也予以排除，計105名病患納入本研究(34名男性，71名女性，平均年齡74歲)。每位患者都接受制式化的當面訪談，並進行一系列前庭平衡功能檢查，包括注視眼振檢查、頭位與頭位變換眼振檢查、重心動搖檢查、眼振電圖檢查、及溫差測驗。並量測和記錄姿態性低血壓、認知功能、基本及工具性日常生活能力、視力及藥物使用狀況。 結果 基本及工具性日常生活能力、簡易認知功能評估的分數分別為99.8 ± 0.9, 22.8 ± 2.5, and 0.7 ± 1.0。六名受試者出現自發性眼振，47名受試者可見半規管麻痺或溫差測驗無反應；追視測驗、跳視測驗、及視運動性眼振測驗的異常率分別為58%、33%、及 52%。與跌倒相關之最重要因子為開眼硬地模式下站立，重心動搖檢查中的矩陣動搖面積 (每增加一個四分位之危險性為1.3倍，95%信賴區間: 1.1-1.6)和異常視力狀態 (危險性=15.3，95%信賴區間: 3.4-69.4)。進一步以ROC 曲線分析比較模型1(包含年齡、性別、認知功能及工具性日常生活能力)和模型2(加入重心動搖檢查、眼振電圖及溫差測驗)預測眩暈老人跌倒之能力。結果發現模型2之area under the ROC curves (AUC) 優於模型1(AUC=0.85 vs. 0.72)，達統計顯著差異 (p=0.036)。 結論 本研究發現，重心動搖儀之矩陣動搖面積與視力狀態與眩暈老人跌倒發生的關聯性最高。同時，包含平衡功能檢查的預測模型為較佳之預測模型。

Objective. The purpose of this study was to determine the association between balance function tests and falls in patients with dizzy spells aged over 60. Methods. The source population was comprised of patients visiting a vertigo special clinic from March 2010 to February 2011. Once the patient aged over sixty years old and be able to grasp verbal instructions clearly was included in this study. Exclusion criteria consisted of previous otological intervention, malignant diseases, neurological diseases, and recent head trauma (within 6 months). Those fell down or moved the feet during stabilometry were also excluded from this study. One hundred and five subjects (34 males and 71 females, aged 61-92 years, mean, 74 years) were enrolled and eligible for this study. All subjects received face-to-face structured interview first, followed by a test battery of vestibular function including gaze nystagmus test, positional test, positioning test, caloric test, electronystagmography and stabilometry under four conditions, namely, A, eyes open with firm surface; B, eyes closed with firm surface; C, eyes open with foam surface, and D, eyes closed with form surface. Orthostatic hypotension, cognition, basic and instrumental activities of daily living, medication use, and visual acuity assessment were also measured and recorded. Results. The mean baseline function scores in terms of the Barthel Index, Lawton’s Instrument Activity of Daily Living and Short Portable Mental Status Questionnaire were 99.8 ± 0.9, 22.8 ± 2.5, and 0.7 ± 1.0, respectively. Occurrence of nystagmus was observed in 6 patients. Caloric test depicted normal responses in 58 patients (55%), and canal paresis or caloric areflexia in 47 patients (45%). Abnormal rates of the pursuit, saccade and optokinetic nystagmus (OKN) tests were 58%, 33%, and 52%, respectively. For the stabilometry, increased rectal sway area during the Condition A, in which, all visual, somatosensory and vestibular inputs interact on balance provided the best parameter for predicting the falls (OR = 1.3, 95% CI = 1.1–1.6). Meanwhile, visual impairment increased the risk of falls (OR=15.3, 95% CI = 3.4-69.4). Comparison of area under ROC curves (AUCs) between the model 1 (including age, gender, cognition and instrumental activities of daily living) (0.72 [95% CI = 0.60–0.83]) and model 2 (model 1 plus stabilometry, visual acuity, and caloric, pursuit and OKN tests) (0.85 [95% CI = 0.76–0.94]) demonstrated that model 2 acts a higher ability to discriminate between aged people with and without falls (p = 0.036). Conclusion Stabilometric evaluation associated with visual acuity assessment may provide useful clinical tools to evaluate falls in the elderly with dizzy spells.