The Association between Balance Function Tests and Falls among the Elderly with Dizzy Spells

• Main Authors: Chun-Hsiang Chang, 張淳翔
• Other Authors: Yung-Ling Leo Lee
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/77325365199764856109

碩士 === 國立臺灣大學 === 流行病學與預防醫學研究所 === 99 === 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.