New Insights on Emotional Contributions to Human Postural Control

Previous cross-sectional studies have shown a correlation between falls and fear of falling, but it is unclear which comes first. Our objectives were to determine the temporal relationship between falls and fear of falling, and to see whether these two outcomes share predictors. A 20-month, population-based, prospective, observational study. Salisbury, Maryland. Each evaluation consisted of a home-administered questionnaire, followed by a 4- to 5-hour clinic evaluation. The 2,212 participants in the Salisbury Eye Evaluation project who had baseline and 20-month follow-up clinic evaluations. At baseline, subjects were aged 65 to 84 and community dwelling and had a Mini-Mental State Examination score of 18 or higher. Demographics, visual function, comorbidities, neuropsychiatric status, medication use, and physical performance-based measures were assessed. Stepwise logistic regression analyses were performed to evaluate independent predictors of falls and fear of falling at the follow-up evaluation, first predicting incident outcomes and then predicting fall or fear-of-falling status at 20 months with baseline falling and fear of falling as predictors. Falls at baseline were an independent predictor of developing fear of falling 20 months later (odds ratio (OR) = 1.75; P <.0005), and fear of falling at baseline was a predictor of falling at 20 months (OR = 1.79; P <.0005). Women with a history of stroke were at risk of falls and fear of falling at follow-up. In addition, Parkinson's disease, comorbidity, and white race predicted falls, whereas General Health Questionnaire score, age, and taking four or more medications predicted fear of falling. Individuals who develop one of these outcomes are at risk for developing the other, with a resulting spiraling risk of falls, fear of falling, and functional decline. Because falls and fear of falling share predictors, individuals who are at a high risk of developing these endpoints can be identified.

Despite or possibly by virtue of the fact that it is one of the most commonly used animal models of anxiety the Elevated Plus-Maze (EPM) results in a wide range of, often contradictory, results following pharmacological experiments. The responses from a questionnaire distributed to 65 groups that have published studies using the EPM in the past 3 years has, along with reference to published reports, enabled some conclusions regarding the influencing factors to be drawn. Some evidence for differential sensitivities between strains exists, with albino rats being more sensitive to the anxiolytic effects of 5-HT3 receptor antagonists and 5-HT1A receptor agonists than pigmented animals. Most important, however, is the manipulation of the animals prior to testing and the aversiveness of the test conditions themselves. Stressing animals before testing (e.g., by moving from holding to test room) or using more aversive test conditions (e.g., elevated light levels) increases sensitivity to potential anxiolytics. Animals that are habituated to gentle handling or tested in less aversive conditions (e.g., EPM with ledges) show reduced likelihood of anxiolytic responses with administration of 5-HT3 antagonists, 5-HT1A agonists, and benzodiazepines.

We studied prospectively the epidemiology, clinical impact and prediction of falls in 59 moderately affected patients with Parkinson's disease (PD) (mean UPDRS motor score 31.5; mean age 61 years) and 55 controls (mean age 60 years). At baseline, balance and gait were evaluated extensively. The retropulsion test (response to sudden shoulder pull) was executed first unexpectedly and five more times following prior warning. All persons used standardised scoring forms to document their falls during six months. Thirty patients (50.8 %) and eight controls (14.5%) fell at least once (relative risk [RR] 6.1; 95% confidence interval [CI] 2.5-15.1, p or = 2) falls occurred in 15 patients (25.4%), but in only two controls (RR 9.0; 95 % CI 2.0-41.7; p=0.001). Recurrent falls were more common among persons taking benzodiazepines (RR 5.0; 95% CI 1.6-15.5; p 100; 95% CI 3.1-585) and asking for prior falls (RR 5.0; 95% CI 1.2-20.9). We conclude that falls are common and disabling, even in relatively early stage PD. Recurrent fallers were best predicted by disease severity and presence of prior falls. Strategies to prevent falls in PD should particularly focus at intrinsic (patient-related) factors, such as minimising the use of benzodiazepines.