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Previous studies suggest that individuals with Williams syndrome (WS), a rare genetically based neurodevelopmental disorder, show specific weaknesses in visual attention and response inhibition within the visuospatial domain. Here we examine the extent to which impairments in attentional control extend to the visuomotor domain using a well-validated measure of choice stepping reaction time (CSRT) in individuals with WS. We examined the interaction between executive control and visually guided stepping using a verbal fluency dual-task or Go/NoGo paradigm during CSRT performance. Relationships between dual-task and inhibitory stepping and behavioural inattention and hyperactivity were also examined. Our results showed clear dual-task costs in stepping response times when performing a concurrent cognitive task in the WS group when compared to spatial and verbal ability matched typically developing controls. Although no group differences in stepping accuracy were observed between the WS and typically developing control groups, the WS group showed progressive slowing and more variable response times across the duration of the Go/NoGo task. These results suggest dysfunction in circuits involved in top-down attentional control processes in WS. These findings provide novel evidence that core executive control deficits in WS extend to the visuomotor domain, and impact on ADHD-related inattentive symptoms. (Contains 6 figures and 4 tables.)

Background Dizziness is common among older people and is associated with a cascade of debilitating symptoms, such as reduced quality of life, depression, and falls. The multifactorial aetiology of dizziness is a major barrier to establishing a clear diagnosis and offering effective therapeutic interventions. Only a few multidisciplinary interventions of dizziness have been conducted to date, all of a pilot nature and none tailoring the intervention to the specific causes of dizziness. Here, we aimed to test the hypothesis that a multidisciplinary dizziness assessment followed by a tailored multifaceted intervention would reduce dizziness handicap and self-reported dizziness as well as enhance balance and gait in people aged 50 years and over with dizziness symptoms. Methods and findings We conducted a 6-month, single-blind, parallel-group randomized controlled trial in community-living people aged 50 years and over who reported dizziness in the past year. We excluded individuals currently receiving treatment for their dizziness, those with degenerative neurological conditions including cognitive impairment, those unable to walk 20 meters, and those identified at baseline assessment with conditions that required urgent treatment. Our team of geriatrician, vestibular neuroscientist, psychologist, exercise physiologist, study coordinator, and baseline assessor held case conferences fortnightly to discuss and recommend appropriate therapy (or therapies) for each participant, based on their multidisciplinary baseline assessments. A total of 305 men and women aged 50 to 92 years (mean [SD] age: 67.8 [8.3] years; 62% women) were randomly assigned to either usual care (control; n = 151) or to a tailored, multifaceted intervention (n = 154) comprising one or more of the following: a physiotherapist-led vestibular rehabilitation programme (35% [n = 54]), an 8-week internet-based cognitive-behavioural therapy (CBT) (19% [n = 29]), a 6-month Otago home-based exercise programme (24% [n = 37]), and/or medical management (40% [n = 62]). We were unable to identify a cause of dizziness in 71 participants (23% of total sample). Primary outcome measures comprised dizziness burden measured with the Dizziness Handicap Inventory (DHI) score, frequency of dizziness episodes recorded with monthly calendars over the 6-month follow-up, choice-stepping reaction time (CSRT), and gait variability. Data from 274 participants (90%; 137 per group) were included in the intention-to-treat analysis. At trial completion, the DHI scores in the intervention group (pre and post mean [SD]: 25.9 [19.2] and 20.4 [17.7], respectively) were significantly reduced compared with the control group (pre and post mean [SD]: 23.0 [15.8] and 21.8 [16.4]), when controlling for baseline scores (mean [95% CI] difference between groups [baseline adjusted]: -3.7 [-6.2 to -1.2]; p = 0.003). There were no significant between-group differences in dizziness episodes (relative risk [RR] [95% CI]: 0.87 [0.65 to 1.17]; p = 0.360), CSRT performance (mean [95% CI] difference between groups [baseline adjusted]: -15 [-40 to 10]; p = 0.246), and step-time variability during gait (mean [95% CI] difference between groups [baseline adjusted]: -0.001 [-0.002 to 0.001]; p = 0.497). No serious intervention-related adverse events occurred. Study limitations included the low initial dizziness severity of the participants and the only fair uptake of the falls clinic (medical management) and the CBT interventions. Conclusions A multifactorial tailored approach for treating dizziness was effective in reducing dizziness handicap in community-living people aged 50 years and older. No difference was seen on the other primary outcomes. Our findings therefore support the implementation of individualized, multifaceted evidence-based therapies to reduce self-perceived disability associated with dizziness in middle-aged and older people. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12612000379819., Author(s): Jasmine C. Menant 1,2, Americo A. Migliaccio 1,3, Daina L. Sturnieks 1,4, Cameron Hicks 1, Joanne Lo 1, Mayna Ratanapongleka 1, Jessica Turner 1, Kim Delbaere 1,2, Nickolai Titov [...]

Background. Trips are the largest contributor to tails in older people, yet little is known about the underlying physiological mechanisms for safe obstacle negotiation. The aims of the study were to determine (i) the effect of a secondary visual task on obstacle contacts when older people negotiated an obstacle course and (ii) physiological factors associated with obstacle contacts. Methods. Thirty community-living adults aged 65 years and older walked along a 14.5-m walkway containing 21 obstacles with and without a secondary task. The secondary task required participants to call out a series of letters presented in front of them at head height and the suit of a playing card framed on the sidewall. Obstacle contacts, secondary task errors, eye peak-to-peak pitch amplitude and head peak-to-peak pitch amplitude (PA-H), and head angle in pitch were measured. Participants also completed assessments of sensorimotor function and balance. Results. Compared with the obstacle-only trials, participants performed the dual-task trials more slowly (p < .001), contacted more obstacles (p = .032), showed greater PA-H (p < .001), and an extended head position (p < .001). Most participants also made secondary task errors. Regression analysis revealed that depth perception was the only significant determinant of obstacle contacts (explaining 20.6% of the variance) in the obstacle-only task and that depth perception and PA-H were independent and significant determinants of obstacle contacts (explaining 42.3% of the variance) in the dual task. Conclusion. The findings demonstrate the importance of depth perception and head movement for safe negotiation of obstacles in older people and suggest that depth perception in particular should form part of fall risk assessments. Key Words: Aged--Depth perception--Gait--Dual tasks--Obstacle avoidance. doi: 10.1093/gerona/glq015

Abstract Background The objective of this study was to examine age and gender differences in seven tests of functional mobility. Methods The study included 50 young participants aged 20 to 39 years, and 684 older participants aged 75 to 98 years. Functional mobility measures included the coordinated stability test, the near tandem balance test, the six metre walk test, the sit to stand test with five repetitions, the alternate step test and the stair ascent and descent tests. Results Older participants performed significantly worse than the younger participants in all of the functional mobility tests (p < 0.001), with the older women performing worse than the older men in all of the tests (p < 0.05). Significant correlations were found within the older group among all the functional mobility tests scores (r = 0.24–0.87, p < 0.001), and between functional mobility performance and age (r = 0.14–0.35, p < 0.001). People with arthritis and stroke performed worse than people without these conditions in these tests. Conclusion This study provides a normative database for performance of young and older community-dwelling people in a battery of validated and reliable functional mobility tests. The results confirm age-related differences in functional mobility between young and older adults.