Emma Stack

Predicting Fallers in a Community-Based Sample of People with Parkinson’s Disease

Background: The risk of people with Parkinson’s disease (PD) falling is greater than that of the general population but to date, disease-specific predictors of falling have not been identified. Objectives: To identify one or more features, which would predict individuals at risk of falling during a 3-month prospective follow-up study. Method: A battery of standardised tests administered in the home and the laboratory with a 3-month follow-up telephone interview. Results: Sixty-three people with PD were recruited from GP practices. Eleven interview variables and six gait laboratory variables were used with subsamples (55 and 44 subjects, respectively) to fit predictive models for identifying future fallers. The number of falls in the previous year was the most important variable, without exception, to be selected as a predictor in various logistic regression models. A history of two or more falls had a sensitivity of 86.4% (95% CI 67.3–96.2%) and a specificity of 85.7% (95% CI 71.2–94.2%) in predicting falling in the next 3 months. Conclusion: Healthcare workers should be asking their patients with PD regularly and carefully about falling, and should consider instigating programmes of fall management for patients with PD who have fallen two or more times in the previous 12 months.

The circumstances of falls among people with Parkinson's disease and the use of Falls Diaries to facilitate reporting

Purpose. Falls are common in Parkinsons disease (PD). Falls Diaries are one way of recording fall frequency and the surrounding circumstances; completing them encourages recall, and their content focuses intervention. We reviewed the diaries completed by people with PD during a randomized controlled trial (RCT) of fall prevention to ascertain the key circumstances surrounding falls. Method. We asked independently mobile, cognitively intact people with a diagnosis of PD to maintain a Falls Diary throughout a six-month RCT. We sent monthly diary sheets on which to answer questions about the ‘Location’, ‘Fall-related activity’, ‘Perceived cause’, ‘Landing’ and ‘Consequences’ of every fall. We coded responses and counted frequencies. Results. Of the 142 RCT participants (mean age 72 years; mean years since diagnosis 8), 135 completed the trial and their diary. We excluded 11 (8%) for missing data and/or unintelligible writing. The 124 remaining diaries recorded 639 falls: 80% happened at home, commonly in bedrooms, living areas, kitchens and gardens. Fallers had been ambulant in 45% of events, standing in 32% and transferring in 21%. Six ‘activity-cause combinations’ accounted for 55% of falls (tripping 13%; freezing, festination and retropulsion 11%; and postural instability when bending or reaching 9%, transferring 8%, walking 7% and washing or dressing 7%). Misjudgement and distraction played a part in 12% of falls described. Conclusions. Of over 600 falls surveyed, most happened at home, provoked by postural instability, tripping and freezing. Environmental adaptation and cognitive training should be trialled in falls prevention in PD, plus or minus traditional movement rehabilitation. Most participants completed Falls Diaries successfully. We advocate diary use, with follow-up interviews, in research and clinically. People with handwriting difficulty may require a typed diary, proxy diarist or interview.

Interference between balance, gait and cognitive task performance among people with stroke living in the community

Purpose. To explore differences in cognitive-motor interference between people with stroke and controls when performing functional tasks and to compare dual task performance of stroke fallers and non-fallers. Method. Thirty-six people with stroke (mean age 66.5, SD 11.8, mean time since onset 16 months, range 7 – 56) and 24 controls (mean age 62.3, SD 11.61) performed balance and gait tasks in isolation and in conjunction with a cognitive task (remembering a seven item-shopping list). Three-dimensional movement analysis was used to assess anterior posterior (AP) and lateral (ML) sway; 5 m walk time, stride length and velocity. Results. In the single task condition, people with stroke had greater AP sway, reduced velocity and stride length and a longer 5 m walk time than controls (p < 0.01). In the dual task condition, sway reduced and gait slowed in both groups (p < 0.01 for AP sway, stride length, velocity, walk time); only the increase in walk time was greater in people with stroke than in the controls (F = 4.2, p = 0.046). Cognitive performance was maintained during the balance trials but deteriorated during the dual task gait trials in people with stroke (p = 0.017). Similar trends were noted for fallers and non-fallers with stroke: Only group effects for stride length and velocity reached significance (p < 0.05) and only the reduction in stride length was significantly greater among fallers than non-fallers (F = 12.3, p = 0.001). Conclusions. People with stroke and controls employed similar strategies during the simultaneous performance of simple functional and silent cognitive tasks and maintained postural stability. Increased walk time and decreased cognitive recall were greater for people with stroke and reduced stride length distinguished fallers from non-fallers.

A pilot study of attention deficits, balance control and falls in the subacute stage following stroke

Objectives: To (1) identify and monitor changes in deficits of attention and balance in the subacute stage following stroke, (2) investigate fall events, (3) explore relationships between deficits of attention, balance and falling post stroke. Design: A prospective observational study. Setting: Hospitalized patients with stroke were recruited from a rehabilitation ward. Subjects: Fourteen subjects were recruited, 13 subjects (age 21–80 years) completed all assessments. Ten had right and three had left hemispheric lesions. Eight subjects were male. Main outcome measures: Subjects were assessed on two occasions during a six-week period. Standardized tests were used to measure unilateral visual neglect, sustained and selective attention and balance. Fall histories were collected by chart review and semi-structured interview. Results: At the initial assessment six subjects had sustained auditory attention deficit, eight had deficits of auditory selective attention, 12 had visual selective attention deficits and seven subjects presented with visual inattention. Scores for visual inattention and visual selective attention improved over time (p = 0.006, p = 0.026 respectively) as did scores for balance control (p = 0.001). Auditory selective attention scores at the first assessment were found to correlate with measures of balance (p < 0.01), subjects with normal attention scores achieved better balance scores. Four subjects fell at least once during the six weeks. Scores for attention and balance of fallers were not found to be significantly different from the scores of nonfallers. Conclusions: The sample size was small but high levels of attention deficit were identified. Findings suggest a weak or no relationship between attention deficits and falls. Further studies are required to explore the extent of attention deficits post stroke and its impact on balance control and falling.

Developing methods to evaluate how people with Parkinson's Disease turn 180°: an activity frequently associated with falls

Purpose: To develop a test that identified fallers from their turning strategies, as people with Parkinsons Disease (PD) commonly fall turning. Method: We compared (1) Turn Types demonstrated when turning 180° during the Timed Up and Go Test (TUG Test) by 19 non-fallers and 29 fallers (median age 71) and (2) Turn Types, Turning Steps, Heelstrike, Stability and the Use of Space and Support demonstrated when turning 180° during an everyday activity by 15 non-fallers and 26 fallers (median age 75). Turns were rated from video by observers blinded to group. Inter-observer agreement was tested. Results: Similar proportions of fallers and non-fallers demonstrated multiple-step Turn Types during the TUG Test (69% v 58%; p = 0.433) and the everyday activity (66% vs. 46%; p = 0.241). When turning, similar proportions of each group lacked Heelstrike, lost Stability and used the available Space and Support (p > 0.7); Turning Step counts were also similar (p = 0.891). Inter-observer agreement proved acceptable except for Turn Type during everyday activity (Kappa = 0.46). Conclusions: The anticipated differences between fallers and non-fallers were not identified, perhaps obscured by insufficiently or overly challenging protocols and/or the compensations deployed by fallers. Further methodological development is needed in the analysis of fall-related activities with high-risk groups.

Dysfunctional turning in Parkinson’s disease

Purpose. People with Parkinsons disease (PD) frequently freeze or fall turning: They turn slowly taking numerous steps. We aimed to describe more fully the differences observed on turning between people with and without PD, in particular the extent of left-right asymmetry and the correlations between turning and age, balance and PD severity, using a simple clinical test. Method. Twenty-eight people with PD (median age 71; median years since diagnosis eight) and 12 controls (median age 70) performed the video-based Standing Start 180° Turn Test. We counted turning steps (n), evaluated turn time (sec), type and quality (0 – 5, based on independence, ground clearance, stability, continuity and posture) and calculated the 95% limits of left-right agreement. Results. The groups differed (p < 0.004) on step count (medians 4.5 vs. 3), time (2.3 sec vs. 1.7 sec) and quality (4 vs. 5). In the PD group, 75% turned ‘on-the-spot’ and differences turning left and right were marked (e.g., 95% upper limit for step count 6.6). Among controls, 42% turned ‘on-the-spot’ and turning was symmetrical (e.g., 95% upper limit for step count 1.7). Step count was most closely correlated with self-assessed disability in PD (r = 0.67; p = 0.001) and with age among controls (r = 0.87; p = 0.001). Conclusions. People having difficulty turning are likely to have trouble with many everyday activities and thus may benefit from rehabilitation. Directional asymmetry in turning is easily identifiable and future studies should explore its diagnostic value.

Impaired bed mobility and disordered sleep in Parkinson's disease.

The contribution of impaired mobility to disordered sleep in Parkinsons disease (PD) remains uncertain. We evaluated the sleep of 38 people with PD and observed their turning strategies. Most reported difficulty maintaining sleep and difficulty turning. Those who hip‐hitched rated themselves more disabled and those who sat up had more severe PD than those who used support. Using multiple strategies was associated with sleep disturbance. As the ability to turn deteriorates, we recommend patients identify the single strategy least disruptive to sleep. Research must address whether improving mobility improves sleep quality.

Psychometric Properties of 3 Functional Mobility Tests for People With Parkinson Disease

Background Standardized outcome measures with high clinical utility are of paramount importance for clinical practice. Objective The purpose of this study was to examine interrater and intrarater reliability, construct validity, discriminant ability, and smallest detectable differences of the sit-to-stand test (STS), Timed “Up & Go” Test (TUG), and bed mobility test for people with Parkinson disease (PD). Design A cross-sectional, psychometric evaluation study was conducted. Methods A group of individuals with PD (PD group) and a group of individuals who were healthy (control group) were recruited through local PD groups and assessed in a movement laboratory in their “on” phase. Measurements of time to perform one STS, TUG, and bed mobility test were collected based on video recordings of that single performance. Results Thirty-eight individuals with PD (Hoehn and Yahr stages I–IV) and 19 age-matched control participants were recruited. Intraclass correlation coefficients for interrater and intrarater reliability for the PD group ranged from .95 to .99. Bland-Altman plots showed mean differences close to zero and narrow confidence intervals. Construct validity was established by means of moderate to good Spearman rho correlation coefficients with part III of the Unified Parkinsons Disease Rating Scale and the Hoehn and Yahr stage (range=.51–.63). Timings of all tests discriminated participants in the PD group from those in the control group and participants in the PD group in Hoehn and Yahr stages I and II from those in Hoehn and Yahr stages III and IV but did not discriminate “nonfallers” or those with single falls from repeat “fallers” or “nonfreezers” from “freezers.” Applicable smallest detectable differences were established. Limitations The results are not generalizable to people in the late stage of PD (Hoehn and Yahr stage IV: n=3). Conclusions Timings of video recordings of 3 functional mobility tests with high clinical utility showed good psychometric properties for community-dwelling, ambulatory people with PD.

Sequence and onset of whole-body coordination when turning in response to a visual trigger: Comparing people with Parkinson's disease and healthy adults

Turning round is a routine everyday activity that can often lead to instability. The purpose of this study was to investigate abnormalities of turning among people with Parkinsons disease (PwPD) through the measurement of sequence of body segments and latency response. Participants were asked to turn 180° and whole-body movements were recorded using CODAmotion and Visio Fast eye tracking equipment. Thirty-one independently mobile PwPD and 15 age-matched healthy controls participated in the study. We found that contrary to common belief, the head preceded movement of all other body segments (eyes, shoulders, pelvis, first and second foot). We also found interaction between group and body segment (P=0.005), indicating that overall, PwPD took longer to move from head to second foot than age-matched healthy controls. For PwPD only, interactions were found between disease severity and body segment (P<0.0001), between age group and body segment (P<0.0001) and between gender and body segments (P<0.0001). For each interaction, longer time periods were noted between moving the first foot after the pelvis, and moving the second foot after the first, and this was noted for PwPD in Hoehn and Yahr stage III-IV (in comparison to Hoehn and Yahr stage I-II); for PwPD who were under 70 years (in comparison with 70 years or over); and for ladies (in comparison with men). Our results indicate that in PwPD and healthy elderly, turning-on-the-spot might not follow the top-to-bottom approach we know from previous research.

Slow Down and Concentrate: Time for a Paradigm Shift in Fall Prevention among People with Parkinson’s Disease?

Introduction. We know little about how environmental challenges beyond home exacerbate difficulty moving, leading to falls among people with Parkinsons (PwP). Aims. To survey falls beyond home, identifying challenges amenable to behaviour change. Methods. We distributed 380 questionnaires to PwP in Southern England, asking participants to count and describe falls beyond home in the previous 12 months. Results. Among 255 responses, 136 PwP (diagnosed a median 8 years) reported falling beyond home. They described 249 falls in detail, commonly falling forward after tripping in streets. Single fallers (one fall in 12 months) commonly missed their footing, walking, or changing position and recovered to standing alone or with unfamiliar help. Repeat fallers (median falls, two) commonly felt shaken or embarrassed and sought medical advice. Very frequent fallers (falling at least monthly; median falls beyond home, six) commonly fell backward, in shops and after collapse but often recovered to standing alone. Conclusion. Even independently active PwP who do not fall at home may fall beyond home, often after tripping. Falling beyond home may result in psychological and/or physical trauma (embarrassment if observed by strangers and/or injury if falling backwards onto a hard surface). Prevention requires vigilance and preparedness: slowing down and concentrating on a single task might effectively prevent falling.