A Randomized Controlled Trial to Reduce Falls in People With Parkinson's Disease.

BACKGROUND: Falls are common and disabling in people with Parkinson's disease (PD). There is a need to quantify the effects of movement rehabilitation on falls in PD. OBJECTIVE: To evaluate 2 physical therapy interventions in reducing falls in PD. METHODS: We randomized 210 people with PD to 3 groups: progressive resistance strength training coupled with falls prevention education, movement strategy training combined with falls prevention education, and life-skills information (control). All received 8 weeks of out-patient therapy once per week and a structured home program. The primary end point was the falls rate, recorded prospectively over a 12 month period, starting from the completion of the intervention. Secondary outcomes were walking speed, disability, and quality of life. RESULTS: A total of 1547 falls were reported for the trial. The falls rate was higher in the control group compared with the groups that received strength training or strategy training. There were 193 falls for the progressive resistance strength training group, 441 for the movement strategy group and 913 for the control group. The strength training group had 84.9% fewer falls than controls (incidence rate ratio [IRR] = 0.151, 95% CI 0.071-0.322, P < .001). The movement strategy training group had 61.5% fewer falls than controls (IRR = 0.385, 95% CI 0.184-0.808, P = .012). Disability scores improved in the intervention groups following therapy while deteriorating in the control group. CONCLUSIONS: Rehabilitation combining falls prevention education with strength training or movement strategy training reduces the rate of falls in people with mild to moderately severe PD and is feasible.

Determinants of health-related quality of life in people with Parkinson's disease: a path analysis.

PURPOSE: To identify the demographic factors, impairments and activity limitations that contribute to health-related quality of life (HRQOL) in people with idiopathic Parkinson's disease (PD). METHOD: Two hundred and ten individuals with idiopathic PD who participated in the baseline assessment of a randomized clinical trial were included. The Parkinson's Disease Questionnaire-39 summary index was used to quantify HRQOL. In order to provide greater clarity regarding the determinants of HRQOL, path analysis was used to explore the relationships between the various predictors in relation to the functioning and disability framework of the International Classification of Functioning model. RESULTS: The two models of HRQOL that were examined in this study had a reasonable fit with the data. Activity limitations were found to be the strongest predictor of HRQOL. Limitations in performing self-care activities contributed the most to HRQOL in Model 1 (ß = 0.38; p < 0.05), while limitations in functional mobility had the largest contribution in Model 2 (ß = -0.31; p < 0.0005). Self-reported history of falls was also found to have a significant and direct relationship with HRQOL in both models (Model 1 ß = -0.11; p < 0.05; Model 2 ß = -0.21; p < 0.05). CONCLUSIONS: Health-related quality of life in PD is associated with self-care limitations, mobility limitations, self-reported history of falls and disease duration. Understanding how these factors are inter-related may assist clinicians focus their assessments and develop strategies that aim to minimize the negative functional and social sequelae of this debilitating disease.

Protocol for a home-based integrated physical therapy program to reduce falls and improve mobility in people with Parkinson's disease.

BACKGROUND: The high incidence of falls associated with Parkinson's disease (PD) increases the risk of injuries and immobility and compromises quality of life. Although falls education and strengthening programs have shown some benefit in healthy older people, the ability of physical therapy interventions in home settings to reduce falls and improve mobility in people with Parkinson's has not been convincingly demonstrated. METHODS/DESIGN: 180 community living people with PD will be randomly allocated to receive either a home-based integrated rehabilitation program (progressive resistance strength training, movement strategy training and falls education) or a home-based life skills program (control intervention). Both programs comprise one hour of treatment and one hour of structured homework per week over six weeks of home therapy. Blinded assessments occurring before therapy commences, the week after completion of therapy and 12 months following intervention will establish both the immediate and long-term benefits of home-based rehabilitation. The number of falls, number of repeat falls, falls rate and time to first fall will be the primary measures used to quantify outcome. The economic costs associated with injurious falls, and the costs of running the integrated rehabilitation program from a health system perspective will be established. The effects of intervention on motor and global disability and on quality of life will also be examined. DISCUSSION: This study will provide new evidence on the outcomes and cost effectiveness of home-based movement rehabilitation programs for people living with PD. TRIAL REGISTRATION: The trial is registered on the Australian and New Zealand Clinical Trials Registry (ACTRN12608000390381).

Health-related quality of life and strain in caregivers of Australians with Parkinson's disease: an observational study.

BACKGROUND: The relationship between health-related quality of life (HRQoL) in people with Parkinson's disease and their caregivers is little understood and any effects on caregiver strain remain unclear. This paper examines these relationships in an Australian sample. METHODS: Using the generic EuroQol (EQ-5D) and disease-specific Parkinson's Disease Questionnaire-39 Item (PDQ-39), HRQoL was evaluated in a sample of 97 people with PD and their caregivers. Caregiver strain was assessed using the Modified Caregiver Strain Index. Associations were evaluated between: (i) caregiver and care-recipient HRQoL; (ii) caregiver HRQoL and caregiver strain, and; (iii) between caregiver strain and care-recipient HRQoL. RESULTS: No statistically significant relationships were found between caregiver and care-recipient HRQoL, or between caregiver HRQoL and caregiver strain. Although this Australian sample of caregivers experienced relatively good HRQoL and moderately low strain, a significant correlation was found between HRQoL of people with PD and caregiver strain (rho 0.43, p < .001). CONCLUSION: Poor HRQoL in people with PD is associated with higher strain in caregivers. Therapy interventions may target problems reported as most troublesome by people with PD, with potential to reduce strain on the caregiver.

Feasibility, safety, and compliance in a randomized controlled trial of physical therapy for Parkinson's disease.

Both efficacy and clinical feasibility deserve consideration in translation of research outcomes. This study evaluated the feasibility of rehabilitation programs within the context of a large randomized controlled trial of physical therapy. Ambulant participants with Parkinson's disease (PD) (n = 210) were randomized into three groups: (1) progressive strength training (PST); (2) movement strategy training (MST); or (3) control ("life skills"). PST and MST included fall prevention education. Feasibility was evaluated in terms of safety, retention, adherence, and compliance measures. Time to first fall during the intervention phase did not differ across groups, and adverse effects were minimal. Retention was high; only eight participants withdrew during or after the intervention phase. Strong adherence (attendance >80%) did not differ between groups (P = .435). Compliance in the therapy groups was high. All three programs proved feasible, suggesting they may be safely implemented for people with PD in community-based clinical practice.

Falls and mobility in Parkinson's disease: protocol for a randomised controlled clinical trial.

BACKGROUND: Although physical therapy and falls prevention education are argued to reduce falls and disability in people with idiopathic Parkinson's disease, this has not yet been confirmed with a large scale randomised controlled clinical trial. The study will investigate the effects on falls, mobility and quality of life of (i) movement strategy training combined with falls prevention education, (ii) progressive resistance strength training combined with falls prevention education, (iii) a generic life-skills social program (control group). METHODS/DESIGN: People with idiopathic Parkinson's disease who live at home will be recruited and randomly allocated to one of three groups. Each person shall receive therapy in an out-patient setting in groups of 3-4. Each group shall be scheduled to meet once per week for 2 hours for 8 consecutive weeks. All participants will also have a structured 2 hour home practice program for each week during the 8 week intervention phase. Assessments will occur before therapy, after the 8 week therapy program, and at 3 and 12 months after the intervention. A falls calendar will be kept by each participant for 12 months after outpatient therapy.Consistent with the recommendations of the Prevention of Falls Network Europe group, three falls variables will be used as the primary outcome measures: the number of fallers, the number of multiple fallers and the falls rate. In addition to quantifying falls, we shall measure mobility, activity limitations and quality of life as secondary outcomes. DISCUSSION: This study has the potential to determine whether outpatient movement strategy training combined with falls prevention education or progressive resistance strength training combined with falls prevention education are effective for reducing falls and improving mobility and life quality in people with Parkinson's disease who live at home. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12606000344594.

Central gait control mechanisms and the stride length - cadence relationship.

The stride length - cadence relationship (SLCrel) was investigated to explore a theory of two alternate but inter-related pathways for gait control. Sixty-three healthy people in three age groups walked along a computerized walkway (GAITRite(®)) at five self-selected speeds from very slow to very fast, five cadences from 70 to 150 steps/min and five stride lengths from 0.8 to 1.6m. The data points from two walks in each level of each condition were examined for linear and quadratic relationships. In the self-selected speed condition 97% of participants had a positive linear or quadratic relationship of R(2)≥0.90. The quadratic relationships showed stride length decreased with very high cadences. When walks with cadences above 150 steps/min were removed, 95% of participants had a positive linear relationship of R(2)≥0.90. No age-related differences were found in slope or intercept of linear relationships or in maximum, minimum or range of stride length or cadence in the self-selected speed condition. In the cadence and stride length conditions, only 32% and 14% of positive linear or quadratic relationships were R(2)≥0.90. The near-invariant SLCrel, unaffected by ageing that exists for nearly all individuals when walking at self-selected speeds, indicates that the SLCrel may be used to simplify central control of automatic gait in healthy individuals. The current investigation also provides SLCrel data for healthy people which can be compared with patient populations.

Cost effectiveness of preventing falls and improving mobility in people with Parkinson disease: protocol for an economic evaluation alongside a clinical trial.

BACKGROUND: Cost of illness studies show that Parkinson disease (PD) is costly for individuals, the healthcare system and society. The costs of PD include both direct and indirect costs associated with falls and related injuries. METHODS: This protocol describes a prospective economic analysis conducted alongside a randomised controlled trial (RCT). It evaluates whether physical therapy is more cost effective than usual care from the perspective of the health care system. Cost effectiveness will be evaluated using a three-way comparison of the cost per fall averted and the cost per quality adjusted life year saved across two physical therapy interventions and a control group. CONCLUSION: This study has the potential to determine whether targetted physical therapy as an adjunct to standard care can be cost effective in reducing falls in people with PD. TRIAL REGISTRATION: No: ACTRN12606000344594.

Head and trunk rotation during walking turns in Parkinson's disease.

Head and trunk axial rotation during walking to align with a new path are integral components of direction change (turning). Turning is problematic in people with Parkinson's disease (PD), who appear to move en-bloc when turning and when walking straight. Axial rotation has been little investigated in this group. Accordingly, head, thorax, and pelvis rotation relative to the laboratory axes (global rotation) was investigated in 10 patients with PD and 10 matched comparison subjects when walking straight and when turning 60 and 120 degrees . Data were selected at three footfalls before and three after a pole denoting the corner. Although rotation was reduced overall in patients with PD, final differences were minimized by rotation commencing at an earlier step in the patient group. When rotation was measured at various distances relative to the corner, the patient group demonstrated greater rotation than their peers. In support of clinical observations, patients constrained thorax and pelvis closely together around the corner, while control subjects maintained a pattern of reciprocal oscillation when turning. Stride length reduction appears to contribute more to inefficient turning in PD than under-scaled amplitude of rotation.

Footstep adjustments used to turn during walking in Parkinson's disease.

Turning during walking is frequently problematic in Parkinson's disease (PD). The spatiotemporal characteristics of footstep adjustments used to turn 60 and 120 degrees were examined in 10 people with PD and 10 age, gender- and height-matched control subjects, using three-dimensional motion analysis. Control subjects used a recognizable pattern of spatial and temporal footstep modulations to turn. Participants with PD demonstrated significant differences in almost all variables. They (1) failed to turn as far as their peers; (2) showed a similar but scaled-down pattern of spatial adjustments to turn; (3) used shorter strides when walking, with exaggerated reductions when turning; and (4) demonstrated small but significant temporal differences in step time adjustments. Group differences were more marked for the larger turn. Spatial results, interpreted in light of hypothesized basal ganglia dysfunction, are consistent with a normal motor command but impaired ability to maintain movement amplitude. Differences in adjustment of step time to turn may reflect impaired locomotor timing control in subjects with PD during challenging gait tasks.

The sequence effect and gait festination in Parkinson disease: contributors to freezing of gait?

Festination and freezing of gait (FOG) are poorly understood gait disorders that cause disability and falls in people with Parkinson disease (PD). In PD, basal ganglia malfunction leads to motor set deficits (hypokinesia), while altered motor cue production leads to a sequence effect, whereby movements becomes progressively smaller as in festination. We suggest both factors may contribute to FOG. Disturbance of set maintenance by the basal ganglia in PD has previously been examined in gait, but limited systematic evaluation of the sequence effect exists. In this study, we investigated the step-to-step amplitude relationship in 10 PD subjects with clinical evidence of festination and FOG. Four conditions were examined: off levodopa, off with attentional strategies, off with visual cues, and on levodopa. Participants demonstrated a sequence effect (F = 6.24; P = 0.001), which was reversed only by use of visual cues. In contrast, medication, attentional strategies, and visual cues all improved hypokinesia. Variability was marked both within and between participants in all conditions. The variability of FOG is suggested to relate to a combination of factors, including the sequence effect and its variability, as well as the severity of hypokinesia and its response to medications.

Three-dimensional gait biomechanics in Parkinson's disease: evidence for a centrally mediated amplitude regulation disorder.

We examined whether people with Parkinson's disease (PD) have a central amplitude regulation disorder using three-dimensional (3-D) gait analyses to compare the effects of medication and attentional strategies on gait in 12 PD subjects and 12 matched comparison subjects. Subjects with PD first performed several 10-m gait trials at preferred speed while off levodopa. They then walked at preferred speed on levodopa; off levodopa with cues; and on levodopa with cues. Control subjects walked at preferred speed and then with visual cues to match their stride length to PD values. As well as spatiotemporal footstep data, pelvic and lower limb kinematic profiles and angle-angle diagrams were produced for sagittal, coronal, and transverse plane movements using a 3-D motion analysis system. In people with PD, decreased step length was accompanied by reduced movement amplitude across all lower limb joints, in all movement planes. When control subjects were required to walk with short steps matched to the size of PD comparisons, they displayed a similar multijoint reduction in amplitude. For PD subjects, both levodopa and visual cues increased movement amplitude across all lower limb joints. Amplitude increased further when levodopa and visual cues were combined, resulting in normalization of step length. This finding suggested that reduced step length is due to a mismatch between cortically selected movement amplitude and basal ganglia maintenance mechanisms. Levodopa and cues normalized amplitude across all joints by altering motor set and bypassing defective basal ganglia mechanisms.

Effects of age on balance control during walking.

OBJECTIVE: To determine the effects of aging on balance control during walking. DESIGN: Two-group repeated-measures design. SETTING: Gait laboratory in Australia. PARTICIPANTS: Convenience sample of 20 healthy older subjects (mean age, 72y) and 20 healthy young subjects (mean age, 24y). INTERVENTIONS: Changes in locomotor performance in response to perturbations to balance were quantified for healthy older adults compared with healthy young adults for (1) straight line walking at preferred speed, (2) straight line walking at fast speed, (3) figure-of-eight walking at preferred speed, and (4) figure-of-eight walking while performing a secondary motor task. MAIN OUTCOME MEASURES: Gait speed, stride length, cadence, and double-limb support duration, using a footswitch system. RESULTS: Healthy older people screened for pathology had gait patterns comparable to young adults for straight line walking at preferred speed. However, multivariate analysis of variance (MANOVA) showed a significant interaction between age and speed when balance was perturbed by requiring subjects to change from walking at preferred to fast speeds (Pillai-Bartlett trace=.259, F(4,35)=3.06, P<.029, partial eta(2)=.259). This occurred because older people did not increase their speed (F(1,38)=7.65, P<.01, partial eta(2)=.168) or stride length (F(1,38)=12.23, P<.01, partial eta(2)=.243) as much as did the young adults. MANOVAs did not show statistically significant interactions between age and turning conditions or age and dual task conditions, although older people walked more slowly and with shorter steps when turning or performing a secondary task. CONCLUSIONS: Balance strategies during gait are task specific and vary according to age. In response to challenges to balance imposed by the requirement to change from preferred to fast walking, older people did not increase their speed and stride length to the same extent as did younger adults. This was possibly a strategy to maintain their stability.

Deep brain stimulation of the subthalamic nucleus in Parkinson's disease.

OBJECTIVE: To evaluate the effects of bilateral deep brain stimulation in the subthalamic nucleus for symptomatic relief of advanced idiopathic Parkinson's disease. DESIGN: Prospective cohort study. SETTING: Patients were assessed and received medical treatment at the Kingston Centre, Southern Health, Melbourne. Surgery took place at Melbourne Neuroscience Centre, The Royal Melbourne Hospital. Both are tertiary public institutions. SUBJECTS: 14 patients with Parkinson's disease with intact cognition and difficult to manage motor symptoms who were referred to Kingston Centre between 1996 and 2000 and were eligible for surgical intervention. INTERVENTIONS: All patients were assessed both after 12 hours' withdrawal from and while taking their levodopa medication on two occasions before surgery. Further assessments were carried out one, three, six and 12 months after surgery. MAIN OUTCOME MEASURES: The Unified Parkinson's Disease Rating Scale motor exam and gait parameters, such as stride length and velocity, were compared at six months after surgery with neither stimulation nor medication, with stimulation only, with medication only, and with stimulation and medication. RESULTS: Stimulators were explanted in one patient after intracranial haemorrhage and relocated to the thalamus in a second. Extraneous factors prevented two patients from attending at six-month follow-up. Motor performance improved significantly with stimulation alone in the 10 remaining patients. Further significant gains were seen with stimulation and medication combined, with an apparent reduction in side-effects such as dyskinesia. CONCLUSIONS: Bilateral deep brain stimulation of the subthalamic nucleus significantly improves motor performance in advanced Parkinson's disease, despite a rather high complication rate.