Fall risk and gait in Parkinson's disease: The role of the LRRK2 G2019S mutation

Patients with Parkinson's disease (PD) who carry the G2019S mutation (a glycine to serine substitution at amino acid 2019) in the leucine‐rich repeat kinase 2 (LRRK2) gene are generally believed to be clinically indistinguishable from patients with sporadic PD. There are, however, conflicting reports on the relationship between the mutation and the motor phenotype. We quantitatively compared gait and mobility in patients with PD carriers of the G2019S mutation to non‐carrier patients with PD to better understand the genotype‐phenotype relationship. Fifty patients with PD carriers of the G2019S LRRK2 mutation and 50 age, disease duration, and disease severity matched PD non‐carriers were studied. An accelerometer quantified gait under three walking conditions: usual‐walking, dual‐tasking, and fast‐walking. The Unified Parkinson's Disease Rating Scale classified patients into PD sub‐types and the Timed Up and Go quantified mobility and fall risk. In all three walking conditions, gait variability was larger and the walking pattern was less consistent among the PD mutation carriers (P < 0.016). The PD carriers also took longer to complete the Timed Up and Go (P = 0.011) and were more likely to report having fallen in the previous year (P = 0.018). 64% of the PD carriers were classified as belonging to the postural‐instability‐gait‐difficulty (PIGD) sub‐type compared to only 17% of the PD non‐carriers (P < 0.0001). Among patients with PD, the G2019S mutation in the LRRK2 gene is apparently associated with increased gait variability, an increased fall risk, and the PIGD sub‐type. Therapeutic approach specifically designed to delay gait disturbances and falls may be justified in patients who carry the G2019S mutation. © 2013 International Parkinson and Movement Disorder Society     

Assessment of dual tasking has no clinical value for fall prediction in Parkinson’s disease

The objective of this study is to investigate the value of dual-task performance for the prediction of falls in patients with Parkinson’s disease (PD). Two hundred sixty-three patients with PD (H&Y 1–3, 65.2?±?7.9?years) walked two times along a 10-m trajectory, both under single-task and dual-task (DT) conditions (combined with an auditory Stroop task). To control for a cueing effect, Stroop stimuli were presented at variable or fixed 1- or 2-s intervals. The auditory Stroop task was also performed alone. Dual-task costs were calculated for gait speed, stride length, stride time, stride time variability, step and stride regularity, step symmetry and Stroop composite scores (accuracy/reaction time). Subsequently, falls were registered prospectively for 1?year (monthly assessments). Patients were categorized as non-recurrent fallers (no or 1 fall) or recurrent fallers (>1 falls). Recurrent fallers (35%) had a significantly higher disease severity, lower MMSE scores, and higher Timed “Up & Go” test scores than non-recurrent fallers. Under DT conditions, gait speed and stride lengths were significantly decreased. Stride time, stride time variability, step and stride regularity, and step symmetry did not change under DT conditions. Stroop dual-task costs were only significant for the 2-s Stroop interval trials. Importantly, recurrent fallers did not show different dual-task costs compared to non-recurrent fallers on any of the gait or Stroop parameters. These results did not change after correction for baseline group differences. Deterioration of gait or Stroop performance under dual-task conditions was not associated with prospective falls in this large sample of patients with PD.     

Identifying fallers with Parkinson's disease using home‐based tests: Who is at risk?

The objective of this work is to determine risk factors for falling in patients with Parkinson's disease (PD) using home‐based assessments and develop a prediction model. Data on falls, balance, gait‐related activities, and nonmotor symptoms were obtained from 153 PD patients (Hoehn‐Yahr 2–4) in their home. Fifty‐one candidate determinants for falling were independently tested using bivariate logistic regression analysis. A multivariate logistic regression model was developed to identify patients susceptible to falls. Sixty‐six subjects (43%) were classified as fallers. Eighteen determinants for falling were selected. The final multivariate model showed an accuracy of 74% and included: (1) Freezing of Gait Questionnaire, (2) Timed Get Up and Go (TGUG) score, (3) disease duration, (4) item 15 of the Unified Parkinson's Disease Rating Scale. Based on disease duration, freezing symptoms, walking problems, and a prolonged TGUG duration, assessed in the home situation, it was possible to accurately identify 74% of PD patients as fallers. © 2008 Movement Disorder Society     

A home-based resistance-training program using elastic bands for elderly patients with orthostatic hypotension

Falls are a common hazard in the elderly. Orthostatic hypotension (OH) is prevalent in older patients and contributes to the high incidence of falls. Our aim was to test whether a home-based resistance-training program (HBRT) using elastic resistance bands could safely and effectively increase muscle strength and functional ability, and attenuate the orthostatic fall in blood pressure. Eight subjects (> 60 yrs) underwent orthostatic provocations; muscle strength testing (isometric and dynamic), and a functional test of gait and mobility (Timed Up & Go), at baseline and following 8 weeks of training. Ten exercises were assigned and customized to each participant. At 8 weeks, significant increases occurred in dynamic strength in the chest press (p = 0.017), quadriceps extension (p = 0.017), and leg press (p = 0.025); no significant differences occurred in isometric strength or in blood pressures. Functional mobility increased in 7 of 8 subjects. There were no falls during the investigation period.Conclusion A HBRT program using elastic resistance bands effectively increases dynamic muscle strength in elderly individuals with OH. Although no changes occurred in orthostatic blood pressures, which could be attributed to the limited length of the program, this therapy may be recognized as a safe method to improve strength, functional ability, and promote physical activity – variables that can reduce the incidence of falls and enhance the quality of life in this population.     

Freezing of Gait Questionnaire: validity and reliability of the Swedish version

Background – Patient‐reported assessments of freezing of gait (FOG) in Parkinson’s disease (PD), such as the FOG questionnaire (FOGQ), are needed because FOG is difficult to assess objectively. However, the measurement properties of the FOGQ have been sparsely assessed. Aim – To assess the measurement properties of the Swedish FOGQ, and to explore relationships between FOGQ scores and other aspects of PD. Methods – Thirty‐seven people with PD were assessed with the FOGQ, Unified PD Rating Scale (UPDRS), Hoehn and Yahr (HY), Falls‐Efficacy Scale [FES(S)], timed gait tests, and the SF‐36 physical functioning (PF) scale. Results – Mean (SD) FOGQ item scores ranged between 1.3 and 2.1 (1.2–1.5); corrected item–total correlations ranged between 0.80 and 0.94. Reliability was 0.95. Mean (SD) and median (q1–q3) FOGQ scores were 9.6 (7.4) and 10 (2–15). Floor and ceiling effects were ≤5.4%. FOGQ correlated strongest with UPDRS part II (ADL), UPDRS item 14 (freezing), and HY (r_S 0.65–0.66). FOGQ scores correlated with PD duration, the Timed Up and Go test, dyskinesia, motor fluctuations, FES(S), and PF scores (r_S 0.40–0.62). Fallers had higher FOGQ scores than non‐fallers (median 12.5 vs 5.0). Conclusion – Data support the measurement properties of the Swedish FOGQ by replicating and extending previous psychometric reports.     

Orthostatic hypotension,balance and falls in Parkinson's disease

Orthostatic hypotension (OH) is a common feature in Parkinson's disease (PD). As the control of balance and gait is already affected by PD per se, OH may further predispose patients to falls and accidents. The study was conducted to evaluate the clinical correlates of OH and its association with mobility and balance in PD. From a total population of 205,000 inhabitants, 120 PD patients were included in the study. Medical data including history of recent falls were collected, and patients were clinically examined using the orthostatic test, the Timed Up & Go test, walking speed, and the quantitative measurement of postural sway. Sixty‐three (52.5%) patients had OH in the orthostatic test. Twenty‐five (39.5%) patients with and 16 (28.1%) patients without OH (P = 0.614) had fallen during the past 3 months. Patients with OH had significantly increased postural sway in standing compared with patients without OH. However, OH was not associated with mobility or walking speed. The current results support the concept that the control of body balance and OH may be closely linked. © 2009 Movement Disorder Society     

Serum levels of brain-derived neurotrophic factor correlate with motor impairment in Parkinson’s disease

The brain-derived neurotrophic factor (BDNF) is a potent inhibitor of apoptosis-mediated cell death and neurotoxin-induced degeneration of dopaminergic neurons. There is a growing body of evidence implicating BDNF in the pathogenesis of Parkinson’s disease (PD), suggesting it may eventually be used in the development of neuroprotective therapies for PD. The serum BDNF of 47 PD patients and of 23 control subjects was assessed, and serum BNDF levels were significantly decreased in PD patients when compared with controls (p = 0.046). Interestingly enough, BDNF correlated positively with a longer time span of the disease, as well as with the severity of the PD symptoms and with more advanced stages of the disease. Additionally, higher BDNF levels also correlated with poor balance as assessed by the Berg Balance Scale, more time spent at the Timed Up & Go Test, reduced speed of gait and shorter distance walked during the Six-Minute Walk Test. Our results corroborate the literature regarding the involvement of BDNF in PD. We hypothesize that lower BDNF levels in early stages of the disease may be associated with pathogenic mechanisms of PD. The increase of BDNF levels with the progression of the disease may be a compensatory mechanism in more advanced stages of PD.     

Measuring gait and gait-related activities in Parkinson's patients own home environment: a reliability, responsiveness and feasibility study

The aim of this study was to assess reliability, responsiveness and feasibility of gait and gait related tests in the home of patients with Parkinson's disease (PD). The Unified Parkinson's Disease Rating Scale, a timed walking test, the Timed Get Up and Go test the Berg Balance Scale and the Functional Reach test were applied by three independent observers on 26 PD patients. Moderate to high Intraclass Correlation Coefficients were found, ranging from 0.74 to 0.88 and 0.64 to 0.87 for the intra- and inter-observer reliability, respectively. All test showed Reliable Change Indexes under 11% and the whole test battery was applicable within 30 min.     

Can the Wii Fit Balance Board be Used as a Fall Risk Assessment Tool among Poststroke Patients?

BackgroundThe prevalence of falls can be as high as 73% in the stroke population. Falls occur as a result of multiple factors. Factors such as balance impairments can be improved through physical therapy intervention. However, insurance payers limit the number of visits per patient. It is crucial to find other ways to assess balance after discharge from rehabilitation.PurposeThe purpose of this study is to determine if the Nintendo Wii Fit can be used as a fall risk assessment tool among the poststroke population.MethodologyA sample of 11 stroke survivors were recruited (mean age 63.36 years). Each participant completed a balance and fall risk assessment using the Berg Balance Scale, Timed Up & Go, Four Square Step Test, Five Times Sit-to-Stand and 8-Foot Walk Test. Bivariate correlation will examine the validity of the Nintendo Wii Fit as a fall risk assessment tool in this population.ResultsThe Nintendo Wii Fit Balance Test was found to be correlated with gait speed measured by the 8-Foot Walk Test. There is no correlation between the Wii Fit Balance Tests and most common standardized fall risk measures. Standardized fall risk outcome measures also significantly correlate with each other.ConclusionsThe study suggests that while there is a potential utility of the game system to be used at home by patient and caregivers, the Wii Fit Balance Test may not be an appropriate substitute to the standardized fall risk assessment tool for stroke patients in the clinical setting.     

Involvement of specific executive functions in mobility in Parkinson's disease

Postural instability and gait disorders (PIGD) in Parkinson's disease (PD) seem to be associated with executive dysfunction. We investigated which specific executive functions are associated with functional mobility in mildly affected PD patients. Functional mobility (Timed Up&Go Test, TUG), PIGD score, (spatial) working memory, set shifting, response inhibition and response generation were assessed in a large cohort of 232 non-demented PD patients. Both performance on the TUG and PIGD score were weakly associated with working memory and response generation (semantic and phonemic fluency). TUG also correlated with semantic fluency when corrected for disease severity and age. These results indicate that response generation and working memory are associated with (and possibly also causally related to) gait and balance deficits. In order to fully interpret gait and postural stability of PD patients in everyday situations, the role of impairments in working memory and response generation should be taken into account.     

Can dual-task paradigms predict Falls better than single task? – A systematic literature review

With about one third of adults aged 65 years and older being reported worldwide to fall each year, and an even higher prevalence with advancing age, aged-related falls and the associated disabilities and mortality are a major public health concern. In this context, identification of fall risk in healthy older adults is a key component of fall prevention. Since dual-task outcomes rely on the interaction between cognition and motor control, some studies have demonstrated the role of dual-task walking performance or costs in predicting future fallers. However, based on previous reviews on the topic, (1) discriminative and (2) predictive powers of dual tasks involving gait and a concurrent task are still a matter of debate, as is (3) their superiority over single tasks in terms of fall-risk prediction. Moreover, less attention has been paid to dual tasks involving postural control and transfers (such as gait initiation and turns) as motor tasks. In the present paper, we therefore systematically reviewed recent literature over the last 7 years in order to answer the three above mentioned questions regarding the future of lab-based dual tasks (involving posture, gait initiation, gait and turning) as easily applicable tests for identifying healthy older adult fallers. Despite great heterogeneity among included studies, we emphasized, among other things, the promising added value of dual tasks including turns and other transfers, such as in the Timed Up and Go test, for prediction of falls. Further investigation of these is thus warranted.     

Quantitative mobility measures complement the MDS-UPDRS for characterization of Parkinson's disease heterogeneity

IntroductionEmerging technologies show promise for enhanced characterization of Parkinson's Disease (PD) motor manifestations. We evaluated quantitative mobility measures from a wearable device compared to the conventional motor assessment, the Movement Disorders Society-Unified PD Rating Scale part III (motor MDS-UPDRS).MethodsWe evaluated 176 PD subjects (mean age 65, 65% male, 66% H&Y stage 2) during routine clinic visits using the motor MDS-UPDRS and a 10-min motor protocol with a body-fixed sensor (DynaPort MT, McRoberts BV), including the 32-ft walk, Timed Up and Go (TUG), and standing posture with eyes closed. Regression models examined 12 quantitative mobility measures for associations with (i) motor MDS-UPDRS, (ii) motor subtype (tremor dominant vs. postural instability/gait difficulty), (iii) Montreal Cognitive Assessment (MoCA), and (iv) physical functioning disability (PROMIS-29). All analyses included age, gender, and disease duration as covariates. Models iii-iv were secondarily adjusted for motor MDS-UPDRS.ResultsQuantitative mobility measures from gait, TUG transitions, turning, and posture were significantly associated with motor MDS-UPDRS (7 of 12 measures, p < 0.05) and motor subtype (6 of 12 measures, p < 0.05). Compared with motor MDS-UPDRS, several quantitative mobility measures accounted for a 1.5- or 1.9-fold increased variance in either cognition or physical functioning disability, respectively. Among minimally-impaired subjects in the bottom quartile of motor MDS-UPDRS, including subjects with normal gait exam, the measures captured substantial residual motor heterogeneity.ConclusionClinic-based quantitative mobility assessments using a wearable sensor captured features of motor performance beyond those obtained with the motor MDS-UPDRS and may offer enhanced characterization of disease heterogeneity.     

Prospective assessment of falls in Parkinson's disease

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 < 0.001). Recurrent (≥ 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 < 0.01). Sixty-two percent of the falls in patients caused soft tissue injuries, but no fractures occurred. A fear of future falls was common (45.8 % of patients) and was accompanied by restriction of daily activities (44.1 % of patients). Seventy percent of falls reported by patients were ‘intrinsic’ (due to patient-related factors), but falls in controls were mainly (50 %) ‘extrinsic’ (due to environmental factors). None of the baseline posture and gait variables predicted falls adequately. The first ‘unexpected’ retropulsion test was more often abnormal than all subsequent (predictable) tests. Irrespective of its method of execution, the retropulsion test did not predict falls. A combination of asking for prior falls, disease severity and the Romberg test yielded the best overall diagnostic utility (sensitivity 65 % and specificity 98 %). Recurrent fallers were best predicted by disease severity (RR for Hoehn and Yahr stage 3 was > 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. Received: 18 December 2000, Received in revised form: 15 March 2001, Accepted: 25 March 2001     

Rotigotine transdermal system for control of early morning motor impairment and sleep disturbances in patients with Parkinson’s disease

This open-label study (NCT00243945) investigated the efficacy of rotigotine transdermal system in 54 Parkinson’s disease (PD) patients with unsatisfactory control of early morning motor impairment and sleep disturbances. Rotigotine dose was up titrated for 8 weeks and maintained for 4 weeks. Mean rotigotine dose at end of maintenance was 11.83 mg/24 h (SD 3.86). Patients had two overnight hospital stays at baseline and end of treatment during which early morning motor performance was assessed, prior to first morning dose of regular oral antiparkinsonian medication. Rotigotine improved mean Unified Parkinson’s Disease Rating Scale (UPDRS) part III score by −9.3 points, mean Timed Up and Go test duration by −1.4 s and mean morning finger tapping by 26.5 taps/min; 46% of patients were considered responders (≥30% improvement of UPDRS III). Mean Nocturnal Akinesia, Dystonia and Cramps Sum Score was reduced by 61%; mean number of nocturias decreased by 32%. Rotigotine also improved sleep quality. These results suggest a role for rotigotine in treatment of nocturnal and early morning motor disabilities in PD patients.     

Motor dual-tasking deficits predict falls in Parkinson's disease: A prospective study

IntroductionFalls severely affect lives of Parkinson's disease (PD) patients. Cognitive impairment including dual-tasking deficits contribute to fall risk in PD. However, types of dual-tasking deficits preceding falls in PD are still unclear.MethodsWalking velocities during box-checking and subtracting serial 7s were assessed twice a year in 40 PD patients over 2.8 ± 1.0 years. Fourteen patients reported a fall within this period (4 excluded fallers already reported falls at baseline). Their dual-task costs (DTC; mean ± standard deviation) 4.2 ± 2.2 months before the first fall were compared with 22 patients never reporting falls. ROC analyses and logistic regressions accounting for DTC, UPDRS-III and disease duration were used for faller classification and prediction.ResultsOnly walking/box-checking predicted fallers. Fallers showed higher DTC for walking while box-checking, p = 0.029, but not for box-checking while walking, p = 0.178 (combined motor DTC, p = 0.022), than non-fallers. Combined motor DTC classified fallers and non-fallers (area under curve: 0.75; 95% confidence interval, CI: 0.60–0.91) with 71.4% sensitivity (95%CI: 41.9%–91.6%) and 77.3% specificity (54.6%–92.2%), and significantly predicted future fallers (p = 0.023). Here, 20.4%-points higher combined motor DTC (i.e. the mean difference between fallers and non-fallers) was associated with a 2.6 (1.1–6.0) times higher odds to be a future faller.ConclusionMotor dual-tasking is a potentially valuable predictor of falls in PD, suggesting that avoiding dual task situations as well as specific motor dual-task training might help to prevent falls in PD. These findings and their therapeutic relevance need to be further validated in PD patients without fall history, in early PD stages, and with various motor-motor dual-task challenges.     

早中期帕金森病患者平衡功能、跌倒风险及步态分析

目的分析早中期帕金森病患者平衡功能、跌倒风险和步态,以为其康复治疗提供临床依据。方法共30例早中期帕金森病患者和15例性别、年龄、受教育程度相匹配的正常对照者采用Berg平衡量表(BBS)评价平衡功能,起立-行走计时测验(TUGT)、站起测验(CRT)和走直线步态测验(TGT)评价跌倒风险,步态分析系统分析步态。结果与对照组相比,帕金森病组患者BBS评分减少(P=0.001)、TUGT时间(P=0.003)和CRT时间(P=0.002)延长、TGT正确步数减少(P=0.041),以及10米步行试验之步长缩短(P=0.020)、步速减慢(P=0.038)、足尖着地比例增加(P=0.000)、摆动相左侧和右侧踝背屈角度减小(P=0.005,0.006)。结论早中期帕金森病患者平衡功能下降、跌倒风险和步态异常风险增加,应早期予康复治疗。     

Virtual functional mobility test: A potential novel tool for assessing mobility of individuals with Parkinson’s disease in a multitask condition

There are few instruments available for evaluating functional mobility during multitasking in people with Parkinson’s Disease (PD). Virtual Reality is a potentially tool capable of aiding in the evaluation of functional mobility. The purpose of this study is to verify the potential of the Virtual Functional Mobility Test (VFMT) as a clinical tool to assess functional mobility of people with PD during multitasking condition. 25 people with PD and 25 people without PD, matched for age and sex, were recruited. Participants were evaluated through the Trail Making Test, Timed “UP and GO” test, Timed “UP and GO” test in dual task condition and through the VFMT, composed of 1) a simple task, and 2) a complex task. The VFMT and clinical tests were sensitive to differentiate the groups, except the trail making test part B (p = 0.332) and complex task (p = 0.052). Strong correlations were observed between parts A and B of the trail making test (r = 0.75) and complex task (r = 0.72); Moderate correlations between Timed Up and Go test and Timed Up and Go test in dual task condition with simple task (r = 0.47) and complex task (r = 0.55), respectively, were found. The complex task and simple task showed excellent and moderate reliability intra-rater, respectively. It was concluded that the novel VFMT is feasible, sensible, reliable and has potential as an instrument for the evaluation of functional mobility during multitasking in people with PD.     

Activity level and balance in subjects with mild Alzheimer's disease

To clarify if Alzheimer's disease has an impact on activity level and postural control, we examined 17 elderly diagnosed with mild Alzheimer's disease (MMSE scores 21-29) and 18 age- and gender-matched healthy controls (MMSE scores 27-30) using the Frenchay Activities Index, Bergs Balance Scale, Timed Up & Go and Walking in a Figure of Eight. Mild AD subjects were less active and had lower scores on Bergs Balance Scale, performed Timed Up & Go in longer time and took more steps outside the Figure of Eight, as compared to healthy elderly. This study shows that motor performance is affected already at mild stages of Alzheimer's disease and also that functional performance other than gait may also be impaired.     

Quantitative evaluation of changes in gait after extended cerebrospinal fluid drainage for normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait instability, urinary incontinence and cognitive dysfunction. These symptoms can be relieved by cerebrospinal fluid (CSF) drainage, but the time course and nature of the improvements are poorly characterized. Attempts to prospectively identify iNPH patients responsive to CSF drainage by evaluating presenting gait quality or via extended lumbar cerebrospinal fluid drainage (eLCD) trials are common, but the reliability of such approaches is unclear. Here we combine eLCD trials with computerized quantitative gait measurements to predict shunt responsiveness in patients undergoing evaluation for possible iNPH. In this prospective cohort study, 50 patients presenting with enlarged cerebral ventricles and gait, urinary, and/or cognitive difficulties were evaluated for iNPH using a computerized gait analysis system during a 3 day trial of eLCD. Gait speed, stride length, cadence, and the Timed Up and Go test were quantified before and during eLCD. Qualitative assessments of incontinence and cognition were obtained throughout the eLCD trial. Patients who improved after eLCD underwent ventriculoperitoneal shunt placement, and symptoms were reassessed serially over the next 3 to 15 months. There was no significant difference in presenting gait characteristics between patients who improved after drainage and those who did not. Gait improvement was not observed until 2 or more days of continuous drainage in most cases. Symptoms improved after eLCD in 60% of patients, and all patients who improved after eLCD also improved after shunt placement. The degree of improvement after eLCD correlated closely with that observed after shunt placement.     

Parkinsonian single fallers versus recurrent fallers: different fall characteristics and clinical features

The study aimed to compare the fall characteristics between parkinsonian single (P-SF) and recurrent fallers (P-RF), and the clinical features among parkinsonian non-fallers (P-NF), P-SF, P-RF and age-matched healthy controls. As many as 72 patients with PD and 74 healthy subjects completed the study. Each subject was evaluated for gait speed, timed up-and-go test, one-leg-stance test, six-minute walk test, five-times-sit-to-stand test, and Activities-specific Balance Confidence (ABC) scale at baseline. Subjects were then followed up for 12 months by telephone interview to record the fall incidence and fall characteristics. Among the PD patients, 12 fell once (P-SF) and 13 fell 2–29 times (P-RF), accounting for a total of 133 falls in the 12-month follow-up period. The most common fall-related activity for both P-SF and P-RF was walking. P-SF fell mostly outdoors due to “tripping”, while P-RF mostly fell at home due to “muscle giving way”. Clinical measures indicated that P-SF did not differ from P-NF. However, P-RF had significantly longer five-times-sit-to-stand time, shorter 6-min walk distance, and lower ABC score than P-SF. P-RF could be distinguished from P-SF by fall characteristics (i.e. location and perceived causes of falls), and by clinical measures including leg muscle weakness, reduced exercise endurance and increased level of fear of falling. Findings from the present study suggest that P-NF/P-SF and P-RF may require different intervention strategies to prevent future falls.