Interventions for preventing falls in Parkinson's disease

BACKGROUND

Most people with Parkinson's disease (PD) experience at least one fall during the course of their disease. Several interventions designed to reduce falls have been studied. An up-to-date synthesis of evidence for interventions to reduce falls in people with PD will assist with informed decisions regarding fall-prevention interventions for people with PD.

OBJECTIVES

To assess the effects of interventions designed to reduce falls in people with PD.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, four other databases and two trials registers were searched on 16 July 2020, together with reference checking, citation searching and contact with study authors to identify additional studies. We also conducted a top-up search on 13 October 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions that aimed to reduce falls in people with PD and reported the effect on falls. We excluded interventions that aimed to reduce falls due to syncope.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane Review procedures. Primary outcomes were rate of falls and number of people who fell at least once. Secondary outcomes were the number of people sustaining one or more fall-related fractures, quality of life, adverse events and economic outcomes. The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

This review includes 32 studies with 3370 participants randomised. We included 25 studies of exercise interventions (2700 participants), three studies of medication interventions (242 participants), one study of fall-prevention education (53 participants) and three studies of exercise plus education (375 participants). Overall, participants in the exercise trials and the exercise plus education trials had mild to moderate PD, while participants in the medication trials included those with more advanced disease. All studies had a high or unclear risk of bias in one or more items. Illustrative risks demonstrating the absolute impact of each intervention are presented in the summary of findings tables. Twelve studies compared exercise (all types) with a control intervention (an intervention not thought to reduce falls, such as usual care or sham exercise) in people with mild to moderate PD. Exercise probably reduces the rate of falls by 26% (rate ratio (RaR) 0.74, 95% confidence interval (CI) 0.63 to 0.87; 1456 participants, 12 studies; moderate-certainty evidence). Exercise probably slightly reduces the number of people experiencing one or more falls by 10% (risk ratio (RR) 0.90, 95% CI 0.80 to 1.00; 932 participants, 9 studies; moderate-certainty evidence).  We are uncertain whether exercise makes little or no difference to the number of people experiencing one or more fall-related fractures (RR 0.57, 95% CI 0.28 to 1.17; 989 participants, 5 studies; very low-certainty evidence). Exercise may slightly improve health-related quality of life immediately following the intervention (standardised mean difference (SMD) -0.17, 95% CI -0.36 to 0.01; 951 participants, 5 studies; low-certainty evidence). We are uncertain whether exercise has an effect on adverse events or whether exercise is a cost-effective intervention for fall prevention. Three studies trialled a cholinesterase inhibitor (rivastigmine or donepezil). Cholinesterase inhibitors may reduce the rate of falls by 50% (RaR 0.50, 95% CI 0.44 to 0.58; 229 participants, 3 studies; low-certainty evidence). However, we are uncertain if this medication makes little or no difference to the number of people experiencing one or more falls (RR 1.01, 95% CI 0.90 to 1.14230 participants, 3 studies) and to health-related quality of life (EQ5D Thermometer mean difference (MD) 3.00, 95% CI -3.06 to 9.06; very low-certainty evidence). Cholinesterase inhibitors may increase the rate of non fall-related adverse events by 60% (RaR 1.60, 95% CI 1.28 to 2.01; 175 participants, 2 studies; low-certainty evidence). Most adverse events were mild and transient in nature.  No data was available regarding the cost-effectiveness of medication for fall prevention. We are uncertain of the effect of education compared to a control intervention on the number of people who fell at least once (RR 10.89, 95% CI 1.26 to 94.03; 53 participants, 1 study; very low-certainty evidence), and no data were available for the other outcomes of interest for this comparisonWe are also uncertain (very low-certainty evidence) whether exercise combined with education makes little or no difference to the number of falls (RaR 0.46, 95% CI 0.12 to 1.85; 320 participants, 2 studies), the number of people sustaining fall-related fractures (RR 1.45, 95% CI 0.40 to 5.32,320 participants, 2 studies), or health-related quality of life (PDQ39 MD 0.05, 95% CI -3.12 to 3.23, 305 participants, 2 studies). Exercise plus education may make little or no difference to the number of people experiencing one or more falls (RR 0.89, 95% CI 0.75 to 1.07; 352 participants, 3 studies; low-certainty evidence). We are uncertain whether exercise combined with education has an effect on adverse events or is a cost-effective intervention for fall prevention.  AUTHORS' CONCLUSIONS: Exercise interventions probably reduce the rate of falls, and probably slightly reduce the number of people falling in people with mild to moderate PD.  Cholinesterase inhibitors may reduce the rate of falls, but we are uncertain if they have an effect on the number of people falling. The decision to use these medications needs to be balanced against the risk of non fall-related adverse events, though these adverse events were predominantly mild or transient in nature. Further research in the form of large, high-quality RCTs are required to determine the relative impact of different types of exercise and different levels of supervision on falls, and how this could be influenced by disease severity. Further work is also needed to increase the certainty of the effects of medication and further explore falls prevention education interventions both delivered alone and in combination with exercise.

[Digital assisted laparoscopy with adhesiolysis in mechanical intestinal obstruction]

Mechanical intestinal obstruction is an important diagnosis and a common cause of acute abdominal pain. Adhesions and scar tissue in the abdomen after previ-ous surgery is a frequent source. Small bowel obstruction caused by adhesions can be treated conservatively, but surgery may be needed. Laparotomy is usually the approach for adhesiolysis, but laparoscopy is an option. This case rapport describes a man in his 50s being admitted with severe abdominal pain and vomiting. Further investigation showed a small bowel obstruction caused by adhesions. After two days expectation, surgery be-came necessary. During laparoscopy, the surgeon's finger was introduced intraabdominally and used to release the adhesion.  We here present a possible approach to a situation encountered during laparoscopic adhesiolysis and encourage creativity and laparoscopy in selected patients with mechanical small bowel obstruction.

People with Parkinson's disease are more willing to do additional exercise if the exercise program has specific attributes: a discrete choice experiment

QUESTION

What specific attributes of exercise programs influence the preferences of people with Parkinson's disease for additional exercise compared with their current practice? What trade-offs are participants willing to make between exercise program attributes?

DESIGN

Discrete choice experiment.

PARTICIPANTS

Five hundred and forty people with Parkinson's disease.

INTERVENTION

Participants decided whether they would adopt a hypothetical program in addition to their current exercise routine.

OUTCOME MEASURES

Exercise program attributes included: type, number of sessions/week, location, travel time/session, delivery mode, supervisor's expertise, extent of supervision, benefits for physical and psychological function and out-of-pocket cost/session.

RESULTS

Participants preferred additional exercise when programs: provided physical (OR 1.85, 95% CI 1.61 to 2.13) or psychological (OR 1.45, 95% CI 1.26 to 1.67) benefit, involved less travel time (ORs 1.50 to 2.02) and were supervised by qualified professionals with Parkinson's disease expertise (ORs 1.51 to 1.91). Participants were most willing to add multimodal exercise to their exercise routine (ORs 2.01 to 2.19). Participants were less likely to prefer higher cost programs (OR 0.65, 95% CI 0.60 to 0.71, per AU$10 cost increase) or group sessions compared to individual sessions (OR 0.72, 95% CI 0.54 to 0.96). Men preferred adding strengthening exercises (OR 2.00, 95% CI 1.23 to 3.26) and women had a preference against adding aerobic exercise (OR 0.33, 95% CI 0.15 to 0.73). Participants not currently exercising were more likely to prefer adding exercise compared with those already exercising 300 minutes weekly (OR 1.74, 95% CI 1.15 to 2.63).

CONCLUSION

People with Parkinson's disease were more willing to participate in exercise programs that cost less, involve less travel, provide physical or psychological benefits and are supervised by qualified professionals. To enable more people with Parkinson's disease to exercise, health services should provide programs addressing these factors and account for sex differences.

Highly challenging balance and gait training for individuals with Parkinson's disease improves pace, rhythm and variability domains of gait - A secondary analysis from a randomized controlled trial

OBJECTIVE

Evaluate immediate and long-term effects of highly challenging balance and gait training on pace-, rhythm-, variability-, asymmetry-, and postural control domains of gait for individuals with Parkinson's disease (PD).

DESIGN

Randomized controlled trial - a secondary analysis.

SETTING

University hospital setting.

PARTICIPANTS

One-hundred older adults with mild to moderate PD (Hoehn & Yahr 2 and 3).

INTERVENTION

Training group (n = 51): 10 weeks (3 times/week) of intensive balance and gait training, incorporating dual tasks. Control group (n = 49): care as usual.

MAIN OUTCOME MEASURES

Spatiotemporal gait variables collected during normal and fast walking on a pressure-sensitive mat. A linear mixed model was used to evaluate training effects post intervention and at the 6 and 12 month follow-up.

RESULTS

Immediate training effects in the pace domain of gait were increased step velocity (normal speed: 8.2 cm/s, P = 0.04; fast: 10.8 cm/s, P < 0.01), increased step length (normal speed: 3 cm, P = 0.05; fast: 2.3 cm, P = 0.05) and reduced swing time variability (fast speed: -2.5 ms, P = 0.02). In the rhythm domain reduced step time (fast speed: -19.3 ms, P = 0.02), stance time (normal: -24.3 ms, P = 0.01; fast: -29.6 ms, P = 0.02) and swing time (fast speed: -8.7 ms, P = 0.04) was seen. Relative to the variability domain, the training decreased step time variability (fast: -2.8 ms, P = 0.02) and stance time variability (fast: -3.9 ms, P = 0.02). No training effects were retained at 6 months.

CONCLUSIONS

Highly challenging balance and gait training improved pace, rhythm and variability aspects of PD gait in the short-term, but effects are not retained long-term.

TRIAL REGISTRATION NUMBER

NCT01417598.

The effects of integrated single- and dual-task training on automaticity and attention allocation in Parkinson's disease: A secondary analysis from a randomized trial

OBJECTIVE

People with Parkinson's disease (PwPD) demonstrate impaired automaticity of motor and cognitive tasks, with unclear prioritization strategies when exposed to dual-task situations. However, no randomized trials have investigated the effects of training on automaticity and prioritization strategies in this population. The purpose of this study was to investigate the effects of training on the automaticity of gait and cognitive processing in PwPD and the allocation of attention between gait and a cognitive task.

METHOD

One-hundred PwPD were randomized to 10 weeks of challenging gait and balance training (including single and dual-task conditions) or to a control group (care as usual). Outcome measure was the absolute dual-task interference (difference between single- and dual-tasks) for gait and cognitive parameters. Differences between baseline and follow-up were compared between the groups. The Mann-Whitney U test was used to assess potential differences. Significance level was set to p = .05. The direction and magnitude of nonparametric effect sizes were used to investigate attention allocation.

RESULTS

No significant between-groups differences were found regarding any gait parameter. The training group significantly improved the dual-task interference of the cognitive task. The direction of between-groups effect sizes indicated that the training group primarily allocated attention to the cognitive task, whereas the control group appeared to prioritize gait.

CONCLUSIONS

The results indicate that challenging training can improve automaticity of cognitive processing during walking. This may have a beneficiary effect on the ability to ambulate safely in the community, thereby improving independence and the quality of life in this population. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Cost-effectiveness of the HiBalance training program for elderly with Parkinson's disease: analysis of data from a randomized controlled trial

OBJECTIVE:

To determine the cost-effectiveness of the HiBalance training program for managing Parkinson's disease (PD)-related balance and gait disorders.

DESIGN:

Cost comparison design following the randomized controlled trial comparing a novel balance training intervention with care as usual.

SUBJECTS:

A total of 100 participants with mild-moderate PD were randomized to either the intervention ( n = 51) or the control group ( n = 49).

INTERVENTION:

A 10-week (three times per week), group-based, progressive balance training program, led by two physical therapists.

MAIN OUTCOMES:

All program costs were collected for both groups. Cost-utility was evaluated using quality-adjusted life years (QALYs) and cost-effectiveness measures were the Mini Balance Evaluation Systems Test (Mini-BESTest; assessing balance performance) and gait velocity. Incremental cost-effectiveness ratios were calculated and a probabilistic sensitivity analysis was conducted.

RESULTS:

The between-group difference in QALYs was 0.043 (95% confidence interval (CI): 0.011-0.075), favoring the intervention group. Between-group differences in balance performance and gait velocity were 2.16 points (95% CI: 1.19-3.13) and 8.2 cm/second (95% CI: 2.9-13.6), respectively, favoring the intervention group. The mean cost per participant in the intervention group was 16,222 SEK (€1649) compared to 2696 SEK (€274) for controls. The estimated incremental cost-effectiveness ratios were 314,558 SEK (€31,969) for an additional QALY, 6262 SEK (€631) for one point improvement in balance performance, and 1650 SEK (€166) for 1 cm/second increase in gait velocity. Sensitivity analyses indicated a high probability (85%) of program success.

CONCLUSION:

In terms of QALYs, the HiBalance program demonstrated a high probability of cost-effectiveness in the short-term perspective when considering the willingness-to-pay thresholds used in Europe.

Patient-reported and performance-based measures of walking in mild-moderate Parkinson's disease

BACKGROUND

Knowledge of the relationships between patient-reported and performance-based walking measures in Parkinson's disease (PD) should inform clinical decision-making. The Walk-12G reliably captures perceived walking difficulties but has not been compared to performance-based walking in laboratory or free-living settings or across different groups.

OBJECTIVES

To investigate the relationship between patient-reported walking difficulties (Walk-12G) and performance-based walking in laboratory and free-living conditions and to determine whether the Walk-12G can distinguish between the subgroups, (i) people with/without PD and (ii) mild/moderate disease stages.

METHODS

Forty-seven people without and 49 people with PD (Hoehn and Yahr stage II and III) were assessed in relation to patient-reported walking difficulties (Walk-12G scale); spatiotemporal gait characteristics (Pace; Rhythm; Asymmetry; Variability; and Postural control) using a laboratory-based electronic walkway; and walking behavior (mean steps/day and minutes of brisk walking/day) using accelerometers in free-living conditions.

RESULTS

The Walk-12G correlated moderately with the spatiotemporal domain step velocity (r = -0.46) and walking behavior, measured as mean steps/day (r = -0.46). Weaker correlations were observed for step length and minutes spent in brisk walking (r = -0.36 and r = -0.35, respectively). Poor correlations were observed for all other spatiotemporal domains. The Walk-12G could distinguish between people with and without PD (Effect size, r = 0.82) and between those at mild/moderate disease stages (r = 0.34).

CONCLUSIONS

Perceived walking difficulties showed weak to moderate associations with performance-based measures of walking in mild-moderate PD. As the strongest associations were observed for step velocity and walking behavior, targeting these specific gait aspects could improve perceived walking difficulties in daily life.

The reliability of gait variability measures for individuals with Parkinson's disease and healthy older adults - The effect of gait speed

BACKGROUND

Step-to-step variability is a marker of reduced motor control and a frequently studied outcome measure in neurodegenerative disorders such as Parkinson's disease (PD) as compared to healthy older adults (HOA). To challenge motor control of gait, walking should be tested at different gait speeds. Good reliability is essential, and gait variability estimates show good reproducibility when sampled at normal gait speed. The aim was therefore to investigate if gait variability could be reliably sampled at slow and fast speeds for individuals with PD and HOA by evaluating test-retest reliability.

METHODS

29 (14 males) subjects with idiopathic PD, Hoehn &Yahr 2 (n = 18) and 3, ≥ 60 years, and 25 age matched HOAwere included. Spatiotemporal gait data was collected (GAITRite) during slow, normal, and fast walking on two occasions.

RESULTS

Measurement error was lowest for gait variability estimates based on 40 steps in both groups. This was true across all speeds in HOA, but only for normal and fast gait speeds in the PD cohort. Due to increased homogeneity in the variability estimates intraclass correlation coefficients (ICC) were low for HOA, except for step width variability. In the PD cohort ICCs were good to excellent for temporal- and step width gait variability across speeds.

CONCLUSION

HOA demonstrated reliable gait variability estimates across all speeds, whereas Individuals with PD were reliable at normal and fast gait speeds only Estimates should be based on at least 40 steps. Step width variability was overall the most reliable variable across groups and speed conditions.

Investigating the Mini-BESTest's construct validity in elderly with Parkinson's disease

OBJECTIVES

The Mini-BESTest consists of items relevant to balance deficiencies among people with Parkinson's disease (PwPD). However, the Mini-BESTest's construct validity has been sparsely evaluated in this population. We therefore aimed to investigate the hypotheses that the Mini-BESTest results would be worse among: (i) PwPD compared to healthy controls; (ii) PwPD with moderate compared to mild motor severity; (iii) PwPD with a history of recurrent compared to non-recurrent falls. Moreover, the relationship between the Mini-BESTest and tests of similar and different constructs was expected to be moderate to strong and poor, respectively.

MATERIALS AND METHODS

One hundred and five PwPD with mild-to-moderate motor severity and 47 healthy controls were included. PwPD were divided into subgroups based on motor severity and fall history. Main outcome measures were the Mini-BESTest, the timed up and go (TUG), and the original Unified Parkinson's Disease Rating Scale, part II (Activities of Daily Living). Independent t-tests and Spearman's rho were used for the analyses.

RESULTS

The Mini-BESTest results were worse among PwPD compared to controls (P<.001), and among people with moderate motor severity compared to those with mild severity (P<.001). However, no differences were found between recurrent and non-recurrent fallers (P=.096). Spearman's rho showed moderate (ρ=-.470) and poor correlations (ρ=-.211) for convergent (TUG) and divergent validity (UPDRS, part II), respectively.

CONCLUSIONS

Overall, the Mini-BESTest appears to adequately measure dynamic balance among PwPD with mild-to-moderate severity, although it was unable to distinguish between recurrent and non-recurrent fallers.

Monitoring training activity during gait-related balance exercise in individuals with Parkinson's disease: a proof-of-concept-study

BACKGROUND

Despite the benefits of balance exercise in clinical populations, balance training programs tend to be poorly described, which in turn makes it difficult to evaluate important training components and compare between programs. However, the use of wearable sensors may have the potential to monitor certain elements of balance training. Therefore, this study aimed to investigate the feasibility of using wearable sensors to provide objective indicators of the levels and progression of training activity during gait-related balance exercise in individuals with Parkinson's disease.

METHODS

Ten individuals with Parkinson's disease participated in 10 weeks of group training (three sessions/week) addressing highly-challenging balance exercises. The training program was designed to be progressive by gradually increasing the amount of gait-related balance exercise exercises (e.g. walking) and time spent dual-tasking throughout the intervention period. Accelerometers (Actigraph GT3X+) were used to measure volume (number of steps/session) and intensity (time spent walking >1.0 m/s) of dynamic training activity. Training activity was also expressed in relation to the participants' total daily volume of physical activity prior to the training period (i.e. number of steps during training/the number of steps per day). Feasibility encompassed the adequacy of data sampling, the output of accelerometer data and the participants' perception of the level of difficulty of training.

RESULTS

Training activity data were successfully obtained in 98% of the training sessions (n = 256) and data sampling did not interfere with training. Reflecting the progressive features of this intervention, training activity increased throughout the program, and corresponded to a high level of the participants' daily activity (28-43%). In line with the accelerometer data, a majority of the participants (n = 8) perceived the training as challenging.

CONCLUSIONS

The findings of this proof-of-concept study support the feasibility of applying wearable sensors in clinical settings to gain objective informative measures of gait-related balance exercise in individuals with Parkinson's disease. Still, this activity monitoring approach needs to be further validated in other populations and programs including gait-related balance exercises.

TRIAL REGISTRATION

NCT01417598 , 15th August 2011.

The Effects of Highly Challenging Balance Training in Elderly With Parkinson's Disease: A Randomized Controlled Trial

Background. Highly challenging exercises have been suggested to induce neuroplasticity in individuals with Parkinson’s disease (PD); however, its effect on clinical outcomes remains largely unknown. Objective. To evaluate the short-term effects of the HiBalance program, a highly challenging balance-training regimen that incorporates both dual-tasking and PD-specific balance components, compared with usual care in elderly with mild to moderate PD. Methods. Participants with PD (n = 100) were randomized, either to the 10-week HiBalance program (n = 51) or to the control group (n = 49). Participants were evaluated before and after the intervention. The main outcomes were balance performance (Mini-BESTest), gait velocity (during normal and dual-task gait), and concerns about falling (Falls Efficacy Scale–International). Performance of a cognitive task while walking, physical activity level (average steps per day), and activities of daily living were secondary outcomes. Results. A total of 91 participants completed the study. After the intervention, the between group comparison showed significantly improved balance and gait performance in the training group. Moreover, although no significant between group difference was observed regarding gait performance during dual-tasking; the participants in the training group improved their performance of the cognitive task while walking, as compared with the control group. Regarding physical activity levels and activities of daily living, in comparison to the control group, favorable results were found for the training group. No group differences were found for concerns about falling. Conclusions. The HiBalance program significantly benefited balance and gait abilities when compared with usual care and showed promising transfer effects to everyday living. Long-term follow-up assessments will further explore these effects.

The Mini-BESTest--a clinically reproducible tool for balance evaluations in mild to moderate Parkinson's disease?

Background

The Mini-BESTest is a clinical balance test that has shown a high sensitivity in detecting balance impairments in elderly with Parkinson's disease (PD). However, its reproducibility between different raters and between test occasions has yet to be investigated in a clinical context. Moreover, no one has investigated the reproducibility of the Mini-BESTest's subcomponents (i.e. anticipatory postural adjustments; postural responses; sensory orientation and dynamic gait).

We aimed to investigate the inter-rater and test-retest reproducibility (reliability as well as agreement) of the Mini-BESTest, as well as its subcomponents, in elderly with mild to moderate PD, performed under conditions assimilating clinical practice.

Method

This was an observational measurement study with a test-retest design.

Twenty-seven individuals with idiopathic PD (66 - 80 years, mean age: 73; Hoehn & Yahr: 2-3; 1-15 years since diagnosis) were included. Two test administrators, having different experiences with the Mini-BESTest, administered the test individually, in separate rooms in a hospital setting. For the test-retest assessment, all participants returned 7 days after the first test session to perform the Mini-BESTest under similar conditions. Intra-class correlation coefficients (ICC_2.1), standard error of measurement (SEM_agreement), and smallest real difference (SRD) were analyzed.

Results

The Mini-BESTest showed good reliability for both inter-rater and test-retest reproducibility (ICC = 0.72 and 0.80). Regarding agreement, the measurement error (SRD) was found to be 4.1 points (accounting for 15% of the maximal total score) for inter-rater reproducibility and 3.4 points (12% of the maximal total score) for test-retest reproducibility. The investigation of the Mini-BESTest's subcomponents showed a similar pattern for both inter-rater and test-retest reproducibility, where postural responses had the largest proportional measurement error, and sensory orientation showed the highest agreement.

Conclusions

Our findings indicate that the Mini-BESTest is able to distinguish between individuals with mild to moderate PD; however, when used in clinical balance assessments, the large measurement error needs to be accounted for.

Is highly challenging and progressive balance training feasible in older adults with Parkinson's disease?

OBJECTIVE

To develop a highly challenging and progressive group balance training regime specific to Parkinson's disease (PD) symptoms and to investigate its feasibility in older adults with mild to moderate PD.

DESIGN

Intervention study, before-after trial with a development and feasibility design.

SETTING

University hospital setting.

PARTICIPANTS

Feasibility was evaluated in older adults (N=5; mean age, 72y; age range, 69-80y) with mild to moderate idiopathic PD.

INTERVENTION

A balance training regime emphasizing specific and highly challenging exercises, performed 3 times per week for 12 weeks, was developed through discussion and workshops by a group of researchers and physiotherapists.

MAIN OUTCOME MEASURES

Indicators of feasibility included attendance rate, safety (adverse events, physical function, and pain), participants' perceptions of the intervention (level of difficulty of the exercises, motivation level, and appreciation), and efficacy of the intervention (balance performance assessed with the Mini-Balance Evaluation Systems Test [Mini-BESTest]).

RESULTS

The incidence rate was high (93%) for attendance and low (1.2%) for adverse events. Ratings by the participants indicated progression throughout the training period. All participants considered the training motivational and stated that they would recommend it to others. The efficacy of the intervention measured with the Mini-BESTest showed that 4 out of 5 participants improved their balance performance.

CONCLUSIONS

These findings support the overall feasibility of this novel balance program in older adults with mild to moderate PD. However, to further evaluate the efficacy of the program, a larger randomized controlled trial is required.

A novel conceptual framework for balance training in Parkinson's disease-study protocol for a randomised controlled trial

Background

There is increasing scientific knowledge about the interaction between physiological (musculoskeletal, neuromuscular, cognitive and sensory) systems and their influence on balance and walking impairments in Parkinson’s disease. We have developed a new conceptual framework for balance training, emphasising specific components of balance control related to Parkinson’s disease symptoms by using highly challenging, progressive and varying training conditions. The primary aim of this proposed randomised controlled trial will be to investigate the short-term and long-term effects of a 10-week balance training regime in elderly with Parkinson’s disease.

Methods/Design

Eighty participants with mild to moderate idiopathic Parkinson’s disease will be recruited and randomly allocated to an intervention group receiving balance training or a control group whose participants will continue to receive their usual care. The intervention will consist of a 10-week group training regime (1-hour training, three times per week), which will be led by two physiotherapists to ensure training progression and safety. The conceptual framework will be applied by addressing specific balance components (sensory integration, anticipatory postural adjustments, motor agility, stability limits) through varying training conditions and structured progression. Assessment will be conducted through a multi-dimensional battery of outcomes, prior to and immediately after the 10-week intervention, and at 9 and 15 months’ follow-up after entering the study. Primary outcome measures will be balance performance (assessed using the Mini Balance Evaluation Systems Test), change in gait velocity (m/s) between single and dual task walking, and fear of falling (evaluated using the Fall Efficacy Scale International).

Discussion

This study has the potential to provide new insight and knowledge of the effects of specific, varied and challenging balance training on a wide health spectrum in elderly with PD. If found to be effective, this pragmatic approach with translation of theory into practice, can be implemented in existing outpatient care.

Trial registration

NCT01417598

Does indomethacin for closure of patent ductus arteriosus affect cerebral function?

OBJECTIVE

To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by electroencephalograms (EEG) evaluated by quantitative measures.

STUDY DESIGN

Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function.

RESULTS

Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion.

CONCLUSION

Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.

Classification of burst and suppression in the neonatal electroencephalogram

Fisher's linear discriminant (FLD), a feed-forward artificial neural network (ANN) and a support vector machine (SVM) were compared with respect to their ability to distinguish bursts from suppressions in electroencephalograms (EEG) displaying a burst-suppression pattern. Five features extracted from the EEG were used as inputs. The study was based on EEG signals from six full-term infants who had suffered from perinatal asphyxia, and the methods have been trained with reference data classified by an experienced electroencephalographer. The results are summarized as the area under the curve (AUC), derived from receiver operating characteristic (ROC) curves for the three methods. Based on this, the SVM performs slightly better than the others. Testing the three methods with combinations of increasing numbers of the five features shows that the SVM handles the increasing amount of information better than the other methods.

Comparison of three methods for classifying burst and suppression in the EEG of post asphyctic newborns

Fisher's linear discriminant, a feed-forward neural network (NN) and a support vector machine (SVM) are compared with respect to their ability to distinguish bursts from suppression in burst-suppression electroencephalogram (EEG) signals using five features inherent in the EEG as input. The study is based on EEG signals from six full term infants who have suffered from perinatal asphyxia, and the methods have been trained with reference data classified by an experienced electroencephalographer. The results are summarized as area under the curve (AUC) values derived from receiver operating characteristic (ROC) curves for the three methods, and show that the SVM is slightly better than the others, at the cost of a higher computational complexity.

Comparing a supervised and an unsupervised classification method for burst detection in neonatal EEG

Hidden Markov Models (HMM) and Support Vector Machines (SVM) using unsupervised and supervised training, respectively, were compared with respect to their ability to correctly classify burst and suppression in neonatal EEG. Each classifier was fed five feature signals extracted from EEG signals from six full term infants who had suffered from perinatal asphyxia. Visual inspection of the EEG by an experienced electroencephalographer was used as the gold standard when training the SVM, and for evaluating the performance of both methods. The results are presented as receiver operating characteristic (ROC) curves and quantified by the area under the curve (AUC). Our study show that the SVM and the HMM exhibit similar performance, despite their fundamental differences.

On evaluation of spectrum estimators for EEG

In the search for how neonatal EEG is affected by asphyxia it is of importance to find reliable estimates of EEG power spectra. Several spectral estimation methods do exist, but since the true spectra are unknown it is hard to tell how well the estimators perform. Therefore a model to generate simulated EEG with known spectrum is proposed and the model is used to evaluate performance of several parametric and Fourier based spectral estimators.

Spectral distance for ARMA models applied to electroencephalogram for early detection of hypoxia

A novel measure of spectral distance is presented, which is inspired by the prediction residual parameter presented by Itakura in 1975, but derived from frequency domain data and extended to include autoregressive moving average (ARMA) models. This new algorithm is applied to electroencephalogram (EEG) data from newborn piglets exposed to hypoxia for the purpose of early detection of hypoxia. The performance is evaluated using parameters relevant for potential clinical use, and is found to outperform the Itakura distance, which has proved to be useful for this application. Additionally, we compare the performance with various algorithms previously used for the detection of hypoxia from EEG. Our results based on EEG from newborn piglets show that some detector statistics divert significantly from a reference period less than 2 min after the start of general hypoxia. Among these successful detectors, the proposed spectral distance is the only spectral-based parameter. It therefore appears that spectral changes due to hypoxia are best described by use of an ARMA- model-based spectral estimate, but the drawback of the presented method is high computational effort.

Detection of bursts in the EEG of post asphyctic newborns

Eight features inherent in the electroencephalogram (EEG) have been extracted and evaluated with respect to their ability to distinguish bursts from suppression in burst-suppression EEG. The study is based on EEG from six full term infants who had suffered from lack of oxygen during birth. The features were used as input in a neural network, which was trained on reference data segmented by an experienced electroencephalographer. The performance was then evaluated on validation data for each feature separately and in combinations. The results show that there are significant variations in the type of activity found in burst-suppression EEG from different subjects, and that while one or a few features seem to be sufficient for most patients in this group, some cases require specific combinations of features for good detection to be possible.

Infraslow EEG activity in burst periods from post asphyctic full term neonates

OBJECTIVE

To investigate whether very low EEG frequency activity can be recorded from post asphyctic full term neonates using EEG equipment where the high pass filter level was lowered to 0.05 Hz.

METHODS

The time constant of the amplifier hardware was set to 3.2 s in order to enable recordings that equal to a high pass filter cut off at 0.05 Hz. Burst episodes were selected from the EEGs of 5 post asphyctic full term neonates. The episodes were analysed visually using different montages and subjected to power spectrum analysis. Powers in two bands were estimated; 0-1 and 1-4 Hz, designated very low- and low-frequency activity, respectively (VLFA, LFA).

RESULTS

In all infants, VLFA coinciding with the burst episodes could be detected. The duration of the VLFA was about the same as that of the burst episode i.e. around 4s. The activity was most prominent over the posterior regions. In this small material, a large amount of VLFA neonatally seemed to possibly be related to a more favourable prognosis.

CONCLUSIONS

VLFA can be recorded from post asphyctic full term neonates using EEG equipment with lowered cut off frequency for the high pass filter.

SIGNIFICANCE

VLFA normally disregarded due to filtering, is present in the EEG of sick neonates and may carry important clinical information.

Spectral analysis of burst periods in EEG from healthy and post-asphyctic full-term neonates

OBJECTIVE

To investigate whether the periodic EEG patterns seen in healthy and sick full term neonates (trace alternant and burst suppression, respectively) have different frequency characteristics.

METHODS

Burst episodes were selected from the EEGs of 9 healthy and 9 post-asphyctic full-term neonates and subjected to power spectrum analysis. Powers in two bands were estimated; 0-4 and 4-30 Hz, designated low- and high-frequency activity, respectively (LFA, HFA). The spectral edge frequency (SEF) was also assessed.

RESULTS

In bursts, the LFA power was lower in periods of burst suppression as compared to those of trace alternant. The parameter that best discriminated between the groups was the relative amount of low- and high-frequency activity. The SEF parameter had a low sensitivity to the group differences. In healthy neonates, the LFA power was higher over the posterior right as compared to the posterior left region.

CONCLUSIONS

Spectral power of low frequencies differs significantly between the burst episodes of healthy and sick neonates.

SIGNIFICANCE

These results can be used when monitoring cerebral function in neonates.