Construct validity, responsiveness and minimal important difference of the cumulated ambulation score in older adults with hip fracture in sub-acute rehabilitation facility

OBJECTIVE

To assess the construct validity, responsiveness and minimal important difference of the cumulated ambulation score in patients with hip fracture in sub-acute rehabilitation facility.

DESIGN

Observational, prospective, monocenter, cohort study.

SETTING

Rehabilitation Institute.

PARTICIPANTS

456 older adults with hip fracture (≥65 years) admitted for inpatient rehabilitation.

MAIN OUTCOME MEASURES

Cumulated ambulation score, functional independence measure and functional ambulation category were collected at admission and discharge. Construct validity and responsiveness were assessed through hypothesis testing and minimal important difference was determined using the anchor-based method; floor and ceiling effects were also assessed.

RESULTS

The cumulated ambulation score showed strong correlations with the functional independence measure and functional ambulation category scores at both admission and discharge, satisfying all the hypotheses for construct validity. The effect size of cumulated ambulation score was 1.63. Changes in cumulated ambulation score had a moderate-to-strong correlation with changes of other instruments and were able to discriminate patients improved from those not-improved, and patients classified as independent ambulators from those dependent. A ceiling effect was found only at discharge. The estimated minimal important difference was 2 points.

CONCLUSIONS

The cumulated ambulation score showed high levels of construct validity and responsiveness according to the hypothesis testing. A two points improvement at the end of rehabilitation was found to be clinically important in people with hip fracture in the sub-acute phase. The ceiling effect found at discharge suggested the limitation of the scale in assessing people with a partially recovered autonomy in performing postural changes and gait.

The Effect of Upright Stance and Vision on a Cognitive Task in Elderly Subjects and Patients with Parkinson's Disease

Standing compared to sitting enhances cognitive performance in healthy subjects. The effect of stance on cognitive performance has been addressed here in patients with Parkinson's disease (PwPD). We hypothesized that a simple cognitive task would be less enhanced in PwPD by standing with respect to sitting, because of a larger cognitive effort for maintenance of standing posture than in healthy subjects. We recruited 40 subjects (20 PwPD and 20 age-matched healthy subjects, HE). Each participant performed an arithmetic task (backward counting aloud by 7) in two postural states, sitting and standing, with eyes open (EO) and with eyes closed (EC). All trials lasted 60 s and were randomized across subjects and conditions. The number of correct subtractions per trial was an index of counting efficiency and the ratio of correct subtractions to total subtractions was an index of accuracy. All conditions collapsed, the efficiency of the cognitive task was significantly lower in PwPD than HE, whilst accuracy was affected to a lower extent. Efficiency significantly improved from sitting to standing in HE under both visual conditions whilst only with EO in PwPD. Accuracy was not affected by posture or vision in either group. We suggest that standing, compared to sitting, increases arousal, thus improving the cognitive performance in HE. Conversely, in PwPD this improvement was present only with vision, possibly due to their greater balance impairment with EC consuming an excess of attentional resources. These findings have implications for balance control and the risk of falling in PwPD in the absence of visual cues.

Minimal clinically important difference of the functional independence measure in older adults with hip fracture

PURPOSE

To investigate the responsiveness and minimal clinically important difference (MCID) of the Functional Independence Measure (FIM) from a clinician's perspective in hip-fractured elderly undergoing inpatient rehabilitation.

MATERIALS AND METHODS

Data of 701 hip-fractured elderly admitted to our rehabilitation institute were retrospectively collected. Ten a priori hypotheses were formulated.

RESULTS

The effect size of the FIM scores after treatment were large (total = 1.38, motor = 1.78). Moderate correlations were found between the change total score of FIM and Barthel Index (BI, rs = 0.51), Functional Ambulation Categories (FAC, rs = 0.52) and a checklist regarding participants' independence in transfers (rs = 0.59). The area under the receiving operating characteristics were 0.82, 0.81, and 0.85 when BI, FAC and checklist were used as anchors, respectively. Based on these findings, the FIM showed high responsiveness (9/10 hypotheses met). Triangulation of findings showed that MCIDs of 22 and 21 points were the most appropriate for the FIM total and motor score, respectively.

CONCLUSIONS

The FIM scale is appropriate for assessing independence and functional recovery in hip-fractured elderly. Improvements of 22 and 21 points at the total and motor FIM were identified as indicators of minimal clinical change in those admitted to a rehabilitation facility with an FIM total score between 40 and 80.

Vertical Ground Reaction Forces in Parkinson's Disease: A Speed-Matched Comparative Analysis with Healthy Subjects

This study aimed to investigate and compare the vertical Ground Reaction Forces (vGRFs) of patients with Parkinson's Disease (PwPD) and healthy subjects (HS) when the confounding effect of walking speed was absent. Therefore, eighteen PwPD and eighteen age- and linear walking speed-matched HS were recruited. Using plantar pressure insoles, participants walked along linear and curvilinear paths at self-selected speeds. Interestingly, PwPD exhibited similar walking speed to HS during curvilinear trajectories (p = 0.48) and similar vGRF during both linear and curvilinear paths. In both groups, vGRF at initial contact and terminal stance was higher during linear walking, while vGRF at mid-stance was higher in curvilinear trajectories. Similarly, the time to peak vGRF at each phase showed no significant group differences. The vGRF timing variability was different between the two groups, particularly at terminal stance (p < 0.001). In conclusion, PwPD and HS showed similar modifications in vGRF and a similar reduction in gait speed during curvilinear paths when matched for linear walking speed. This emphasized the importance of considering walking speed when assessing gait dynamics in PwPD. This study also suggests the possibility of the variability of specific temporal measures in differentiating the gait patterns of PwPD versus those of HS, even in the early stages of the disease.

Comparison of Two Techniques Performing the Supine-to-Sitting Postural Change in Patients with Sternotomy

Patients with sternotomy are advised to follow sternal precautions to avoid the risk of sternal complications. However, there are no standard recommendations, in particular to perform the supine-to-sitting postural change, where sternal asymmetrical force may be applied. The aim of this study was to compare the rotational movement and the use of a tied rope (individual device for supine-to-sitting, "IDSS") to perform the supine-to-sitting postural change. A total of 92 patients (26% female) admitted to a rehabilitative post-surgery ward with sternotomy were assessed for sternal instability. Levels of pain and perceived effort during the two modalities of postural change and at rest were assessed. Patients reported higher values of pain and perceived effort (both p < 0.0005) during rotational movement with respect to the use of the IDSS. Moreover, patients with sternal instability (14%) and female patients with macromastia (25%) reported higher pain than those stable or without macromastia (both p < 0.05). No other risk factors were associated with pain. Thus, the IDSS seems to reduce the levels of pain and perceived effort during the supine-to-sitting postural change. Future studies with quantitative assessments are required to suggest the adoption of this technique, mostly in patients with high levels of pain or with sternal instability.

Effects of Aerobic Training in Patients with Subacute COVID-19: A Randomized Controlled Feasibility Trial

Many clinical practice recommendations indicate rehabilitation as essential for patients with sequelae of severe or critical COVID-19 and suggest the prompt initiation of a multicomponent rehabilitation program focused on aerobic and endurance training. However, randomized controlled trials (RCTs) regarding aerobic exercise are lacking. Therefore, we aimed to assess the feasibility and effectiveness of the addition of aerobic training to standard rehabilitation in subjects with subacute COVID-19. Participants were 32/214 patients with the sequelae of severe or critical COVID-19 in the acute phase who were eligible and agreed to participate in the study (eligibility = 15%, recruitment = 100%). After randomization and assessment with functional and strength tests, all the participants underwent an inpatient-tailored rehabilitation program (50 min/day, 5 days/week, 10 sessions); in addition, the experimental group performed a low- to moderate-intensity aerobic exercise (30 min/day, 10 sessions). No dropouts or severe adverse events were reported, with an attendance rate of 95.6%. Most of the secondary outcomes significantly improved in both groups, but the improvement in the Functional Independence Measure and Cumulated Ambulation Score-Italian version was significantly greater in the experimental group (at least, p < 0.05). This RCT showed that aerobic exercise is feasible and safe in subacute COVID-19. Moreover, it appears to be beneficial and useful in improving patients' independence and mobility.

Writing Blindly in Incomplete Locked-In Syndrome with A Custom-Made Switch-Operated Voice-Scanning Communicator—A Case Report

Background: Locked-In Syndrome (LIS) is a rare neurological condition in which patients’ ability to move, interact, and communicate is impaired despite their being conscious and awake. After assessing the patient’s needs, we developed a customized device for an LIS patient, as the commercial augmentative and alternative communication (AAC) devices could not be used. Methods: A 51-year-old woman with incomplete LIS for 15 years came to our laboratory seeking a communication tool. After excluding the available AAC devices, a careful evaluation led to the creation of a customized device (hardware + software). Two years later, we assessed the patient’s satisfaction with the device. Results: A switch-operated voice-scanning communicator, which the patient could control by residual movement of her thumb without seeing the computer screen, was implemented, together with postural strategies. The user and her family were generally satisfied with the customized device, with a top rating for its effectiveness: it fit well the patient’s communication needs. Conclusions: Using customized AAC and strategies provides greater opportunities for patients with LIS to resolve their communication problems. Moreover, listening to the patient’s and family’s needs can help increase the AAC’s potential. The presented switch-operated voice-scanning communicator is available for free on request to the authors.

The Coronavirus Footprint on Dual-Task Performance in Post-Acute Patients after Severe COVID-19: A Future Challenge for Rehabilitation

Recent studies suggest that also the non-critical form of COVID-19 infection may be associated with executive function impairments. However, it is not clear if they result from cognitive impairments or by COVID-19 infection per se. We aimed to investigate if patients in the post-acute stage of severe COVID-19 (PwCOVID), without manifest cognitive deficits, reveal impairments in performing dual-task (DT) activities compared to healthy controls (HS). We assessed balance in 31 PwCOVID vs. 30 age-matched HS by stabilometry and the Timed Up and Go (TUG) test with/without a cognitive DT. The DT cost (DTC), TUG test time and sway oscillations were recorded; correct cognitive responses (CCR) were calculated to evaluate cognitive performance. Results show a significant difference in overall DT performance between PwCOVID and HS in both stabilometry (p < 0.01) and the TUG test (p < 0.0005), although with similar DTCs. The main difference in the DTs between groups emerged in the CCR (effect size > 0.8). Substantially, PwCOVID gave priority to the motor task, leaving out the cognitive one, while HS performed both tasks simultaneously. Our findings suggest that PwCOVID, even without a manifest cognitive impairment, may present a deficit in executive function during DTs. These results encourage the use of DTs and CCR in PwCOVID.

Balance performance in patients with post-acute COVID-19 compared to patients with an acute exacerbation of chronic obstructive pulmonary disease and healthy subjects

COVID-19 leaves important sequelae in patients, not only in those who had the experience of a critical illness but also in patients with severe form. Understanding the impairments allows us to target rehabilitation to patients' real needs; balance impairments are an assumed sequela of COVID-19, but no study has specifically evaluated balance performance in these patients. Their performance was compared to that of patients with a pulmonary disease that leads to systemic diseases, such as patients with an acute exacerbation of chronic obstructive pulmonary disease (PwAECOPD), and of healthy subjects. A total of 75 subjects were assessed: 25 patients with COVID-19 (PwCOVID) with a severe form in the acute phase, 25 PwAECOPD and 25 healthy subjects sex- and age-matched. A stabilometric platform was used to evaluate static balance, both with eyes open and closed, while the dynamic balance was assessed with the Mini-BESTest and the Timed Up and Go test. When compared to healthy subjects, results showed that PwCOVID had worse performance in both static (P < 0.005) and dynamic (P < 0.0001) balance, with a large effect size in all measures (>0.8). Moreover, PwCOVID showed similar results to those of PwAECOPD. In conclusion, PwCOVID showed a balance deficit in both dynamic and static conditions. Therefore, as for PwAECOPD, they should require not only respiratory rehabilitation but also balance and mobility physiotherapy to prevent today's PwCOVID from becoming tomorrow's fallers.

A pathophysiological model of gait captures the details of the impairment of pace/rhythm, variability and asymmetry in Parkinsonian patients at distinct stages of the disease

Locomotion in people with Parkinson' disease (pwPD) worsens with the progression of disease, affecting independence and quality of life. At present, clinical practice guidelines recommend a basic evaluation of gait, even though the variables (gait speed, cadence, step length) may not be satisfactory for assessing the evolution of locomotion over the course of the disease. Collecting variables into factors of a conceptual model enhances the clinical assessment of disease severity. Our aim is to evaluate if factors highlight gait differences between pwPD and healthy subjects (HS) and do it at earlier stages of disease compared to single variables. Gait characteristics of 298 pwPD and 84 HS able to walk without assistance were assessed using a baropodometric walkway (GAITRite®). According to the structure of a model previously validated in pwPD, eight spatiotemporal variables were grouped in three factors: pace/rhythm, variability and asymmetry. The model, created from the combination of three factor scores, proved to outperform the single variables or the factors in discriminating pwPD from HS. When considering the pwPD split into the different Hoehn and Yahr (H&Y) stages, the spatiotemporal variables, factor scores and the model showed that multiple impairments of gait appear at H&Y stage 2.5, with the greatest difference from HS at stage 4. A contrasting behavior was found for the asymmetry variables and factor, which showed differences from the HS already in the early stages of PD. Our findings support the use of factor scores and of the model with respect to the single variables in gait staging in PD.

Insights Into the Mini-BESTest Scoring System: Comparison of 6 Different Structural Models

OBJECTIVE

The Mini-Balance Evaluation Systems Test (Mini-BESTest) is a balance scale common to clinical practice, but different scoring has been proposed, that is, total score and/or subsections. This study aimed to investigate Mini-BESTest validity by comparing 6 structural models and to establish the best model for discriminating fallers from nonfallers, that is, those who did or did not report at least 2 falls in the 6 months before evaluation.

METHODS

In this cross-sectional validation study, data from 709 individuals with idiopathic Parkinson disease (Hoehn and Yahr stages 1-3) were analyzed. Individuals were evaluated with the Mini-BESTest, and fall history was recorded. Construct, convergent, and discriminant validity and reliability of the 6 models were analyzed. The ability of the models to adequately identify individuals with or without a history of falls was tested with receiving operating characteristic curves.

RESULTS

Confirmatory factor analysis showed that the unidimensional models and the 4-factor solutions showed the best fit indexes. Conversely, second-order models, which allowed reporting of both total and subsections, did not converge. Most models and factors showed a low convergent validity (average variance extracted values <0.5). Correlations among the anticipatory postural adjustments factor with both the sensory orientation and the dynamic gait factors of multidimensional models were high (r ≥ 0.85). Unidimensional model reliability was good, whereas low values were found in one-half of the subsections. Finally, both unidimensional models showed a large area under the receiving operating characteristic curve (0.81).

CONCLUSION

The original unidimensional Mini-BESTest model-with a total score of 28-showed the highest validity and reliability and was best at discriminating fallers from nonfallers. Conversely, its 4 subsections should not be reported separately, because they were highly correlated and had low reliability; therefore, they are not actually capable of measuring different aspects of balance.

IMPACT

This study shows that the Mini-BESTest should be used only with the original unidimensional scoring system in people with Parkinson disease.

Does the type of hip fracture affect functional recovery in elderly patients undergoing inpatient rehabilitation?

BACKGROUND

Hip fractures should not be considered as a single, homogeneous condition. Various determinants of functional recovery of patients with hip fracture have been proposed, such as age or type of fracture. The aim of this study was to determine if patients with an intertrochanteric fracture (ITF) had lower functional recovery characteristics with respect to those with a femoral neck fracture (FNF).

METHODS

A retrospective study was carried out on 531 elderly patients with hip fracture, surgically treated, admitted to a rehabilitation institute between December 1, 2014, and December 31, 2017. Patients underwent an individualized rehabilitation program for improving their physical function. The outcome measures of this study were the length of stay (LOS) in the rehabilitation institute, the Functional Independence Measure (FIM) gain, i.e. the difference in FIM score between discharge and admission, and the FIM efficiency, which represents the daily gain. Patients were also stratified by age categories and by different levels of functional independence, as evaluated with the FIM total score at baseline.

RESULTS

Age (p<0.05), LOS (p<0.005) and rehabilitation outcomes (FIM score and efficiency; p<0.05) differed significantly between patients with FNF and ITF. In particular, patients with ITF were older and more dependent at baseline. Moreover, they showed a lower FIM efficiency with respect to patients with FNF (p<0.05), which obtained a similar improvement in FIM total score of about 26 points but were discharged on average 3 days before. With aging, FIM efficiency decreased, while LOS increased. Patients highly dependent at baseline (FIM total score <40) had the lowest FIM gain and efficiency and the longest LOS respect to the more independent patients. Moreover, in older (85+ years) and in higher dependent patients the differences in the outcome measures between ITF and FNF were reduced.

CONCLUSIONS

The type of hip fracture could affect the LOS and FIM efficiency of younger and more independent patients with hip fracture during inpatient rehabilitation. In particular, patients with ITF require a longer rehabilitation period to achieve a similar functional gain as those with FNF.

Addition of aerobic training to conventional rehabilitation after hip fracture: a randomized, controlled, pilot feasibility study

OBJECTIVES

To determine the feasibility and safety of aerobic training with an arm crank ergometer and its effectiveness in improving functional capacity and gait in patients with recent hip fracture.

DESIGN

Randomized, controlled, assessor-blinded pilot study, with intention-to-treat analysis.

SETTING

Inpatients, rehabilitation department.

SUBJECTS

40 patients with hip fracture surgically treated.

INTERVENTIONS

Training group performed aerobic exercise with an arm crank ergometer (15 sessions, 30 minutes/day) at an intensity of 64% to 76% of maximum heart rate, in addition to conventional inpatient rehabilitation.

MAIN MEASURES

Primary outcome was the feasibility (including eligibility rate, recruitment rate, number of drop-outs and adverse events, adherence). Secondary measures were the Timed Up and Go test, ability to walk independently, muscle torque of knee extensors of fractured and non-fractured leg, Functional Independence Measure.

RESULTS

Mostly due to pre-existing disability and fracture type, only 40/301 (13%) patients were eligible (age 84.6 ± 7.6 years, 75% female); all agreed to participate and 90% completed the trial, without adverse events. Adherence to aerobic exercise was good, with high attendance at sessions (93%), a strong compliance to exercise duration (95%) but lower compliance to the prescribed intensity (73%). After the program, more patients were able to walk independently in the training group (n = 18) compared to control (n = 13) (P < 0.05). Also the muscle torque of fractured leg knee extensors was higher in the training group (P < 0.05).

CONCLUSION

Aerobic training in addition to conventional rehabilitation after a hip fracture is feasible and safe and it was effective in improving gait performance and strength of fractured leg.

TRIAL REGISTRATION

NCT04025866.

Responsiveness and minimal clinically important difference of the Mini-BESTest in patients with Parkinson's disease

BACKGROUND

Balance problems in Parkinson's Disease (PD) require appropriate evaluation. While the Mini-BESTest is commonly used to assess dynamic balance, some of its psychometric properties have not yet been addressed.

RESEARCH QUESTION

What is the responsiveness and the Minimal Clinically Important Difference (MCID) of the Mini-BESTest in patients with PD?

METHODS

One-hundred forty-eight patients with PD underwent a treatment specific for balance skills (1-h session, three times/week for four weeks). All patients were initially evaluated with the Mini-BESTest and Activities-Specific Balance Confidence scale 5-levels (ABC-5L). Post-treatment, patients were assessed with the Mini-BESTest, ABC-5L and Global Rating of Change (GRC, both patient- and physiotherapist-rated). Responsiveness to treatment and MCID were calculated with distribution and anchor-based methods: effect size, area under the curve (AUC) of receiver operating characteristics (ROC), and correlations between evaluations (change in score of Mini-BESTest, ABC-5L, GRC). Eleven a priori hypotheses were formulated for testing responsiveness.

RESULTS

The effect size of treatment measured with the Mini-BESTest was 0.44, revealing moderate responsiveness. AUCs were 0.75, 0.82 and 0.59 for the patient-rated GRC, physiotherapist-rated GRC and ABC-5L, respectively. There was a moderate correlation between changes in the Mini-BESTest and patient-rated (r_s = 0.42) or physiotherapist-rated (r_s = 0.62) GRC scores. Conversely, a low correlation (r_s = 0.17) was found between changes in the Mini-BESTest and ABC-5L. Consequently, 72.7% of hypotheses were met. The Mini-BESTest MCID was between 3.4 and 4.0 when calculated with distribution and anchor-based methods, respectively.

SIGNIFICANCE

The Mini-BESTest showed moderate responsiveness for detecting treatment-related improvement in dynamic balance. A 4.0-point MCID value is useful to identify clinical effects of balance rehabilitation in a single patient with PD. Values ranging from 3.4 and 4.0 are recommended for interpretation of results at a group level.

Development of a new high sensitivity mechanical switch for augmentative and alternative communication access in people with amyotrophic lateral sclerosis

BACKGROUND

People with Amyotrophic Lateral Sclerosis (PwALS) in the advanced phase are critically affected by an almost total loss of mobility and severe communication problems. Scanning access based on the patient's interaction with a sensor (or switch) that intercepts even a weak body movement is a valid communication aid. However, its use becomes limited with the progressive decline of residual movements. To overcome this problem, we designed a new sensor, the Lever Magnetic-spring Mechanical Switch (LeMMS), allowing repeated activation/release cycles requiring a very small activation force.

METHODS

The LeMMS was applied and validated in a group of 20 PwALS in an advanced stage of disease. All subjects were regular users of communication aids employing other sensors, but which they could no longer operate their sensors (different from LeMMS). Patients were assessed at baseline (t0) and after one (t1), 6 (t2) and 12 (t3) months. Assessment at t0 included administration of standardized clinical scales, the Click-Test-30 counting the maximum number of LeMMS activations in 30 s, and thumb/fingers strength assessment with the Kendall scale. The QUEST 2.0-Dev questionnaire was administered at t1. Some use-related information and the Click-Test-30 were collected at t1, t2 and t3.

RESULTS

After one training session, all patients could operate the LeMMS with minimal residual movement of one finger. At t1, they used it on average 5.45 h/day. The mean score of the QUEST 2.0-Dev was 4.63, suggesting strong satisfaction with the LeMMS. Regarding Click-Test-30 scores, no significant difference was found between t0 and t1, but performance at t2 and t3 declined significantly (p < 0.005 vs. t0). At t3, 9/20 patients were still able to use their communication aid.

CONCLUSIONS

This new switch sensor can enable PwALS to use their communication aids for a prolonged time even in the advanced phase of disease. It is easy to use, reliable and cheap, thus representing an intermediate alternative to more sophisticated and costly devices.

Is the Brief-BESTest Brief Enough? Suggested Modifications Based on Structural Validity and Internal Consistency

BACKGROUND

The Brief Balance Evaluation Systems Test (Brief-BESTest) could be a useful tool for balance assessment. Although some psychometric characteristics have been examined, others still need to be clarified.

OBJECTIVE

The objective was to assess the structural validity, convergent validity, discriminant validity, and internal consistency of the Brief-BESTest in neurological patients.

DESIGN

This was a cross-sectional study.

METHODS

Data were from 416 patients with neurological disease and related balance disorders. Patients were assessed with the 5-levels Activities-Specific Balance Confidence Scale (ABC 5-levels), Brief-BESTest, and some simple balance tests (ie, 1-leg stance, Timed "Up & Go" test, functional reach, and a fall history questionnaire). Three Brief-BESTest models were examined through confirmatory factor analysis, and the following indexes were calculated: Comparative Fit Index, Tucker-Lewis Index, and root-mean-square error of approximation. Convergent validity was assessed by calculating the correlation between Brief-BESTest and ABC 5-levels total scores. Receiver operating characteristics assessed the ability of each model to differentiate between people with falls and those without falls. Internal consistency was measured with Cronbach α and coefficient ω.

RESULTS

Confirmatory factor analysis showed model 3 (Comparative Fit Index = 0.97; Tucker-Lewis Index = 0.95; root-mean-square error of approximation = 0.05), with item 1 removed and error covariance between items 3 and 4 and between items 5 and 6, to have a significantly better structure than models 1 and 2. The correlation between Brief-BESTest and ABC 5-levels was 0.61 (Spearman ρ) for all 3 models. The area under the curve of the receiver operating characteristics showed an acceptable accuracy (0.72) in distinguishing patients with a history of falls from those without a history of falls (95% confidence interval = 0.66-0.78) for all models and was superior to the areas under the curve of other simple balance tests (1-leg stance, Timed "Up & Go" test, functional reach). Cronbach α was good for Brief-BESTest models 1 (0.92) and 3 (0.92), but ω was greater than 0.80 only for model 3.

LIMITATIONS

The sample was heterogeneous.

CONCLUSIONS

The Brief-BESTest, after some changes, shows good validity and internal consistency in patients affected by different balance disorders.

Proposal of a new conceptual gait model for patients with Parkinson's disease based on factor analysis

Background

Gait impairment is a risk factor for falls in patients with Parkinson’s disease (PD). Gait can be conveniently assessed by electronic walkways, but there is need to select which spatiotemporal gait variables are useful for assessing gait in PD. Existing models for gait variables developed in healthy subjects and patients with PD show some methodological shortcomings in their validation through exploratory factor analysis (EFA), and were never confirmed by confirmatory factor analysis (CFA). The aims of this study were (1) to create a new model of gait for PD through EFA, (2) to analyze the factorial structure of our new model and compare it with existing models through CFA.

Results

From the 37 variables initially considered in 250 patients with PD, 10 did not show good-to-excellent reliability and were eliminated, while further 19 were eliminated after correlation matrix and Kaiser–Meyer–Olkin measure. The remaining eight variables underwent EFA and three factors emerged: pace/rhythm, variability, and asymmetry. Structural validity of our new model was then examined with CFA, using the structural equation modeling. After some modifications, suggested by the Modification Indices, we obtained a final model that showed an excellent fit. In contrast, when the structure of previous models of gait was analyzed, no model achieved convergence with our sample of patients.

Conclusions

Our model for spatiotemporal gait variables of patients with PD is the first to be developed through an accurate EFA and confirmed by CFA. It contains eight gait variables divided into three factors and shows an excellent fit. Reasons for the non-convergence of other models could be their inclusion of highly inter-correlated or low-reliability variables or could be possibly due to the fact that they did not use more recent methods for determining the number of factors to extract.

Walking Along Curved Trajectories. Changes With Age and Parkinson's Disease. Hints to Rehabilitation

In this review, we briefly recall the fundamental processes allowing us to change locomotion trajectory and keep walking along a curved path and provide a review of contemporary literature on turning in older adults and people with Parkinson's Disease (PD). The first part briefly summarizes the way the body exploits the physical laws to produce a curved walking trajectory. Then, the changes in muscle and brain activation underpinning this task, and the promoting role of proprioception, are briefly considered. Another section is devoted to the gait changes occurring in curved walking and steering with aging. Further, freezing during turning and rehabilitation of curved walking in patients with PD is mentioned in the last part. Obviously, as the research on body steering while walking or turning has boomed in the last 10 years, the relevant critical issues have been tackled and ways to improve this locomotor task proposed. Rationale and evidences for successful training procedures are available, to potentially reduce the risk of falling in both older adults and patients with PD. A better understanding of the pathophysiology of steering, of the subtle but vital interaction between posture, balance, and progression along non-linear trajectories, and of the residual motor learning capacities in these cohorts may provide solid bases for new rehabilitative approaches.

Abnormal gait pattern emerges during curved trajectories in high-functioning Parkinsonian patients walking in line at normal speed

Background

Several patients with Parkinson´s disease (PD) can walk normally along straight trajectories, and impairment in their stride length and cadence may not be easily discernible. Do obvious abnormalities occur in these high-functioning patients when more challenging trajectories are travelled, such as circular paths, which normally implicate a graded modulation in the duration of the interlimb gait cycle phases?

Methods

We compared a cohort of well-treated mildly to moderately affected PD patients to a group of age-matched healthy subjects (HS), by deliberately including HS spontaneously walking at the same speed of the patients with PD. All participants performed, in random order: linear and circular walking (clockwise and counter-clockwise) at self-selected speed. By means of pressure-sensitive insoles, we recorded walking speed, cadence, duration of single support, double support, swing phase, and stride time. Stride length-cadence relationships were built for linear and curved walking. Stride-to-stride variability of temporal gait parameters was also estimated.

Results

Walking speed, cadence or stride length were not different between PD and HS during linear walking. Speed, cadence and stride length diminished during curved walking in both groups, stride length more in PD than HS. In PD compared to HS, the stride length-cadence relationship was altered during curved walking. Duration of the double-support phase was also increased during curved walking, as was variability of the single support, swing phase and double support phase.

Conclusion

The spatio-temporal gait pattern and variability are significantly modified in well-treated, high-functioning patients with PD walking along circular trajectories, even when they exhibit no changes in speed in straight-line walking. The increased variability of the gait phases during curved walking is an identifying characteristic of PD. We discuss our findings in term of interplay between control of balance and of locomotor progression: the former is challenged by curved trajectories even in high-functioning patients, while the latter may not be critically affected.

Instrumental or Physical-Exercise Rehabilitation of Balance Improves Both Balance and Gait in Parkinson's Disease

We hypothesised that rehabilitation specifically addressing balance in Parkinson's disease patients might improve not only balance but locomotion as well. Two balance-training protocols (standing on a moving platform and traditional balance exercises) were assessed by assigning patients to two groups (Platform, n = 15, and Exercises, n = 17). The platform moved periodically in the anteroposterior, laterolateral, and oblique direction, with and without vision in different trials. Balance exercises were based on the Otago Exercise Program. Both platform and exercise sessions were administered from easy to difficult. Outcome measures were (a) balancing behaviour, assessed by both Index of Stability (IS) on platform and Mini-BESTest, and (b) gait, assessed by both baropodometry and Timed Up and Go (TUG) test. Falls Efficacy Scale-International (FES-I) and Parkinson's Disease Questionnaire (PDQ-8) were administered. Both groups exhibited better balance control, as assessed both by IS and by Mini-BESTest. Gait speed at baropodometry also improved in both groups, while TUG was less sensitive to improvement. Scores of FES-I and PDQ-8 showed a marginal improvement. A four-week treatment featuring no gait training but focused on challenging balance tasks produces considerable gait enhancement in mildly to moderately affected patients. Walking problems in PD depend on postural instability and are successfully relieved by appropriate balance rehabilitation. This trial is registered with ClinicalTrials.gov NCT03314597.

Gait abnormalities of COPD are not directly related to respiratory function

STUDY OBJECTIVE

To assess whether gait abnormalities in COPD depend on mere impairment of respiratory function.

METHODS

In 40 patients with COPD at different GOLD stages and 28 controls, we evaluated: forced expiratory volume in 1s (FEV1); partial pressure of oxygen; Mini-Mental State Examination (MMSE); dynamic balance through the Mini-BESTest (MBT); Timed Up and Go (TUG) test without and with dual task counting aloud back by three; 6-min walk test (6MWT); body sway during quiet stance (stabilometry); spatial-temporal variables of gait by a 4-m long sensorized walkway (baropodometry). Lower-limb muscle strength, tendon reflexes, and sensation were also clinically evaluated.

RESULTS

Muscle strength of proximal but not distal muscles was slightly reduced in patients, whereas reflexes and sensation were unaffected. FEV1, partial pressure of oxygen, MMSE, MBT, stabilometry, as well as baropodometry, were abnormal and unrelated to muscle weakness. The time taken to perform the TUG test was increased, and to a larger extent with than without dual task. At baropodometry, variability of step length was increased; abnormalities of gait variables were associated with larger body sway but not with FEV1 or hypoxemia. Gait speed at 6MWT was correlated with MBT score and with FEV1 as well as hypoxemia.

CONCLUSIONS

6MWT findings give a measure of gait disability linked to endurance-related respiratory failure. Gait at baropodometry is associated with impairment of balance, cognitive status and abnormal dual task performance. We suggest that central nervous lesions, presumably of vascular origin, are detrimental to balance and gait in COPD.

Curved Walking Rehabilitation with a Rotating Treadmill in Patients with Parkinson's Disease: A Proof of Concept

Training subjects to step-in-place eyes open on a rotating platform while maintaining a fixed body orientation in space [podokinetic stimulation (PKS)] produces a posteffect consisting in inadvertent turning around while stepping-in-place eyes closed [podokinetic after-rotation (PKAR)]. Since the rationale for rehabilitation of curved walking in Parkinson's disease is not fully known, we tested the hypothesis that repeated PKS favors the production of curved walking in these patients, who are uneasy with turning, even when straight walking is little affected. Fifteen patients participated in 10 training sessions distributed in 3 weeks. Both counterclockwise and clockwise PKS were randomly administered in each session. PKS velocity and duration were gradually increased over sessions. The velocity and duration of the following PKAR were assessed. All patients showed PKAR, which increased progressively in peak velocity and duration. In addition, before and at the end of the treatment, all patients walked overground along linear and circular trajectories. Post-training, the velocity of walking bouts increased, more so for the circular than the linear trajectory. Cadence was not affected. This study has shown that parkinsonian patients learn to produce turning while stepping when faced with appropriate training and that this capacity translates into improved overground curved walking.

[Prolonged neuromuscular block caused by succinylcholine in a patient with normal cholinesterase activity]

The authors describe a case of prolonged neuromuscular blockade following suxamethonlum in a patient with a normal cholinesterase activity and dibucaine number > or = 75%. In this case a peripheral nerve stimulator and capnography allowed neuromuscular blockade evaluation and fresh frozen plasma infusion led to a normal recovery from suxamethonium neuromuscular blockade. This report suggests a case of abnormal cholinesterase activity described as "silent variant".

Prospects for a pharmacological treatment of phenylketonuria

The present study deals with a new tentative therapeutic approach of phenylketonuria, based on the use of Anabolic Steroids. Data have been obtained in 10 children, 3 females and 7 males, aged 4-12 years, all presenting the stigmata of true phenylketonuria. The Anabolic Steroids used were Norandrostenolone Phenylpropionate, administered intramuscularly, in increasing doses from 25 to 75 mg.a.d., for 2 years. The 3 older patients were always on a totally free diet, the 7 younger ones on a semi-free diet. The results obtained demonstrate a total normalization of the blood levels of phenylalanine and tyrosine all along the treatment. Moreover, improvements of the psychoneurological disorders were observed.