Characterizing ambulatory function in children with PPP2R5D-related neurodevelopmental disorder

BACKGROUND

Individuals with PPP2R5D-related neurodevelopmental disorder have an atypical gait pattern characterized by ataxia and incoordination. Structured, quantitative assessments are needed to further understand the impact of these impairments on function.

RESEARCH QUESTION

How do gait parameters and ambulatory function of individuals with PPP2R5D-related neurodevelopmental disorder compare to age and sex matched healthy norms?

METHODS

Twenty-six individuals with PPP2R5D pathogenic genetic variants participated in this observational, single visit study. Participants completed at least one of the following gait assessments: quantitative gait analysis at three different speeds (preferred pace walking (PPW), fast paced walking (FPW) and running, six-minute walk test (6MWT), 10-meter walk run (10MWR), and timed up and go (TUG). Descriptive statistics were used to summarize gait variables. Percent of predicted values were calculated using published norms. Paired t-tests and regression analyses were used to compare gait variables.

RESULTS

The median age of the participants was 8 years (range 4-27) and eighteen (69.2 %) were female. Individuals with PPP2R5D-related neurodevelopmental disorder walked slower and with a wider base of support than predicted for their age and sex. Stride velocity ranged from 48.9 % to 70.1 % and stride distance from 58.5 % to 81.9 % of predicted during PPW. Percent of predicted distance walked on the 6MWT ranged from 30.6 % to 71.1 % representing varied walking impairment. Increases in stride distance, not cadence, were associated with changes in stride velocity in FPW (R2 = 0.675, p =< 0.001) and running conditions (R2 = 0.918, p =< 0.001).

SIGNIFICANCE

We quantitatively assessed the abnormal gait in individuals with PPP2R5D-related neurodevelopmental disorder. These impairments may affect ability to adapt to environmental changes and participation in daily life. Rehabilitative interventions targeting gait speed and balance may improve function and safety for individuals with PPP2R5D-related neurodevelopmental disorder.

Integrity of the Inferior Cerebellar Peduncle Correlates with Ambulatory Function after Hemorrhagic Stroke

OBJECTIVES

Cerebro-cerebellar connectivity plays a critical role in motor recovery after stroke; however, the underlying mechanism of walking recovery is unclear. The dorsal spinocerebellar pathway has been suggested as a biomarker of poststroke ambulatory function. We aimed to explore the association between ambulatory function and the dorsal spinocerebellar pathway's integrity after intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

Twenty-seven patients with ICH who were admitted for inpatient rehabilitation during the subacute phase of stroke and 27 age-matched healthy controls were included retrospectively. Ambulatory function was assessed using the Berg Balance Scale and Mobility score. We measured the fractional anisotropy (FA) values of the corticospinal tract (CST) and inferior cerebellar peduncle (ICP) as the final route of the dorsal spinocerebellar pathway. The FA laterality indices, representing the degree of degeneration, were calculated. A Spearman correlation analysis and multivariate linear regression models were used to determine the associations between the FA laterality indices and ambulatory function.

RESULTS

An FA reduction was found in both the ipsilesional CST and contralesional ICP of the patients. The ICP FA laterality index exhibited a moderate correlation with ambulatory function (Berg Balance Scale, ρ_BBS=0.589; Mobility score, ρ_MS=0.619). On dividing the patient group into the moderate (mRS 3, 4) and severe disability (mRS 5) groups, a stronger correlation was found (ρ_BBS=0.777, ρ_MS=0.856, moderate disability; ρ_BBS=0.732, ρ_MS=0.797, severe disability). The ICP FA laterality index and age were independently associated with the Mobility score (R²=0.525).

CONCLUSIONS

ICP degeneration occurs after ICH, and its degree is associated with ambulatory function after ICH.

Evaluating ambulatory function as an outcome following treatment for spinal metastases: a systematic review

BACKGROUND CONTEXT

Studies regarding treatment of spinal metastases are critical to evidence-based decision-making. However, variation exists in how a key outcome, ambulatory function, is assessed.

PURPOSE

To characterize the sources and tools investigators have used to evaluate ambulatory function as an outcome following treatment of spinal metastases. We also sought to understand the ways ambulatory function has been conceptualized in prior studies.

STUDY DESIGN

Systematic review of the literature.

PATIENT SAMPLE

We identified 44 published studies for inclusion. Samples within these investigations ranged from 20 to 2,096 subjects.

OUTCOME MEASURES

We describe the methods investigators have used to evaluate ambulatory function following treatment for spinal metastases.

METHODS

We conducted a systematic review through PubMed, Scopus and Web of Science following PRISMA guidelines. We included studies that consisted of adult patients receiving operative or non-operative treatment for spinal metastases. We also required that study investigators specified post-treatment ambulatory function as an outcome. We recorded year of publication, study design, types of spinal metastases included in the study, treatments employed, and sample size. We also described the source (medical record, study-specific observer and/or provider, patient and/or participant), tool (standardized measure, quantitative, qualitative) and concept (eg, ambulatory vs. non-ambulatory; independent ambulation vs. ambulatory with assistance vs. non-ambulatory) used to assess ambulatory function.

RESULTS

We found the plurality of studies relied on medical record documentation as their source. Amongst prospective studies, only a minority used a quantitative measure (eg, prespecified degree of walking ability) to assess ambulatory function. Most studies conceptualized ambulatory function as a dichotomized outcome, typically ambulatory versus non-ambulatory or a similar equivalent.

CONCLUSIONS

Wide variation exists in how ambulatory function is defined in studies involving patients with spinal metastases. We suggest several improvements that will allow a more robust assessment of the quality and quantity of ambulatory function among patients treated for spinal metastases.

Non-operative management of spinal metastases: A prognostic model for failure

OBJECTIVES

To describe patient-specific characteristics associated with non-operative failure leading to surgery.

PATIENTS AND METHODS

We conducted a retrospective review of patients treated for spinal metastases from 2005 to 2017. We deemed patients as failures if they were treated non-operatively and then received a surgical intervention within one year of starting a non-operative regimen. We used multivariable Poisson regression to identify factors associated with non-operative failure. We conducted internal validation using bootstrapping with 1000 replications.

RESULTS

We identified 1205 patients with spinal metastases, of whom 834 were initially treated non-operatively and constituted the analytic sample. Of these 77 (9%) went on to have surgery within 1-year of presentation and were deemed non-operative treatment failures. We identified vertebral body collapse and/or pathologic fracture (adjusted Risk Ratio [RR] 1.75; 95% Confidence Interval [CI] 1.11, 2.76) and neurologic signs or symptoms at presentation (RR 1.90; 95% CI 1.19, 3.03) as factors independently associated with an increased risk of non-operative failure. Platelet-lymphocyte ratio >155, a marker for inflammatory state, was also associated with an increased risk of failure (RR 2.32; 95% CI 1.15, 4.69). Failure rates among those with 0, 1, 2 or all three of these risk factors were 5%, 7%, 12% and 20%, respectively (p = 0.004).

CONCLUSION

We found that 9% of patients with spinal metastases initially treated non-operatively received surgery within 1-year of commencing care. The likelihood of surgery increased with the number of risk factors. These results can be used in counseling and shared decision making at the time of initial presentation.

Ergometer cycling improves the ambulatory function and cardiovascular fitness of stroke patients-a randomized controlled trial

[Purpose] The aim of this study was to assess the effects of ergometer cycling on the ambulatory function and cardiovascular fitness of patients with stroke in the sub-acute phase. [Participants and Methods] Twenty (20) patients with stroke in the sub-acute phase were randomly allocated to either an ergometer cycling group (n=10) or a control group (n=10). The experimental (ergometer cycling) group performed cycling exercises in addition to conventional physiotherapy for 60 minutes per session, three times per week for 8 weeks. The control group only received conventional physiotherapy for the same duration as the experimental group. Assessments of participants’ functional ambulatory category, ambulatory velocity, 6-minute walk test, heart rate and blood pressure were conducted at baseline and at the end of the 8-week intervention. [Results] The means of the ambulatory velocity and distance walked in 6 minutes were significantly higher in the ergometer cycling group than those of the control group at week 8. However, the increase in the FAC score was not significant. The means of heart rate, systolic and diastolic blood pressures significantly decreased in the ergometer cycling group compared to the control group at the end of the 8-week of intervention. [Conclusion] This study demonstrated that ergometer cycling improved the ambulatory function and cardiovascular fitness of patients with stroke in the sub-acute phase.

A New Functional Scale and Ambulatory Functional Classification of Duchenne Muscular Dystrophy: Scale Development and Preliminary Analyses of Reliability and Validity

Objective

To develop a simplified functional scale and classification system to evaluate the functional abilities of patients with Duchenne muscular dystrophy (DMD).

Methods

A Comprehensive Functional Scale for DMD (CFSD) was developed using the modified Delphi method. The accompanying Ambulatory Functional Classification System for DMD (AFCSD) was developed based on previously published classification systems.

Results

The CFSD consists of 21 items and 78 sub-items, assessing body structure and function, activities, and participation. Inter-rater intraclass correlation coefficient values were above 0.7 for 17 items. The overall limits of agreement between the two examiners ranged from -6.21 to 3.11. The Spearman correlation coefficient between the total score on the AFCSD and the Vignos Functional Scale was 0.833, and 0.714 between the total score of the AFCSD and the Brooke scale. Significant negative correlations existed between the total score for each functional level of the AFCSD and each functional grade of the Vignos and Brooke scales. The total scores of the CFSD varied significantly between the functional grades of the Vignos scale, and specific grades of the Brooke scale. For the AFCSD, total scores of the CFSD varied significantly between the functional levels.

Conclusion

We have developed a new scale and the associated classification system, to assess the functional ability of children diagnosed with DMD. Preliminary evaluation of the psychometric properties of the functional scale and classification systems indicate sufficient reliability and concurrent validity.

Urinary prostaglandin metabolites as Duchenne muscular dystrophy progression markers

BACKGROUND

Patients with Duchenne muscular dystrophy (DMD) exhibit increased prostaglandin D₂ (PGD₂) expression in necrotic muscle and increased PGD₂ metabolites in their urine. In mouse models, inhibiting PGD₂ production suppresses muscle necrosis, suggesting a possible intervention through PGD₂-mediated activities.

OBJECTIVE

We investigated the involvement of PGD₂ and its potential use as a marker of pathological progression in DMD.

METHODS

Sixty-one male children with DMD and thirty-five age-matched controls were enrolled in the study. DMD patients were divided into "ambulant" and "non-ambulant" groups, which were further subdivided into "steroid" and "non-steroid" therapy groups. Levels of the PGD₂ metabolite tetranor-PGDM (t-PGDM) and creatinine were measured in both spot and 24-hour urine samples, with comparisons between groups made according to geometric mean values.

RESULTS

DMD patients had significantly higher levels of creatinine-corrected t-PGDM in spot urine samples as compared with the control group. Additionally, both ambulant and non-ambulant DMD groups had significantly higher levels of t-PGDM as compared with controls, with no significant difference in t-PGDM levels observed between steroid and non-steroid groups. Moreover, total creatinine excretion in 24-hour urine samples was significantly lower in DMD patients as compared with controls, and although DMD patients had lower muscle mass than controls, their overall levels of t-PGDM did not differ significantly from those in the non-ambulant and control groups.

CONCLUSION

PGD₂ might help explain the progression and symptomatic presentations (e.g., ambulatory difficulty) associated with DMD, suggesting it as a useful pathological marker and use of a selective PGD₂ inhibitor as a potential treatment modality.

Determinants of Functional Outcomes Using Clinical Pathways for Rehabilitation After Hip Fracture Surgery

Background

This study evaluated functional outcomes using newly established clinical pathways after hip fracture surgery in older adults and analyzed the major determinants of successful functional outcomes in rehabilitation programs using standardized clinical pathways.

Methods

This was a retrospective cohort study performed in a tertiary rehabilitation facility. A total of 220 patients who had received unilateral hip fracture surgery were followed up from immediately after surgery to 6 months postoperatively. Clinical pathways for rehabilitation included early, individualized rehabilitation, education for activities of daily living, review of general medical conditions, and arrangement of discharge settings. One rehabilitation specialist consecutively checked ambulatory function using 3-level grading, and patients were classified into good recovery and poor recovery groups based on ambulatory function at 6 months postoperatively. Logistic regression analysis was performed using 7 representative variables (age, sex, bone mineral density, Mini-Mental Status Examination [MMSE], Berg Balance Scale [BBS], premorbid ambulatory function, and length of hospital stay).

Results

A total of 86.8% of patients could walk with or without assistance at 6 months after surgery and 75.5% of patients involved in the rehabilitation program were classified into the good recovery group in this study. the good recovery group showed higher mmse and bbs scores compared with the poor recovery group. the factors in the model most strongly correlated with recovery were mmse and bbs.

Conclusion

This study showed that a well-designed rehabilitation program could improve ambulatory function in older patients after hip fracture surgery and that cognitive impairment and poor balance control may inhibit the recovery of ambulatory function.

Categorizing natural history trajectories of ambulatory function measured by the 6-minute walk distance in patients with Duchenne muscular dystrophy

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This paper shows that DMD boys could be grouped into classes sharing trajectories.

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Using analysis accounting for trajectory classes, the variation was strongly reduced.

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Reducing unexplained variation could help to improve DMD clinical trial design.

High variability in patients' changes in 6 minute walk distance (6MWD) over time has complicated clinical trials of treatment efficacy in Duchenne muscular dystrophy (DMD). We assessed whether boys with DMD could be grouped into classes that shared similar ambulatory function trajectories as measured by 6MWD. Ambulatory boys aged 5 years or older with genetically confirmed DMD who were enrolled in a natural history study at 11 care centers throughout Italy were included. For each boy, standardized assessments of 6MWD were available at annual intervals spanning 3 years. Trajectories of 6MWD vs. age and trajectories of 6MWD vs. time from enrollment were examined using latent class analysis. A total of 96 boys were included. At enrollment, the mean age was 8.3 years (mean 6MWD: 374 meters). After accounting for age, baseline 6MWD, and steroid use, four latent trajectory classes were identified as explaining 3-year 6MWD outcomes significantly better than a single average trajectory. Patient trajectories of 6MWD change from enrollment were categorized as having fast decline (n = 25), moderate decline (n = 19), stable function (n = 37), and improving function (n = 15) during the 3-year follow-up. After accounting for trajectory classes, the standard deviation of variation in 6MWD was reduced by approximately 40%. The natural history of ambulatory function in DMD may be composed of distinct trajectory classes. The extent to which trajectories are associated with novel and established prognostic factors warrants further study. Reducing unexplained variation in patient outcomes could help to further improve DMD clinical trial design and analysis.