Subclinical Disability Research Articles

Clinical monitoring of multiple sclerosis patients by means of digital technology, a field in the midst of a revolution

Despite the great advances that have occurred in the diagnosis and treatment of ? multiple sclerosis (MS), few changes have taken place in terms of clinical monitoring. The lack of time and space in clinical practice limits the assessment of invisible symptoms and certain motor symptoms as manual dexterity and walking ability, which have a clear impact on the patient functional situation. To review the potential role of technological tools in the clinical monitoring of MS patients. A bibliographic search was carried out through PubMed, selecting those studies focused on biosensors and digital tools aimed at evaluating the general functional situation, and specific aspects of the disease or certain functional systems. Different digital tools such as biosensors, mobile or web applications, both for remote and hospital use, self-completed or administered by healthcare personnel, seem to offer a more 'complete and real' picture of the functional situation of patients. Some studies have shown that digital technology could detect subclinical disability progression, which traditional tests, including the EDSS, fail to reflect, favouring the adoption of appropriate therapeutic measures and actions in an early and personalized manner. Digital tools, capable of collecting detailed and extensive clinical information, could play an important role in decision-making and clinical monitoring of patients with MS.

Subclinical motor impairment assessed with an engineered glove correlates with magnetic resonance imaging tissue damage in radiologically isolated syndrome.

An engineered glove measuring finger motor performance previously showed ability to discriminate early-stage multiple sclerosis (MS) patients from healthy controls (HCs). Radiologically isolated syndrome (RIS) classifies asymptomatic subjects with brain magnetic resonance imaging (MRI) abnormalities suggestive of multiple sclerosis. Seventeen asymptomatic subjects with RIS and 17 HCs were assessed. They performed finger-to-thumb opposition sequences at their maximal velocity, metronome-paced bimanual movements and conventional and diffusion tensor MRI. Subjects with RIS showed lower (P = 0.005) maximal velocity and higher (P = 0.006) bimanual coordination impairment than HCs. In RIS, bimanual coordination correlated with T2-lesion volume, fractional anisotropy and radial diffusivity in the white matter. These findings point out the relevance of fine hand measures as a robust marker of subclinical disability.

Occupational Performance and Subclinical Disability in Community-Dwelling Older Adults

Occupational Performance and Subclinical Disability in Community-Dwelling Older Adults

The Mirror Neuron System in Relapsing Remitting Multiple Sclerosis Patients with Low Disability.

To study the visuospatial/visuoperceptive function using a mirror neuron system (MNS) based approach in multiple sclerosis (MS) patients and a healthy control group. Two task-based fMRIs (an execution task and an observation task) and one resting-fMRI were performed in a group of MS patients (n = 24) and a group of healthy controls (n = 15). The execution and observation tasks consisted of the performance or observation of the index-thumb opposition task. Statistical parametric mapping approaches were used to identify differences in the brain activity and functional connectivity (FC) of the MNS between MS patients and healthy controls. Furthermore, visuospatial and visuoperceptive evaluation was performed by a neuropsychologist on all the participants. No global differences between groups were identified when the activity during both the execution and the observation conditions was tested. Nevertheless, differences in FC maps were identified: healthy controls showed higher connectivity between the MNS regions (between the inferior parietal lobule and the inferior frontal gyrus bilaterally) than MS patients. The absence of differences between the studied groups may be the consequence of the selection of a cohort of MS patients with low disability and with no recent relapse. However, the presence of a decrease in functional connectivity within the MNS in MS patients could indicate the presence of subclinical disability in MNS functioning, not measurable by neuropsychological tests.

Disability and Fatigue Can Be Objectively Measured in Multiple Sclerosis.

BackgroundThe available clinical outcome measures of disability in multiple sclerosis are not adequately responsive or sensitive.ObjectiveTo investigate the feasibility of inertial sensor-based gait analysis in multiple sclerosis.MethodsA cross-sectional study of 80 multiple sclerosis patients and 50 healthy controls was performed. Lower-limb kinematics was evaluated by using a commercially available magnetic inertial measurement unit system. Mean and standard deviation of range of motion (mROM, sROM) for each joint of lower limbs were calculated in one minute walking test. A motor performance index (E) defined as the sum of sROMs was proposed.ResultsWe established two novel observer-independent measures of disability. Hip mROM was extremely sensitive in measuring lower limb motor impairment, being correlated with muscle strength and also altered in patients without clinically detectable disability. On the other hand, E index discriminated patients according to disability, being altered only in patients with moderate and severe disability, regardless of walking speed. It was strongly correlated with fatigue and patient-perceived health status.ConclusionsInertial sensor-based gait analysis is feasible and can detect clinical and subclinical disability in multiple sclerosis.

Diving Below the Surface of Progressive Disability: Considering Compensatory Strategies as Evidence of Sub-Clinical Disability

To provide a comprehensive review regarding the role of activity and participation compensations within the disablement process, identify directions for future research, and discuss the implications of compensation pertaining to public health initiatives aimed at preventing and reversing disability. This article evaluated how using compensatory strategies to cope with functional deficits reveals important transitions within the disablement process and signifies a unique opportunity to identify early declines in function. Previous research suggests that (a) adopting compensatory strategies to maintain activity/participation is strongly associated with functional decline and disease severity and significantly predicts the onset of limitations/restrictions; (b) compensation can be reliably quantified; and (c) contextual knowledge about how individuals adapt to functional decline can be used to describe transitions in the disablement process. Characterizing subtle adaptations prior to the onset of activity limitations and participation restrictions will not only aid in understanding the complex disablement process but also help inform social services and future prevention strategies. Overall, this article integrates the concept of compensation into the current model of disability and proposes a framework for identifying and interpreting compensatory behavior.

Measuring Fitness of Kenyan Children with Polyparasitic Infections Using the 20-Meter Shuttle Run Test as a Morbidity Metric

BackgroundTo date, there has been no standardized approach to the assessment of aerobic fitness among children who harbor parasites. In quantifying the disability associated with individual or multiple chronic infections, accurate measures of physical fitness are important metrics. This is because exercise intolerance, as seen with anemia and many other chronic disorders, reflects the body's inability to maintain adequate oxygen supply (VO2 max) to the motor tissues, which is frequently linked to reduced quality-of-life in terms of physical and job performance. The objective of our study was to examine the associations between polyparasitism, anemia, and reduced fitness in a high risk Kenyan population using novel implementation of the 20-meter shuttle run test (20mSRT), a well-standardized, low-technology physical fitness test.Methodology/Principal FindingsFour villages in coastal Kenya were surveyed during 2009–2010. Children 5–18 years were tested for infection with Schistosoma haematobium (Sh), malaria, filaria, and geohelminth infections by standard methods. After anthropometric and hemoglobin testing, fitness was assessed with the 20 mSRT. The 20 mSRT proved easy to perform, requiring only minimal staff training. Parasitology revealed high prevalence of single and multiple parasitic infections in all villages, with Sh being the most common (25–62%). Anemia prevalence was 45–58%. Using multiply-adjusted linear modeling that accounted for household clustering, decreased aerobic capacity was significantly associated with anemia, stunting, and wasting, with some gender differences.Conclusions/SignificanceThe 20 mSRT, which has excellent correlation with VO2, is a highly feasible fitness test for low-resource settings. Our results indicate impaired fitness is common in areas endemic for parasites, where, at least in part, low fitness scores are likely to result from anemia and stunting associated with chronic infection. The 20 mSRT should be used as a common metric to quantify physical fitness and compare sub-clinical disability across many different disorders and community settings.

Subclinical disability in valued life activities among individuals with rheumatoid arthritis

Subclinical disability, the need for modifications in task performance or frequency without reported difficulty with the task, has been identified as a stage along the disability continuum. We estimated the prevalence of subclinical disability in valued life activities (VLAs) among individuals with rheumatoid arthritis (RA), identified characteristics of individuals with VLA subclinical disability, and estimated the ability of VLA subclinical disability to predict later decrements in functioning. Data were from 3 years of a longitudinal panel study of individuals with RA, for which annual structured telephone interviews are conducted (n=508 in year 1, n=442 in year 3). Respondents rated difficulty in VLAs and then reported whether they used any of 4 behavioral modifications (limitations, extra time, help, or equipment) for each. Subclinical disability was defined for each VLA as no reported difficulty with use of any modification. Multiple regression analyses identified predictors of subclinical disability in year 1 and the role of year 1 subclinical disability in development of overt disability between year 1 and year 3. Almost three-quarters of the subjects exhibited subclinical disability in at least 1 VLA in year 1. Duration of RA was consistently associated with subclinical disability. Individuals with subclinical disability at baseline were significantly more likely to experience increases in functional limitations (odds ratio [OR] 1.09, 95% confidence interval [95% CI] 1.01-1.18) and VLA disability (OR 1.14, 95% CI 1.06-1.23) over a prospective 2-year period. Subclinical disability may be a valuable marker of individuals in a disability transition phase who are particularly susceptible to intervention that would enable them to maintain functioning.

Further Evidence for the Importance of Subclinical Functional Limitation and Subclinical Disability Assessment in Gerontology and Geriatrics

The objectives of this work were to determine the prevalence of self-reported subclinical status for functional limitation and disability at baseline and assess their independent effects on the onset of functional limitation and disability 1-2 years later. Nine hundred ninety-eight African American men and women 49-65 years old in St. Louis, MO, received comprehensive in-home evaluations at baseline and two annual telephone follow-ups. Outcome measures included walking a half-mile, climbing steps, stooping-crouching-kneeling, lifting or carrying 10 lbs., and doing heavy housework. The baseline prevalence of subclinical status was 26.4% for walking a half-mile, 26.8% for climbing steps, 39.0% for stooping-crouching-kneeling, 29.1% for lifting or carrying 10 lbs., and 22.7% for doing heavy housework. The adjusted odds ratios for the task-specific subclinical status measure at baseline on developing difficulty 1-2 years later were 1.68 (p < .05) for walking a half-mile, 4.46 (p < .001) for climbing steps, 2.48 (p < .001) for stooping-crouching-kneeling, 2.51 (p < .001) for lifting or carrying 10 lbs., and 2.22 (p < .001) for doing heavy housework. Performance tests (tandem stand, chair stands, and preferred gait speed) did not have consistent independent effects on the onset of functional limitation or disability. The subclinical status measures were the main predictors of the onset of difficulty in all tasks and functions 1-2 years later. Interventions to reduce frailty should focus on self-reported subclinical status as an early warning system.

Inner City, Middle-Aged African Americans Have Excess Frank and Subclinical Disability

Healthy People 2010 seeks to decrease or eliminate the health disparities experienced by disadvantaged minority groups. African American Health (AAH) is a population-based panel study of community-dwelling African Americans born between 1936 and 1950 from two strata. The first encompasses a poor, inner city area, and the second involves a suburban population with higher socioeconomic status. The authors recruited 998 participants (76% recruitment). Frank disability was assessed for 25 tasks and defined as inability or difficulty performing that task. Subclinical disability was assessed for 12 tasks and defined as no difficulty but a change in either manner or frequency of task performance. Frank disability prevalences were compared with national data for community-dwelling non-Hispanic white persons (NHW) and African American persons in the same age range. Compared with the suburban sample, the inner city group had a higher prevalence of frank disability for all 25 tasks (p<.05 for 16) and subclinical disability for 11 of the 12 tasks (p<.05 for 5). Both strata had more frank disability compared with the national NHW population. The inner city area had higher frank disability proportions than did the national African American sample, whereas the suburban group had similar disability levels. The AAH inner city group experiences more frank disability than other populations of African Americans and NHWs. The increased prevalence of subclinical disability in the inner city group compared with the suburban group suggests that the disparity in frank disability will continue. These findings indicate that African Americans living in poor inner city areas in particular need intensive and targeted clinical and public health efforts.

1188 Subclinical infarcts and functional disability in ischaemic stroke patient

1188 Subclinical infarcts and functional disability in ischaemic stroke patient

Measuring subclinical disability in older mexican americans.

The purpose of this study was to develop a comprehensive list of adaptive strategies to prevent disability and use this information to devise a preliminary measure of subclinical disability (state of sustained independence in the presence of latent or manifest functional limitations) suitable for older Mexican Americans. Semistructured interviews were conducted with 24 community-dwelling Mexican American elders (> or =65 years old) to elicit information about adaptations in performance of daily living tasks (eg, walking, dressing, and shopping) that may indicate presence of subclinical disability. This information was used to construct a quantitative self-report measure of subclinical disability administered to 207 older Mexican Americans. Item and factor analyses were performed to reduce the number of items and establish their underlying structure. Construct and discriminant validity of the reduced instrument was determined. A framework comprised of nine categories of daily living tasks, three functional levels, and five adaptation types was generated from the qualitative data. The initial 133-item measure (named the ADAPT) was reduced to a 44-item scale with three subscales (physical, household, and social). ADAPT scores correlated significantly in the expected direction with standard functional status measures, but the shared variance was modest, indicating that the ADAPT captured substantial, unique variance. Mean ADAPT scores differed significantly and were monotonically lower across subgroups classified as independent, subclinically disabled, and disabled, respectively. The ADAPT seems to have construct and discriminant validity as a measure of subclinical disability. Additional research is required to determine sensitivity to change and clinically significant cut points for varying risk of frank disability.

Comments on “Causal Relation” in Workmen's Compensation Proceedings

The lack of “fit” between legal and medical concepts is perhaps best shown in the psychiatric disability of injured workmen. In the particular case discussed in this article, the problem is illustrated (1) in the long-standing preexistence of organic brain disease over many years, (2) in the occurrence of a heart attack from which the claimant recovered in “physical” terms. The heart attack forced a break in his employment and made his previously subclinical disability obvious to employer, wife, and the claimant himself. The resulting disability featured depression, anhedonia, and loss of identity, thus becoming primarily psychiatric in nature. No one of these disorders is “causally related” as a single entity; the problem is the outcome of a cumulative stress in a person made highly vulnerable through prior deterioration. Of particular import is the demonstration of “context-dependence”: workers depend for their own sense of identity and responsibility upon their occupation, and the loss of work becomes itself a “causal” factor.