Discriminant Accuracy of Standing Balance Tests for the Level of Gait Dependency in Hospitalized Patients with Alzheimer's Disease

INTRODUCTION

When determining the level of gait independence in patients with Alzheimer's disease (AD), detailed functional assessment is difficult in some patients. The previous literature has suggested simple standing balance tests for patients with AD due to their ease of implementation in clinical practice and relevance to gait. However, their usefulness for discriminating the level of gait independence remains unclear. This study aimed to investigate the discrimination accuracy of a simple standing balance test in the level of gait independence among hospitalized patients with AD.

METHODS

This cross-sectional study was a post hoc analysis of a study conducted on 63 inpatients with AD in a single hospital. Participants were divided into three groups according to their level of gait independence: independent, modified independent (independent, walking with walking aids), and dependent groups (supervision). Gait independence was determined using the Functional Independence Measure. Four standing balance tests were used - closed-leg, semi-tandem, tandem, and one-leg standings - and the discrimination accuracy of each test was calculated by receiver operating characteristic analysis.

RESULTS

One-leg standing was best at discriminating between the independent and modified independent groups (positive predictive value = 80.0%, negative predictive value = 94.1%). Tandem standing was best at discriminating between the modified independent and dependent groups (positive predictive value = 74.1%, negative predictive value = 93.3%).

CONCLUSION

A simple standing balance test may assist in the determining level of gait independence in patients with AD when it is difficult to perform a mobility assessment.

Relationship between gait parameters and cognitive indexes in adult aging

PURPOSE

This study aimed to identify the most effective summary cognitive index predicted from spatio-temporal gait features (STGF) extracted from gait patterns.

METHODS

The study involved 125 participants, including 40 young (mean age: 27.65 years, 50% women), and 85 older adults (mean age: 73.25 years, 62.35% women). The group of older adults included both healthy adults and those with Mild Cognitive Impairment (MCI). Participant´s performance in various cognitive domains was evaluated using 12 cognitive measures from five neuropsychological tests. Four summary cognitive indexes were calculated for each case: 1) the z-score of Mini-Mental State Examination (MMSE) from a population norm (MMSE z-score); 2) the sum of the absolute z-scores of the patients' neuropsychological measures from a population norm (ZSum); 3) the first principal component scores obtained from the individual cognitive variables z-scores (PCCog); and 4) the Mahalanobis distance between the vector that represents the subject's cognitive state (defined by the 12 cognitive variables) and the vector corresponding to a population norm (MDCog). The gait patterns were recorded using a body-fixed Inertial Measurement Unit while participants executed four walking tasks (normal, fast, easy- and hard-dual tasks). Sixteen STGF for each walking task, and the dual-task costs for the dual tasks (when a subject performs an attention-demanding task and walks at the same time) were computed. After applied Principal Component Analysis to gait measures (96 features), a robust regression was used to predict each cognitive index and individual cognitive variable. The adjusted proportion of variance (adjusted-R2) coefficients were reported, and confidence intervals were estimated using the bootstrap procedure.

RESULTS

The mean values of adjusted-R2 for the summary cognitive indexes were as follows: 0.0248 for MMSE z-score, 0.0080 for ZSum, 0.0033 for PCCog, and 0.4445 for MDCog. The mean adjusted-R2 values for the z-scores of individual cognitive variables ranged between 0.0009 and 0.0693. Multiple linear regression was only statistically significant for MDCog, with the highest estimated adjusted-R2 value.

CONCLUSIONS

The association between individual cognitive variables and most of the summary cognitive indexes with gait parameters was weak. However, the MDCog index showed a stronger and significant association with the STGF, exhibiting the highest value of the proportion of the variance that can be explained by the predictor variables. These findings suggest that the MDCog index may be a useful tool in studying the relationship between gait patterns and cognition.

Characteristics associated with decrements in objective measures of physical function in older patients with cancer during chemotherapy

PURPOSE

Study purposes were to evaluate for inter-individual variability in the trajectories of three objective measures of physical function (PF) in older patients receiving chemotherapy (n = 112) and determine which characteristics were associated with worse PF.

METHODS

Balance, gait speed, and chair-stand test were evaluated at initiation and 1, 3, 6, 9, and 12 months following chemotherapy. Hierarchical linear modeling was used to assess inter-individual variability in the trajectories of the three tests. Demographic, clinical, and symptom characteristics, and levels of cognitive function associated with initial levels and changes over time in each of the tests were determined.

RESULTS

Gait speed and chair-stand tests improved over time. Balance declined until month 6, then increased. Characteristics associated with decreases in balance scores at initiation of chemotherapy were lower level of education and lower Karnofsky Performance Status (KPS) score. For initial levels of poorer gait speed, older age, poorer Trail Making Test B (TMTB), and worse Attentional Function Index scores were the associated characteristics. Lower KPS scores, higher body mass index, and poorer TMTB scores were associated with poorer chair-stand times at initiation of chemotherapy. Worse trajectories of chair-stand times were associated with poorer chair-stand time at enrollment. Characteristic associated with lower initial levels and improved trajectories of balance was older age at enrollment.

CONCLUSIONS

Determination of characteristics associated with decrements in balance, gait speed, and chair-stand can assist clinicians to identify older oncology patients at risk for decrements in PF. Interventions to maintain and improve PF need to be implemented with higher risk patients.

Severe Dizziness Related to Postural Instability, Changes in Gait and Cognitive Skills in Patients with Chronic Peripheral Vestibulopathy

Introduction  Peripheral vestibular disorders can lead to cognitive deficits and are more common in elderly patients. Objective  To evaluate and correlate cognitive, balance and gait aspects in elderly women with chronic peripheral vestibular dizziness, and to compare them with elderly women without vestibular disorders. Methods  Twenty-two women presenting peripheral vestibular dizziness episodes for at least six months participated in the study. The individuals were categorized by dizziness severity level: moderate ( n  = 11) or severe ( n  = 11). The control group ( n  = 11) included women showing no vestibulopathy, light-headedness or dizziness. Cognitive assessments and semi-static and dynamic balance assessments were performed with the Balance Master (Neurocom International, Inc., Clackamas, OR), while the Dizziness Handicap Inventory provided a score for the severity of the symptoms. The groups were submitted to statistics of inference and correlation between cognitive, balance and stability variables. Results  The group with severe dizziness showed higher sway speed of the center of pressure in the anteroposterior direction, smaller step length, and slower gait than the control group. Regarding the cognitive variables, the group with severe dizziness symptoms presented significant correlations with stability and gait variables. Conclusion  The relationship between cognitive aspects, balance and gait was stronger in women with severe dizziness than in those with no vestibulopathy.

Is balance performance reduced after mild traumatic brain injury?: Interim analysis from chronic effects of neurotrauma consortium (CENC) multi-centre study

OBJECTIVES

Determine if mild traumatic brain injury (mTBI) history is associated with balance disturbances.

SETTING

Chronic Effects of Neurotrauma Consortium (CENC) centres.

PARTICIPANTS

The CENC multi-centre study enrols post-9/11 era Service Members and Veterans with combat exposure. This sample (n = 322) consisted of enrolees completing initial evaluation by September 2016 at the three sites conducting computerized dynamic post-urography (CDP) testing.

DESIGN

Observational study with cross-sectional analyses using structural equation modelling.

MAIN MEASURES

Comprehensive structured interviews were used to diagnose all lifetime mild traumatic brain injuries (mTBIs). The outcome, Sensory Organization Test (SOT), was measured on CDP dual-plate force platform. Other studied variables were measured by structured interviews, record review and questionnaires.

RESULTS

The overall positive/negative mTBI classification did not have a significant effect on the composite equilibrium score. However, the repetitive mTBI classification showed lower scores for participants with ≥ 3 mTBI versus 1-2 lifetime mTBIs. For repetitive mTBI, pain interference acted as a mediator for the indirect effect, and a direct effect was evident on some sensory condition equilibrium scores.

CONCLUSION

These findings show that repeated mTBI, partially mediated by pain, may lead to later balance disturbances among military combatants. Further study of CDP outcomes within this accruing cohort is warranted.

Blood pressure change does not associate with Center of Pressure movement after postural transition in geriatric outpatients

BACKGROUND

Orthostatic hypotension (OH), a blood pressure drop after postural change, is associated with impaired standing balance and falls in older adults. This study aimed to assess the association between blood pressure (BP) and a measure of quality of standing balance, i.e. Center of Pressure (CoP) movement, after postural change from supine to standing position in geriatric outpatients, and to compare CoP movement between patients with and without OH.

METHODS

In a random subgroup of 75 consecutive patients who were referred to a geriatric outpatient clinic, intermittent BP measurements were obtained simultaneously with CoP measurements in mediolateral and anterior-posterior direction directly after postural change during 3 min of quiet stance with eyes open on a force plate. Additional measurements of continuous BP were available in n = 38 patients. Associations between BP change during postural change and CoP movement were analyzed using Spearman correlation. Mann-Whitney-U tests were used to compare CoP movement between patients with OH and without OH, in which OH was defined as a BP drop exceeding 20 mmHg of systolic BP (SBP) and/or 10 mmHg of diastolic BP (DBP) within 3 min after postural change.

RESULTS

OH measured intermittently was found in 8 out of 75 (11%) and OH measured continuously in 22 out of 38 patients (57.9%). BP change did not associate with CoP movement. CoP movement did not differ significantly between patients with and without OH.

CONCLUSIONS

Results do not underpin the added value of CoP movement measurements in diagnosing OH in a clinical setting. Neither could we identify the role of CoP measurements in the understanding of the relation between OH and impaired standing balance.

Do subjective memory complaints predict falls, fractures and healthcare utilization? A two-year prospective study based on a cohort of older women recruited from primary care

OBJECTIVE

A proportion of older individuals report subjective memory complaints (SMCs), which can predict the development of cognitive impairment and dementia. Previous studies based on secondary care suggest that SMC is also associated with other adverse health consequences, including falls, fractures and increased healthcare utilization. In this study, we aimed to establish whether similar findings are observed in the wider population.

METHODS

Prospective analysis of the Cohort for Skeletal Health in Bristol and Avon, a population-based cohort recruited from primary care, was carried out. Data were collected by self-completion questionnaire at baseline and 2 years. SMC was assessed at baseline. Fractures, measures of falls, mobility and healthcare utilization were assessed 2 years later. A random 5% subsample of data was validated against electronic general practitioner records. Logistic regression was used to identify independent associations, following adjustment for a range of confounders assessed at baseline.

RESULTS

Data were available on 3184 women. Three hundred and fifty participants (11.0%) reported SMC. They were older (73.3 ± 4.5 vs 72.0 ± 4.2 years) and less mobile compared with those not reporting SMC. SMCs at baseline were associated with an increased risk of upper limb fractures over the following 2 years (OR 1.72, 95% CI 1.02-2.90). SMCs were also associated with an increased risk of falls (OR 1.83, 95% CI 1.41-2.38) and increased healthcare utilization (OR for hospital appointments 2.20, 95% CI 1.26-3.86). No association was observed with bone mineral density at any site.

CONCLUSIONS

Subjective memory complaints are important markers of adverse health outcomes and should prompt interventions to reduce fractures such as physiotherapy-led fall reduction programmes. Copyright © 2016 John Wiley & Sons, Ltd.

The effects of physical training without equipment on pain perception and balance in the elderly: A randomized controlled trial

BACKGROUND

Research supports a link between exercise and falls prevention in the older population.

OBJECTIVES

Our aims were to evaluate pain perception and balance skills in a group of elderly subjects and to examine the consequences of a standardized equipment-free exercise program intervention on these variables. The study utilized a randomized controlled trial method.

METHODS

92 subjects were recruited from a rural Sicilian village (Resuttano, Sicily, Italy). Subjects were randomly split into two groups, an experimental group (EG; n = 49) and a control group (CG; n = 43). Qualified fitness instructors delivered the standardized physical exercise program for the EG whilst the CG did not receive this exercise intervention. The Berg Balance Scale and the Oswestry Disability Index were administered in both groups before (T0) and after the intervention (T1).

RESULTS

At T1, the EG group significantly improvement in balance (p < 0.0001) and pain perception (p < 0.0001). No significant differences were found within the CG both in BBS and ODI, respectively.

CONCLUSIONS

Our findings suggest that a 13-weeks standardized exercise equipment-free program is effective in improving balance and perception of pain in the elderly. This type of intervention can consequently provide a low cost strategy to counteract the rate of disability in elderly.

Postural Stability of Elderly People With Cognitive Impairments

INTRODUCTION

Falls are one of the major problems among the elderly population. It has been established that people with dementia fall down more often. It is believed that this is a consequence of risky decision making by people with dementia resulting from cognitive deterioration. The aim of the present study was to evaluate the relationship between cognitive status and postural stability while standing.

METHODS

A total of 47 people, aged 71.6 years on average (±7.2), were divided based on results of the Mini Mental State Examination (MMSE) into a dementia group (MMSE ≤ 23) and a control group (MMSE > 23). Postural stability was tested using a force plate (with eyes open, with eyes closed, and with visual biofeedback). The parameters of movement of the center of pressure were analyzed.

RESULTS

Both in test with eyes open and eyes closed, significant difference was shown between the dementia group and the control groups. In visual feedback test, the dementia group showed 32% poorer performance than the controls.

CONCLUSION

The falls experienced in dementia group may be caused by a disturbed balance control process of the central nervous system.

Adaptation of multijoint coordination during standing balance in healthy young and healthy old individuals

Standing balance requires multijoint coordination between the ankles and hips. We investigated how humans adapt their multijoint coordination to adjust to various conditions and whether the adaptation differed between healthy young participants and healthy elderly. Balance was disturbed by push/pull rods, applying two continuous and independent force disturbances at the level of the hip and between the shoulder blades. In addition, external force fields were applied, represented by an external stiffness at the hip, either stabilizing or destabilizing the participants' balance. Multivariate closed-loop system-identification techniques were used to describe the neuromuscular control mechanisms by quantifying the corrective joint torques as a response to body sway, represented by frequency response functions (FRFs). Model fits on the FRFs resulted in an estimation of time delays, intrinsic stiffness, reflexive stiffness, and reflexive damping of both the ankle and hip joint. The elderly generated similar corrective joint torques but had reduced body sway compared with the young participants, corresponding to the increased FRF magnitude with age. When a stabilizing or destabilizing external force field was applied at the hip, both young and elderly participants adapted their multijoint coordination by lowering or respectively increasing their neuromuscular control actions around the ankles, expressed in a change of FRF magnitude. However, the elderly adapted less compared with the young participants. Model fits on the FRFs showed that elderly had higher intrinsic and reflexive stiffness of the ankle, together with higher time delays of the hip. Furthermore, the elderly adapted their reflexive stiffness around the ankle joint less compared with young participants. These results imply that elderly were stiffer and were less able to adapt to external force fields.

NeuroControl of movement: system identification approach for clinical benefit

Progress in diagnosis and treatment of movement disorders after neurological diseases like stroke, cerebral palsy (CP), dystonia and at old age requires understanding of the altered capacity to adequately respond to physical obstacles in the environment. With posture and movement disorders, the control of muscles is hampered, resulting in aberrant force generation and improper impedance regulation. Understanding of this improper regulation not only requires the understanding of the role of the neural controller, but also attention for: (1) the interaction between the neural controller and the "plant", comprising the biomechanical properties of the musculaskeletal system including the viscoelastic properties of the contractile (muscle) and non-contractile (connective) tissues: neuromechanics; and (2) the closed loop nature of neural controller and biomechanical system in which cause and effect interact and are hence difficult to separate. Properties of the neural controller and the biomechanical system need to be addressed synchronously by the combination of haptic robotics, (closed loop) system identification (SI), and neuro-mechanical modeling. In this paper, we argue that assessment of neuromechanics in response to well defined environmental conditions and tasks may provide for key parameters to understand posture and movement disorders in neurological diseases and for biomarkers to increase accuracy of prediction models for functional outcome and effects of intervention.

Effects of different types of physical activity on the cognitive functions and attention in older people: A randomized controlled study

This study aimed to evaluate the effects of different types of exercise on cognition. Eighty participants, 32 males and 48 females, aged 66.96 ± 11.73, volunteered for this study. The participants were randomly divided into the four following groups: Resistance Group (RG; n=20), involved in high intensity strength training; Cardiovascular Group (CVG; n=20), involved in high intensity cardiovascular training; Postural Group (PG; n=20) involved in low intensity training, based on postural and balance exercises; and Control Group (CG; n=20). Exercises were performed over the course of 12 weeks. All participants were tested for their cognitive functions pre- and post-intervention using the following neurocognitive tests: the Attentive Matrices Test, Raven's Progressive Matrices, Stroop Color and Word Interference Test, Trail Making Test and Drawing Copy Test. Statistical analysis showed that the CVG group improved significantly in the Attentive Matrices Test and Raven's Progressive Matrices (both p=<0.05), whereas the RG group improved in Drawing Copy Test time (p=<0.05). These results confirm that different types of exercise interventions have unique effects on cognition. Cardiovascular training is effective in improving performance attentive and analytic tasks, whereas resistance training is effective in improving praxis. Further investigation is necessary to evaluate the combination of the two exercise types in order to ascertain if their respective effects can be summated when performed together.