A prospective study of focal brain atrophy, mobility and fitness

BACKGROUND

The parallel decline of mobility and cognition with ageing is explained in part by shared brain structural changes that are related to fitness. However, the temporal sequence between fitness, brain structural changes and mobility loss has not been fully evaluated.

METHODS

Participants were from the Baltimore Longitudinal Study of Aging, aged 60 or older, initially free of cognitive and mobility impairments, with repeated measures of fitness (400-m time), mobility (6-m gait speed) and neuroimaging markers over 4 years (n = 332). Neuroimaging markers included volumes of total brain, ventricles, frontal, parietal, temporal and subcortical motor areas, and corpus callosum. Autoregressive models were used to examine the temporal sequence of each brain volume with mobility and fitness, adjusted for age, sex, race, body mass index, height, education, intracranial volume and APOE ɛ4 status.

RESULTS

After adjustment, greater volumes of total brain and selected frontal, parietal and temporal areas, and corpus callosum were unidirectionally associated with future faster gait speed over and beyond cross-sectional and autoregressive associations. There were trends towards faster gait speed being associated with future greater hippocampus and precuneus. Higher fitness was unidirectionally associated with future greater parahippocampal gyrus and not with volumes in other areas. Smaller ventricle predicted future higher fitness.

CONCLUSION

Specific regional brain volumes predict future mobility impairment. Impaired mobility is a risk factor for future atrophy of hippocampus and precuneus. Maintaining fitness preserves parahippocampal gyrus volume. Findings provide new insight into the complex and bidirectional relationship between the parallel decline of mobility and cognition often observed in older persons.

Cognitive Performance Does not Limit Physical Activity Participation in the Lifestyle Interventions and Independence for Elders Pilot Study (LIFE-P)

OBJECTIVES

We examined whether multiple domains of baseline cognitive performance were associated with prospective physical activity (PA) adherence in the Lifestyle Interventions and Independence for Elders Pilot study (LIFE-P).

DESIGN, SETTING, PARTICIPANTS

The LIFE-P study was a single-blind, multicenter, randomized controlled trial of a PA intervention compared to a successful aging educational intervention in sedentary, mobility-limited older adults.

INTERVENTION

A 12-month structured, moderate-intensity, multi-modal PA program that included walking, resistance training, and flexibility exercises. For the first 2 months (adoption), 3 center-based exercise sessions (40-60 min) / week were conducted. During the next 4 months (transition), center-based sessions were conducted 2 times / week. The subsequent maintenance phase consisted of optional once-to-twice-per-week center-based sessions and home-based PA.

MEASUREMENTS

Tests of executive and global cognitive functioning, working memory and psychomotor speed were administered at baseline. Median test scores were used to dichotomize participants into low or high cognitive performance groups.

RESULTS

52 mobility-limited older adults (age: 76.9 ±5 yrs) were randomized to the PA arm of LIFE-P. Compared to participants with high cognitive performance, participants with low performance had similar PA adherence rates (all P ≥ 0.34). Furthermore, weak and non-significant univariate relationships were elicited between all measures of cognition and overall PA adherence levels (r values ranged: -0.20 to 0.12, P ≥ 0.12).

CONCLUSION

These data suggest that cognitive performance does not limit long-term PA adherence in mobility-limited older adults. Additional studies in larger cohorts are warranted to verify these findings.

History of falls in Parkinson disease is associated with reduced cholinergic activity

OBJECTIVE

To investigate the relationships between history of falls and cholinergic vs dopaminergic denervation in patients with Parkinson disease (PD).

BACKGROUND

There is a need to explore nondopaminergic mechanisms of gait control as the majority of motor impairments associated with falls in PD are resistant to dopaminergic treatment. Alterations in cholinergic neurotransmission in PD may be implicated because of evidence that gait control depends on cholinergic system-mediated higher-level cortical and subcortical processing, including pedunculopontine nucleus (PPN) function.

METHODS

In this cross-sectional study, 44 patients with PD (Hoehn & Yahr stages I-III) without dementia and 15 control subjects underwent a clinical assessment and [(11)C]methyl-4-piperidinyl propionate (PMP) acetylcholinesterase (AChE) and [(11)C]dihydrotetrabenazine (DTBZ) vesicular monoamine transporter type 2 (VMAT2) brain PET imaging.

RESULTS

Seventeen patients (38.6%) reported a history of falls and 27 patients had no falls. Analysis of covariance of the cortical AChE hydrolysis rates demonstrated reduced cortical AChE in the PD fallers group (-12.3%) followed by the PD nonfallers (-6.6%) compared to control subjects (F = 7.22, p = 0.0004). Thalamic AChE activity was lower only in the PD fallers group (-11.8%; F = 4.36, p = 0.008). There was no significant difference in nigrostriatal dopaminergic activity between PD fallers and nonfallers.

CONCLUSIONS

Unlike nigrostriatal dopaminergic denervation, cholinergic hypofunction is associated with fall status in Parkinson disease (PD). Thalamic AChE activity in part represents cholinergic output of the pedunculopontine nucleus (PPN), a key node for gait control. Our results are consistent with other data indicating that PPN degeneration is a major factor leading to impaired postural control and gait dysfunction in PD.

Lifestyle predicts falls independent of physical risk factors

SUMMARY

Many falls occur among older adults with no traditional risk factors. We examined potential independent effects of lifestyle on fall risk. Not smoking and going outdoors frequently or infrequently were independently associated with more falls, indicating lifestyle-related behavioral and environmental risk factors are important causes of falls in older women.

INTRODUCTION

Physical and lifestyle risk factors for falls and population attributable risks (PAR) were examined.

METHODS

We conducted a 4-year prospective study of 8,378 community-dwelling women (mean age = 71 years, SD = 3) enrolled in the Study of Osteoporotic Fractures. Data on number of falls were self-reported every 4 months. Fall rates were calculated (# falls/woman-years). Poisson regression was used to estimate relative risks (RR).

RESULTS

Physical risk factors (p < or = 0.05 for all) included tall height (RR = 0.89 per 5 in.), dizziness (RR = 1.16), fear of falling (RR = 1.20), self-reported health decline (RR = 1.19), difficulty with Instrumental Activities of Daily Living (IADLs) (RR = 1.12, per item), fast usual-paced walking speed (RR = 1.18, per 2 SD), and use of antidepressants (RR = 1.20), benzodiazepines (RR = 1.11), or anticonvulsants (RR = 1.62). Protective physical factors (p < or = 0.05 for all) included good visual acuity (RR = 0.87, per 2 SD) and good balance (RR = 0.85 vs. poor). Lifestyle predicted fewer falls including current smoking (RR = 0.76), going outdoors at least twice weekly but not more than once a day (RR = 0.89 and vs. twice daily). High physical activity was associated with more falls but only among IADL impaired women. Five potentially modifiable physical risk factors had PAR > or = 5%.

CONCLUSIONS

Fall interventions addressing modifiable physical risk factors with PAR > or = 5% while considering environmental/behavioral risk factors are indicated.

Age-associated leukoaraiosis and cortical cholinergic deafferentation

OBJECTIVE

To investigate the relationship between age-associated MRI leukoaraiosis or white matter hyperintensities (WMH) and cortical acetylcholinesterase (AChE) activity.

BACKGROUND

One possible mechanism of cognitive decline in elderly individuals with leukoaraiosis is disruption of cholinergic fibers by strategically located white matter lesions. Periventricular lesions may have a higher chance of disrupting cholinergic projections compared with more superficial nonperiventricular white matter lesions because of anatomic proximity to the major cholinergic axonal projection bundles that originate from the basal forebrain.

METHODS

Community-dwelling, middle-aged and elderly subjects without dementia (mean age 71.0 +/- 9.2 years; 55-84 years; n = 18) underwent brain MRI and AChE PET imaging. The severity of periventricular and nonperiventricular WMH on fluid-attenuated inversion recovery MRI images was scored using the semiquantitative rating scale of Scheltens et al. [11C]methyl-4-piperidinyl propionate AChE PET imaging was used to assess cortical AChE activity. Age-corrected Spearman partial rank correlation coefficients were calculated.

RESULTS

The severity of periventricular (R = -0.52, p = 0.04) but not nonperiventricular (R = -0.20, not significant) WMH was inversely related to global cortical AChE activity. Regional cortical cholinergic effects of periventricular WMH were most significant for the occipital lobe (R = -0.58, p = 0.02).

CONCLUSIONS

The presence of periventricular but not nonperiventricular white matter hyperintensities (WMH) is significantly associated with lower cortical cholinergic activity. These findings support a regionally specific disruption of cholinergic projection fibers by WMH.

What is a meaningful change in physical performance? Findings from a clinical trial in older adults (the LIFE-P study)

OBJECTIVE

Performance measures provide important information, but the meaning of change in these measures is not well known. The purpose of this research is to 1) examine the effect of treatment assignment on the relationship between self-report and performance; 2) to estimate the magnitude of meaningful change in 400-meter walk time (400MWT), 4-meter gait speed (4MGS), and Short Physical Performance Battery (SPPB) and 3) to evaluate the effect of direction of change on estimates of magnitude.

DESIGN

This is a secondary analysis of data from the LIFE-P study, a single blinded randomized clinical trial. Using change over one year, we applied distribution-based and anchor-based methods for self-reported mobility to estimate minimally important and substantial change in 400MWT, 4MGS and SPPB.

SETTING

Four university-based clinical research sites.

PARTICIPANTS

Sedentary adults aged 70-89 whose SPPB scores were less than 10 and who were able to complete a 400MW at baseline (n=424).

INTERVENTIONS

A structured exercise program versus health education.

MEASUREMENTS

400MWT, 4MGS, SPPB.

RESULTS

Relationships between self-report and performance measures were consistent between treatment arms. Minimally significant change estimates were 400MWT: 20-30 seconds, 4MGS: 0.03-0.05m/s and SPPB: 0.3 - 0.8 points. Substantial changes were 400MWT: 50-60 seconds, 4MGS: 0.08m/s, SPPB: 0.4 - 1.5 points. Magnitudes of change for improvement and decline were not significantly different.

CONCLUSIONS

The magnitude of clinically important change in physical performance measures is reasonably consistent using several analytic techniques and appears to be achievable in clinical trials of exercise. Due to limited power, the effect of direction of change on estimates of magnitude remains uncertain.

Diagnostic performance of clinical motor and non-motor tests of Parkinson disease: a matched case-control study

BACKGROUND AND PURPOSE

The diagnosis of Parkinson disease (PD) is made typically on the basis of motor abnormalities. PD is now recognized to have both motor and non-motor manifestations, indicating a need for the development of reliable non-motor diagnostic tests for PD. The aim of the present study was to compare the accuracy of various clinical motor and non-motor tests for the diagnosis of PD.

METHODS

Forty-five PD patients (Hoehn and Yahr stages 1-3; mean age 59.5 +/- 10.0 years) and 45 healthy controls matched for gender and age completed a clinimetric motor test battery to assess limb bradykinesia, tremor and balance. Non-motor tests consisted of depression, anxiety and smell identification ratings. Area under the receiver operator characteristic curve (AUC) analysis was used.

RESULTS

We found that smell identification was the most accurate predictor of the presence of PD within the overall group of patients and matched control subjects (AUC = 0.886) and also in the subgroups of mild severity (Hoehn and Yahr stages 1-1.5; AUC = 0.923), young-onset (AUC = 0.888) and female PD patients (AUC = 0.797). The second best diagnostic test was the grooved pegboard test for the clinically most affected body side.

CONCLUSIONS

We conclude that olfactory function is the most accurate diagnostic predictor within a heterogeneous sample of patients with PD.

Striatal dopaminergic denervation and gait in healthy adults

Parkinsonian-like motor impairments are common in the elderly. The etiology of these symptoms in the absence of clinically diagnosable Parkinson's disease (PD) is unknown. The aim of this study was to evaluate associations between striatal dopaminergic neuron losses that occur with aging and gait in healthy adults. Forty healthy subjects aged 21-85 years old underwent [(11)C]-beta-CFT dopamine transporter (DAT) positron emission tomography (PET). Subjects were also asked to walk in a gait laboratory at their own pace. Gait variables of interest included average general spatiotemporal characteristics of walking patterns and their standard deviation reflecting gait variability. Segmented nonlinear models were used to investigate the relationship between striatal DAT activity and gait while controlling for age. Gait speed, cadence, and single and double support durations were significantly slower than age-based predictions in adults with lower striatal DAT activity (P < 0.05). After controlling for age, striatal DAT activity was not significantly associated with average step length and step width and with gait variability. We conclude that dopaminergic physiology influences certain aspects of gait independent of age-related changes. The findings of this study may augur novel therapeutic approaches to treating gait disorders in the elderly.

Patient safety culture assessment in the nursing home

OBJECTIVE

To assess patient safety culture (PSC) in the nursing home setting, to determine whether nursing home professionals differ in their PSC ratings, and to compare PSC scores of nursing homes with those of hospitals.

METHODS

The Hospital Survey on Patient Safety Culture was modified for use in nursing homes (PSC-NH) and distributed to 151 professionals in four non-profit nursing homes. Mean scores on each PSC-NH dimension were compared across professions (doctors, pharmacists, advanced practitioners and nurses) and with published benchmark scores from 21 hospitals.

RESULTS

Response rates were 68.9% overall and 52-100% for different professions. Most respondents (76%) were women and had worked in nursing homes for an average of 9.8 years, and at their current facility for 5.4 years. Professions agreed on 11 of 12 dimensions of the survey and differed significantly (p<0.05) only in ratings for one PSC dimension (attitudes about staffing issues), where nurses and pharmacists believed that they had enough employees to handle the workload. Nursing homes scored significantly lower (ie, worse) than hospitals (p<0.05) in five PSC dimensions (non-punitive response to error, teamwork within units, communication openness, feedback and communication about error, and organisational learning).

CONCLUSIONS

Professionals in nursing homes generally agree about safety characteristics of their facilities, and the PSC in nursing homes is significantly lower than that in hospitals. PSC assessment may be helpful in fostering comparisons across nursing home settings and professions, and identifying targets for interventions to improve patient safety.

Higher 1,25-dihydroxyvitamin D3 concentrations associated with lower fall rates in older community-dwelling women

INTRODUCTION

The purpose of this study was to examine the relationships of vitamin D supplementation and serum concentrations of vitamin D metabolites and parathyroid hormone (PTH) with neuromuscular function and falls in older community-dwelling women.

METHODS

We examined these relationships using a 4-year prospective multi-center study among 9,526 community-dwelling women enrolled in the Study of Osteoporotic Fractures (median age: 70 years; interquartile range: 67-75) and a subset of 389 women (97%) out of 400 who were randomly selected from the entire cohort for serum measures. Measurements included: vitamin D supplementation, serum 25-hydroxyvitamin D(3) [25(OH)D(3)], serum 1,25-dihydroxyvitamin D(3) [1,25(OH) (2)D(3)], and serum intact parathyroid hormone (iPTH); grip and quadriceps strength, chair-stand time, walking speed, reaction time, and balance-walk time (including changes in grip strength, chair-stand time, walking speed and balance-walk time over approximately 3.7 years); and incident fall rates (number of falls/woman-years).

RESULTS

In 9,526 women, vitamin D supplementation was not associated with any measures of neuromuscular function, change in neuromuscular function, or fall rates (p>0.01 for all). In a subgroup of 389 women, there was a trend of higher 25(OH)D(3) concentration with slightly weaker grip strength (p=0.007), and women in the fourth quartile of 1,25(OH)(2)D(3) had a faster chair-stand time (p=0.017) than women in the first quartile; still, in general, concentrations of 25(OH)D(3), 1,25(OH)(2)D(3), and iPTH were not associated with either neuromuscular function or changes in neuromuscular function (p>0.05 for all). However, higher 1,25(OH)(2)D(3) concentration was associated with lower fall rates (p=0.039).

CONCLUSIONS

Higher 1,25(OH)(2)D(3) concentration is associated with a lower fall risk in older community-dwelling women, but vitamin D supplementation, and 25(OH)D(3) and iPTH concentrations are not associated with either neuromuscular function or falls.

Predicting stroke recovery: three- and six-month rates of patient-centered functional outcomes based on the orpington prognostic scale

OBJECTIVE

To provide recovery rates after stroke for specific functions using the Orpington Prognostic Scale (OPS).

DESIGN

Prospective cohort.

SETTING

Hospital and community.

PARTICIPANTS

413 stroke survivors entered the study 3 to 14 days after suffering a stroke.

MEASUREMENTS

A cohort of hospitalized stroke survivors were recruited 3 to 14 days after stroke and assessed at 1, 3, and 6 months poststroke for neurological, functional, and health status. Baseline OPS score was used to predict five functional outcomes at 3 and 6 months using development and validation datasets and receiver operating characteristic (ROC) curves.

RESULTS

In 413 stroke survivors, functional recovery rates at 3 and 6 months were similar. Baseline OPS predicted significant differences in recovery rates for all five outcomes (P < .0001 for all five outcomes at 3 and 6 months). Personal care dependence was present at 3 months in only 3% of persons with baseline OPS scores of 3.2 or less compared with over 50% with OPS of 4.8 or higher. Independent personal care, meal preparation, and self-administration of medication were achieved by 80% who had baseline OPS scores of 2.4 or lower compared with less than 20% when OPS scores were 4.4 or higher. Independent community mobility was achieved in 50% of those who had OPS scores of 2.4 or lower but only 3% of those with OPS scores of 4.4 or higher. The area under ROC curves assessing OPS scores against each of the five outcomes ranged from 0.805 to 0.863 at 3 months and 0.74 to 0.806 at 6 months.

CONCLUSION

OPS scores can predict widely differing rates of functional recovery in five important functional abilities. These estimates can be useful to survivors, families, providers, and healthcare systems who need to plan for the future.

Effects of central nervous system polypharmacy on falls liability in community-dwelling elderly

BACKGROUND

While central nervous system (CNS) active medications such as psychotropics and narcotic analgesics have been implicated in contributing to falls in older adults, the combined effect of multiple CNS-active medications has not been investigated. The purpose of this study was to examine the influence, in community-dwelling elderly, of (1) taking multiple CNS-active medications on fall liability and (2) individual classes of CNS-active medications (using discrete drug classification) on the risk of falls after controlling for important confounders--age, mobility, cognition and depression.

METHODS

305 community-dwelling male veterans (age: 70-104) were screened at study entry for mobility, cognition and depression. CNS-active medications were categorized as benzodiazepines, other sedative-hypnotics, neuroleptics, tricyclic antidepressants, and opioid analgesics. Subjects were prospectively followed for 6 months to monitor falls; at the end of this time period, subjects were classified as fallers (at least one fall) or nonfallers. The relationship between CNS-active drug use and falls was examined using multivariable analyses.

RESULTS

The risk of falls was significantly greater in CNS-active medication users as compared with nonusers. Adjusted odds ratio for one CNS-active drug was 1.54 (95% confidence interval 1.07-2.22) and for two or more agents 2.37 (95% confidence interval 1.14-4.94).

CONCLUSIONS

In community-dwelling elderly, the use of multiple CNS-active medications is associated with enhanced falls liability, over and above the use of one CNS-active drug alone. This apparent dose-response relationship provides support for causality.

Spinal-flexibility-plus-aerobic versus aerobic-only training: effect of a randomized clinical trial on function in at-risk older adults

BACKGROUND

As exercise is associated with favorable health outcomes, impaired older adults may benefit from specialized exercise interventions to achieve gains in function. The purpose of this study was to determine the added benefit of a spinal flexibility-plus-aerobic exercise intervention versus aerobic-only exercise on function among community-dwelling elders.

METHODS

We employed a randomized clinical trial consisting of 3 months of supervised exercise followed by 6 months of home-based exercise with telephone follow-up. A total of 210 impaired males and females over age 64 enrolled in this study. Of these, 134 were randomly assigned to either spinal flexibility-plus-aerobic exercise or aerobic-only exercise, with 116 individuals completing the study. Primary outcomes obtained at baseline, after 3 months of supervised exercise, and after 6 months of home-based exercise included: axial rotation, maximal oxygen uptake (VO2max); functional reach, timed-bed-mobility; and the Physical Function Scale (PhysFunction) of the Medical Outcomes Study SF-36.

RESULTS

Differences between the two interventions were minimal. Overall change scores for both groups combined indicated significant improvement for: axial rotation (p=.001), VO2max (p=.0001), and PhysFunction (p=.0016). Secondary improvements were noted for overall health (p=.0025) and reduced symptoms (p=.0008). Differences between groups were significant only for VO2max (p=.0014) at 3 months with the aerobic-only group improving twice as much in aerobic capacity as the spinal flexibility-plus-aerobic group. Repeated measures indicated both groups improved during the supervised portion of the intervention but tended to return toward baseline following the home-based portion of the trial.

CONCLUSIONS

Gains in physical functioning and perceived overall health are obtained with moderate aerobic exercise. No differential improvements were noted for the spinal flexibility-plus-aerobic intervention.

Factors associated with suboptimal analgesic use in community-dwelling elderly

OBJECTIVE

To examine patterns and factors associated with overall and suboptimal analgesic use among community-dwelling elderly.

DESIGN

Cross-sectional survey.

SETTING

Five-county urban and rural region in Piedmont, NC.

PARTICIPANTS

A stratified random sample from the Duke Established Populations for Epidemiologic Studies of the Elderly of 3973 participants aged 65 years or older.

MAIN OUTCOME MEASURES

Use of any analgesic medication, suboptimal analgesic use (taking 2 or more analgesics from the same class, using 3 or more analgesics concurrently, or use of an analgesic that has a major interaction with another drug).

RESULTS

Analgesics were used by 60.4% of the participants. Use was more likely for those who had physical functional impairment, a history of cardiovascular disease, one or more health visits in the previous year, or were female. Use was less likely for older participants and for African-Americans with adequate financial status. Suboptimal use occurred in 9.2% of analgesic users. Therapeutic duplication was more likely in those who were depressed, needed help with basic activities of daily living, or used alcohol, and was less likely in those with adequate financial status. Multiple analgesic use was more likely in those who were depressed, had impaired physical functional status, had one or more health visits in the previous year, were African-American (of either sex), or were white women. Only two persons had a potential major analgesic-drug interaction.

CONCLUSIONS

Suboptimal analgesic use is common in community-dwelling elderly, and its risk in consistently increased in those who are depressed or have impaired physical functional status.

The relationship of postural sway to sensorimotor function, functional performance, and disability in the elderly

OBJECTIVE

To examine the relationship of postural sway to sensorimotor impairment, functional performance, and self-reported disability.

DESIGN

Cross-sectional cohort.

SETTING

Department of Veterans' Affairs Medical Center.

PATIENTS

One hundred community-dwelling elderly unable to climb stairs step over step.

MAIN OUTCOME MEASURES

Postural sway (area of ellipse and path length, eyes open and closed), sensorimotor (strength, sensation, range of motion, central processing time), functional performance (functional reach, timed gait, mobility skills, endurance), and disability (MOS-SF36, Falls Efficacy Scale [FES]).

RESULTS

Postural sway area measures correlated with sensorimotor measures: (1) During eyes-closed conditions, increased sway occurs in individuals with sensory deficits (p < .05); (2) Sway was positively correlated with tibialis anterior latency (p < .05); (3) Sway area measures increased with increased strength (p < .05). The sway/strength relationship may be explained by week subjects improving their stability by limiting rather than increasing sway. Sway was not significantly correlated with any measures of physical performance. Sway was correlated with some measures of disability: (1) Eyes-closed measures of postural sway were correlated with FES scores (p < .05); (2) Sway was not correlated with the MOS-36 physical functioning question. When controlling for functional measures, eyes-closed measures of sway significantly predicted FES scores (p < .03).

CONCLUSIONS

Measures of postural sway are more likely capturing sensorimotor deficits rather than differentiating functional performance abilities, and the relationship between postural sway and self-reported disability is inconsistent.

Relationships between mobility of axial structures and physical performance

BACKGROUND AND PURPOSE

Many day-to-day activities require bending and twisting motions of the spine (axial mobility). Because little is known about the relationship between axial mobility and physical performance, this investigation explored these relationships.

SUBJECTS

Thirty-one men and 26 women, aged 20 to 91 years (chi=58.4, SD=24.4), participated.

METHODS

Subjects were assigned to one of three age groups: 20 to 40 years, 60 to 74 years, or 75 years and older. Five sets of variables were identified and measured: cervical, lumbar, sagittal configuration (ie, kyphosis, lordosis), combined spinal motion, and physical performance.

RESULTS

A multivariate analysis of variance revealed age effects for all sets of variables; a post hoc analysis of variance revealed age effects for all variables within the sets. Canonical correlations, controlling for age, demonstrated associations between the cervical and combined spinal motion sets of variables and between the combined spinal motion and physical performance sets of variables.

CONCLUSION AND DISCUSSION

This investigation demonstrated an age effect for selected measures of axial mobility, sagittal configuration, and physical performance thought to depend on axial motion. Controlling for age, the results also demonstrated associations between measures of axial mobility and physical performance.

Postural responses to platform perturbation: kinematics and electromyography

Dynamic postural control may be studied using feedback paradigms which disturb standing balance. In this study the kinematics and electromyography of the reaction to an unexpected slip were examined simultaneously in 16 young, healthy volunteers to characterize the response to postural perturbation in the context of the perturbation characteristics. Kinematically, results showed ankle plantarflexion, knee flexion, hip extension, and shoulder flexion. Electromyographically, sequences of activation of the postural muscles of the leg were primarily anterior distal. Data is presented that supports a new model of the reaction to perturbation which incorporates the timing and type of muscular activity, the type of motion (active or passive), and the perturbation characteristics. RELEVANCE--:Understanding the interplay of the neurophysiological and biomechanical aspects of dynamic postural control gives insight into balance reactions. Simultaneous consideration of the kinematics, muscle activation, and perturbation characteristics allows a more comprehensive view of recovery of balance.

A clinical tool for measuring functional axial rotation

BACKGROUND AND PURPOSE

Motion of the neck and back accompany many daily functional activities. Available range of motion is usually measured regionally and within single planes of motion. This report describes a device and measurement technique that can be used to quantify axial motion in a functionally relevant context. Functional axial rotation (FAR) refers to the available motion that persons use to turn toward the posterior, without regard to the plane of motion; FAR-p refers to the physical motion available, and FAR-v refers to the ability to identify objects.

SUBJECTS

Nine men and eight women, aged 20 to 74 years, participated.

METHODS

Functional axial rotation was determined for each subject. The seated subjects were measured on 2 different days to determine test-retest reliability. Fifteen subjects were measured by two different examiners on the same day to determine interrater reliability. Intraclass correlation coefficients (ICCs) were computed to determine reliability.

RESULTS

The FAR-p ranged from 78 to 190 degrees; FAR-v ranged from 135 to 250 degrees. Test-retest reliability of FAR-p and FAR-v was excellent (ICC[1, 1] values of .95 and .90, respectively, to the right and equivalent to the left). Interrater reliability likewise was excellent, with ICC(2, 1) values of .97 to the right and equivalent to the left.

CONCLUSIONS AND DISCUSSION

Functional axial rotation provides one means of quantifying a patient's axial motion as it would be used in functional context. The FAR device is easy to construct and portable. Measurement of FAR provides the clinician with reliable information regarding the patient's functional use of available spinal motion, combined with visual ability.

Does functional reach improve with rehabilitation?

Functional reach (FR, maximal safe standing forward reach) is a precise, reliable, clinically accessible, age-sensitive measure of balance that approximates center of pressure excursion and validly estimates physical frailty. We now test its ability to detect improvement in balance over time. Twenty-eight inpatient male veterans (age 40 to 105, mean, 67.3) undergoing physical rehabilitation and 13 nonrehabilitation controls were evaluated at baseline and every 4 weeks using FR (yardstick method), 10-foot walking time (WT), the Duke hierarchical mobility skills protocol (HMS) and a portion of the Functional Independence Measure (FIM). Their sensitivity to change was determined using the responsiveness index (RI). FR as well as the other physical performance instruments tested were found to be sensitive to change (RI for FR = 0.97, WT = 11.26, HMS = 4.63, FIM = 4.93) and therefore, appropriate measures for use in prospective clinical trials.

Functional reach: a marker of physical frailty

OBJECTIVE

To establish the concurrent validity of our new balance instrument, functional reach (FR = maximal safe standing forward reach), as a marker of physical frailty compared with other clinical measures of physical performance.

DESIGN, SETTING AND PARTICIPANTS

45 community-dwelling persons age 66-104 were evaluated at one point in time using (1) FR (yardstick method), (2) Physical and Instrumental Activities of Daily Living (PADL, IADL), (3) Life Space, a 3-point measure of social mobility, (4) 10-item hierarchical mobility skills protocol, (5) 10-foot walking speed, (6) one-footed standing, and (7) tandem walking. Data analysis employed Spearman correlations. Partial r's were also calculated after controlling for age.

RESULTS

The FR performance range was broad (4.3-16.5 inches, mean 10.9, SD 3.1). Except for PADL, the association of FR with the other physical performance measures was strong, with r's ranging from 0.64-0.71; the association of FR with PADL was 0.48. After controlling for age in the regression analysis, partial r's ranged from 0.52-0.63. The association of FR with age was -0.50.

CONCLUSIONS

Based on cross-sectional data, FR is a practical instrument that correlates with physical frailty even more than with age.

Balance performance on the postural stress test: comparison of young adults, healthy elderly, and fallers

The purpose of this study was to compare the postural responses of three groups of individuals--healthy young adults (n = 42; age, 20-40 years); healthy, community-dwelling, elderly individuals (n = 66; age, 60-102 years), and elderly individuals with a history of frequent falls (n = 10; age, 66-95 years)--using the postural stress test (PST). The PST is a simple, clinically applicable, quantitative measure of an individual's ability to withstand a series of graded destabilizing forces applied at the level of the subject's waist. Elderly fallers tend to score lower on the PST than elderly nonfallers, but age-related differences in postural responses during the PST have not been established. Each subject underwent the PST using a method and scoring procedure described previously. Results of this study confirm previous findings that elderly fallers score significantly lower on the PST than either young adult or nonfalling elderly individuals. This study also showed that there was no difference in balance strategy scores between the young adults and the healthy elderly subjects. Therefore, it appears that poor performance on the PST cannot be attributed to age alone, but may be predictive of pathological processes that predispose an individual to frequent falls.

Cardiopulmonary resuscitation policies and practices. A statewide nursing home study

We determined the prevalence of written cardiopulmonary resuscitation policies in North Carolina nursing homes and evaluated their content according to predetermined criteria. Questionnaires were mailed to 236 state-registered facilities. Two hundred nine nursing homes (88.5%) responded to the questionnaire; 83% reported having a written policy, and half (86 nursing homes) provided copies. Nine of ten nursing homes reported that cardiopulmonary resuscitation was performed at their institution, and a similar number (92%) permitted physician orders restricting cardiopulmonary resuscitation. Written policies were systematically compared with 10 model criteria. Policy content varied substantially. More than half of the policies contained provisions for authorization, informed consent, documentation, competency, review, and applicability of do not resuscitate orders. Less than half contained criteria for autonomy, treatment alternatives, dignity and quality of care, and patient identification. Nursing homes that had written policies were newer, larger, and for-profit; had a greater proportion of skilled nursing care beds; and were more likely to have both Medicare and Medicaid certification. The variations in these policies place nursing home residents at risk for having important personal rights limited or ignored. Inclusion of these 10 policy criteria in a comprehensive cardiopulmonary resuscitation policy would represent an important step toward enhancing the quality of decision making by nursing home residents.

Polymyalgia rheumatica and temporal arteritis

Polymyalgia rheumatica and temporal arteritis are a clinical syndrome and clinicopathologic entity, respectively. Polymyalgia rheumatica occurs more commonly than temporal arteritis, with approximately half of all patients with temporal arteritis having the polymyalgia rheumatica syndrome. Both conditions are found in the population over 50 years of age and are associated with an elevated ESR. The etiology of both is unclear, although genetic, and potentially, environmental factors may play significant roles. Both conditions respond to corticosteroid therapy, but patients with temporal arteritis require significantly higher doses to control symptoms and to prevent blindness.