Anne D. Kloos

A RANDOMIZED CONTROLLED TRIAL OF RESISTANCE EXERCISE IN INDIVIDUALS WITH ALS

Objective: To determine the effects of resistance exercise on function, fatigue, and quality of life in individuals with ALS. Methods: Subjects with a diagnosis of clinically definite, probable, or laboratory-supported ALS, forced vital capacity (FVC) of 90% predicted or greater, and an ALS Functional Rating Scale (ALSFRS) score of 30 or greater were randomly assigned to a resistance exercise group that received a home exercise program consisting of daily stretching and resistance exercises three times weekly or to a usual care group, who performed only the daily stretching exercises. ALSFRS, the Fatigue Severity Scale (FSS), and Short Form-36 (SF-36) were completed at baseline and monthly for 6 months. FVC and maximum voluntary isometric contraction (MVIC) were monitored monthly throughout the study. Results: Of 33 subjects screened, 27 were randomly assigned (resistance = 13; usual care = 14). Eight resistance exercise subjects and 10 usual care subjects completed the trial. At 6 months, the resistance exercise group had significantly higher ALSFRS and SF-36 physical function subscale scores. No adverse events related to the intervention occurred, MVIC and FVC indicated no negative effects, and less decline in leg strength measured by MVIC was found in the resistance exercise group. Conclusion: Our study, although small, showed that the resistance exercise group had significantly better function, as measured by total ALS Functional Rating Scale and upper and lower extremity subscale scores, and quality of life without adverse effects as compared with subjects receiving usual care.

Reliability and Validity of the Tinetti Mobility Test for Individuals With Parkinson Disease

Background and Purpose: This study examined the interrater and intrarater reliability, concurrent validity, and criterion validity of the Tinetti Mobility Test (TMT) as a fall risk screening tool in individuals with Parkinson disease (PD). Subjects: Thirty individuals with PD voluntarily participated in the study, and data from a retrospective review of 126 patient records were included. Methods: Physical therapists and physical therapist students rated live and videotaped performances of the TMT. Tinetti Mobility Test scores were correlated with Unified Parkinsons Disease Rating Scale (UPDRS) motor scores and comfortable gait speed. The ability of the TMT to accurately assess fall risk was determined. Results: Interrater and intrarater reliability was good to excellent (intraclass correlation coefficient of >.80). Tinetti Mobility Test scores correlated with UPDRS motor scores (rs=−.45) and gait speed (rs=.53). The sensitivity and specificity of the TMT to identify fallers were 76% and 66%, respectively. Discussion and Conclusion: The TMT is a reliable and valid tool for assessing the mobility status of and fall risk for individuals with PD.

Stepwise motor and all-or-none sensory recovery is associated with nonlinear sparing after incremental spinal cord injury in rats.

Spinal cord injury (SCI) causes motor and sensory deficits that impair functional performance. While more functional recovery occurs with greater white matter sparing (WMS), it is unclear which locomotor features are more vulnerable to SCI than others, if recovery of certain features depends on specific amounts of WMS, and whether motor recovery patterns differ from sensory recovery. Locomotor and sensory recovery after graded contusive SCI with cord displacements of 0.3, 0.5, 0.7, 0.9, 1.1, 1.25, and 1.3 mm was examined for 6 weeks in 80 female Sprague-Dawley rats. Seven SCI gradations resulted in three locomotor performance levels measured with BBB (P < 0.01): High: laminectomy (LAM) controls and 0.3 (19.87 +/- 0.35 SEM); Intermediate: 0.5-0.9 (13.71 +/- 0.32); and Low: 1.1-1.3 (9.23 +/- 0.36). Normal paw position was most susceptible to SCI requiring 90% WMS, while consistent plantar stepping was least susceptible depending on 10% WMS. A threshold at the 0.9 severity for coordination, toe clearance, and nearly normal trunk stability and tail usage required 25% WMS. Analysis of interlimb coordination using new phase dispersion (PD) techniques delineated three recovery patterns: synchronous (0.3), modified concordance (0.5, 0.7), and disengaged (0.9, 1.1). Lesion severity correlated to WMS (r(2) = 0.96) and to BBB (r(2) = 0.87) by nonlinear polynomial regressions. Mechanical allodynia developed only after injuries resulting in < or =10% WMS. Nonlinear motor and sensory recovery patterns suggest that small reparative changes may substantially improve function in individuals with SCI. A hierarchical locomotor recovery based on simple segmental versus complex supraspinal motor control is proposed.

Fall risk assessment using the Tinetti mobility test in individuals with Huntington's disease†

The Tinetti Mobility Test (TMT) is a clinical balance and gait test that predicts fall risk in the elderly. This study examined the concurrent validity, usefulness of the TMT as a fall risk screening tool, and the potential ability of the TMT to predict falls in individuals with Huntingtons disease (HD). Data from a retrospective review of 94 patient records were used. TMT scores were correlated with Unified Huntington Disease Rating Scale (UHDRS) motor scores. The ability of the TMT to accurately assess fall risk was determined using validity index measures. Logistic regression was used to assess the ability of the TMT to predict falls. TMT scores correlated with UHDRS motor scores (rs = −0.751, P < 0.0001). Using a cutoff value of 21, the TMT had a sensitivity of 74% and a specificity of 60% to identify fallers. Lower TMT scores and younger age were significant predictors of falls. The TMT is a valid tool for assessing balance and gait status and fall risk of individuals with HD.

Video game play (Dance Dance Revolution) as a potential exercise therapy in Huntington’s disease: a controlled clinical trial

Objective: To investigate the feasibility, acceptability, and safety of a supervised video game exercise program administered via Dance Dance Revolution in individuals with Huntington’s disease. Design: A cross-over, controlled, single-blinded, six-week trial. Setting: Home-based. Participants: Eighteen ambulatory individuals with Huntington’s disease (seven male, mean age 50.7 SD 14.7). Interventions: Participants played the Dance Dance Revolution game with supervision and the handheld game without supervision for 45 minutes, two days per week for six weeks. Outcome measures: Game play performance and adherence, participant perceptions of the game, safety (vital signs, adverse health changes), spatiotemporal gait measures, Four-Square Step Test, Tinetti Mobility Test, Activities-Specific Balance Confidence Scale, and World Health Organization Quality of Life – Bref, before and after each intervention. Results: Most participants improved on game play, enjoyed playing the game, and wanted to continue playing after study completion. After playing Dance Dance Revolution, participants showed significant reductions in double support percentage (adjusted mean difference (95% confidence intervals): –2.54% (–4.75, –0.34) for forward walking and −4.18 (–6.89, –0.48) for backward walking) and those with less severe motor symptoms had reductions in heel-to-heel base of support during forward walking. The remaining measures were not significantly impacted by the intervention. Conclusion: Dance Dance Revolution appears to be a feasible, motivating, and safe exercise intervention for individuals with Huntington’s disease.

Validity of acute and chronic tactile sensory testing after spinal cord injury in rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia. Measuring the development of allodynia in rodent models of SCI is challenging due to spinal shock and marked motor impairments. Assessment of SCI-induced allodynia is not standardized across labs, making interpretation of results difficult. Therefore, we validated sensory threshold assessment after SCI and developed a novel assessment of allodynia prior to motor recovery in a rat SCI model. One hundred fifty-six Sprague-Dawley rats received T8 laminectomy or mild to moderate SCI using the OSU SCI device (0.3 mm to 1.3 mm cord displacement). To determine tactile thresholds, von Frey hairs (VFH) were applied in Up-Down or ascending order to the dorsal or plantar hindpaw. The most efficient and valid procedures that maintain high sensitivity and specificity were identified. Ten Up-Down VFH applications yielded stable thresholds; reducing the risk of threshold decay and unnecessary exposure to painful stimuli. Importantly, distraction of SCI-rats with food revealed differential decay of thresholds than when distraction is not provided. The new test uses dorsal VFH stimulation and is independent of trunk or hindlimb control. Acute dorsal VFH thresholds collected before recovery of hindlimb weight support accurately predicted plantar VFH thresholds measured at late timepoints (chi(2)=8.479; p<0.05). Thus, standardized testing early after SCI using the dorsal VFH test or later using 10 stimuli in the Up-Down test produces valid measures of tactile sensation across many SCI severities. Early detection of allodynia in experimental SCI will allow identification of mechanisms responsible for pain development and determine targets for therapeutic interventions.

The Impact of Different Types of Assistive Devices on Gait Measures and Safety in Huntington's Disease

Background Gait and balance impairments lead to frequent falls and injuries in individuals with Huntingtons disease (HD). Assistive devices (ADs) such as canes and walkers are often prescribed to prevent falls, but their efficacy is unknown. We systematically examined the effects of different types of ADs on quantitative gait measures during walking in a straight path and around obstacles. Methods Spatial and temporal gait parameters were measured in 21 subjects with HD as they walked across a GAITRite walkway under 7 conditions (i.e., using no AD and 6 commonly prescribed ADs: a cane, a weighted cane, a standard walker, and a 2, 3 or 4 wheeled walker). Subjects also were timed and observed for number of stumbles and falls while walking around two obstacles in a figure-of-eight pattern. Results Gait measure variability (i.e., coefficient of variation), an indicator of fall risk, was consistently better when using the 4WW compared to other ADs. Subjects also walked the fastest and had the fewest number of stumbles and falls when using the 4WW in the figure-of-eight course. Subjects walked significantly slower using ADs compared to no AD both across the GAITRite and in the figure-of-eight. Measures reflecting gait stability and safety improved with the 4WW but were made worse by some other ADs.

Reliability and Minimal Detectable Change of Physical Performance Measures in Individuals With Pre-manifest and Manifest Huntington Disease

Background Clinical intervention trials in people with Huntington disease (HD) have been limited by a lack of reliable and appropriate outcome measures. Objective The purpose of this study was to determine the reliability and minimal detectable change (MDC) of various outcome measures that are potentially suitable for evaluating physical functioning in individuals with HD. Design This was a multicenter, prospective, observational study. Methods Participants with pre-manifest and manifest HD (early, middle, and late stages) were recruited from 8 international sites to complete a battery of physical performance and functional measures at 2 assessments, separated by 1 week. Test-retest reliability (using intraclass correlation coefficients) and MDC values were calculated for all measures. Results Seventy-five individuals with HD (mean age=52.12 years, SD=11.82) participated in the study. Test-retest reliability was very high (>.90) for participants with manifest HD for the Six-Minute Walk Test (6MWT), 10-Meter Walk Test, Timed “Up & Go” Test (TUG), Berg Balance Scale (BBS), Physical Performance Test (PPT), Barthel Index, Rivermead Mobility Index, and Tinetti Mobility Test (TMT). Many MDC values suggested a relatively high degree of inherent variability, particularly in the middle stage of HD. Minimum detectable change values for participants with manifest HD that were relatively low across disease stages were found for the BBS (5), PPT (5), and TUG (2.98). For individuals with pre-manifest HD (n=11), the 6MWT and Four Square Step Test had high reliability and low MDC values. Limitations The sample size for the pre-manifest HD group was small. Conclusions The BBS, PPT, and TUG appear most appropriate for clinical trials aimed at improving physical functioning in people with manifest HD. Further research in people with pre-manifest HD is necessary.

Backward walking measures are sensitive to age-related changes in mobility and balance

Many falls occur from backward perturbations or during transitional movements that require a person to turn and step backwards, suggesting that deficits in backward stepping may negatively impact mobility. Previous studies found significant declines in backward walking (BW) spatiotemporal measures in healthy elderly compared to young adults. No studies to date have examined BW performance in middle-aged adults and in elderly with impaired mobility. This study compared spatiotemporal measures of BW and forward walking (FW) in young, middle-aged, and elderly and in elderly fallers and non-fallers; and compared the strength of the relationship between age and BW and FW spatiotemporal measures to determine the utility of BW performance as a clinical tool for examining safety and mobility. BW measures were significantly more impaired in the elderly (n=62) compared to young (n=37) and middle-aged (n=31) adults and age effects were greater in BW than FW. No significant differences were found between young and middle-aged except for base of support in BW. Stronger correlations were found between age and BW measures than between age and FW measures, particularly correlations between age and BW velocity and stride length. Elderly fallers had greater deficits in BW performance than non-fallers. All elderly fallers had BW velocities<.6m/s. Clinicians are encouraged to assess BW, particularly BW velocity, as part of mobility examinations.

Assistive devices alter gait patterns in Parkinson disease: Advantages of the four-wheeled walker

Gait abnormalities are a hallmark of Parkinsons disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety.