Nancy N. Byl

COPD as a systemic disease: impact on physical functional limitations.

PURPOSE Although chronic obstructive pulmonary disease (COPD) has a major impact on physical health, the specific impact of COPD on physical functional limitations has not been characterized clearly. We aimed to elucidate the physical functional limitations that are directly attributable to COPD compared to a matched referent group without the condition. METHODS We used the Function, Living, Outcomes, and Work (FLOW) cohort study of adults with COPD (n=1202) and referent subjects matched by age, sex, and race (n=302) to study the impact of COPD on the risk of a broad array of functional limitations using validated measures: lower extremity function (Short Physical Performance Battery [SPPB]), submaximal exercise performance (Six Minute Walk Test [SMWT]), standing balance (Functional Reach Test), skeletal muscle strength (manual muscle testing with dynamometry), and self-reported functional limitation (standardized item battery). Multivariate analysis was used to control for confounding by age, sex, race, height, educational attainment, and cigarette smoking. RESULTS COPD was associated with poorer lower extremity function (mean SPPB score decrement for COPD vs referent -1.0 points; 95% CI, -1.25 to -0.73 pts) and less distance walked during the SMWT (-334 feet; 95% CI, -384 to -282 ft). COPD also was associated with weaker muscle strength in every muscle group tested, including both the upper and lower extremities (P<.0001 in all cases) and with a greater risk of self-reported functional limitation (OR 6.4; 95% CI, 3.7 to 10.9). CONCLUSIONS A broad array of physical functional limitations were specifically attributable to COPD. COPD affects a multitude of body systems remote from the lung.

Effectiveness of Sensory and Motor Rehabilitation of the Upper Limb Following the Principles of Neuroplasticity: Patients Stable Poststroke:

Based on the principles of neuroplasticity, the purpose of this crossover study was to determine if improvement in upper extremity (UE) function and independence could be achieved in patients 6 months to 7 years poststroke following an outpatient rehabilitation program (supervised 1.5 hours per week for 8 weeks reinforced with home gloving unaffected side and attended, graded, repetitive sensory and motor training activities). Twenty-one subjects (right or left hemiparesis; able to walk 100 feet with or without a cane; partially opened and closed the hand; partially elevated the shoulder and elbow against gravity) were randomly assigned to Group A (sensory training 4 weeks, motor training 4 weeks) or Group B (motor training 4 weeks, sensory training 4 weeks). Greater than 20% (P <0.01) improvement was measured in functional independence and UE function (fine motor, sensory discrimination, and musculoskeletal performance). Gains were hemispheric and training specific and maintained over 3 months. This study provides evidence documenting significant improvement in function in the late poststroke recovery period following 12 hours of supervised learning based sensory motor training.

Effect of sensory discrimination training on structure and function in patients with focal hand dystonia: a case series.

OBJECTIVE To measure the effects of sensorimotor training based on the principles of neuroplasticity for patients with focal hand dystonia. DESIGN Case series of 3 subjects with focal hand dystonia of the left hand, compared with age-matched normative controls. SETTING Outpatient clinic. PARTICIPANTS Three consecutive clinic patients-musicians with focal hand dystonia-who described a history of repetitive practice and performance (2 women; ages, 23 y and 35 y; 1 man; age, 24 y). INTERVENTION Subjects were asked to stop performing the tasks that caused the abnormal movements, to participate in a wellness program (aerobics, postural exercises, stress free hand use), and to carry out supervised, attended, individualized, repetitive sensorimotor training activities at least once week for 12 weeks and reinforced daily at home. MAIN OUTCOME MEASURES Standard tests documenting somatosensory hand representation, target-specific hand control, and clinical function. RESULTS On the affected side, the 3 subjects improved an average of 86.8% on somatosensory hand representation, 117% on target-specific performance, 23.9% on fine motor skills, 22.7% on sensory discrimination, 31.9% on musculoskeletal skills, and 32.3% on independence. All 3 subjects improved 10% or more on 90% of the subtests with 20% improvement on 50% of the subtests. CONCLUSION Individuals with focal hand dystonia who have a history of repetitive hand use can improve cortical somatosensory responses and clinical motor function after individualized sensorimotor training consistent with the principles of neural adaptation.

Treatment effectiveness for patients with a history of repetitive hand use and focal hand dystonia: A planned, prospective follow-up study

Recent studies show that rapid, nearly simultaneous, stereotypical repetitive fine motor movements can degrade the sensory representation of the hand and lead to a loss of normal motor control with a target task, referred to as occupational hand cramps or focal hand dystonia. The purpose of this prospective follow-up study was to determine whether symptomatic patients in jobs demanding high levels of repetition could be relieved of awkward, involuntary hand movements following sensory discriminative retraining complemented by a home program of sensory exercises, plus traditional posture, relaxation, mobilization, and fitness exercises. Twelve patients participated in the study. They all had occupational hand cramps, as diagnosed by a neurologist. Each patient was evaluated by a trained, independent research assistant before treatment and three to six months after treatment, by use of a battery of sensory, motor, physical, and functional performance tests. Care was provided by a physical therapist or a supervised physical therapist student in an outpatient clinic. Patients were asked to stop performing the target task and to come once a week for supervised treatment that included 1) heavy schedules of sensory training with and without biofeedback to restore the sensory representation of the hand, and 2) instructions in stress-free hand use, mirror imagery, mental rehearsal, and mental practice techniques designed to stop the abnormal movements and facilitate normal hand control. Patients were instructed in therapeutic exercises to be performed in the home to improve postural alignment, reduce neural tension, facilitate relaxation, and promote cardiopulmonary fitness. Following the defined treatment period, all patients were independent in activities of daily living, and all but one patient returned to work. Significant gains were documented in motor control, motor accuracy; sensory discrimination, and physical performance (range of motion, strength, posture, and balance). This descriptive study that includes patients with occupation-related focal hand dystonia provides evidence that aggressive sensory discriminative training complemented by traditional fitness exercises to facilitate musculoskeletal health can improve sensory processing and motor control of the hand.

Altered trunk position sense and its relation to balance functions in people post-stroke.

Objective: To determine whether trunk position sense is impaired in people with poststroke hemiparesis. Background: Good trunk stability is essential for balance and extremity use during daily functional activities and higher level tasks. Dynamic stability of the trunk requires adequate flexibility, muscle strength, neural control, and proprioception. While deficits of trunk muscle strength have been identified in people post-stroke, it is not clear whether they have adequate postural control and proprioception to ensure a stable foundation of balance to enable skilled extremity use. Trunk position sense is an essential element of trunk postural control. Even a small impairment in trunk position sense may contribute to trunk instability. However, a specific impairment of trunk position sense has not been reported in people post-stroke. Subjects: Twenty subjects with chronic stroke and 21 nonneurologically impaired subjects participated in the study. Main outcome measures: Trunk repositioning error during sitting forward flexion movements was assessed using an electromagnetic movement analysis system, Flock of Birds. Subjects post-stroke were also evaluated with clinical measures of balance (Berg Balance Scale), postural control (Postural Assessment Scale for Stroke), and extremity motor impairment severity (Fugl-Meyer Assessment-Motor Score). Results: There were significant differences in absolute trunk repositioning error between stroke and control groups in both the sagittal (P = 0.0001) and transverse (P = 0.0012) planes. Mean sagittal plane error: post-stroke: 6.9 ± 3.1 degrees, control: 3.2 ± 1.8 degrees; mean transverse plane error: post-stroke 2.1 ± 1.3 degrees, control: 1.0 ± 0.6 degrees. There was a significant negative correlation between sagittal plane absolute repositioning error and the Berg Balance Scale score (r = −0.49, P = 0.03), transverse plane absolute repositioning error and Berg Balance Scale score (r = −0.48, P = 0.03), and transverse plane repositioning error and the Postural Assessment Scale for Stroke score (r = −0.52, P = 0.02) Conclusions: Subjects with poststroke hemiparesis exhibit greater trunk repositioning error than age-matched controls. Trunk position sense retraining, emphasizing sagittal and transverse movements, should be further investigated as a potential poststroke intervention strategy to improve trunk balance and control.

Upper extremity impairments in women with or without lymphedema following breast cancer treatment

IntroductionBreast-cancer-related lymphedema affects ∼25% of breast cancer (BC) survivors and may impact use of the upper limb during activity. The purpose of this study is to compare upper extremity (UE) impairment and activity between women with and without lymphedema after BC treatment.Methods144 women post BC treatment completed demographic, symptom, and Disability of Arm-Shoulder-Hand (DASH) questionnaires. Objective measures included Purdue pegboard, finger-tapper, Semmes-Weinstein monofilaments, vibration perception threshold, strength, range of motion (ROM), and volume.ResultsWomen with lymphedema had more lymph nodes removed (p < .001), more UE symptoms (p < .001), higher BMI (p = .041), and higher DASH scores (greater limitation) (p < .001). For all participants there was less strength (elbow flexion, wrist flexion, grip), less shoulder ROM, and decreased sensation at the medial upper arm (p < .05) in the affected UE. These differences were greater in women with lymphedema, particularly in shoulder abduction ROM (p < .05). Women with lymphedema had bilaterally less elbow flexion strength and shoulder ROM (p < .05). Past diagnosis of lymphedema, grip strength, shoulder abduction ROM, and number of comorbidities contributed to the variance in DASH scores (R2 of 0.463, p < .001).Implications for cancer survivorsUE impairments are found in women following treatment for BC. Women with lymphedema have greater UE impairment and limitation in activities than women without. Many of these impairments are amenable to prevention measures or treatment, so early detection by health care providers is essential.

The neural consequences of repetition: Clinical implications of a learning hypothesis

Repetitive strain injuries (RSIs) are difficult to treat. Some individuals with RSIs may ultimately develop chronic pain syndromes or movement problems like focal hand dystonia (FDh), a disorder of motor control manifested in a specific context during skilled, hand tasks. This paper reports on the results of four neuroplasticity studies suggesting that repetitive hand opening and closing can lead to motor control problems, measurable somatosensory changes, and problems in graphesthesia and stereognosis. The experiments support a learning hypothesis for the origin of severe RSIs, particularly FDh. This degradation in the sensory representation of the hand may not only explain the therapeutic challenge of returning these patients to work, but also provide a foundation for developing more effective physical rehabilitation strategies. Implications and conjectures for the applications of this learning hypothesis to conditions of chronic pain are also discussed.

Sensory representation abnormalities that parallel focal hand dystonia in a primate model.

In our hypothesis of focal dystonia, attended repetitive behaviors generate aberrant sensory representations. Those aberrant representations interfere with motor control. Abnormal motor control strengthens sensory abnormalities. The positive feedback loop reinforces the dystonic condition. Previous studies of primates with focal hand dystonia have demonstrated multi-digit or hairy-glabrous responses at single sites in area 3b, receptive fields that average ten times larger than normal, and high receptive field overlap as a function of horizontal distance. In this study, we strengthen and elaborate these findings. One animal was implanted with an array of microelectrodes that spanned the border between the face and digits. After the animal developed hand dystonia, responses in the initial hand representation increasingly responded to low threshold stimulation of the face in a columnar substitution. The hand-face border that is normally sharp became patchy and smeared over 1 mm of cortex within 6 weeks. Two more trained animals developed a focal hand dystonia variable in severity across the hand. Receptive field size, presence of multi-digit or hairy-glabrous receptive fields, and columnar overlap covaried with the animals ability to use specific digits. A fourth animal performed the same behaviors without developing dystonia. Many of its physiological measures were similar to the dystonic animals, but receptive field overlap functions were minimally abnormal, and no sites shared response properties that are normally segregated such as hairy-glabrous combined fields, or multi-digit fields. Thalamic mapping demonstrated proportionate levels of abnormality in thalamic representations as were found in cortical representations.

Kinematic Data Analysis for Post-Stroke Patients Following Bilateral Versus Unilateral Rehabilitation With an Upper Limb Wearable Robotic System

Robot-assisted stroke rehabilitation has become popular as one approach to helping patients recover function post-stroke. Robotic rehabilitation requires four important elements to match the robot to the patient: realistic biomechanical robotic elements, an assistive control scheme enabled through the human-robot interface, a task oriented rehabilitation program based on the principles of plasticity, and objective assessment tools to monitor change. This paper reports on a randomized clinical trial utilizing a complete robot-assisted rehabilitation system for the recovery of upper limb function in patients post-stroke. In this study, a seven degree-of-freedom (DOF) upper limb exoskeleton robot (UL-EXO7) is applied in a rehabilitation clinical trial for patients stable post-stroke (greater than six months). Patients had a Fugl-Meyer Score between 16-39, were mentally alert (19 on the VA Mini Mental Status Exam) and were between 27 and 70 years of age. Patients were randomly assigned to three groups: bilateral robotic training, unilateral robotic training, and usual care. This study is concerned with the changes in kinematics in the two robotic groups. Both patient groups played eight therapeutic video games over 12 sessions (90 min, two times a week). In each session, patients intensively played the different combination of video games that directly interacted with UL-EXO7 under the supervision of research assistant. At each session, all of the joint angle data was recorded for the evaluation of therapeutic effects. A new assessment metric is reported along with conventional metrics. The experimental result shows that both groups of patients showed consistent improvement with respect to the proposed and conventional metrics.

Resting state alpha-band functional connectivity and recovery after stroke

After cerebral ischemia, disruption and subsequent reorganization of functional connections occur both locally and remote to the lesion. However, the unpredictable timing and extent of sensorimotor recovery reflects a gap in understanding of these underlying neural mechanisms. We aimed to identify the plasticity of alpha-band functional neural connections within the perilesional area and the predictive value of functional connectivity with respect to motor recovery of the upper extremity after stroke. Our results show improvements in upper extremity motor recovery in relation to distributed changes in MEG-based alpha band functional connectivity, both in the perilesional area and contralesional cortex. Motor recovery was found to be predicted by increased connectivity at baseline in the ipsilesional somatosensory area, supplementary motor area, and cerebellum, contrasted with reduced connectivity of contralesional motor regions, after controlling for age, stroke onset-time and lesion size. These findings support plasticity within a widely distributed neural network and define brain regions in which the extent of network participation predicts post-stroke recovery potential.