Brian M. Kelly

Sense of Effort Determines Lower Limb Force Production During Dynamic Movement in Individuals with Poststroke Hemiparesis

Objective. This study’s purpose was to determine if individuals who have had a stroke primarily use sense of effort to gauge force production during static and dynamic lower limb contractions. If relying on sense of effort while attempting to generate equal limb forces, participants should produce equal percentages of their maximum voluntary strength rather than equal absolute forces in their limbs. Methods. Ten stroke participants performed isometric and isotonic lower limb extensions on an exercise machine. Results. When participants attempted to produce equal bilateral isometric forces, there was a significant difference in absolute force between limbs (ANOVA, P < .0001) but no significant difference when force was normalized to each limb’s maximum voluntary contraction (MVC) force (P = .5129). During bilateral isotonic contractions, participants produced less absolute force in their paretic limb (P = .0005) and less relative force in their paretic limb (normalized to MVC force) when participants were given no instructions on how to perform the extension (P = .0002). When participants were instructed to produce equal forces, there was no significant difference between relative forces in the 2 limbs (P = .2111). Conclusions. For both isometric and isotonic conditions hemiparetic participants relied primarily on sense of effort, rather than proprioceptive feedback, for gauging lower limb force production. This outcome indicates that sense of effort is the major factor determining force production during movements. Lower limb rehabilitation therapies should not only train strength in the paretic limb but should also train patients to recalibrate force-scaling abilities to improve function.

Venous Thromboembolic Events in the Rehabilitation Setting

Venous thromboembolism (VTE) is a disease entity that encompasses both deep venous thrombosis and pulmonary embolism. During the past decade there have been significant advances in the understanding of prophylaxis and treatment of VTE. There is an extensive research base from which conclusions can be drawn, but the heterogeneity within the rehabilitation patient population makes the development of rigid VTE protocols challenging and overwhelming for the busy clinician. Given the prevalence of this condition and its associated morbidity and mortality, we review the evidence for the prevention, identification, and optimal treatment of VTE in the rehabilitation population. Our goal is to highlight studies that have the most clinical applicability for the care of VTE patients from a physiatrists perspective. At times, information about acute care protocols is included in our discussion because these situations are encountered during the consultation process that identifies patients for rehabilitation needs.

Baclofen-induced sexual dysfunction

Baclofen, a γ-aminobutyric acid B (GABA-B) agonist, is commonly used to treat spasticity associated with the upper motor neuron syndrome. Sexual dysfunction has been reported in men using intrathecal baclofen1 but has not been reported with oral baclofen use or in women. We present three cases of sexual dysfunction induced by oral baclofen. Case 1 is a 25-year-old woman with spastic diplegic cerebral palsy who was having increasing functional problems. She had never been treated with medication for her spasticity. She was started on baclofen, 10 mg nightly, titrating the dose up to 10 mg four times a day (QID) over 4 weeks. At follow-up, she was taking 10 mg three times daily (TID), as QID dosing caused fatigue. She noted improvements in tone and function but also noted a new difficulty in attaining orgasm as well as decreased intensity of orgasm. (She denied prior sexual dysfunction.) Orgasm could be reached, but additional …

A controlled clinical trial of a clinically-tuned powered ankle prosthesis in people with transtibial amputation:

Objective: To determine whether there are changes in level walking performance for people using a powered ankle prosthesis that was tuned by an independent, manufacturer-certified prosthetist in accordance with device recommendations. Design: Intervention study with cross-over design. Setting: Laboratory. Participants: Convenience sample of 10 individuals with unilateral, transtibial amputation, and 10 age- and gender-matched control participants. Interventions: Powered ankle prosthesis (BiOM T2 Ankle System). Main outcome metrics: Metabolic costs of walking, preferred walking speed. Results: There were no significant differences in oxygen consumption (2.9% difference; P = 0.606, d = 0.26), cost of transport (~1% difference; P = 0.652, d = 0.23), or preferred walking speed (~1% difference; P = 0.147, d = 0.76) when using the powered ankle compared to unpowered prostheses. Secondary analyses of user characteristics revealed that participants who were classified as having the highest function (K4 on Medicare’s 5-point scale from K0 to K4) were significantly more likely to exhibit energy cost savings than those classified as having lower function (K3; P = 0.014, d = 2.36). Conclusions: Participants did not demonstrate significant improvements in energetics or preferred speed when wearing a clinically tuned powered ankle prosthesis compared to their non-powered prostheses. Prescribers of powered devices should understand that not all users will show an immediate reduction in energy expenditure.

Preliminary trial of symmetry-based resistance in individuals with post-stroke hemiparesis

We tested a novel control strategy for robotic rehabilitation devices used by individuals with post-stroke hemiparesis. Symmetry-based resistance increases resistance when limb forces become more asymmetric during bilateral exercise. The underlying rationales for the control mode are that it will guide patients to increase paretic limb activation while teaching them to accurately gauge paretic limb force production relative to the non-paretic limb. During a one day training session, seven subjects post-stroke performed lower limb extensions in symmetry-based resistance mode on a robotic exercise machine. Subjects improved lower limb symmetry from 28.6%±3.9% to 36.2%±4.3% while under symmetry-based resistance training (ANOVA, P = 3D0.03), but did not maintain the improved lower limb symmetry during a constant resistance post-test. Two subjects that showed the large improvements in symmetry during the one day session performed additional days of training. Those results suggest that some patients demonstrate long lasting benefits with symmetry-based resistance training.

Factors associated with interest in novel interfaces for upper limb prosthesis control

Background Surgically invasive interfaces for upper limb prosthesis control may allow users to operate advanced, multi-articulated devices. Given the potential medical risks of these invasive interfaces, it is important to understand what factors influence an individual’s decision to try one. Methods We conducted an anonymous online survey of individuals with upper limb loss. A total of 232 participants provided personal information (such as age, amputation level, etc.) and rated how likely they would be to try noninvasive (myoelectric) and invasive (targeted muscle reinnervation, peripheral nerve interfaces, cortical interfaces) interfaces for prosthesis control. Bivariate relationships between interest in each interface and 16 personal descriptors were examined. Significant variables from the bivariate analyses were then entered into multiple logistic regression models to predict interest in each interface. Results While many of the bivariate relationships were significant, only a few variables remained significant in the regression models. The regression models showed that participants were more likely to be interested in all interfaces if they had unilateral limb loss (p ≤ 0.001, odds ratio ≥ 2.799). Participants were more likely to be interested in the three invasive interfaces if they were younger (p < 0.001, odds ratio ≤ 0.959) and had acquired limb loss (p ≤ 0.012, odds ratio ≥ 3.287). Participants who used a myoelectric device were more likely to be interested in myoelectric control than those who did not (p = 0.003, odds ratio = 24.958). Conclusions Novel prosthesis control interfaces may be accepted most readily by individuals who are young, have unilateral limb loss, and/or have acquired limb loss However, this analysis did not include all possible factors that may have influenced participant’s opinions on the interfaces, so additional exploration is warranted.

Poster 481 Metastatic Crohn Disease Manifesting as Skin Ulcerations in a Stroke Patient With Quadriplegia: A Case Report

Disclosures: S. R. Smith, none. Patients or Programs: A 46-year-old woman with a history of brainstem stroke that occurred 21 years ago, with quadriplegia, spasticity, and recently developed ulcers admitted for inpatient rehabilitation to increase mobility and transfers to assist with caregiver assistance for activities of daily living. Program Description: Skin wounds thought to be due to insufficient pressure relief that are actually caused by inflammatory bowel disease. Setting: University of Michigan Hospital inpatient rehabilitation unit. Results: We present a case of cutaneous metastatic Crohn disease that resulted in ulcerations around the buttocks, vulva, and inguinal folds of a 46-year-old woman who had a brain stem stroke more than 20 years ago. She had been cared for by her father and had never previously had any skin breakdown. In a span of 2 weeks, she developed deep skin ulcerations that penetrated beneath the dermis despite frequent pressure relief. Additional symptoms included watery, nonbloody stools and painful, blurry vision. These symptoms began approximately 3 months before presenting to the hospital with intractable wounds. While at the hospital, it was thought that her wounds were due to a lack of repositioning due to her inability to do pressure relief. She did not respond to aggressive wound therapy, and the ulcers continued to enlarge while she was in rehabilitation. Furthermore, the loose stool posed a risk of infection and irritation to the wounds and macerated the surrounding skin. Gastroenterology was consulted for the persistent diarrhea, and biopsies obtained from endoscopy were inconclusive. Biopsies of her skin ulcerations, however, revealed metastatic Crohn disease. She was treated with intravenous azathioprine, and her skin lesions rapidly improved over 4-6 weeks. She received prednisolone and atropine eye drops for ocular symptoms, which was diagnosed as uveitis, a serious and known complication of Crohn disease. Her loose stools resolved quickly with treatment. Conclusions: It is not intuitive to use an immunomodulating agent for the treatment of ulcers, but nonhealing ulcers should be evaluated for inflammatory bowel disease if the clinical situation fits. Treatment with immunomodulating agents such as azathioprine can rapidly improve the lesions.

Poster 321: Calciphylaxis Disguised as Phantom Limb Pain: A Case Report

delayed 36 hours for insurance reason. Lumbar MRI showed huge abscess from T10 to entire lumbar region and into psoas muscles bilaterally. Emergent multilevel decompresson to evacuate the abscess was successful with no neurological sequal. Setting: Tertiary medical center. Results: Low back pain is common in outpatient practice. It was easy to consider him just like any other back pain patient especially when there were no neurological deficits at the time. I was puzzled by the subjective report of sudden transient positional weakness he had and thought he might have mass of some sort. I did not suspect abscess since there is no fever or other risk factor such as prior spinal injection, intravenous drug use or diabetes. He had positive outcome with our suspicion and early intervention. Discussion: Epidural abscess of this magnitude is almost unheard of, especially when no source is identifiable. This case illustrates how crucial it is to consider mass lesion especially in a patient who gives peculiar/unusual history. In spite of negative risk factors, it is important to get imaging when the history and physical findings do not fit. There is no question a good history is the key. If the diagnosis was delayed for another day or two he could have died of sepsis or had major spinal cord compromise. Conclusions: One should always suspect mass lesion when there is major weakness or sensory change with positional change. Look further if the history and physical findings do not fit. One or 2 additional delays can be disastrous.