Premotor and Posterior Parietal Cortex Activity is Increased for Slow, as well as Fast Walking Poststroke: An fNIRS Study.

Methods: Twenty individuals in the chronic stage of stroke walked: (1) at their normal pace, (2) slower than normal, and (3) as fast as possible. Functional near-infrared spectroscopy was used to assess bilateral prefrontal, premotor, sensorimotor, and posterior parietal cortices during walking. Results: No significant differences in laterality were observed between walking speeds. The ipsilesional prefrontal cortex was overall more active than the contralesional prefrontal cortex. Premotor and posterior parietal cortex activity were larger during slow and fast walking compared to normal-paced walking with no differences between slow and fast walking. Greater increases in brain activation in the ipsilesional prefrontal cortex during fast compared to normal-paced walking related to greater gait speed modulation. Conclusions: Brain activation is not linearly related to gait speed. Ipsilesional prefrontal cortex, bilateral premotor, and bilateral posterior parietal cortices are important areas for gait speed modulation and could be an area of interest for neurostimulation.

Brain activity during real-time walking and with walking interventions after stroke: a systematic review.

Investigations of real-time brain activations during walking have become increasingly important to aid in recovery of walking after a stroke. Individual brain activation patterns can be a valuable biomarker of neuroplasticity during the rehabilitation process and can result in improved personalized medicine for rehabilitation. The purpose of this systematic review is to explore the brain activation characteristics during walking post-stroke by determining: (1) if different components of gait (i.e., initiation/acceleration, steady-state, complex) result in different brain activations, (2) whether brain activations differ from healthy individuals. Six databases were searched resulting in 22 studies. Initiation/acceleration showed bilateral activation in frontal areas; steady-state and complex walking showed broad activations with the majority exploring and finding increases in frontal regions and some studies also showing increases in parietal activation. Asymmetrical activations were often related to performance asymmetry and were more common in studies with slower gait speed. Hyperactivations and asymmetrical activations commonly decreased with walking interventions and as walking performance improved. Hyperactivations often persisted in individuals who had experienced severe strokes. Only a third of the studies included comparisons to a healthy group: individuals post-stroke employed greater brain activation compared to young adults, while comparisons to older adults were less clear and limited. Current literature suggests some indicators of walking recovery however future studies investigating more brain regions and comparisons with healthy age-matched adults are needed to further understand the effect of stroke on walking-related brain activation.

Passive, yet not inactive: robotic exoskeleton walking increases cortical activation dependent on task.

BACKGROUND: Experimental designs using surrogate gait-like movements, such as in functional magnetic resonance imaging (MRI), cannot fully capture the cortical activation associated with overground gait. Overground gait in a robotic exoskeleton may be an ideal tool to generate controlled sensorimotor stimulation of gait conditions like 'active' (i.e. user moves with the device) and 'passive' (i.e. user is moved by the device) gait. To truly understand these neural mechanisms, functional near-infrared spectroscopy (fNIRS) would yield greater ecological validity. Thus, the aim of this experiment was to use fNIRS to delineate brain activation differences between 'Active' and 'Passive' overground gait in a robotic exoskeleton. METHODS: Fourteen healthy adults performed 10 walking trials in a robotic exoskeleton for Passive and Active conditions, with fNIRS over bilateral frontal and parietal lobes, and electromyography (EMG) over bilateral thigh muscles. Digitization of optode locations and individual T1 MRI scans were used to demarcate the brain regions fNIRS recorded from. RESULTS: Increased oxyhemoglobin in the right frontal cortex was found for Passive compared with Active conditions. For deoxyhemoglobin, increased activation during Passive was found in the left frontal cortex and bilateral parietal cortices compared with Active; one channel in the left parietal cortex decreased during Active when compared with Passive. Normalized EMG mean amplitude was higher in the Active compared with Passive conditions for all four muscles (p ≤ 0.044), confirming participants produced the conditions asked of them. CONCLUSIONS: The parietal cortex is active during passive robotic exoskeleton gait, a novel finding as research to date has not recorded posterior to the primary somatosensory cortex. Increased activation of the parietal cortex may be related to the planning of limb coordination while maintaining postural control. Future neurorehabilitation research could use fNIRS to examine whether exoskeletal gait training can increase gait-related brain activation with individuals unable to walk independently.

Increased Sensorimotor Cortex Activation With Decreased Motor Performance During Functional Upper Extremity Tasks Poststroke.

BACKGROUND AND PURPOSE: Current literature has focused on identifying neuroplastic changes associated with stroke through tasks and in positions that are not representative of functional rehabilitation. Emerging technologies such as functional near-infrared spectroscopy (fNIRS) provide new methods of expanding the area of neuroplasticity within rehabilitation. This study determined the differences in sensorimotor cortex activation during unrestrained reaching and gripping after stroke. METHODS: Eleven individuals with chronic stroke and 11 neurologically healthy individuals completed reaching and gripping tasks under 3 conditions using their (1) stronger, (2) weaker, and (3) both arms together. Performance and sensorimotor cortex activation using fNIRS were collected. Group and arm differences were calculated using mixed analysis of covariance (covariate: age). Pairwise comparisons were used for post hoc analyses. Partial Pearson correlations between performance and activation were assessed for each task, group, and hemisphere. RESULTS: Larger sensorimotor activations in the ipsilesional hemisphere were found for the stroke compared with healthy group for reaching and gripping conditions despite poorer performance. Significant correlations were observed between gripping performance (with the weaker arm and both arms simultaneously) and sensorimotor activation for the stroke group only. DISCUSSION AND CONCLUSIONS: Stroke leads to significantly larger sensorimotor activation during functional reaching and gripping despite poorer performance. This may indicate an increased sense of effort, decreased efficiency, or increased difficulty after stroke. fNIRS can be used for assessing differences in brain activation during movements in functional positions after stroke. This can be a promising tool for investigating possible neuroplastic changes associated with functional rehabilitation interventions in the stroke population.Video Abstract available for more insights from the authors (see Video Abstract, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A269).

The Efficacy of Lower Extremity Mirror Therapy for Improving Balance, Gait, and Motor Function Poststroke: A Systematic Review and Meta-Analysis.

BACKGROUND: Mirror therapy is less commonly used to target the lower extremity after stroke to improve outcomes but is simple to perform. This review and meta-analysis aimed to evaluate the efficacy of lower extremity mirror therapy in improving balance, gait, and motor function for individuals with stroke. METHODS: PubMed, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database, and PsychINFO were searched from inception to May 2018 for randomized controlled trials (RCTs) comparing lower extremity mirror therapy to a control intervention for people with stroke. Pooled effects were determined by separate meta-analyses of gait speed, mobility, balance, and motor recovery. RESULTS: Seventeen RCTs involving 633 participants were included. Thirteen studies reported a significant between-group difference favoring mirror therapy in at least one lower extremity outcome. In a meta-analysis of 6 trials that reported change in gait speed, a large beneficial effect was observed following mirror therapy training (standardized mean differences [SMD] = 1.04 [95% confidence interval [CI] = .43, 1.66], I2 = 73%, and P < .001). Lower extremity mirror therapy also had a positive effect on mobility (5 studies, SMD = .46 [95% CI = .01, .90], I2 = 43%, and P = .05) and motor recovery (7 studies, SMD = .47 [95% CI = .21, .74], I2 = 0%, and P < .001). A significant pooled effect was not found for balance capacity. CONCLUSIONS: Mirror therapy for the lower extremity has a large effect for gait speed improvement. This review also found a small positive effect of mirror therapy for mobility and lower extremity motor recovery after stroke.

Postural threat influences vestibular-evoked muscular responses.

Standing balance is significantly influenced by postural threat. While this effect has been well established, the underlying mechanisms of the effect are less understood. The involvement of the vestibular system is under current debate, and recent studies that investigated the effects of height-induced postural threat on vestibular-evoked responses provide conflicting results based on kinetic (Horslen BC, Dakin CJ, Inglis JT, Blouin JS, Carpenter MG. J Physiol 592: 3671-3685, 2014) and kinematic (Osler CJ, Tersteeg MC, Reynolds RF, Loram ID. Eur J Neurosci 38: 3239-3247, 2013) data. We examined the effect of threat of perturbation, a different form of postural threat, on coupling (cross-correlation, coherence, and gain) of the vestibulo-muscular relationship in 25 participants who maintained standing balance. In the "No-Threat" conditions, participants stood quietly on a stable surface. In the "Threat" condition, participants' balance was threatened with unpredictable mediolateral support surface tilts. Quiet standing immediately before the surface tilts was compared to an equivalent time from the No-Threat conditions. Surface EMG was recorded from bilateral trunk, hip, and leg muscles. Hip and leg muscles exhibited significant increases in peak cross-correlation amplitudes, coherence, and gain (1.23-2.66×) in the Threat condition compared with No-Threat conditions, and significant correlations were observed between threat-related changes in physiological arousal and medium-latency peak cross-correlation amplitude in medial gastrocnemius (r = 0.408) muscles. These findings show a clear threat effect on vestibular-evoked responses in muscles in the lower body, with less robust effects of threat on trunk muscles. Combined with previous work, the present results can provide insight into observed changes during balance control in threatening situations. NEW & NOTEWORTHY: This is the first study to show increases in vestibular-evoked responses of the lower body muscles under conditions of increased threat of postural perturbation. While robust findings were observed in hip and leg muscles, less consistent results were found in muscles of the trunk. The present findings provide further support in the ongoing debate for arguments that vestibular-evoked balance responses are influenced by fear and anxiety and explain previous threat-related changes in balance.

Manipulating visual-motor experience to probe for observation-induced after-effects in adaptation learning.

Observers can learn to move in novel, adapted environments after watching a learning or expert model. Although this is an effective practice technique, it is unclear how this learning is achieved and if observers update an internal model of their visual-motor environment, as shown through the presence of after-effects (i.e., negative carry-over effects when aiming in a normal environment following exposure to perturbed conditions). For such updating to occur via observational practice, it has been reasoned that the observer requires the motor capabilities to perform the task they are observing. To test this, we first trained three groups to physically move in clockwise (CW) or counterclockwise (CCW) rotated environments. When immediately returned to a normal environment, after-effects were seen. We then attempted to wash out these effects before allowing two of these groups (CW and CCW), and a naïve observation only group, to watch a video of an actor performing in a CW environment. This observation phase was immediately followed by another test for after-effects and a direct test of learning when aiming in the rotated environment. Consistent with previous data, there were direct learning effects due to observation. Although after-effects increased for the experienced observers, these were small and were not significantly different from a physical practice only group that did not undergo the observation phase. Therefore, even with a motor repertoire for the rotated environment, there was a lack of evidence that observational practice results in implicit (re)updating of an internal model for aiming.

Implementation of increased physical therapy intensity for improving walking after stroke: Walk 'n watch protocol for a multisite stepped-wedge cluster-randomized controlled trial.

RATIONALE: Clinical practice guidelines support structured, progressive protocols for improving walking after stroke. Yet, practice is slow to change, evidenced by the little amount of walking activity in stroke rehabilitation units. Our recent study (n = 75) found that a structured, progressive protocol integrated with typical daily physical therapy improved walking and quality-of-life measures over usual care. Research therapists progressed the intensity of exercise by using heart rate and step counters worn by the participants with stroke during therapy. To have the greatest impact, our next step is to undertake an implementation trial to change practice across stroke units where we enable the entire unit to use the protocol as part of standard of care. AIMS: What is the effect of introducing structured, progressive exercise (termed the Walk 'n Watch protocol) to the standard of care on the primary outcome of walking in adult participants with stroke over the hospital inpatient rehabilitation period? Secondary outcomes will be evaluated and include quality of life. METHODS AND SAMPLE SIZE ESTIMATES: This national, multisite clinical trial will randomize 12 sites using a stepped-wedge design where each site will be randomized to deliver Usual Care initially for 4, 8, 12, or 16 months (three sites for each duration). Then, each site will switch to the Walk 'n Watch phase for the remaining duration of a total 20-month enrolment period. Each participant will be exposed to either Usual Care or Walk 'n Watch. The trial will enroll a total of 195 participants with stroke to achieve a power of 80% with a Type I error rate of 5%, allowing for 20% dropout. Participants will be medically stable adults post-stroke and able to take five steps with a maximum physical assistance from one therapist. The Walk 'n Watch protocol focuses on completing a minimum of 30 min of weight-bearing, walking-related activities (at the physical therapists' discretion) that progressively increase in intensity informed by activity trackers measuring heart rate and step number. STUDY OUTCOME(S): The primary outcome will be the change in walking endurance, measured by the 6-Minute Walk Test, from baseline (T1) to 4 weeks (T2). This change will be compared across Usual Care and Walk 'n Watch phases using a linear mixed-effects model. Additional physical, cognitive, and quality of life outcomes will be measured at T1, T2, and 12 months post-stroke (T3) by a blinded assessor. DISCUSSION: The implementation of stepped-wedge cluster-randomized trial enables the protocol to be tested under real-world conditions, involving all clinicians on the unit. It will result in all sites and all clinicians on the unit to gain expertise in protocol delivery. Hence, a deliberate outcome of the trial is facilitating changes in best practice to improve outcomes for participants with stroke in the trial and for the many participants with stroke admitted after the trial ends.

Frontal, Sensorimotor, and Posterior Parietal Regions Are Involved in Dual-Task Walking After Stroke.

Background: Walking within the community requires the ability to walk while simultaneously completing other tasks. After a stroke, completing an additional task while walking is significantly impaired, and it is unclear how the functional activity of the brain may impact this. Methods: Twenty individual in the chronic stage post-stroke participated in this study. Functional near-infrared spectroscopy (fNIRS) was used to measure prefrontal, pre-motor, sensorimotor, and posterior parietal cortices during walking and walking while completing secondary verbal tasks of varying difficulty. Changes in brain activity during these tasks were measured and relationships were accessed between brain activation changes and cognitive or motor abilities. Results: Significantly larger activations were found for prefrontal, pre-motor, and posterior parietal cortices during dual-task walking. Increasing dual-task walking challenge did not result in an increase in brain activation in these regions. Higher general cognition related to lower increases in activation during the easier dual-task. With the harder dual-task, a trend was also found for higher activation and less motor impairment. Conclusions: This is the first study to show that executive function, motor preparation/planning, and sensorimotor integration areas are all important for dual-task walking post-stroke. A lack of further brain activation increase with increasing challenge suggests a point at which a trade-off between brain activation and performance occurs. Further research is needed to determine if training would result in further increases in brain activity or improved performance.

Phase-dependent Brain Activation of the Frontal and Parietal Regions During Walking After Stroke - An fNIRS Study.

Background: Recovery of walking post-stroke is highly variable. Accurately measuring and documenting functional brain activation characteristics during walking can help guide rehabilitation. Previous work in this area has been limited to investigations of frontal brain regions and have not utilized recent technological and analytical advances for more accurate measurements. There were three aims for this study: to characterize the hemodynamic profile during walking post-stroke, to investigate regional changes in brain activation during different phases of walking, and to related brain changes to clinical measures. Methods: Functional near-infrared spectroscopy (fNIRS) along the pre-frontal, premotor, sensorimotor, and posterior parietal cortices was used on twenty individuals greater than six months post-stroke. Individual fNIRS optodes were digitized and used to estimate channel locations on each participant and short separation channels were used to control for extracerebral hemodynamic changes. Participants walked at their comfortable pace several times along a hallway while brain activation was recorded. Exploratory cluster analysis was conducted to determine if there was a link between brain activation and clinical measures. Results: Sustained activation was observed in the pre-frontal cortex with the ipsilesional hemisphere showing greater activation compared to the contralesional side. Sensorimotor cortex was active during the early, acceleration stage of walking only. Posterior parietal cortex showed changes in activation during the later, steady-state stage of walking. Faster gait speeds also related to increased activation in contralesional sensorimotor and posterior parietal cortices. Exploratory analysis clustered participants into two distinct groups based on their brain activation profiles and generally showed that individuals with greater activation tended to have better physical outcomes. Conclusions: These findings can guide future research for obtaining adequate power and determining factors that can be used as effect modifiers to reduce inter-subject variability. Overall, this is the first study to report specific oxygenated and deoxygenated hemoglobin changes in frontal to parietal regions during walking in the stroke population. Our results shed light on the importance of measuring brain activation across the cortex and show the importance of pre-frontal, sensorimotor, and posterior parietal cortices in walking after a stroke.

Telework and telerehabilitation programs for workers with a stroke during the COVID-19 pandemic: A commentary.

BACKGROUND: Due to the coronavirus disease 2019 (COVID-19) pandemic, rehabilitation facilities have become less accessible for patients with a stroke. Lack of early, intensive rehabilitation misses the opportunity for recovery during the critical time window of endogenous plasticity and improvement post-stroke. OBJECTIVES: The purpose of this commentary was to highlighting the benefits of telework and telerehabilitation programs for workers with a stroke during the COVID-19 pandemic. METHODS: Relevant publications regarding the management of individuals with a stroke, telerehabilitation and teleworking in the setting of COVID-19 were reviewed. RESULTS: Previous studies showed that telerehabilitation can effectively provide an alternate method of promoting recovery for patients with a stroke. With the physical distancing precautions in place for mitigating viral spread, teleworking can also provide a method for long term recovery and improvements in quality of life after a stroke. CONCLUSIONS: Overall, this commentary addresses the benefits of physically distant, safe and effective alternatives to support individuals who live with a stroke during COVID-19 pandemic.

A cross-sectional study of breast pain in a diverse population of breast cancer patients.

BACKGROUND: Breast cancer is the most common cancer in women, and postoperative breast pain has been reported to be anywhere from 25% to 60%. However, there is sparse data regarding racial/ethnic differences in breast pain among breast cancer patients. METHODS: We performed a cross-sectional anonymous survey of breast cancer patients from the Hawaii Cancer Consortium over a 6-week period between 2019 and 2020. The 237 breast cancer participants were ages 29 to 98, 74% Asian, and mainly from outpatient oncology clinics. We evaluated the prevalence of breast pain in a diverse group of breast cancer patients and characterized the pain using a modified short-form McGill pain questionnaire (sfMPQ). RESULTS: Eighty-fourrespondents(35.4%) reported breast pain. On univariable analysis, we found significant racial/ethnic differences in the amount of breast pain, where Chinese and Japanese participants reported significantly less pain compared to White participants on a 10-point pain scale. We found differences in breast pain according to age and endocrine therapy use as well as survey location, however, no differences were seen according to chemotherapy, radiation, or breast surgery. Based on the sfMPQ, the most common descriptors of breast pain were sensory (throbbing, shooting, and stabbing) compared to affective (tiring-exhausting, sickening, fearful, and punishing-cruel) characteristics. Although they were described as mild and intermittent, in women with breast pain, 33.4% reported the breast pain affected their sleep, 16.7% their work, and 15.4% their sexual activity. CONCLUSIONS: Breast pain is a significant problem in our breast cancer community. This survey assessment has informed our understanding of breast pain in our diverse population. In turn, we are developing culturally appropriate pain management strategies to treat this challenging symptom common in breast cancer survivors.

Cortical Activation During Shoulder and Finger Movements in Healthy Adults: A Functional Near-Infrared Spectroscopy (fNIRS) Study.

Characterization of cortical activation patterns during movement of the upper extremity in healthy adults is helpful in understanding recovery mechanisms following neurological disorders. This study explores cortical activation patterns associated with movements of the shoulder and fingers in healthy adults using functional near-infrared spectroscopy (fNIRS). Twelve healthy right-handed participants were recruited. Two motor tasks (shoulder abduction and finger extension) with two different trial lengths (10 s and 20 s) were performed in a sitting position at a rate of 0.5 Hz. The hemodynamic response, as indicated by oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR), over both hemispheres was acquired using a 54-channel fNIRS system. We found a generalized bilateral cortical activation during both motor tasks with greater activation in the contralateral compared to the ipsilateral primary motor cortex. Particularly in the more medial part of the contralateral hemisphere, significant higher activation was found during the shoulder compared to finger movements. Furthermore, cortical activation patterns are affected not only by motor tasks but also by trial lengths. HbO is more sensitive to detect cortical activation during finger movements in longer trials, while HbR is a better surrogate to capture active areas during shoulder movement in shorter trials. Based on these findings, reporting both HbO and HbR is strongly recommended for future fNIRS studies, and trial lengths should be taken into account when designing experiments and explaining results. Our findings demonstrating distinct cortical activation patterns associated with shoulder and finger movements in healthy adults provide a foundation for future research to study recovery mechanisms following neurological disorders.

A consensus guide to using functional near-infrared spectroscopy in posture and gait research.

BACKGROUND: Functional near-infrared spectroscopy (fNIRS) is increasingly used in the field of posture and gait to investigate patterns of cortical brain activation while people move freely. fNIRS methods, analysis and reporting of data vary greatly across studies which in turn can limit the replication of research, interpretation of findings and comparison across works. RESEARCH QUESTION AND METHODS: Considering these issues, we propose a set of practical recommendations for the conduct and reporting of fNIRS studies in posture and gait, acknowledging specific challenges related to clinical groups with posture and gait disorders. RESULTS: Our paper is organized around three main sections: 1) hardware set up and study protocols, 2) artefact removal and data processing and, 3) outcome measures, validity and reliability; it is supplemented with a detailed checklist. SIGNIFICANCE: This paper was written by a core group of members of the International Society for Posture and Gait Research and posture and gait researchers, all experienced in fNIRS research, with the intent of assisting the research community to lead innovative and impactful fNIRS studies in the field of posture and gait, whilst ensuring standardization of research.

Immunotherapy for the Treatment of Breast Cancer: Emerging New Data.

Breast cancer is the most common type of cancer affecting women in the United States. Triple-negative breast cancer remains the most aggressive molecular subtype secondary to a lack of therapeutic targets. The search for a target has led us to investigate immunotherapeutic agents. Immunotherapy has recently demonstrated significant breakthroughs in various types of cancers that are refractory to traditional therapies including melanoma and Non-Small Cell Lung Cancer (NSCLC). Breast cancer however remains one of the tumors that was initially least investigated because of being considered to have a low immunogenic potential and a low mutational load. Over the past few years, antiPD1/PDL1 drugs have started to make progress in the triple-negative subtype with more promising outcomes. In this report, we review the treatment of triple-negative breast cancer and specifically shed light on advances in immunotherapy and newly approved drugs in this challenging disease.

Benefits of multi-session balance and gait training with multi-modal biofeedback in healthy older adults.

Real-time balance-relevant biofeedback from a wearable sensor can improve balance in many patient populations, however, it is unknown if balance training with biofeedback has lasting benefits for healthy older adults once training is completed and biofeedback removed. This study was designed to determine if multi-session balance training with and without biofeedback leads to changes in balance performance in healthy older adults; and if changes persist after training. 36 participants (age 60-88) were randomly divided into two groups. Both groups trained on seven stance and gait tasks for 2 consecutive weeks (3×/week) while trunk angular sway and task duration were monitored. One group received real-time multi-modal biofeedback of trunk sway and a control group trained without biofeedback. Training effects were assessed at the last training session, with biofeedback available to the feedback group. Post-training effects (without biofeedback) were assessed immediately after, 1-week, and 1-month post-training. Both groups demonstrated training effects; participants swayed less when standing on foam with eyes closed (EC), maintained tandem-stance EC longer, and completed 8 tandem-steps EC faster and with less sway at the last training session. Changes in sway and duration, indicative of faster walking, were also observed after training for other gait tasks. While changes in walking speed persisted post-training, few other post-training effects were observed. These data suggest there is little added benefit to balance training with biofeedback, beyond training without, in healthy older adults. However, transient use of wearable balance biofeedback systems as balance aides remains beneficial for challenging balance situations and some clinical populations.

"Stepping Up" Activity Poststroke: Ankle-Positioned Accelerometer Can Accurately Record Steps During Slow Walking.

BACKGROUND: As physical activity in people poststroke is low, devices that monitor and provide feedback of walking activity provide motivation to engage in exercise and may assist rehabilitation professionals in auditing walking activity. However, most feedback devices are not accurate at slow walking speeds. OBJECTIVE: This study assessed the accuracy of one accelerometer to measure walking steps of community-dwelling individuals poststroke. DESIGN: This was a cross-sectional study. METHODS: Two accelerometers were positioned on the nonparetic waist and ankle of participants (N=43), and walking steps from these devices were recorded at 7 speeds (0.3-0.9 m/s) and compared with video recordings (gold standard). RESULTS: When positioned at the waist, the accelerometer had more than 10% error at all speeds, except 0.8 and 0.9 m/s, and numerous participants recorded zero steps at 0.3 to 0.5 m/s. The device had 10% or less error when positioned at the ankle for all speeds between 0.4 and 0.9 m/s. LIMITATIONS: Some participants were unable to complete the faster walking speeds due to their walking impairments and inability to maintain the requested walking speed. CONCLUSIONS: Although not recommended by the manufacturer, positioning the accelerometer at the ankle (compared with the waist) may fill a long-standing need for a readily available device that provides accurate feedback for the altered and slow walking patterns that occur with stroke.

Capturing step counts at slow walking speeds in older adults: comparison of ankle and waist placement of measuring device.

OBJECTIVE: It is important for older adults to be physically active, but many older adults walk slowly. This study examined the accuracy of a commercially available step-count device (Fitbit One) at slow speeds and compared the accuracy of the device when worn at the ankle and waist in older adults. METHODS: The Fitbit One was placed at the ankle and waist of participants (n=42; mean age 73 years) while they performed walking trials at 7 different speeds (0.3-0.9 m/s). Step counts obtained from video recordings were used as the gold standard comparison to determine the accuracy of the device. RESULTS: The ankle-worn device had significantly less error than the waist-worn device at all speeds. The percentage error of the ankle-worn device was less than 10% at speeds of 0.4-0.9 m/s and did not record zero steps at any speed. The percentage error of the waist-worn device was below 10% at only the 2 fastest speeds (0.8 and 0.9 m/s) and recorded zero steps for numerous participants at speeds of 0.3-0.5 m/s. CONCLUSION: The Fitbit One can accurately capture steps at slow speeds when placed at the ankle and thus may be appropriate for capturing physical activity in slow-walking older adults.

Elevated International Normalized Ratio in a patient concurrently using warfarin and vismodegib.

PURPOSE: A case report of a sharp rise in International Normalized Ratio (INR) values during a patient's concomitant use of warfarin and the antineoplastic agent vismodegib is presented. SUMMARY: About three weeks after he was prescribed vismodegib for skin cancer, a 78-year-old Caucasian man whose INR had been stable during nine months of warfarin use was found to have a critical INR value (9.5) during a visit to a pharmacy anticoagulation clinic. After clinic interventions including brief suspensions of warfarin therapy and an incremental 36% decrease in the weekly dose, the patient's INR returned to a high-normal value over the next few weeks, and treatment with warfarin was resumed. One week later, the man was admitted to the emergency department for altered mental status and loss of consciousness, which were thought to be unrelated to anticoagulation therapy. The patient died in the hospital shortly thereafter of unknown causes. At the time of death, laboratory values were stable, the most recent INR was 1.8, and the patient was hemodynamically stable and on a non-intensive care ward. Assessment with the Drug Interaction Probability Scale indicated a probable interaction between warfarin and vismodegib. Since its introduction in 2012, vismodegib has been implicated as a possible factor in seven reports of patient deaths. CONCLUSION: Concurrent use of vismodegib and warfarin was deemed the probable cause of acute INR elevation in this case, suggesting the need for close monitoring of INR values in patients receiving this combination of drugs.