Dynamic Visual Stimulations Produced in a Controlled Virtual Reality Environment Reveals Long-Lasting Postural Deficits in Children With Mild Traumatic Brain Injury.

Motor control deficits outlasting self-reported symptoms are often reported following mild traumatic brain injury (mTBI). The exact duration and nature of these deficits remains unknown. The current study aimed to compare postural responses to static or dynamic virtual visual inputs and during standard clinical tests of balance in 38 children between 9 and 18 years-of-age, at 2 weeks, 3 and 12 months post-concussion.

A Brain Penetrant Mutant IDH1 Inhibitor Provides In Vivo Survival Benefit.

Mutations in IDH1 are highly prevalent in human glioma. First line treatment is radiotherapy, which many patients often forego to avoid treatment-associated morbidities. The high prevalence of IDH1 mutations in glioma highlights the need for brain-penetrant IDH1 mutant-selective inhibitors as an alternative therapeutic option.

Patellar tendon vibration reduces the increased facilitation from quadriceps to soleus in post-stroke hemiparetic individuals.

Background: Stimulation of the femoral nerve in healthy people can facilitate soleus H-reflex and electromyography (EMG) activity. In stroke patients, such facilitation of transmission in spinal pathways linking the quadriceps and soleus muscles is enhanced and related to co-activation of knee and ankle extensors while sitting and walking. Soleus H-reflex facilitation can be depressed by vibration of the quadriceps in healthy people, but the effects of such vibration have never been studied on the abnormal soleus facilitation observed in people after stroke.

First- and Second-Order Stimuli Reaction Time Measures Are Highly Sensitive to Mild Traumatic Brain Injuries.

Mild traumatic brain injury (mTBI) has subtle effects on several brain functions that can be difficult to assess and follow up. We investigated the impact of mTBI on the perception of sine-wave gratings defined by first- and second-order characteristics. Fifteen adults diagnosed with mTBI were assessed at 15 days, 3 months, and 12 months postinjury.

Motor unit firing pattern, synchrony and coherence in a deafferented patient.

The firing of spinal motoneurons (MNs) is controlled continuously by inputs from muscle, joint and skin receptors. Besides altering MN synaptic drive, the removal of these inputs is liable to alter the synaptic noise and, thus, the variability of their tonic activity. Sensory afferents, which are a major source of common and/or synchronized inputs shared by several MNs, may also contribute to the coupling in the time and frequency domains (synchrony and coherence, respectively) observed when cross-correlation and coherence analyses are applied to the discharges of MN pairs.

Changes in activation timing of knee and ankle extensors during gait are related to changes in heteronymous spinal pathways after stroke.

Background: Extensor synergy is often observed in the paretic leg of stroke patients. Extensor synergy consists of an abnormal stereotyped co-activation of the leg extensors as patients attempt to move. As a component of this synergy, the simultaneous activation of knee and ankle extensors in the paretic leg during stance often affects gait pattern after stroke.

Complex muscle vibration patterns to induce gait-like lower-limb movements: proof of concept.

Muscle vibrations can induce motor responses and illusions of complex movements. However, inducing gait-like cyclical movements and illusions requires the application of multiple fast alternating vibrations to lower-limb muscles. The objectives were (1) to test the feasibility of delivering complex vibrations in a time-organized manner and (2) to illustrate the possibility of inducing alternate gait-in-place-like movements using these vibrations.

The potential impact of intelligent power wheelchair use on social participation: perspectives of users, caregivers and clinicians.

Purpose: To explore power wheelchair users', caregivers' and clinicians' perspectives regarding the potential impact of intelligent power wheelchair use on social participation.

Methods: Semi-structured interviews were conducted with power wheelchair users (n = 12), caregivers (n = 4) and clinicians (n = 12). An illustrative video was used to facilitate discussion.

Exploring powered wheelchair users and their caregivers' perspectives on potential intelligent power wheelchair use: a qualitative study.

Power wheelchairs (PWCs) can have a positive impact on user well-being, self-esteem, pain, activity and participation. Newly developed intelligent power wheelchairs (IPWs), allowing autonomous or collaboratively-controlled navigation, could enhance mobility of individuals not able to use, or having difficulty using, standard PWCs. The objective of this study was to explore the perspectives of PWC users (PWUs) and their caregivers regarding if and how IPWs could impact on current challenges faced by PWUs, as well as inform current development of IPWs.

Discovery of MK-1439, an orally bioavailable non-nucleoside reverse transcriptase inhibitor potent against a wide range of resistant mutant HIV viruses.

The optimization of a novel series of non-nucleoside reverse transcriptase inhibitors (NNRTI) led to the identification of pyridone 36. In cell cultures, this new NNRTI shows a superior potency profile against a range of wild type and clinically relevant, resistant mutant HIV viruses. The overall favorable preclinical pharmacokinetic profile of 36 led to the prediction of a once daily low dose regimen in human.

Design and validation of an intelligent wheelchair towards a clinically-functional outcome.

Background: Many people with mobility impairments, who require the use of powered wheelchairs, have difficulty completing basic maneuvering tasks during their activities of daily living (ADL). In order to provide assistance to this population, robotic and intelligent system technologies have been used to design an intelligent powered wheelchair (IPW). This paper provides a comprehensive overview of the design and validation of the IPW.

Abnormal coactivation of knee and ankle extensors is related to changes in heteronymous spinal pathways after stroke.

Background: Abnormal coactivation of leg extensors is often observed on the paretic side of stroke patients while they attempt to move. The mechanisms underlying this coactivation are not well understood. This study (1) compares the coactivation of leg extensors during static contractions in stroke and healthy individuals, and (2) assesses whether this coactivation is related to changes in intersegmental pathways between quadriceps and soleus (Sol) muscles after stroke.

Poor back muscle endurance is related to pain catastrophizing in patients with chronic low back pain.

Study Design: An experimental and comparative study of chronic low back pain (CLBP) patients and healthy controls.

Objective: To use a motivation-independent electromyography (EMG) based test of back muscle capacity to determine whether back muscle deconditioning is present in CLBP patients and whether it is related to pain-related psychological variables.

Summary Of Background Data: The verification of the deconditioning syndrome in CLBP patients might be biased by the use of performance-based measures to assess physical fitness, especially in patients having fear of injury.

Control of wrist position and muscle relaxation by shifting spatial frames of reference for motoneuronal recruitment: possible involvement of corticospinal pathways.

It has previously been established that muscles become active in response to deviations from a threshold (referent) position of the body or its segments, and that intentional motor actions result from central shifts in the referent position. We tested the hypothesis that corticospinal pathways are involved in threshold position control during intentional changes in the wrist position in humans. Subjects moved the wrist from an initial extended to a final flexed position (and vice versa).

The effect of sex and chronic low back pain on back muscle reflex responses.

Different back muscle reflex assessment protocols have shown abnormally longer reflex latency responses of back muscles in chronic low back pain (CLBP). However, many confounding variables are difficult to control, such as the load magnitude and the preactivation of trunk muscles. The aims of this study were to evaluate, in 30 subjects with CLBP and 30 healthy controls, the activation levels of back muscles during pre-loading and their reflex responses to sudden loading.

Using activity diaries to measure children's and adolescents' compliance with activity restrictions after mild traumatic brain injury.

Purpose: To examine the extent to which children and adolescents with a mild traumatic brain injury (MTBI) comply with the activity restrictions received upon discharge from a pediatric trauma center.

Participants: Thirty-four children with MTBI (aged 8-16 years) and 34 control children matched for age, sex, and premorbid level of physical activity.

Main Measure: Activity diary documenting the exact level of activity during 3 consecutive days during the 1st, 4th, and 12th week post-MTBI (corresponding time intervals for controls) and the Physical Activity Questionnaire.

Transmission in heteronymous spinal pathways is modified after stroke and related to motor incoordination.

Changes in reflex spinal pathways after stroke have been shown to affect motor activity in agonist and antagonist muscles acting at the same joint. However, only a few studies have evaluated the heteronymous reflex pathways modulating motoneuronal activity at different joints. This study investigates whether there are changes in the spinal facilitatory and inhibitory pathways linking knee to ankle extensors and if such changes may be related to motor deficits after stroke.

Mild traumatic brain injury induces prolonged visual processing deficits in children.

Primary Objective: To compare the sensitivity to simple and complex visual stimuli of children who have sustained a mild traumatic brain injury (mTBI) to that of matched non-injured children and to determine the evolution of visuo-perceptual performance over time.

Research Design: A prospective design was used to assess 18 children with mTBI and 18 matched healthy controls (8-16 years of age).

Methods And Procedures: Sensitivity to static and dynamic forms of simple (first-order) and complex (second-order) stimuli were assessed at 1, 4 and 12 weeks post-injury and at equivalent times for controls.

Postural changes after sustained neck muscle contraction in persons with a lower leg amputation.

Lower leg amputation generally induces asymmetrical weight-bearing, even after rehabilitation treatment is completed. This is detrimental to the amputees' long term quality of life. In particular, increasing strains on joint surfaces that receive additional weight load causes back and leg pain, premature wear and tear and arthritis.

Exploring the comparability of the Sensory Organization Test and the Pediatric Clinical Test of Sensory Interaction for Balance in children.

Background And Purpose: The Sensory Organization Test (SOT) and the Pediatric Clinical Test of Sensory Interaction for Balance (PCTSIB) quantify the ability to maintain balance in the presence of sensory conflicts. The purposes were to explore the concurrent validity of these two assessments by comparing the performance of healthy children on the tests and examine the relationship between age and assessment performances thereby exploring the construct validity of the measures.

Subjects: Sixteen healthy children (9.

Excipient quantitation and drug distribution during formulation optimization.

An oral granules formulation experienced high drug content and increased variability when the process was scaled up from lab scale to clinical manufacturing scale. It was suspected that mannitol, due to its smaller particle size and lower density, was preferentially lost during the top spray granulation process, thereby causing active enrichment in the remaining granules. In order to troubleshoot the problem, rapidly evaluate solutions, and further optimize the formulation, a simple and rapid analytical technique was required.

The utilization of activity-based cost accounting in hospitals.

Healthcare costs are being examined on all fronts. Healthcare accounts for 11% of the gross national product and will continue to rise as the "babyboomers" reach retirement age. While ascertaining costs is important, most research shows that costing methods have not been implemented in hospitals.

Exploring children's self-efficacy related to physical activity performance after a mild traumatic brain injury.

Objective: To evaluate children's self-efficacy related to their practice of physical activities prior to and after a mild traumatic brain injury (mTBI), and compare these to those of noninjured children matched for age, sex, and premorbid level of physical activity.

Participants And Methods: Thirty-four children (mean age: 12 +/- 3 years) in each group. Children with mTBI were assessed 1 day postinjury (to document preinjury status) and at 12 weeks post-mTBI using a self-efficacy questionnaire, the Physical Activity Questionnaire, the Athletic Competence subscale of the Self-Perception Profile for Children or Adolescents, and the Rivermead Post-Concussion Symptoms Questionnaire.

Perception of local DC and AC electric fields in humans.

The goal of this study was to address some of the factors that contribute to the human ability to detect the presence of weak electric fields generated by direct current (DC) and alternating current (AC) sources. An exposure chamber allowed us to expose a limited surface of the body (forearm and hand) to DC fields of up to 65 kV/m and AC fields up to a maximum of 35 kV/m (frequency 60 Hz). Perception was examined using a staircase procedure and a rating procedure derived from signal detection theory.

Bilateral changes in somatosensory sensibility after unilateral below-knee amputation.

Objective: To evaluate possible alteration in proprioceptive and cutaneous sensibility in the nonamputated leg of unilateral transtibial amputees.

Design: Cross-sectional study with between-subjects (amputees vs controls) and within-subjects (nonamputated vs amputated leg) comparisons.

Setting: Canadian rehabilitation hospital research laboratory.