Advances in Ambulatory Oxygen workshop and Longterm Oxygen therapy in real-life practice.

The practical workshop presented recent advances in the field of ambulatory oxygen (AO), with experts discussing identification of patients who would benefit from AO, as well as current trials to measure specific benefits of AO in chronic patients. In particular, AO prescription in clinical practice and developments in pulsed-dose delivery of AO as a more efficient method of oxygen delivery were extensively discussed. After audience questions, the attendees had the opportunity to handle the AO systems on display in order to gain greater insight into their functionality and wearability, which should assist them in providing the most appropriate device for each patient. The symposium addressed considerations required when prescribing long-term oxygen therapy (LTOT). Dr Kampelmacher reviewed current indications for LTOT, emphasising the importance of accurate assessment of patients for LTOT, optimisation of oxygen dose, and patient education. Dr Vivodtzev discussed the evidence for LTOT in patients with exercise-induced desaturation, the role of portable oxygen concentrators, and the optimisation necessary to benefit from their use. The symposium concluded with a health economic study presented by Dr Little, demonstrating the cost benefits of a reform of the Scottish healthcare oxygen supply service

Acceptability and feasibility of magnetic femoral nerve stimulation in older, functionally impaired patients

Abstract Objective Magnetic femoral nerve stimulation to test muscle function has been largely unexplored in older people. We assessed acceptability, feasibility, along with reproducibility and correlation with other physical function measures. Results Study 1 recruited older people with sarcopenia. Stimulation was performed at baseline and 2 weeks along with six minute walk (6MW), maximum voluntary quadriceps contraction, short physical performance battery and grip strength. Acceptability was measured using visual analog scales. Study 2 used baseline data from a trial of older people. We correlated stimulation results with 6MW, maximal voluntary contraction and muscle mass. Maximum quadriceps twitch tension was measured in both studies, evoked using biphasic magnetic stimulation of the femoral nerve. In study 1 (n = 12), magnetic stimulation was well tolerated with mean discomfort rating of 9% (range 0–40%) on a visual analog scale. Reproducibility was poor (intraclass correlation coefficient 0.06; p = 0.44). Study 2 (n = 64) showed only weak to moderate correlations for maximum quadriceps twitch tension with other measures of physical function (6 minute walk test r = 0.24, p = 0.06; maximal voluntary contraction r = 0.26; p = 0.04). We conclude that magnetic femoral nerve stimulation is acceptable and feasible but poorly reproducible in older, functionally impaired people

Effects of acute fatigue on the volitional and magnetically-evoked electromechanical delay of the knee flexors in males and females

Neuromuscular performance capabilities, including those measured by evoked responses, may be adversely affected by fatigue; however, the capability of the neuromuscular system to initiate muscle force rapidly under these circumstances is yet to be established. Sex-differences in the acute responses of neuromuscular performance to exercise stress may be linked to evidence that females are much more vulnerable to ACL injury than males. Optimal functioning of the knee flexors is paramount to the dynamic stabilisation of the knee joint, therefore the aim of this investigation was to examine the effects of acute maximal intensity fatiguing exercise on the voluntary and magnetically-evoked electromechanical delay in the knee flexors of males and females. Knee flexor volitional and magnetically-evoked neuromuscular performance was assessed in seven male and nine females prior to and immediately after: (i) an intervention condition comprising a fatigue trial of 30-seconds maximal static exercise of the knee flexors, (ii) a control condition consisting of no exercise. The results showed that the fatigue intervention was associated with a substantive reduction in volitional peak force (PFV) that was greater in males compared to females (15.0%, 10.2%, respectively, p < 0.01) and impairment to volitional electromechanical delay (EMDV) in females exclusively (19.3%, p < 0.05). Similar improvements in magnetically-evoked electromechanical delay in males and females following fatigue (21%, p < 0.001), however, may suggest a vital facilitatory mechanism to overcome the effects of impaired voluntary capabilities, and a faster neuromuscular response that can be deployed during critical times to protect the joint system

A new paradigm of neuromuscular electrical stimulation for the quadriceps femoris muscle.

PURPOSE: Neuromuscular electrical stimulation (NMES) with large electrodes and multiple current pathways (m-NMES) has recently been proposed as a valid alternative to conventional NMES (c-NMES) for quadriceps muscle (re)training. The main aim of this study was to compare discomfort, evoked force and fatigue between m-NMES and c-NMES of the quadriceps femoris muscle in healthy subjects. METHODS: Ten healthy subjects completed two experimental sessions (c-NMES and m-NMES), that were randomly presented in a cross-over design. Maximal electrically evoked force at pain threshold, self-reported discomfort at different levels of evoked force, and fatigue-induced force declines during and following a series of 20 NMES contractions were compared between c-NMES and m-NMES. RESULTS: m-NMES resulted in greater evoked force (P &lt; 0.05) and lower discomfort in comparison to c-NMES (P &lt; 0.05-0.001), but fatigue time course and magnitude did not differ between the two conditions. CONCLUSIONS: The use of quadriceps m-NMES appears legitimate for (re)training purposes because it generated stronger contractions and was less discomfortable than c-NMES (due to multiple current pathways and/or lower current density with larger electrodes)

Brain Mapping Using Topology Graphs Obtained by Surface Segmentation

Schloss Dagstuhl, Germany, Octobre 2005International audienceBrain mapping is a technique used to alleviate the tedious and time-consuming process of annotating brains by mapping existing annotations from brain atlases to individual brains. We introduce an automated surface-based brain mapping approach. After reconstructing a volume data set (trivariate scalar field) from raw imaging data, an isosurface is extracted approximating the brain cortex. The cortical surface can be segmented into gyral and sulcal regions by exploiting geometrical properties. Our surface segmentation is executed art a coarse level of resolution, such that discrete curvature estimates can be used to detect cortical regions. The topological information obtained from the surface segmentation is stored in a topology graph. A topology graph contains a high-level representation of the geometrical regions of a brain cortex. By deriving topology graphs for both atlas brain and individual brains, a graph node matching defines a mapping of brain cortex regions and their annotations