Is robot-assisted gait training intensity a determinant of functional recovery early after stroke? A pragmatic observational study of clinical care

Gait rehabilitation is a critical factor in functional recovery after a stroke. The aim of this pragmatic observational study was to identify the optimal dose and timing of robot-assisted gait training (RAGT) that can lead to a favourable outcome in a sample of subacute stroke survivors. Subacute patients with stroke who underwent a RAGT within a multidisciplinary rehabilitation program were enrolled. A set of clinical (i.e. age, type of stroke and time since stroke) and rehabilitation stay outcomes (length of stay and RAGT number of sessions) were recorded to evaluate their impact on functional outcome measures by functional independence measure (FIM) or functional ambulation category (FAC). We included 236 patients (62.73 ± 11.82 year old); 38.44% were females, and 59.32% were ischaemic stroke patients. Patients that received at least 14 RAGT sessions, had 15.83% more chance to be responders compared to those that receive less sessions (P = 0.006). Similarly, younger patients (≤60 years) were more prone to be responders (+15.1%). Lastly, an early rehabilitation (<6 weeks) was found to be more efficient (+21.09%) in determining responsiveness (P < 0.001). Becoming newly independent for gait, that refers to a FAC score ≥4, was related with age and RAGT sessions (P = 0.001). In conclusion, a younger age (≤60 years), an early rehabilitation (<6 weeks since stroke) and a higher RAGT dose (at least 14 sessions) were related to a favourable outcome in patients with subacute stroke

Effects of a Robot-Assisted Arm Training Plus Hand Functional Electrical Stimulation on Recovery After Stroke: A Randomized Clinical Trial

Objective: To compare the effects of unilateral, proximal arm robot-assisted therapy combined with hand functional electrical stimulation with intensive conventional therapy for restoring arm function in survivors of subacute stroke. Design: This was a single-blinded, randomized controlled trial. Setting: Inpatient rehabilitation university hospital. Participants: Patients (N=40) diagnosed as having ischemic stroke (time since stroke <8wk) and upper limb impairment were enrolled. Interventions: Participants randomized to the experimental group received 30 sessions (5 sessions/wk) of robot-assisted arm therapy and hand functional electrical stimulation (RAT+FES). Participants randomized to the control group received a time-matched intensive conventional therapy. Main Outcome Measures: The primary outcome was arm motor recovery measured with the Fugl-Meyer Motor Assessment. Secondary outcomes included motor function, arm spasticity, and activities of daily living. Measurements were performed at baseline, after 3 weeks, at the end of treatment, and at 6-month follow-up. Presence of motor evoked potentials (MEPs) was also measured at baseline. Results: Both groups significantly improved all outcome measures except for spasticity without differences between groups. Patients with moderate impairment and presence of MEPs who underwent early rehabilitation (<30d post stroke) demonstrated the greatest clinical improvements. Conclusions: RAT+FES was no more effective than intensive conventional arm training. However, at the same level of arm impairment and corticospinal tract integrity, it induced a higher level of arm recovery

Cortical Oxygenation during a Motor Task to Evaluate Recovery in Subacute Stroke Patients: A Study with Near-Infrared Spectroscopy

In subacute stroke patients we studied cortical oxygenation changes by near-infrared spectroscopy (NIRS) during a motor task performed with the hemiparetic arm (15 s of reaching and grasping, 45 s of rest, repeated 6 times). Twenty-three subjects were included at baseline, compared with six healthy subjects, and restudied after 6 weeks of rehabilitation. Motor/premotor cortical changes in oxyhemoglobin detected by NIRS were quantified as the area under the curve (AUC) for the total cortex (TOT-AUC) and for both affected (AFF-AUC) and unaffected hemispheres (UN-AUC). The ratio between AUC and the number of task repetitions performed identified the cortical metabolic cost (CMC) or the oxygenation increase for a single movement. Fugl–Meyer assessment of the upper extremity (FMA-UE) was also performed. At baseline, both total and hemispheric CMC were significantly higher in stroke patients than in healthy subjects and inversely correlated with FMA-UE. After rehabilitation, changes in total-CMC and unaffected-CMC, but not Affected-CMC, were inversely correlated with variations in the FMA-UE score. A value > 5000 a.u. for the ratio baseline TOT-CMC /days since stroke was associated with not reaching the clinically important difference for FMA-UE after rehabilitation. In subacute stroke the CMC, a biomarker assessed by NIRS during a motor task with the hemiparetic arm, may describe cortical time/treatment reorganization and favor patient selection for rehabilitation

The cognitive level does not interfere with recovery after robot-assisted gait training in traumatic brain injury: A 10-year cohort study

BACKGROUND: There is still no clear evidence available on the role of robot-assisted gait training (RAGT) in severe traumatic brain injury (TBI) and on the relationship between this intervention and cognitive impairment. OBJECTIVE: This study investigates the impact of the cognitive level at admission on functional recovery in a cohort of patients with severe TBI who received RAGT training within a multidisciplinary rehabilitation setting. METHODS: We included patients with gait disturbance due to a severe TBI. Patients were grouped into three classes according to their level of cognitive functioning (LCF) at admission (LCF 2-3; LCF 4-5-6; LCF 7-8). We collected demographics (sex, age), clinical data, and a set of outcome measures at admission and discharge. RESULTS: We registered 80 patients, 19 females and 61 males, 35.3 ± 14.85 years. Patients with a low cognitive level at admission were mostly subacute (p= 0.001). Cognitive impairment despite longer length stay in the hospital (LOS) (p= 0.001) did not preclude recovery after RAGT in terms of cognition (R2= 0.68; p< 0.0001), functional independence (R2= 0.30; p< 0.0001) and overall disability (R2= 0.32; p< 0.0001). CONCLUSION: Irrespective of their level of cognition, patients with severe TBI might benefit from RAGT during a multidisciplinary program

A Dynamic Objective Evaluation of Peripheral Arterial Disease by Near-Infrared Spectroscopy

AbstractObjectivesNear-Infrared Spectroscopy (NIRS), suitable for dynamic measurements, is not routinely used for peripheral arterial disease (PAD). We propose a dynamic NIRS-based measurement to quantify variations in muscle metabolism in PAD.MethodSixty-seven consecutive PAD patients (males=56, age 71.6±8.7 years) and 28 healthy subjects (males=12, age 30.4±11.9 years) were studied. An echo-colour Doppler (ECD) was performed and the ankle–brachial index (ABI) was calculated. Participants performed an incremental treadmill test with NIRS probes on the gastrocnemius. Variations in oxygenated (HbO2), deoxygenated (HHb), total (tHb=HbO2+HHb), and differential (dHb=HbO2−HHb) haemoglobin were recorded and quantified as area-under-curve (AUC) within the range 1.7–3.0kmh−1. Heart rate was recorded, and the number of beats in the same interval was calculated (dHr).ResultsO2HbAUC, HHbAUC and dHbAUC differed between diseased and non-diseased legs (P<0.0001) and exhibited different patterns related to PAD severity according to the ABI value. A compensatory heart rate increase was observed in PAD patients. Compared with the ECD positivity for occlusions/stenoses or multiple plaques, only the receiver-operating characteristic (ROC) analysis of dHbAUC (area=0.932, P<0.0001) showed a sensitivity/specificity of 87.6/93.4 for values ≤−197 (LR+LR−: 13.36/0.13).ConclusionThe dynamic NIRS-based test, quantifying muscle metabolic response according to presence and degree of PAD, allows the evaluation of patients with walking disabilities

Strong interface-induced spin-orbit coupling in graphene on WS2

Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of graphene on hexagonal boron nitride (hBN) substrates. Ongoing research strives to explore interfacial interactions in a broader class of materials in order to engineer targeted electronic properties. Here we show that at an interface with a tungsten disulfide (WS2) substrate, the strength of the spin-orbit interaction (SOI) in graphene is very strongly enhanced. The induced SOI leads to a pronounced low-temperature weak anti-localization (WAL) effect, from which we determine the spin-relaxation time. We find that spin-relaxation time in graphene is two-to-three orders of magnitude smaller on WS2 than on SiO2 or hBN, and that it is comparable to the intervalley scattering time. To interpret our findings we have performed first-principle electronic structure calculations, which both confirm that carriers in graphene-on-WS2 experience a strong SOI and allow us to extract a spin-dependent low-energy effective Hamiltonian. Our analysis further shows that the use of WS2 substrates opens a possible new route to access topological states of matter in graphene-based systems.Comment: Originally submitted version in compliance with editorial guidelines. Final version with expanded discussion of the relation between theory and experiments to be published in Nature Communication

Review of Particle Physics

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,873 new measurements from 758 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 118 reviews are many that are new or heavily revised, including a new review on Neutrinos in Cosmology.Starting with this edition, the Review is divided into two volumes. Volume 1 includes the Summary Tables and all review articles. Volume 2 consists of the Particle Listings. Review articles that were previously part of the Listings are now included in volume 1.The complete Review (both volumes) is published online on the website of the Particle Data Group (http://pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is also available.The 2018 edition of the Review of Particle Physics should be cited as: M. Tanabashi (Particle Data Group), Phys. Rev. D 98, 030001 (2018)