Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state

Background: The rate of recovery from the vegetative state (VS) is low. Currently, little is known of the mechanisms and cerebral changes that accompany those relatively rare cases of good recovery. Here, we combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to study the evolution of one VS patient at one month post-ictus and again twelve months later when he had recovered consciousness. Methods fMRI was used to investigate cortical responses to passive language stimulation as well as task-induced deactivations related to the default-mode network. DTI was used to assess the integrity of the global white matter and the arcuate fasciculus. We also performed a neuropsychological assessment at the time of the second MRI examination in order to characterize the profile of cognitive deficits. Results: fMRI analysis revealed anatomically appropriate activation to speech in both the first and the second scans but a reduced pattern of task-induced deactivations in the first scan. In the second scan, following the recovery of consciousness, this pattern became more similar to that classically described for the default-mode network. DTI analysis revealed relative preservation of the arcuate fasciculus and of the global normal-appearing white matter at both time points. The neuropsychological assessment revealed recovery of receptive linguistic functioning by 12-months post-ictus. Conclusions: These results suggest that the combination of different structural and functional imaging modalities may provide a powerful means for assessing the mechanisms involved in the recovery from the VS.

Pronounced species divergence in corticospinal tract reorganization and functional recovery after lateralized spinal cord injury favors primates.

Experimental and clinical studies suggest that primate species exhibit greater recovery after lateralized compared to symmetrical spinal cord injuries. Although this observation has major implications for designing clinical trials and translational therapies, advantages in recovery of nonhuman primates over other species have not been shown statistically to date, nor have the associated repair mechanisms been identified. We monitored recovery in more than 400 quadriplegic patients and found that functional gains increased with the laterality of spinal cord damage. Electrophysiological analyses suggested that corticospinal tract reorganization contributes to the greater recovery after lateralized compared with symmetrical injuries. To investigate underlying mechanisms, we modeled lateralized injuries in rats and monkeys using a lateral hemisection, and compared anatomical and functional outcomes with patients who suffered similar lesions. Standardized assessments revealed that monkeys and humans showed greater recovery of locomotion and hand function than did rats. Recovery correlated with the formation of corticospinal detour circuits below the injury, which were extensive in monkeys but nearly absent in rats. Our results uncover pronounced interspecies differences in the nature and extent of spinal cord repair mechanisms, likely resulting from fundamental differences in the anatomical and functional characteristics of the motor systems in primates versus rodents. Although rodents remain essential for advancing regenerative therapies, the unique response of the primate corticospinal tract after injury reemphasizes the importance of primate models for designing clinically relevant treatments.

Alteration and recovery of arm usage in daily activities after rotator cuff surgery.

BACKGROUND: The objective measurement of dominant/nondominant arm use proportion in daily life may provide relevant information on healthy and pathologic arm behavior. This prospective case-control study explored the potential of such measurements as indicators of upper limb functional recovery after rotator cuff surgery. METHODS: Data on dominant/nondominant arm usage were acquired with body-worn sensors for 7 hours. The postsurgical arm usage of 21 patients was collected at 3, 6, and 12 months after rotator cuff surgery in the sitting, walking, and standing postures and compared with a reference established with 41 healthy subjects. The results were calculated for the dominant and nondominant surgical side subgroups at all stages. The correlations with clinical scores were calculated. RESULTS: Healthy right-handed and left-handed dominant arm usage was 60.2% (±6.3%) and 53.4% (±6.6%), respectively. Differences in use of the dominant side were significant between the right- and left-handed subgroups for sitting (P = .014) and standing (P = .009) but not for walking (P = .328). The patient group showed a significant underuse of 10.7% (±8.9%) at 3 months after surgery (P < .001). The patients recovered normal arm usage within 12 months, regardless of surgical side. The arm underuse measurement was weakly related to function and pain scores. CONCLUSION: This study provided new information on arm recovery after rotator cuff surgery using an innovative measurement method. It highlighted that objective arm underuse measurement is a valuable indicator of upper limb postsurgical outcome that captures a complementary feature to clinical scores.

Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an "hypoxic to normoxic recovery" approach.

To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, 13 active males performed eight 5-s sprints (recovery = 25 s) on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%), moderate (MH; FiO2 = 16.8%) or severe normobaric hypoxia (SH; FiO2 = 13.3%) followed, 6 min later, by four 5-s sprints (recovery = 25 s) in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (-8.2%) compared to SL (-5.3%) and MH (-7.2%); P < 0.05], changes in contact time, step frequency and root mean square activity (surface electromyography) of the quadriceps (Rectus femoris muscle) in SH exceeded those in SL and MH (P < 0.05). During first sprint of the subsequent normoxic set, the distance covered (99.6, 96.4, and 98.3% of sprint 1 in SL, MH, and SH, respectively), the main kinetic (mean vertical, horizontal, and resultant forces) and kinematic (contact time and step frequency) variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1-8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure), sprint mechanical performance and neural alterations were largely influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level, with a similar fatigue pattern across conditions during subsequent repeated sprints in normoxia.

Reliability of maximal grip strength measurements and grip strength recovery following a stroke.

STUDY DESIGN: Clinical measurement. PURPOSE: The test-retest reliability of maximal grip strength measurements (MGSM) is examined in subjects for 12 weeks post-stroke together with maximal grip strength recovery and the maximal-grip and upper-extremity strength measurements' relationship with capacity and performance test scores. METHODS: A Jamar dynamometer and the Motricity Index (MI) were used for strength measurements. The Chedoke Arm and Hand Activity Inventory and ABILHAND questionnaire for evaluating capacities and performances. RESULTS: MGSM were reliable (Intraclass Correlation Coefficients = 0.97-0.99, Minimal Detectable Differences = 2.73-4.68 kg). Among the 34 participants, 47% did not have a measurable grip strength one week post-stroke but 50% of these recovered some strength within the first eight weeks. The MGSM and MI scores were correlated with scores of tests of capacity and performance (Spearman's Rank Correlation Coefficients = 0.69-0.94). CONCLUSIONS: MGSM are reliable in the first weeks after a stroke. LEVEL OF EVIDENCE: N/A.

Electric energy recovery system for a hydraulic forklift

This thesis studies the possibilities to recover energy in a hydraulic forklift system. Controlling of the system is done directly with an electric servo motor drive and a hydraulic pump. A real system was built and tested and simulations of the system were made with Matlab. Results of the system and simulations were analysed and compared and according to them, energy can be recovered efficiently from the hydraulic forklift system. Also new ideas and directions of further research were obtained with the help of this research.

Recovery Risk and Labor Costs in Public-Private Partnerships : Contractual Choice in the US Water industry

We use an ordered logistic model to empirically examine the factors that explain varying degrees of private involvement in the U.S. water sector through public-private partnerships. Our estimates suggest that a variety of factors help explain greater private participation in this sector. We find that the risk to private participants regarding cost recovery is an important driver of private participation. The relative cost of labor is also a key factor in determining the degree of private involvement in the contract choice. When public wages are high relative to private wages, private participation is viewed as a source of cost savings. We thus find two main drivers of greater private involvement: one encouraging private participation by reducing risk, and another encouraging government to seek out private participation in lowering costs.

Active Damping and Energy Recovery in a Hydraulic Boom Controlled by an Electric Drive

The aim of the study is to obtain a mathematical description for an alternative variant of controlling a hydraulic circuit with an electrical drive. The electrical and hydraulic systems are described by basic mathematical equations. The flexibilities of the load and boom is modeled with assumed mode method. The model is achieved and proven with simulations. The controller is constructed and proven to decrease oscillations and improve the dynamic response of the system.

Factors affecting hospital admission and recovery stay duration of in-patient motor victims in Spain

Hospital expenses are a major cost driver of healthcare systems in Europe, with motor injuries being the leading mechanism of hospitalizations. This paper investigates the injury characteristics which explain the hospitalization of victims of traffic accidents that took place in Spain. Using a motor insurance database with 16.081 observations a generalized Tobit regression model is applied to analyse the factors that influence both the likelihood of being admitted to hospital after a motor collision and the length of hospital stay in the event of admission. The consistency of Tobit estimates relies on the normality of perturbation terms. Here a semi-parametric regression model was fitted to test the consistency of estimates, concluding that a normal distribution of errors cannot be rejected. Among other results, it was found that older men with fractures and injuries located in the head and lower torso are more likely to be hospitalized after the collision, and that they also have a longer expected length of hospital recovery stay.

The impact of an enhanced recovery pathway on nursing workload: A retrospective cohort study.

BACKGROUND & AIMS: The importance of nursing for surgical patients has been frequently underestimated. The success of enhanced recovery programs after surgery (ERAS) depends on preferably complete fulfilment of the protocol and nurses are an important part of it. Due to the additional nursing action required, such protocols are suspected to increase the nursing workload. The aim of the present study was to observe and measure objectively nursing workload before, during and after systematic implementation of a comprehensive enhanced recovery pathway in colorectal surgery. METHODS: The program ERAS was introduced systematically in our tertiary academic centre 2011, since then our experience is based on more than 1500 ERAS patients. Nursing workload was prospectively assessed for all patients on a routine basis by means of a standardized and validated point system (PRN). In a retrospective cohort study, we compared nursing workload based on prospective data before, during and after ERAS implementation and correlated nursing workload to the compliance with the ERAS protocol. RESULTS: The study cohort included 50 patients before ERAS implementation (2010) and 69 (2011) and 148 (2012) consecutive patients after implementation; the baseline characteristics of the 3 groups were similar. Mean PRN values were 61.2 ± 19.7 per day in 2010 and decreased to 52.3 ± 13.7 (P = 0.005) and 51.6 ± 18.6 (P < 0.002) in 2011 and 2012, respectively. Increasing compliance with the ERAS protocol was significantly correlated to decreasing nursing workload (ρ = -0.42; P < 0.001). CONCLUSIONS: Nursing workload is - against a common belief - decreased by systematic implementation of enhance recovery protocol. The higher the compliance with the pathway, the lower the burden for the nurses!

Cost-benefit analysis of an enhanced recovery protocol for pancreaticoduodenectomy.

BACKGROUND: Enhanced recovery after surgery (ERAS) programmes have been shown to decrease complications and hospital stay. The cost-effectiveness of such programmes has been demonstrated for colorectal surgery. This study aimed to assess the economic outcomes of a standard ERAS programme for pancreaticoduodenectomy. METHODS: ERAS for pancreaticoduodenectomy was implemented in October 2012. All consecutive patients who underwent pancreaticoduodenectomy until October 2014 were recorded. This group was compared in terms of costs with a cohort of consecutive patients who underwent pancreaticoduodenectomy between January 2010 and October 2012, before ERAS implementation. Preoperative, intraoperative and postoperative real costs were collected for each patient via the hospital administration. A bootstrap independent t test was used for comparison. ERAS-specific costs were integrated into the model. RESULTS: The groups were well matched in terms of demographic and surgical details. The overall complication rate was 68 per cent (50 of 74 patients) and 82 per cent (71 of 87 patients) in the ERAS and pre-ERAS groups respectively (P = 0·046). Median hospital stay was lower in the ERAS group (15 versus 19 days; P = 0·029). ERAS-specific costs were euro922 per patient. Mean total costs were euro56 083 per patient in the ERAS group and euro63 821 per patient in the pre-ERAS group (P = 0·273). The mean intensive care unit (ICU) and intermediate care costs were euro9139 and euro13 793 per patient for the ERAS and pre-ERAS groups respectively (P = 0·151). CONCLUSION: ERAS implementation for pancreaticoduodenectomy did not increase the costs in this cohort. Savings were noted in anaesthesia/operating room, medication and laboratory costs. Fewer patients in the ERAS group required an ICU stay.

Monitoring of the training load and recovery parameters in competitive swimmers

Nombreux sont les groupes de recherche qui se sont intéressés, ces dernières années, à la manière de monitorer l'entraînement des sportifs de haut niveau afin d'optimaliser le rendement de ce dernier tout en préservant la santé des athlètes. Un des problèmes cardinaux d'un entraînement sportif mal conduit est le syndrome du surentraînement. La définition du syndrome susmentionné proposée par Kreider et al. est celle qui est actuellement acceptée par le « European College of Sport Science » ainsi que par le « American College of Sports Medicine», à savoir : « An accumulation of training and/or non-training stress resulting in long-term decrement in performance capacity with or without related physiological and psychological signs and symptoms of maladaptation in which restoration of performance capacity may take several weeks or months. » « Une accumulation de stress lié, ou non, à l'entraînement, résultant en une diminution à long terme de la capacité de performance. Cette dernière est associée ou non avec des signes et des symptômes physiologiques et psychologiques d'inadaptation de l'athlète à l'entraînement. La restauration de ladite capacité de performance peut prendre plusieurs semaines ou mois. » Les recommandations actuelles, concernant le monitoring de l'entraînement et la détection précoce du syndrome du surentrainement, préconisent, entre autre, un suivi psychologique à l'aide de questionnaires (tel que le Profile of Mood State (POMS)), un suivi de la charge d'entraînement perçue par l'athlète (p.ex. avec la session rating of perceived exertion (RPE) method selon C. Foster), un suivi des performances des athlètes et des charges d'entraînement effectuées ainsi qu'un suivi des problèmes de santé (blessures et maladies). Le suivi de paramètres sanguins et hormonaux n'est pas recommandé d'une part pour des questions de coût et de faisabilité, d'autre part car la littérature scientifique n'a, jusqu'ici, pas été en mesure de dégager des évidences à ce sujet. A ce jour, peu d'études ont suivi ces paramètres de manière rigoureuse, sur une longue période et chez un nombre d'athlète important. Ceci est précisément le but de notre étude.