The experimental findings herein reported are aimed at gaining a perspective on the complex neural events that follow lesions of the motor cortical areas. Cortical damage, whether by trauma or stroke, interferes with the flow of descending signals to the modular interneuronal structures of the spinal cord. These spinal modules subserve normal motor behaviors by activating groups of muscles as individual units (muscle synergies). Damage to the motor cortical areas disrupts the orchestration of the modules, resulting in abnormal movements. To gain insights into this complex process, we recorded myoelectric signals from multiple upper-limb muscles in subjects with cortical lesions. We used a factorization algorithm to identify the muscle synergies. Our factorization analysis revealed, in a quantitative way, three distinct patterns of muscle coordination-including preservation, merging, and fractionation of muscle synergies-that reflect the multiple neural responses that occur after cortical damage. These patterns varied as a function of both the severity of functional impairment and the temporal distance from stroke onset. We think these muscle-synergy patterns can be used as physiological markers of the status of any patient with stroke or trauma, thereby guiding the development of different rehabilitation approaches, as well as future physiological experiments for a further understanding of postinjury mechanisms of motor control and recovery.motor primitive | electromyography | neurorehabilitation | nonnegative matrix factorization | Virtual Reality Rehabilitation System

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BackgroundWe conducted a nested case–control study in a cohort of European asphalt workers in which an increase in lung cancer risk has been reported among workers exposed to airborne bitumen fume, although potential bias and confounding were not fully addressed.ObjectiveWe investigated the contribution of exposure to bitumen, other occupational agents, and tobacco smoking to the risk of lung cancer among asphalt workers.MethodsCases were cohort members in Denmark, Finland, France, Germany, the Netherlands, Norway, and Israel who had died of lung cancer between 1980 and the end of follow-up (2002–2005). Controls were individually matched in a 3:1 ratio to cases on year of birth and country. We derived exposure estimates for bitumen fume and condensate, organic vapor, and polycyclic aromatic hydrocarbons, as well as for asbestos, crystalline silica, diesel motor exhaust, and coal tar. Odds ratios (ORs) were calculated for ever-exposure, duration, average exposure, and cumulative exposure after adjusting for tobacco smoking and exposure to coal tar.ResultsA total of 433 cases and 1,253 controls were included in the analysis. The OR was 1.12 [95% confidence interval (CI), 0.84–1.49] for inhalation exposure to bitumen fume and 1.17 (95% CI, 0.88–1.56) for dermal exposure to bitumen condensate. No significant trend was observed between lung cancer risk and duration, average exposure, or cumulative exposure to bitumen fume or condensate.ConclusionsWe found no consistent evidence of an association between indicators of either inhalation or dermal exposure to bitumen and lung cancer risk. A sizable proportion of the excess mortality from lung cancer relative to the general population observed in the earlier cohort phase is likely attributable to high tobacco consumption and possibly to coal tar exposure, whereas other occupational agents do not appear to play an important role.

Background: Falls, mobility impairments and lack of social support lead to participation restrictions in people with neurological conditions. The aim of this multicenter, single blinded randomized controlled trial was to test whether an educational program focusing on fall prevention and safe mobility reduces falls and increases social participation among people with neurological conditions.Methods: Ninety people with Stroke (n = 25), multiple sclerosis (n = 33) and Parkinson disease (n = 32), median age 63 (31–89), were randomized. A permuted block algorithm stratified by field center was used to allocate participants to an education group (EG, n = 42) consisting of an educational program focused on fall prevention and tailored balance exercises and a control group (CG, n = 48) receiving usual treatments. After baseline assessment, each participants was followed for 6 months with telephone contacts by blinded interviewers. Being fallers (>1 fall) and time to become a faller were used as primary outcomes. Community Integration Questionnaire (CIQ) and Instrumental Activities of Daily Living (IADL) scales assessed treatment effects on social integration and daily living activities.Results: Over a median (Interquartile Range) follow-up of 189 (182–205) days, [EG = 188 (182–202), CG = 189 (182–209)] fallers were 10 in the CG and 11 in the EG (hazard ratio 0.95, 95% confidence interval (CI) 0.45 to 2.5; P = 0.94). At follow-up the EG scored significantly better than CG on the CIQ (+1.7 points, CI: 0.1 to 3.3) and IADL (+2.2 points, CI: 0.4 to 4.0).Conclusions: This educational program did not reduce the risk of falls but it improved the ability to carry out activities of daily living and decreased participation restrictions in people with neurological conditions.

BackgroundThe central nervous system (CNS) has plastic properties allowing its adaptation through development. These properties are still maintained in the adult age and potentially activated in case of brain lesion. In the present study authors hypothesized that a significant recovery of voluntary muscle contraction in post stroke patients experiencing severe upper limb paresis can be obtained, when proprioceptive based stimulations are provided. Proprioceptive based training (PBT) is based on performing concurrent movements with both unaffected and affected arm, with the aim to foster motor recovery through some mutual connections of interhemispheric and transcallosal pathways. The aim of this pre-post pilot study was to evaluate the feasibility of PBT on recovery of voluntary muscle contraction in subacute phase after stroke.MethodsThe treatment lasted 1 h daily, 5 days per week for 3 weeks. The PBT consisted of multidirectional exercises executed synchronously with unaffected limb and verbal feedback. The Medical Research Council scale (MRC), Dynamometer, Fugl-Meyer Upper Extremity scale (F-M UE), Functional Independence Measure scale (FIM) and modified Ashworth scale were administered at the beginning and at the end of training. Statistical significance was set at p < 0.05.ResultsSix patients with severe paresis of the upper limb within 6 months after stroke were enrolled in the study (5 ischemic and 1 hemorrhagic stroke, 3 men and 3 women, mean age 65.7 ± 8.7 years, mean distance from stroke 4.1 ± 1.5 months) and all of them well tolerated the training. The clinical changes of voluntary muscle contraction after PBT were statistically significant at the MRC scale overall (p = 0.028), and dynamometer assessment overall (p = 0.028). Each patient improved muscle contraction of one or more muscles and in 4 out of 6 patients voluntary active movement emerged after therapy. The functional outcomes (i.e. F-M UE and FIM) did not show significant change within group.ConclusionsThe findings of this preliminary research revealed that PBT may be a feasible intervention to improve the motricity of upper limb in stroke survivors.

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The study was supported by a grant from the Italian Ministry of Health (RF-2010-2318552). The authors are indebted with Ms. Judith Baggott for revising the English text and with Ms. Susanna Franceschi for typing the manuscript.

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