Human left ventral premotor cortex mediates matching of hand posture to object use

Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP) has been identified as the anterior part of the intraparietal sulcus (aIPS), whereas the putative human equivalent of the monkey frontal region (F5) is located in the ventral part of the premotor cortex (vPMC). Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS), the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA) 44). We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands

Technological challenges in the development of optogenetic closed-loop therapy approaches in epilepsy and related network disorders of the brain

Epilepsy is a chronic, neurological disorder affecting millions of people every year. The current available pharmacological and surgical treatments are lacking in overall efficacy and cause side-effects like cognitive impairment, depression, tremor, abnormal liver and kidney function. In recent years, the application of optogenetic implants have shown promise to target aberrant neuronal circuits in epilepsy with the advantage of both high spatial and temporal resolution and high cell-specificity, a feature that could tackle both the efficacy and side-effect problems in epilepsy treatment. Optrodes consist of electrodes to record local field potentials and an optical component to modulate neurons via activation of opsin expressed by these neurons. The goal of optogenetics in epilepsy is to interrupt seizure activity in its earliest state, providing a so-called closed-loop therapeutic intervention. The chronic implantation in vivo poses specific demands for the engineering of therapeutic optrodes. Enzymatic degradation and glial encapsulation of implants may compromise long-term recording and sufficient illumination of the opsin-expressing neural tissue. Engineering efforts for optimal optrode design have to be directed towards limitation of the foreign body reaction by reducing the implant’s elastic modulus and overall size, while still providing stable long-term recording and large-area illumination, and guaranteeing successful intracerebral implantation. This paper presents an overview of the challenges and recent advances in the field of electrode design, neural-tissue illumination, and neural-probe implantation, with the goal of identifying a suitable candidate to be incorporated in a therapeutic approach for long-term treatment of epilepsy patients

Lifestyle behaviour and risk factor control in coronary patients : Belgian results from the cross-sectional EUROASPIRE surveys

Objective: The aim of this study was to assess lifestyle behaviour as well as risk factor management across Belgian coronary patients who participated in the cross-sectional European Action on Secondary Prevention through Intervention to Reduce Events (EUROASPIRE) surveys. Methods: Analyses are based on a series of coronary patients by combining data from the Belgian participants in the EUROASPIRE III (328 patients; in 2006-2007) and EUROASPIRE IV (343 patients; in 2012-2013) surveys. Four hospitals located in the Ghent area participated in the surveys. Patients included in the analyses were >= 18 years old and had been hospitalised for a coronary event. Information on cardiovascular risk factors, lifestyle behaviour and medical treatment were obtained. Results: Overall, the proportion of smokers was 11% with 40% persistent smokers. Adequate physical activity levels were reported by 17%, 28% of patients were obese, 47% was central obese and known diabetes was prevalent in 21% of patients. Hypertension was observed in 46% of patients and 20% had a total cholesterol >= 5 mmol/L. About 80% had participated in a cardiac rehabilitation programme and the majority of patients were treated with blood pressure (92%) or lipid-lowering drugs (92%). Anxiety and depressive symptoms were reported by 30% and 24%, respectively. Differences between EUROASPIRE III and IV were limited. Conclusions: Compared to the overall EUROASPIRE results in Europe, Belgian CHD patients seem to do slightly better. However, tackling obesity, physical inactivity, hypertension and psychosocial distress remains an important challenge in the management of coronary patients

The Current Role of Coronal Plane Alignment in Total Knee Arthroplasty in a Preoperative Varus Aligned Population: an Evidence Based Review

• BackgroundBased on historical data, the current standard of care in Total Knee Artrhroplasty (TKA) is to restore the overall alignment to a neutral mechanical axis of 0° ± 3° or even slight valgus. However, there is significant controversy in literature regarding intentionally placing the TKA in the patient’s physiologic, rather than neutral (0 ± 3°), mechanical alignment.• Questions/purposesThe goal of this review is to provide a concise update on the present knowledge of frontal plane alignment TKA in a varus population• MethodsA systematic overview of the present literature was undertaken to determine basic science and clinical results in frontal plane alignment in primary TKA.• ResultsResults of studies based on laboratory research, retrieval analysis, cadaver research, finite models, survival scores, clinical outcome, gait analysis and radiographic outcome upon today are provided.• ConclusionsCurrently placement of a TKA in neutral alignment of 0°±3° of frontal plane alignment is the standard of care.  However, frontal plane alignment in neutral may not be as strongly correlated to survivorship as previously thought.  Caution needs to be exercised before changing the standard of care, and more research needs to be done.  

The contralateral limb is no reliable reference to restore coronal alignment in TKA

Purpose Implementation of morphometric reference data from the contralateral, unaffected lower limb is suggested when reconstructing the coronal plane alignment in TKA. Limited information, however, is available which confirms this left-to-right symmetry in coronal alignment based upon radiographs. The purpose of the study was, therefore, (1) to verify if a left-to-right symmetry is present and (2) to assess whether the contralateral lower limb would be a reliable reference for reconstructing the frontal plane alignment. Methods Full-leg standing radiographs of 250 volunteers (male, 125; female,125) were reviewed for three alignment parameters (Hip-Knee-Ankle angle (HKA), Femoral Mechanical Angle (FMA) and Tibial Mechanical Angle (TMA)). Evaluation of assumed left-to-right symmetry was performed according to two coronal alignment classifications (HKA subdivisions (HKA) and limb, femoral and tibial phenotypes (HKA, FMA and TMA)). Inter- and within-subject variability was calculated, along with correlations coefficients (r) and coefficients of determination (r(2)). Reliability of the contralateral limb as a personalized reference to reconstruct the constitutional alignment was investigated by intervals, expanding by 1 degrees increments (0.5 degrees increment both to varus and valgus) around the right knee alignment parameters. Subsequently, it was verified whether or not the left knee parameters fell within this interval. Results Symmetrical distribution in coronal alignment was found in 79% (HKA subdivision) and 59% (limb phenotype) of the cohort. Gender differences were present for the most common symmetric limb phenotypes (VAR(HKA)3 degrees (23.2%) in males and NEU(HKA)0 degrees (38.4%) in females). Inter-subject variability was more prominent than the within-subject side differences for all parameters. Correlations analyses revealed mostly moderate correlations between the alignment measurements. Coefficients of determination showed overall weak left-to-right relationship, except for a moderate predictability for HKA (r(2) = 0.538,p < 0.001) and FMA (r(2) = 0.618,p < 0.001) in females. FMA and TMA marked weak predictive values for contralateral HKA. Only 60% of left knees were referenced within a 3 degrees interval around the right knee. Conclusion No strict left-to-right symmetry was observed in coronal alignment measurements. There is insufficient left-to-right agreement to consider the concept of the contralateral unaffected limb as an idealized reference for frontal plane alignment reconstruction based upon full-leg standing radiographs

The current role of coronal plane alignment in Total Knee Arthroplasty in a preoperative varus aligned population: An evidence based review

© 2016, Acta Orthopædica Belgica. Background : Based on historical data, the current standard of care in Total Knee Arthroplasty (TKA) is to restore the overall alignment to a neutral mechanical axis of 0° ± 3° or even slight valgus. However, there is significant controversy in literature regarding intentionally placing the TKA in the patient\u27s physiologic, rather than neutral (0 ± 3°), mechanical alignment. Questions/purposes : The goal of this review is to provide a concise update on the present knowledge of coronal plane alignment TKA in a varus population. Methods : A systematic overview of the present literature was undertaken to determine basic science and clinical results in frontal plane alignment in primary TKA. Results : Results of studies based on laboratory research, retrieval analysis, cadaver research, finite models, survival scores, clinical outcome, gait analysis and radiographic outcome upon today are provided. Conclusions : Currently placement of a TKA in neutral alignment of 0° ± 3° of frontal plane alignment is the standard of care. However, frontal plane alignment in neutral may not be as strongly correlated to survivorship as previously thought. Caution needs to be exercised before changing the standard of care, and more research needs to be performed

The use of a prosthetic inlay resurfacing as a salvage procedure for a failed cartilage repair

This study was designed to describe the clinical and radiographical outcome of the HemiCAP(A (R)) resurfacing system as a salvage treatment for a failed index cartilage procedure. Fourteen patients were treated consecutively and clinically prospectively followed for a mean period of 26.1 +/- A 12.8 months. All patients were previously treated for their cartilage lesion. Radiographical data were analysed based on the Kellgren and Lawrence system. The patients involved in this study demonstrated a gradual clinical improvement in time. However, radiographically significant osteoarthritic changes were observed during the follow-up period. The position of the HemiCAP(A (R)) resurfacing system was adequate in all cases, and no signs of loosening were observed during the follow-up period. The HemiCAP(A (R)) resurfacing system is feasible as a salvage treatment for a failed index cartilage procedure and resulted in a gradual clinical improvement. However, the favourable clinical outcome was not confirmed by the radiographical findings