Visual spatial integration in the elderly.

PURPOSE. To investigate the effect of ageing on contour integration in subjects whose ages ranged from 20 to 99 years. METHODS. Detection thresholds were measured for a closed chain of Gabor patches oriented tangentially to a circle (target) embedded in a background of randomly positioned and oriented Gabors (noise). Detection thresholds were measured for different distances of elements composing the target. RESULTS. Sensitivity decreases gradually with age at all interelement distances. Sensitivity decreases with increasing interelement distance, in both young and elderly subjects. The decrease of integration capability with age is not related to a decrease in contrast sensitivity. CONCLUSIONS. Overall, the data provide evidence of a deterioration of cortical functionality with age, in agreement with other studies on texture and motion processing

Visual Spatial Integration in the Elderly

PURPOSE. To investigate the effect of ageing on contour integration in subjects whose ages ranged from 20 to 99 years. METHODS. Detection thresholds were measured for a closed chain of Gabor patches oriented tangentially to a circle (target) embedded in a background of randomly positioned and oriented Gabors (noise). Detection thresholds were measured for different distances of elements composing the target. RESULTS. Sensitivity decreases gradually with age at all interelement distances. Sensitivity decreases with increasing interelement distance, in both young and elderly subjects. The decrease of integration capability with age is not related to a decrease in contrast sensitivity. CONCLUSIONS. Overall, the data provide evidence of a deterioration of cortical functionality with age, in agreement with other studies on texture and motion processing. (Invest Ophthalmol Vis Sci. 2007;48:2940 -2946) DOI:10.1167/iovs.06-0729 V isual abilities decline during normal (nonpathologic) ageing, but our understanding of the nature and causes of visual changes in the elderly is still limited. Damages to optical properties of the eyes (e.g., presbyopia, senile miosis) are the most common cause of visual deficits in the old population, producing deterioration of low-level visual functions, such as visual acuity and contrast sensitivity. 1-3 However, visual acuity reduction is not exclusively due to changes in the eye's optical properties. 4 -7 Ageing produces loss of photoreceptor, bipolar, or ganglion cells and changes in their connections that could account for visual acuity losses. 17 found small differences in PERG, whereas VEP amplitudes and phases of old subjects were lower than those of young subjects, suggesting that visual impairment in the elderly occurs primarily in V1. More in general, ageing affects PERG and VEPs at low temporal frequencies, producing lower amplitudes and increased latency, particularly at high spatial frequencies. 22 If our understanding of age-related changes in low-level processes is limited, it is also true that not much is known about the effects of ageing on the way neurons elaborate and integrate complex information from the external environment and about the relationship between behavior and diminished neural functions. There are several studies indicating a decreased activity in the ageing brain related to high-level cognitive tasks. Measurements of cerebral blood flow (rCBF) by standard positron emission tomography (PET) reveal differences in activation between young and old subjects in object-recognition tasks, 23,24 face recognition, 25 and stimulus encoding. 26 In some recent studies, investigators have begun to examine also the consequences of ageing on visual perception, finding some abilities to be particularly affected by ageing whereas others are relatively spared. Snowden and Kavanagh 27 have explored several aspects of motion perception and found a variety of deficits not accompanied by a significant loss in contrast sensitivity. These deficits were ascribed to a deterioration of the brain areas responsible for global motion perception, such as the medial temporal area. 28 -30 O'Brien et al. 31 also found a diminished sensitivity to optic flow motion in healthy elderly subjects. Changes due to ageing do not necessarily bring about a deterioration of visual function. Some investigators have found that motion perception of large, highcontrast stimuli is even better in old subjects than in young adults. 34 Some studies report particularly low performance of the elderly in midlevel tasks, such as bilateral symmetry detection, 37 Contour integration is a complex ability, widely investigated in multiple-choice detection tasks, in which a chain of Gabor patches (GPs)-sinusoidal luminance signals within a Gaussian envelope-must be segregated from a noisy background. 38 -40 In these stimuli, there is no global cue-orientation, color, or texture-for the segregation of the chain. The global patterns seem to emerge from interactions between local mechanisms, influenced by variables such as relative orientation of nearby cues, relative distance, and colinearity. This contour segregation ability, which is part of a more general task of figure-ground segmentation, 39 is a secondorder task, involving integration of locally oriented elements in a global percept. This task would require larger networks that, according to some investigators, 37 could generate age-related deficits. A multiple-stage analysis could also explain why this ability undergoes protracted development during childFrom th

EMG Signs of Motor Units’ Enlargement in Stroke Survivors

The degeneration of lower motoneurons has often been reported in stroke survivors, with possible collateral reinnervation from the surviving motoneurons to the denervated muscle fibers. Under this assumption, a stroke would be expected to increase the size of motor units in paretic muscles. We indirectly address this issue with electrical stimulation and surface electromyography, asking whether stroke leads to greater variations in the amplitude of M waves elicited in paretic muscles than in contralateral, non-paretic muscles. Current pulses at progressively greater intensities were applied to the musculocutaneous nerve, stimulating motoneurons supplying the biceps brachii of eight stroke patients. The size of increases in the amplitude of M waves elicited consecutively, hereafter defined as increments, was considered to evaluate changes in the innervation ratio of biceps brachii motor units following stroke. Our findings showed that patients presented significantly (p = 0.016) greater increments in muscles of paretic than in non-paretic limbs. This result corroborates the notion that collateral reinnervation takes place after stroke, enlarging motor units’ size and the magnitude of the muscle responses. Therefore, the non-invasive analysis proposed here may be useful for health professionals to assess disease progression by tracking for neuromuscular changes likely associated with clinical outcomes in stroke survivors, such as in the muscles’ strength

Abuso sexual contra crianças através das relações de confiança: um olhar sobre o autor da agressão

Analisa o abuso sexual contra crianças, perpetrado por pessoas de suas relações de confiança, trazendo assim um olhar sobre o autor de agressão sexual. O estudo foi desenvolvido através do levantamento de material bibliográfico e entrevistas com profissionais da área. Identificamos um escasso número de pesquisas e equipamentos institucionais voltados para a intervenção junto aos adultos autores de abuso sexual e suas famílias e a ausência de políticas públicas efetivas que se coloquem para além da responsabilização desse adulto, onde as intervenções judiciais e terapêuticas apresentam-se desarticuladas. Acreditamos por fim, que esta análise auxiliaria nos estudos sobre a prevenção do abuso sexual e consequentemente, as possibilidades de intervenção junto ao adulto autor de abuso sexual de crianças, à vítima e ao adulto não agressor, proporcionando, de alguma forma, uma melhor intervenção na instituição familiar como um todo

Reinforced Feedback in Virtual Environment for Plantar Flexor Poststroke Spasticity Reduction and Gait Function Improvement

Background. Ankle spasticity is a frequent phenomenon that limits functionality in poststroke patients. Objectives. Our aim was to determine if there was decreased spasticity in the ankle plantar flex (PF) muscles in the plegic lower extremity (LE) and improvement of gait function in stroke patients after traditional rehabilitation (TR) in combination with virtual reality with reinforced feedback, which is termed "reinforced feedback virtual environment" (RFVE). Methods. The evaluation, before and after treatment, of 10 hemiparetic patients was performed using the Modified Ashworth Scale (MAS), Functional Ambulatory Category (FAC), and Functional Independence Measure (FIM). The intervention consisted of 1 hour/day of TR plus 1 hour/day of RFVE (5 days/week for 3 weeks; 15 sessions in total). Results. The MAS and FAC reached statistical significance (P<0.05). The changes in the FIM did not reach statistical significance (P=0.066). The analysis between the ischemic and haemorrhagic patients showed significant differences in favour of the haemorrhagic group in the FIM scale. A significant correlation between the FAC and the months after the stroke was established (P=-0.711). Indeed, patients who most increased their score on the FAC at the end of treatment were those who started the treatment earliest after stroke. Conclusions. The combined treatment of TR and RFVE showed encouraging results regarding the reduction of spasticity and improvement of gait function. An early commencement of the treatment seems to be ideal, and future research should increase the sample size and assessment tools

Functional changes in the lower extremity after non-immersive virtual reality and physiotherapy following stroke

Objective: To analyse the effect of virtual reality (VR) ther-apy combined with conventional physiotherapy on balance, gait and motor functional disturbances, and to determine whether there is an influence on motor recovery in the subacute ( 6 months) phases after stroke. Methods: A total of 59 stroke inpatients (mean age 60.3 years (standard deviation (SD) 14.8); 14.0 months (SD 25.7) post-stroke) were stratified into 2 groups: subacute (n = 31) and chronic (n = 28). Clin-ical scales (Fugl-Meyer lower extremity (FM LE); Func-tional Independence Measure (FIM); Berg Balance Scale (BBS); Functional Ambulation Category (FAC); modified Ashworth scale (MAS); 10-metre walk test (10MWT); and kinematic parameters during specific motor tasks in sitting and standing position (speed; time; jerk; spatial error; length) were applied before and after treatment. The VR treatment lasted for 15 sessions, 5 days/week, 1 h/day. Results: The subacute group underwent significant change in all variables, except MAS and length. The chronic group underwent significant improvement in clinical scales, except MAS and kinematics. Motor impairment improved in the severe = 19 FM LE points, moderate 20-28 FM LE points, mild =29 FM LE points. Neither time since stroke onset nor affected hemisphere differed significantly between groups. The correlations were investigated between the clinical scales and the kinematic parameters of the whole sample. Moreover, FM LE, BBS, MAS, and speed showed high correlations (R2>0.70) with independent variables. Conclusion: VR therapy combined with conventional physiotherapy can contribute to func-tional improvement in the subacute and chronic phases after stroke

Telerehabilitation for neurological motor impairment: a systematic review and meta-analysis on quality of life, satisfaction, and acceptance in stroke, multiple sclerosis, and Parkinson’s disease

Telerehabilitation (TR) seems to be a viable and feasible solution to face the rehabilitative challenges posed by neurological impairments and to improve patients’ quality of life (QoL). This review aims to synthesize and analyze the evidence on the impact of physiotherapy intervention through TR on QoL in patients with stroke, Parkinson’s disease (PD), and multiple sclerosis (MS), together with an evaluation of their satisfaction and technology acceptance levels. Through a systematic search of the literature and a screening process, treatment effects were assessed with meta-analyses using the standardized mean difference, setting the confidence interval at 95%. We included 28 studies in the review, which were analyzed for methodological quality, whereas 16 studies were included in the meta-analyses. The results suggest a significant improvement in QoL in patients who underwent TR. We were unable to perform analyses for satisfaction and technology acceptance outcomes due to insufficient data. Overall, motor TR has a positive impact on the QoL of patients with neurological diseases, especially in stroke patients; although caution is needed in the interpretation of the results due to the high heterogeneity found. For PD and MS, TR seems to yield comparable results to in-person treatment

Experimental protocol to investigate cortical, muscular and body representation alterations in adolescents with idiopathic scoliosis

Background: Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis. AIS is a three-dimensional morphological spinal deformity that affects approximately 1-3% of adolescents. Not all factors related to the etiology of AIS have yet been identified. Objective: The primary aim of this experimental protocol is to quantitatively investigate alterations in body representation in AIS, and to quantitatively and objectively track the changes in body sensorimotor representation due to treatment. Methods: Adolescent girls with a confirmed diagnosis of mild (Cobb angle: 10°-20°) or moderate (21°-35°) scoliosis as well as age and sex-matched controls will be recruited. Participants will be asked to perform a 6-min upright standing and two tasks-named target reaching and forearm bisection task. Eventually, subjects will fill in a self-report questionnaire and a computer-based test to assess body image. This evaluation will be repeated after 6 and 12 months of treatment (i.e., partial or full-time brace and physiotherapy corrective postural exercises). Results: We expect that theta brain rhythm in the central brain areas, alpha brain rhythm lateralization and body representation will change over time depending on treatment and scoliosis progression as a compensatory strategy to overcome a sensorimotor dysfunction. We also expect asymmetric activation of the trunk muscle during reaching tasks and decreased postural stability in AIS. Conclusions: Quantitatively assess the body representation at different time points during AIS treatment may provide new insights on the pathophysiology and etiology of scoliosis

The expression analysis of mouse interleukin-6 splice variants argued against their biological relevance

Alternative splicing generates several interleukin-6 (IL-6) isoforms; for them an antagonistic activity to the wild-type IL-6 has been proposed. In this study we quantified the relative abundance of IL-6 mRNA isoforms in a panel of mouse tissues and in C2C12 cells during myoblast differentiation or after treatment with the Ca2+ ionophore A23187, the AMP-mimetic AICAR and TNF-alpha. The two mouse IL-6 isoforrns identified, IL-6 delta 5 (deletion of the first 58 bp of exon 5) and IL-6 delta 3 (lacking exon 3), were not conserved in rat and human, did not exhibit tissue specific regulation, were expressed at low levels and their abundance closely correlated to that of full-length IL-6. Species-specific features of the IL-6 sequence, such as the presence of competitive 3' acceptor site in exon 5 and insertion of retrotransposable elements in intron 3, could explain the production of IL-6 delta 5 and IL-6 delta 3. Our results argued against biological significance for mouse IL-6 isoforms