New atherogenic index for the prediction of carotid atherosclerosis based on the non-ultrasensitive c-reactive protein/HDL ratio. / Nuevo índice aterogénico para la predicción de aterosclerosis carotídea basado en la ratio proteína C reactiva no ultrasensible/HDL.

INTRODUCTION: Current guidelines recommend cardiovascular risk assessment as a preventive measure for cardiovascular diseases, whose fundamental etiology is arteriosclerosis. One of the tools used to estimate risk in clinical practice are atherogenic indices (AI), ratios between lipid fractions with well-established reference ranges. Despite its widespread use, there is still limited information on its clinical utility. In recent years, some research has reinforced the role of inflammation in the etiology and chronicity of the atherosclerotic process. The inclusion of inflammatory parameters in the AI calculation could improve its diagnostic performance in the detection of arteriosclerosis. We sought to evaluate a new AI as a ratio between C-reactive protein (CRP) values and high-density lipoprotein cholesterol (HDL) values. METHODS: A total of 282 asymptomatic patients with no history of cardiovascular disease were included in the study. Laboratory tests with lipid profile and CRP, and carotid ultrasound to assess the presence of atheromatosis were performed in all of them. The new AI is established as the ratio between non-ultrasensitive CRP value in mg/dL (multiplied by 100) and HDL value in mg/dL. It was compared with the Castelli I and II indices, and the plasma atherogenic index. The optimal cut-off point of the new AI was value=1 as determined by ROC curve, with an area under the curve of 0.678 (95% CI 0.60-0.75; p<0.001). RESULTS: Mean age of patients was 60.4±14.5 years. A total of 118 patients (41.8% of total) had carotid arteriosclerosis. When evaluating the diagnostic performance of different AIs, we found that CRP·100/HDL ratio showed the highest values of sensitivity and positive predictive value (0.73 and 0.68, respectively) compared to the Castelli I and II indices, and the plasma atherogenic index. It was also the only predictor of carotid atheromatosis both when considering its values quantitatively (with OR 1.4 [95% CI 1.1-1.7]; p=0.005), and qualitatively (with OR 2.9 [95% CI 1.5-5.5]; p<0.001) in patients with a CRP·100/HDL ratio>1. CONCLUSIONS: The new PCR·100/HDL index showed the best diagnostic performance in the detection of carotid atheromatosis compared to other classic AIs in this Spanish population of asymptomatic patients.

Changes in cardiovascular health and white matter integrity with aerobic exercise, cognitive and combined training in physically inactive healthy late-middle-aged adults: the "Projecte Moviment" randomized controlled trial.

INTRODUCTION: This is a 12-weeks randomized controlled trial examining the effects of aerobic exercise (AE), computerized cognitive training (CCT) and their combination (COMB). We aim to investigate their impact on cardiovascular health and white matter (WM) integrity and how they contribute to the cognitive benefits. METHODS: 109 participants were recruited and 82 (62% female; age = 58.38 ± 5.47) finished the intervention with > 80% adherence. We report changes in cardiovascular risk factors and WM integrity (fractional anisotropy (FA); mean diffusivity (MD)), how they might be related to changes in physical activity, age and sex, and their potential role as mediators in cognitive improvements. RESULTS: A decrease in BMI (SMD = - 0.32, p = 0.039), waist circumference (SMD = - 0.42, p = 0.003) and diastolic blood pressure (DBP) (SMD = - 0.42, p = 0.006) in the AE group and a decrease in BMI (SMD = - 0.34, p = 0.031) and DBP (SMD = - 0.32, p = 0.034) in the COMB group compared to the waitlist control group was observed. We also found decreased global MD in the CCT group (SMD = - 0.34; p = 0.032) and significant intervention-related changes in FA and MD in the frontal and temporal lobes in the COMB group. CONCLUSIONS: We found changes in anthropometric measures that suggest initial benefits on cardiovascular health after only 12 weeks of AE and changes in WM microstructure in the CCT and COMB groups. These results add evidence of the clinical relevance of lifestyle interventions and the potential benefits when combining them. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT031123900.

Effects and mechanisms of mindfulness training and physical exercise on cognition, emotional wellbeing, and brain outcomes in chronic stroke patients: Study protocol of the MindFit project randomized controlled trial.

Background: Post-stroke cognitive and emotional complications are frequent in the chronic stages of stroke and have important implications for the functionality and quality of life of those affected and their caregivers. Strategies such as mindfulness meditation, physical exercise (PE), or computerized cognitive training (CCT) may benefit stroke patients by impacting neuroplasticity and brain health. Materials and methods: One hundred and forty-one chronic stroke patients are randomly allocated to receive mindfulness-based stress reduction + CCT (n = 47), multicomponent PE program + CCT (n = 47), or CCT alone (n = 47). Interventions consist of 12-week home-based programs five days per week. Before and after the interventions, we collect data from cognitive, psychological, and physical tests, blood and stool samples, and structural and functional brain scans. Results: The effects of the interventions on cognitive and emotional outcomes will be described in intention-to-treat and per-protocol analyses. We will also explore potential mediators and moderators, such as genetic, molecular, brain, demographic, and clinical factors in our per-protocol sample. Discussion: The MindFit Project is a randomized clinical trial that aims to assess the impact of mindfulness and PE combined with CCT on chronic stroke patients' cognitive and emotional wellbeing. Furthermore, our design takes a multimodal biopsychosocial approach that will generate new knowledge at multiple levels of evidence, from molecular bases to behavioral changes. Clinical trial registration: www.ClinicalTrials.gov, identifier NCT04759950.

Molecular and Brain Volume Changes Following Aerobic Exercise, Cognitive and Combined Training in Physically Inactive Healthy Late-Middle-Aged Adults: The Projecte Moviment Randomized Controlled Trial.

Behavioral interventions have shown promising neuroprotective effects, but the cascade of molecular, brain and behavioral changes involved in these benefits remains poorly understood. Projecte Moviment is a 12-week (5 days per week-45 min per day) multi-domain, single-blind, proof-of-concept randomized controlled trial examining the cognitive effect and underlying mechanisms of an aerobic exercise (AE), computerized cognitive training (CCT) and a combined (COMB) groups compared to a waitlist control group. Adherence was > 80% for 82/109 participants recruited (62% female; age = 58.38 ± 5.47). In this study we report intervention-related changes in plasma biomarkers (BDNF, TNF-α, HGF, ICAM-1, SDF1-α) and structural-MRI (brain volume) and how they related to changes in physical activity and individual variables (age and sex) and their potential role as mediators in the cognitive changes. Our results show that although there were no significant changes in molecular biomarker concentrations in any intervention group, changes in ICAM-1 and SDF1-α were negatively associated with changes in physical activity outcomes in AE and COMB groups. Brain volume changes were found in the CCT showing a significant increase in precuneus volume. Sex moderated the brain volume change in the AE and COMB groups, suggesting that men may benefit more than women. Changes in molecular biomarkers and brain volumes did not significantly mediate the cognitive-related benefits found previously for any group. This study shows crucial initial molecular and brain volume changes related to lifestyle interventions at early stages and highlights the value of examining activity parameters, individual difference characteristics and using a multi-level analysis approach to address these questions.

Sense of Coherence Mediates the Relationship Between Cognitive Reserve and Cognition in Middle-Aged Adults.

In recent years, supported by new scientific evidence, the conceptualization of cognitive reserve (CR) has been progressively enriched and now encompasses not only cognitive stimulating activities or educational level, but also lifestyle activities, such as leisure physical activity and socialization. In this context, there is increasing interest in understanding the role of psychological factors in brain health and cognitive functioning. In a previous study, we have found that these factors mediated the relationship between CR and self-reported cognitive functioning. In this study, we have confirmed an association between two important constructs included in the psychological wellbeing and salutogenic models, "purpose in life" and "sense of coherence," CR, as assessed using a questionnaire, and cognitive functioning, as evaluated using a comprehensive neuropsychological battery. Results from 888 middle-aged healthy participants from the Barcelona Brain Health Initiative indicate that both sense of coherence (SoC) and CR were positively associated with verbal memory, reasoning and attention, working memory, and global cognition. Moreover, the relation between CR and cognitive functioning in the different domains is partially mediated by SoC. When we controlled for brain integrity, introducing into the model neurofilament light chain measures, the mediator role of SoC was confirmed for reasoning and attention and global cognition. However, purpose in life was not associated with cognitive functioning. These results reveal the central role of the SoC construct, which mediates the association between classic CR estimates and cognitive functions, potentially representing a modifiable target for interventions that aim to promote brain health.

TMS-Evoked Prefrontal Perturbation as a Toy Model of Brain Resilience to Stress During the COVID-19 Pandemic.

Psychosocial hardships associated with the COVID-19 pandemic led many individuals to suffer adverse mental health consequences, however, others show no negative effects. We hypothesized that the electroencephalographic (EEG) response to transcranial magnetic stimulation (TMS) could serve as a toy-model of an individual's capacity to resist psychological stress, in this case linked to the COVID-19 pandemic. We analyzed data from 74 participants who underwent mental health monitoring and concurrent electroencephalography with transcranial magnetic stimulation of the left dorsolateral prefrontal cortex (L-DLPFC) and left inferior parietal lobule (L-IPL). Within the following 19 months, mental health was reassessed at three time points during lock-down confinement and different phases of de-escalation in Spain. Compared with participants who remained stable, those who experienced increased mental distress showed, months earlier, significantly larger late EEG responses locally after L-DLPFC stimulation (but not globally nor after L-IPL stimulation). This response, together with years of formal education, was significantly predictive of mental health status during the pandemic. These findings reveal that the effect of TMS perturbation offers a predictive toy model of psychosocial stress resilience, as exemplified by the COVID-19 pandemic, and point to the L-DLPFC as a promising target for resilience promotion.

Effects of Aerobic Exercise, Cognitive and Combined Training on Cognition in Physically Inactive Healthy Late-Middle-Aged Adults: The Projecte Moviment Randomized Controlled Trial.

BACKGROUND: Lifestyle interventions are promising strategies to promote cognitive health in aging. Projecte Moviment examines if aerobic exercise (AE), computerized cognitive training (CCT), and their combination (COMB) improves cognition, psychological health, and physical status compared to a control group. We assessed the moderating role of age and sex and the mediating effects of cardiorespiratory fitness (CRF), physical activity (PA), and psychological health on intervention-related cognitive benefits. METHODS: This was a 12-week multi-domain, single-blind, proof-of-concept randomized controlled trial (RCT). 96 healthy adults aged 50-70 years were assigned to AE, CCT, COMB, and a wait-list control group. The per protocol sample, which completed the intervention with a level of adherence > 80%, consisted of 82 participants (62% female; age = 58.38 ± 5.47). We assessed cognition, psychological health, CRF, and energy expenditure in PA at baseline and after the intervention. We regressed change in each outcome on the treatment variables, baseline score, sex, age, and education. We used PROCESS Macro to perform the mediation and moderation analyses. RESULTS: AE benefited Working Memory (SMD = 0.29, p = 0.037) and Attention (SMD = 0.33, p = 0.028) including the Attention-Speed (SMD = 0.31, p = 0.042) domain, compared to Control. COMB improved Attention (SMD = 0.30, p = 0.043), Speed (SMD = 0.30, p = 0.044), and the Attention-Speed (SMD = 0.30, p = 0.041) domain. CTT group did not show any cognitive change compared to Control. Sportive PA (S-PA) and CRF increased in AE and COMB. Age and sex did not moderate intervention-related cognitive benefits. Change in S-PA, but not in CRF, significantly mediated improvements on Attention-Speed in AE. CONCLUSION: A 12-week AE program improved Executive Function and Attention-Speed in healthy late-middle-aged adults. Combining it with CCT did not provide further benefits. Our results add support to the clinical relevance of even short-term AE as an intervention to enhance cognition and highlight the mediating role of change in S-PA in these benefits. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT03123900.

Effects and Mechanisms of Cognitive, Aerobic Exercise, and Combined Training on Cognition, Health, and Brain Outcomes in Physically Inactive Older Adults: The Projecte Moviment Protocol.

INTRODUCTION: Age-related health, brain, and cognitive impairment is a great challenge in current society. Cognitive training, aerobic exercise and their combination have been shown to benefit health, brain, cognition and psychological status in healthy older adults. Inconsistent results across studies may be related to several variables. We need to better identify cognitive changes, individual variables that may predict the effect of these interventions, and changes in structural and functional brain outcomes as well as physiological molecular correlates that may be mediating these effects. Projecte Moviment is a multi-domain randomized trial examining the effect of these interventions applied 5 days per week for 3 months compared to a passive control group. The aim of this paper is to describe the sample, procedures and planned analyses. METHODS: One hundred and forty healthy physically inactive older adults will be randomly assigned to computerized cognitive training (CCT), aerobic exercise (AE), combined training (COMB), or a control group. The intervention consists of a 3 month home-based program 5 days per week in sessions of 45 min. Data from cognitive, physical, and psychological tests, cardiovascular risk factors, structural and functional brain scans, and blood samples will be obtained before and after the intervention. RESULTS: Effects of the interventions on cognitive outcomes will be described in intention-to-treat and per protocol analyses. We will also analyze potential genetic, demographic, brain, and physiological molecular correlates that may predict the effects of intervention, as well as the association between cognitive effects and changes in these variables using the per protocol sample. DISCUSSION: Projecte Moviment is a multi-domain intervention trial based on prior evidence that aims to understand the effects of CCT, AE, and COMB on cognitive and psychological outcomes compared to a passive control group, and to determine related biological correlates and predictors of the intervention effects.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03123900.

Objective motor assessment for personalized rehabilitation of upper extremity in brain injury patients.

BACKGROUND: The increasing number of patients with acquired brain injury and the current subjectivity of the conventional upper extremity (UE) assessment tests require new objective assessment techniques. OBJECTIVE: This research proposes a novel objective motor assessment (OMA) methodology based on the Fugl-Meyer assessment (FMA). The goals are to automatically calculate the objective scores (OSs) of FMA-UE movements (as well as a global OS) and to interpret the estimated OSs. METHODS: Fifteen patients participated in the study. The OMA algorithm was designed to detect small-scale variations in UE movements. The OSs for 14 FMA-UE movements and the global OSs were automatically calculated using the algorithm and evaluated by 2 therapists. The interpretation of the global OSs was performed at 3 levels: by item, movement and globally. RESULTS: The global OSs calculated by our algorithm had a significant correlation with the therapists' scores (0.783 and 0.938, p <  0.01). All OSs for each movement were correlated with the scores given by the therapists. The correlation coefficient can reach values as high as 0.981 (p <  0.01). CONCLUSIONS: We provide a new objective assessment tool for therapists to help them improve the diagnostic accuracy and to achieve a more personalized and potentially effective physical rehabilitation of brain injury patients.

Monitoring and Prognosis System Based on the ICF for People with Traumatic Brain Injury.

The objective of this research is to provide a standardized platform to monitor and predict indicators of people with traumatic brain injury using the International Classification of Functioning, Disability and Health, and analyze its potential benefits for people with disabilities, health centers and administrations. We developed a platform that allows automatic standardization and automatic graphical representations of indicators of the status of individuals and populations. We used data from 730 people with acquired brain injury performing periodic comprehensive evaluations in the years 2006-2013. Health professionals noted that the use of color-coded graphical representation is useful for quickly diagnose failures, limitations or restrictions in rehabilitation. The prognosis system achieves 41% of accuracy and sensitivity in the prediction of emotional functions, and 48% of accuracy and sensitivity in the prediction of executive functions. This monitoring and prognosis system has the potential to: (1) save costs and time, (2) provide more information to make decisions, (3) promote interoperability, (4) facilitate joint decision-making, and (5) improve policies of socioeconomic evaluation of the burden of disease. Professionals found the monitoring system useful because it generates a more comprehensive understanding of health oriented to the profile of the patients, instead of their diseases and injuries.

Cognitive rehabilitation with right hemifield eye-patching for patients with sub-acute stroke and visuo-spatial neglect: a randomized controlled trial.

OBJECTIVE: To assess whether, following a right-hemisphere stroke, the combined administration of computer-based cognitive rehabilitation and right hemifield eye-patching in patients with visuo-spatial neglect is more effective than computer-based cognitive rehabilitation alone. METHODS: Twelve patients were randomized into two treatment groups: a single treatment group (n = 7) and a combination treatment group (n = 5). In both cases, the treatment consisted of a mean number of 15 sessions, each lasting 1 hour. Visuo-spatial neglect was assessed using a specific exploration protocol (Bell Cancellation Test, Figure Copying of Odgen, Line Bisection, Baking Tray Task and Reading Task). The functional effects of the treatment were assessed using the Catherine Bergego Scale. RESULTS: Significant between-group differences were observed when comparing the pre- and post-treatment scores for the Reading Task. No differences were observed in either group in the Catherine Bergego Scale administered at baseline and at the final intervention. CONCLUSION: The results obtained do not allow one to conclude that the combination treatment with cognitive rehabilitation and right hemifield eye-patching is more effective than cognitive rehabilitation alone. Although partial improvement in the performance of neuropsychological tests was observed, this improvement is not present at functional level.

Cortical Excitability During Passive Action Observation in Hospitalized Adults With Subacute Moderate to Severe Traumatic Brain Injury: A Preliminary TMS Study.

Studies indicate that motor functions in patients with traumatic brain injury (TBI) can be improved with action observation. It has been hypothesized that this clinical practice relies on modulation of motor cortical excitability elicited by passive action observation in patients with TBI, a phenomenon shown thus far only in normal controls. The purpose of this work was to test this hypothesis and characterize the modulation of motor cortex excitability during passive action observation in patients with subacute moderate to severe TBI. We measured motor evoked potentials induced by single-pulse transcranial magnetic stimulation to the left primary motor cortex and recorded from the contralateral first dorsal interosseus while 20 participants observed videos of static and moving right index finger. Results were compared with those of 20 age-and gender-matched healthy controls. As expected, greater excitability was elicited during moving than static stimuli in healthy subjects. However, this was not observed in patients with TBI. Modulation of motor excitability during action observation is impaired in patients with TBI depending on motor dysfunction, lesion site, and number of days postinjury. These preliminary results suggest a strategy to identify patients in whom action observation might be a valuable neurorehabilitative strategy.

ICF profiling of patients with traumatic brain injury: an international professional survey.

PURPOSE: A worldwide internet survey was conducted (1) to identify problems of individuals with traumatic brain injury (TBI) addressed by health professionals and (2) to summarize these problems using the International Classification of Functioning, Disability and Health (ICF). METHOD: A pool of professionals involved in the TBI rehabilitation process that included physicians, nurses, physical therapists, occupational therapists, social workers and psychologists were surveyed to identify problems in functioning and contextual factors of individuals with TBI using open-ended questions. All answers were translated ("linked") to the ICF based on established rules. The frequencies of the linked ICF categories were reported stratified based on context. RESULTS: One-hundred thirty seven professionals from the six World Health Organization regions identified 5656 concepts. 92.66% could be linked to the ICF; 33.03% were related to the domain of body functions, 27.28% to activities and participation, 10.98% to structures and 21.38% to environmental factors. CONCLUSIONS: The complexity of TBI was described through the identification of a wide variety of ICF categories. ICF language proved to be a neutral framework allowing the comparison of answers between different professionals in different world regions. IMPLICATIONS FOR REHABILITATION: People that suffered a traumatic brain injury (TBI) may have a variety of sequelae that impair functioning. The International Classification of Functioning, Disability and Health (ICF) can help in providing information regarding the identification of patients problems and needs as well as planning, implementing and coordinating the rehabilitation process. The ICF provides a frame of reference process illustrated as the rehabilitation cycle that can help during the rehabilitation process in goal setting bringing together the clinicians' and patient's perspectives in a patient oriented biopsychosocial approach. In the field of TBI rehabilitation, activity limitations and participation restrictions are broadly affected as reported by the professionals interviewed and highly influenced by cognitive and moreover behavioral problems.

[Interindividual variability in recovery after traumatic brain injury: effect of cognitive reserve]. / Variabilidad interindividual en la recuperación después de un traumatismo craneoencefálico: efecto de la reserva cognitiva.

BACKGROUND AND OBJECTIVE: The aim of this study was to examine the effect of cognitive reserve in recovery after a moderate or severe traumatic brain injury (TBI). Different authors proposed that this construct might account for the mismatch between TBI severity, its clinical expression, and subsequent recovery. PATIENTS AND METHOD: Eighty-four patients who sustained moderate-to-severe TBI participated in the study. Participants were divided into a high cognitive reserve group (n=46) or low cognitive reserve group (n=38) based on premorbid educational and occupational attainment. Patient's functional status was examined with the Patient Competency Rating Scale (PCRS). RESULTS: There were no significant differences between groups in demographic and injury variables (sex, age, severity of injury, post-traumatic amnesia duration, and time since injury). The analysis revealed statistically significant differences between the 2 groups on the PCRS: The high cognitive reserve group scored better than the low cognitive reserve group. CONCLUSIONS: The results of this study suggest that cognitive reserve may mediate recovery after a moderate or severe TBI. Educational and occupational attainments provide a cognitive provision that would be associated with better functional status after injury.

Risk taking in hospitalized patients with acute and severe traumatic brain injury.

Rehabilitation can improve cognitive deficits observed in patients with traumatic brain injury (TBI). However, despite rehabilitation, the ability of making a choice often remains impaired. Risk taking is a daily activity involving numerous cognitive processes subserved by a complex neural network. In this work we investigated risk taking using the Balloon Analogue Risk Task (BART) in patients with acute TBI and healthy controls. We hypothesized that individuals with TBI will take less risk at the BART as compared to healthy individuals. We also predicted that within the TBI group factors such as the number of days since the injury, severity of the injury, and sites of the lesion will play a role in risk taking as assessed with the BART. Main findings revealed that participants with TBI displayed abnormally cautious risk taking at the BART as compared to healthy subjects. Moreover, healthy individuals showed increased risk taking throughout the task which is in line with previous work. However, individuals with TBI did not show this increased risk taking during the task. We also investigated the influence of three patients' characteristics on their performance at the BART: Number of days post injury, Severity of the head injury, and Status of the frontal lobe. Results indicate that performance at the BART was influenced by the number of days post injury and the status of the frontal lobe, but not by the severity of the head injury. Reported findings are encouraging for risk taking seems to naturally improve with time postinjury. They support the need of conducting longitudinal prospective studies to ultimately identify impaired and intact cognitive skills that should be trained postinjury.

Abnormal modulation of corticospinal excitability in adults with Asperger's syndrome.

Most candidate genes and genetic abnormalities linked to autism spectrum disorders (ASD) are thought to play a role in developmental and experience-dependent plasticity. As a possible index of plasticity, we assessed the modulation of motor corticospinal excitability in individuals with Asperger's syndrome (AS) using transcranial magnetic stimulation (TMS). We measured the modulatory effects of theta-burst stimulation (TBS) on motor evoked potentials (MEPs) induced by single-pulse TMS in individuals with AS as compared with age-, gender- and IQ-matched neurotypical controls. The effect of TBS lasted significantly longer in the AS group. The duration of the TBS-induced modulation alone enabled the reliable classification of a second study cohort of subjects as AS or neurotypical. The alteration in the modulation of corticospinal excitability in AS is thought to reflect aberrant mechanisms of plasticity, and might provide a valuable future diagnostic biomarker for the disease and ultimately offer a target for novel therapeutic interventions.

Enhancing plasticity through repeated rTMS sessions: the benefits of a night of sleep.

OBJECTIVE: Previous work has demonstrated that corticospinal facilitation from 20Hz repetitive transcranial magnetic stimulation (rTMS) was greater during a second rTMS session 24h after the first. We sought to determine whether such metaplasticity is dependent on a particular phase of the normal sleep-wake/circadian cycle. METHODS: Twenty healthy participants received two sessions of 20Hz rTMS over the hand motor cortex (M1) spaced 12h apart, either over-day or overnight. RESULTS: Baseline corticospinal excitability did not differ by group or session. The time-of-day of Session 1 did not influence the relative increase in excitability following rTMS. However, the increase in excitability from the second rTMS session was 2-fold greater in the overnight group. CONCLUSIONS: When a night with sleep follows rTMS to M1, the capacity to induce subsequent plasticity in M1 is enhanced, suggesting sleep-wake and/or circadian-dependent modulation of processes of metaplasticity. SIGNIFICANCE: TMS treatment of neuropsychiatric disorders entails repeated sessions of rTMS. Our findings suggest that the timing of sessions relative to the sleep-wake/circadian cycle may be a critical factor in the cumulative effect of treatment. Future studies using this paradigm may provide mechanistic insights into human metaplasticity, leading to refined strategies to enhance non-invasive stimulation therapies.

Modulation of cortical motor outputs by the symbolic meaning of visual stimuli.

The observation of an action modulates motor cortical outputs in specific ways, in part through mediation of the mirror neuron system. Sometimes we infer a meaning to an observed action based on integration of the actual percept with memories. Here, we conducted a series of experiments in healthy adults to investigate whether such inferred meanings can also modulate motor cortical outputs in specific ways. We show that brief observation of a neutral stimulus mimicking a hand does not significantly modulate motor cortical excitability (Study 1) although, after prolonged exposure, it can lead to a relatively nonspecific modulation (Study 2). However, when such a neutral stimulus is preceded by exposure to a hand stimulus, the latter appears to serve as a prime, perhaps enabling meaning to the neutral stimulus, which then modulates motor cortical excitability in accordance with mirror neuron-driving properties (Studies 2 and 3). Overall results suggest that a symbolic value ascribed to an otherwise neutral stimulus can modulate motor cortical outputs, revealing the influence of top-down inputs on the mirror neuron system. These findings indicate a novel aspect of the human mirror neuron system: an otherwise neutral stimulus can acquire specific mirror neuron-driving properties in the absence of a direct association between motor practice and perception. This significant malleability in the way that the mirror neuron system can code otherwise meaningless (i.e. arbitrarily associated) stimuli may contribute to coding communicative signals such as language. This may represent a mirror neuron system feature that is unique to humans.

Motor cortical hyperexcitability in idiopathic scoliosis: could focal dystonia be a subclinical etiological factor?

The aetiology of idiopathic scoliosis (IS) remains unknown; however, there is a growing body of evidence suggesting that the spine deformity could be the expression of a subclinical nervous system disorder. A defective sensory input or an anomalous sensorimotor integration may lead to an abnormal postural tone and therefore the development of a spine deformity. Inhibition of the motor cortico-cortical excitability is abnormal in dystonia. Therefore, the study of cortico-cortical inhibition may shed some insight into the dystonia hypothesis regarding the pathophysiology of IS. Paired pulse transcranial magnetic stimulation was used to study cortico-cortical inhibition and facilitation in nine adolescents with IS, five teenagers with congenital scoliosis (CS) and eight healthy age-matched controls. The effect of a previous conditioning stimulus (80% intensity of resting motor threshold) on the amplitude of the motor-evoked potential induced by the test stimulus (120% of resting motor threshold) was examined at various interstimulus intervals (ISIs) in both abductor pollicis brevis muscles. The results of healthy adolescents and those with CS showed a marked inhibitory effect of the conditioning stimulus on the response to the test stimulus at interstimulus intervals shorter than 6 ms. These findings do not differ from those reported for normal adults. However, children with IS revealed an abnormally reduced cortico-cortical inhibition at the short ISIs. Cortico-cortical inhibition was practically normal on the side of the scoliotic convexity while it was significantly reduced on the side of the scoliotic concavity. In conclusion, these findings support the hypothesis that a dystonic dysfunction underlies in IS. Asymmetrical cortical hyperexcitability may play an important role in the pathogenesis of IS and represents an objective neurophysiological finding that could be used clinically.

Knowledge discovery about quality of life changes of spinal cord injury patients: clustering based on rules by states.

In this paper, an integral Knowledge Discovery Methodology, named Clustering based on rules by States, which incorporates artificial intelligence (AI) and statistical methods as well as interpretation-oriented tools, is used for extracting knowledge patterns about the evolution over time of the Quality of Life (QoL) of patients with Spinal Cord Injury. The methodology incorporates the interaction with experts as a crucial element with the clustering methodology to guarantee usefulness of the results. Four typical patterns are discovered by taking into account prior expert knowledge. Several hypotheses are elaborated about the reasons for psychological distress or decreases in QoL of patients over time. The knowledge discovery from data (KDD) approach turns out, once again, to be a suitable formal framework for handling multidimensional complexity of the health domains.