Sergio Machado - Academia.edu (original) (raw)

Papers by Sergio Machado

Journal of applied physiology (Bethesda, Md. : 1985), Jan 15, 2016

The authors present an interesting analysis of the effect of moderate-intensity exercise-induced ... more The authors present an interesting analysis of the effect of moderate-intensity exercise-induced catecholamines on cognition speed (4). They summarize that moderate and catecholamine threshold (CT) exercise facilitates the speed of cognition and attribute it to activation of adrenergic neurons in the vagal/ NTS/LC pathway (4). Catecholamine release is also regulated by stress (1), in addition to other factors. Stress, and subsequent stress hormone release, may affect this pathway and the resulting speed of cognition. Even moderate-intensity exercise is a stressor, which requires adaptive responses of many body systems (3), including the vagal/NTS afferent pathway. Corticotropin-releasing hormone (CRH) neurons release CRH to the pituitary gland for subsequent release of ACTH, but they also possess axons that terminate in the LC/NE-sympathetic system neurons in the NTS (3). Physiological stressors have been shown to activate neurons in the NTS and induce ACTH release (5). Cortisol released by the adrenal cortex in response to ACTH can result in negative feedback effects on ACTH secretion, the hypothalamic CRH neurons, and the LC/ NE-sympathetic system (5). In this way, cortisol may cause disruptions in dopamine neurochemistry or alter regulation of dopamine release. Alterations in dopamine neurotransmission (excessive or insufficient) by cortisol can affect cognitive function (2), and individual responses to the stress of exercise may explain the lack of mean effect size differences for moderate vs. CT exercise. Conversely, moderate-intensity exercise-induced cortisol release may parallel the CT and positively affect dopaminecontaining neurons excitability and speed of cognition. HOW DOES ACUTE EXERCISE INFLUENCE COGNITION? TO THE EDITOR: McMorris (4) composed a well-written and interesting Viewpoint. The main hypothesis is that acute exercise changes the concentration of catecholamines in the brain, which leads to a higher speed of cognition. This adds

CNS & Neurological Disorders - Drug Targets, 2015

In the present study we examined the moderating effect of the power motive on salivary cortisol r... more In the present study we examined the moderating effect of the power motive on salivary cortisol responses to acute psychosocial stress and exercise in adolescents. Fifty-seven high school students aged M = 14.8 years participated in the study. The Operant Motive Test was applied to measure the implicit power motive and the Personality Research Fonn was used to measure the explicit power motive. Salivary cortisol levels were assessed before and after the stress stimuli. Participants were randomly assigned to three experimental groups. An exercise group ran 15 minutes at a defmed heart rate of 65-75% HRmax• A psychosocial stress group worked on a standard intelligence test for the same amount of time under the assumption, that their test scores will be made public in class after the test. The control group participated in a regular class session. The implicit power motive was significantly associated with increased cortisol levels in the psychosocial stress group. The explicit power motive was not associated with cortisol responses. Findings suggest that the implicit power motive moderates the cortisol responses to acute stress in an adolescent age group with higher responses to psychosocial stress in comparison to exercise or control conditions.

Medical Express, 2016

INTRODUCTION: Facebook is the world's most widely accessed social network, where millions of peop... more INTRODUCTION: Facebook is the world's most widely accessed social network, where millions of people intercommunicate. Behavioral and psychological changes relate to abusive and uncontrolled use creating severe impacts on users' life. METHOD: A critical revision was performed through MedLine, Lilacs, SciELO and Cochrane databases using the terms: "Facebook Addiction, " "Social Network Sites, " "Facebook Abuse. " The search covered the past 5 years up to January 2015. Articles that examine dependence on Facebook in the general population were included; we analyzed how this concept evolved over the last five years, and hope to contribute to the better understanding of the issue and its impacts. RESULTS: Although controversial, published reports correlate Facebook addiction to mechanisms of reward and gratification. Some users developed an abusive relationship stimulated by the false feeling of satisfaction or as a way to feel better or more self-assured (increased level of excitement or escape). Studies from several countries indicate different prevalence, probably due to lack of consensus, and the use of different denominations, giving rise to the adoption of different diagnostic criteria. CONCLUSION: Social Networks are modern communication tools; however, not only benefits, but also subsequent damage caused by its abusive use must be monitored. Many users with abusive usage and dependence recognize significant losses in their personal, professional, academic, social and family lives. Further investigation is needed to determine if abusive Facebook usage is a new psychiatric classification or merely the substrate of other disorders.

CNS & Neurological Disorders - Drug Targets, 2015

Mental practice is an internal reproduction of a motor act (whose intention is to promote learnin... more Mental practice is an internal reproduction of a motor act (whose intention is to promote learning and improving motor skills). Some studies have shown that other cognitive strategies also increase the strength and muscular resistance in healthy people by the enhancement of the performance during dynamic tasks. Mental training sessions may be primordial to improving muscle strength in different subjects. The aim of this study was to systematically review and meta-analiyze studies that assessed whether mental practice is effective in improving muscular strength. We conducted an electronic-computed search in Pub-Med/Medline and ISI Web of Knowledge, Scielo and manual searchs, searching papers written in English between 1991 and 2014. There were 44 studies in Pub-Med/Medline, 631 in ISI Web of Knowledge, 11 in Scielo and 3 in manual searchs databases. After exclusion of studies for duplicate, unrelated to the topic by title and summary, different samples and methodologies, a meta-analysis of 4 studies was carried out to identify the dose-response relationship. We did not find evidence that mental practice is effective in increasing strength in healthy individuals. There is no evidence that mental practice alone can be effective to induce strength gains or to optimize the training effects.

Journal of physical therapy science, 2015

Strength training is recommended for children with cerebral palsy. However, it is difficult for m... more Strength training is recommended for children with cerebral palsy. However, it is difficult for moderately impaired children with cerebral palsy, who require crutches for ambulation, to participate in this type of training. The purpose of this study was to investigate whether whole-body vibration training is an effective method of strengthening in a moderately impaired child with cerebral palsy. [Subject and Methods] This report describes an 8-year-old Japanese boy with cerebral palsy, who was ambulatory with crutches. The subject participated in physical therapy twice a week for 5 weeks. Whole-body vibration training was selected to complement the standing practice. The patient's crutch-walking ability, gross motor function, and spasticity were evaluated. [Results] The number of steps and walking duration were reduced in a 5-m walk test with crutches and gross motor function was improved. Further, the spasticity was reduced. [Conclusion] Whole-body vibration training is an effective physical therapy intervention in moderately impaired children with cerebral palsy, who are unable to walk without crutches.

Revista de neurologia, 2010

Sensorimotor integration is defined as the capability of the central nervous system to integrate ... more Sensorimotor integration is defined as the capability of the central nervous system to integrate different sources of stimuli, and parallelly, to transform such inputs in motor actions. To review the basic principles of sensorimotor integration, such as, its neural bases and its elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects, and the abnormalities reported in the most common movement disorders, such as, Parkinson' disease, dystonia and stroke, like the cortical reorganization-related mechanisms. Whether these disorders are associated with an abnormal peripheral sensory input or defective central processing is still unclear, but most of the data support a central mechanism. We found that the sensorimotor integration process plays a potential role in elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects and in occurrence of abnormalities in most common movement disorders and, moreover, play a pote...

American Journal of Neuroscience, 2011

Problem statement: The visual analysis of Electroencephalogram (EEG) activity has shown useful as... more Problem statement: The visual analysis of Electroencephalogram (EEG) activity has shown useful as a complementary tool in Alzheimer Disease (AD diagnosis) when the diagnosis remains uncertain, in addition to be used in some clinical protocols. However, this analysis is subject to the inherent equipment imprecision, biological artifact, electrical records, and subjective physician interpretation of the visual analysis variation. The Artificial Neural Network (ANN) could be a helpful tool, appropriate to address problems such as prediction and pattern recognition. Approach: In this study, it was used a new class of ANN, namely the Paraconsistent Artificial Neural Network (PANN), which is capable of handling uncertain, inconsistent, and paracomplete information, for recognizing predetermined patterns of EEG activity and to assess its value as a possible complementary method for AD diagnosis. Thirty three AD patients and thirty four controls patients of EEG records were obtained during relaxed wakefulness. It was considered as normal patient pattern, the background EEG activity between 8.0 Hz and 12.0 Hz (with an average frequency of 10.0 Hz), allowing a range of 0.5 Hz. Results: The PANN was able to recognize waves that belonging to their respective bands of clinical use (theta, delta, alpha, and beta), leading to an agreement with the clinical diagnosis at 80% of sensitivity and at 73% of specificity. Conclusion: Supported by results, the PANN could be a promising tool to manipulate EEG analysis, bearing in mind the following considerations: the growing interest of specialists in EEG visual analysis and the ability of the PANN to deal in directly imprecise, inconsistent and paracomplete data, providing an interesting quantitative and qualitative analysis.

PLoS ONE, 2013

There is increasing evidence that hand immobilization is associated with various changes in the b... more There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter-and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter-and intra-hemispheric changes.

American Journal of Neuroscience, 2011

Problem statement: Amyotrophic Lateral Sclerosis (ALS) is a progressive and degenerative disease ... more Problem statement: Amyotrophic Lateral Sclerosis (ALS) is a progressive and degenerative disease that affects the anterior horn motor neurons of the spinal cord and pyramidal tracts. In Brazil, there are few epidemiological data on this disease. Recently, some important findings have been reported, allowing a better understanding on the underlying processes of neuronal death, as well as the characteristics of this population. To discuss the clinical and functional profile of a convenience sample of patients with ALS in Rio de Janeiro and Neurology Department-Federal Fluminense University to compare the data with studies of other regions and countries. Approach: We used the Severity and Functional Ability Scale (SFAS) as a clinical and functional indicator for ALS. The modified El Escorial criteria were used to establish the diagnosis. The participants underwent five quarterly assessments during the study period. The research took place at

Reviews in the Neurosciences, 2010

Some patients are no longer able to communicate effectively or even interact with the outside wor... more Some patients are no longer able to communicate effectively or even interact with the outside world in ways that most of us take for granted. In the most severe cases, tetraplegic or post-stroke patients are literally 'locked in' their bodies, unable to exert any motor control after, for example, a spinal cord injury or a brainstem stroke, requiring alternative methods of communication and control. But we suggest that, in the near future, their brains may offer them a way out. Non-invasive electroencephalogram (EEG)-based brain-computer interfaces (BCI) can be characterized by the technique used to measure brain activity and by the way that different brain signals are translated into commands that control an effector (e.g., controlling a computer cursor for word processing and accessing the internet). This review focuses on the basic concepts of EEG-based BCI, the main advances in communication, motor control restoration and the downregulation of cortical activity, and the mirror neuron system (MNS) in the context of BCI. The latter appears to be relevant for clinical applications in the coming years, particularly for severely limited patients. Hypothetically, MNS could provide a robust way to map neural activity to behavior, representing the high-level information about goals and intentions of these patients. Non-invasive EEG-based BCIs allow brain-derived communication in patients with amyotrophic lateral sclerosis and motor control restoration in patients after spinal cord injury and stroke. Epilepsy and attention deficit and hyperactive disorder patients were able to downregulate their cortical activity. Given the rapid progression of EEG-based BCI research over the last few years and the swift ascent of computer processing speeds and signal analysis techniques, we suggest that emerging ideas (e.g., MNS in the context of BCI) related to clinical neurorehabilitation of severely limited patients will generate viable clinical applications in the near future.

Neurological Sciences, 2012

Spinal cord injury (SCI) is a disease that affects millions of people worldwide, causing a tempor... more Spinal cord injury (SCI) is a disease that affects millions of people worldwide, causing a temporary or permanent impairment of neuromotor functions. Mostly associated to traumatic lesions, but also to other forms of disease, the appropriate treatment is still unsure. In this review, several ongoing studies are presented that aim to provide methods of prevention that ensure quality of life, and rehabilitation trends to patients who suffer from this injury. Stem cell research, highlighted in this review, seeks to reduce damage caused to the tissue, as also provide spinal cord regeneration through the application of several types of stem cells. On the other hand, research using brain-computer interface (BCI) technology proposes the development of interfaces based on the interaction of neural networks with artificial tools to restore motor control and full mobility of the injured area. PubMed, MED-LINE and SciELO data basis analyses were performed to identify studies published from 2000 to date, which describe the link between SCI with stem cells and BCI technology.

CNS & Neurological Disorders - Drug Targets, 2011

Clinical Practice & Epidemiology in Mental Health, 2010

Background: The impact of physical activity on brain metabolic functions has been investigated in... more Background: The impact of physical activity on brain metabolic functions has been investigated in different studies and there is growing evidence that exercise can be used as a preventive and rehabilitative intervention in the treatment of depressive disorders. However, the exact neuronal mechanisms underlying the latter phenomenon have not been clearly elucidated. The present article summarises key results derived from studies that focussed on the neurobiological impact of exercise on brain metabolic functions associated with depressive disorders. Since major depressive disorder (MDD) is a life threatening disease it is of great significance to find reliable strategies to prevent or to cure this illness. Therefore, the aim of this paper is to review (1) the physiological relationship between physical activity and depressive disorders and (2) the potential neurobiological alterations induced by exercise that might lead to the relief of mental disorders like depression. Methods: We searched electronic databases for literature concerning the relationship between exercise and depression from 1963 until 2009. Results: The data suggests an association between physical inactivity and higher levels of depressive symptoms. Properly designed studies could show that exercise training can be as effective as antidepressive medications. Conclusion: The exact mechanisms how exercise affects the brain are not fully understood and the literature lacks of well designed studies concerning the effects of exercise training on depressive disorders. But the observed antidepressant actions of exercise are strong enough that it already can be used as an alternative to current medications in the treatment of depressive disorders.

Brain Research Bulletin, 2012

Arquivos de Neuro-Psiquiatria, 2011

This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 health... more This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 healthy right-handed subjects had to catch a free falling object through quantitative electroencephalogram (qEEG). For this reason, we used coherence that represents a measurement of linear covariation between two signals in the frequency domain. In addition, we investigated gamma-band (30-100 Hz) activity that is related to cognitive and somatosensory processes. We hypothesized that gamma coherence will be increase in both parietal and occipital areas during moment after ball drop, due to their involvement in manipulation of objects, visuospatial processing, visual perception, stimuli identification and attention processes. We confirmed our hypothesis, an increase in gamma coherence on P3-P4 (t= -2.15; p=0.033) and PZ-OZ (t= -2.16; p=0.034) electrode pairs was verified for a paired t-test. We conclude that to execute tasks involving anticipatory movements (feedforward mechanisms), like our ow...

Revista Brasileira de Psiquiatria, 2013

Revista Brasileira de Psiquiatria, 2013

Clinical practice and epidemiology in mental health : CP & EMH, 2016

Facebook is notably the most widely known and used social network worldwide. It has been describe... more Facebook is notably the most widely known and used social network worldwide. It has been described as a valuable tool for leisure and communication between people all over the world. However, healthy and conscience Facebook use is contrasted by excessive use and lack of control, creating an addiction with severely impacts the everyday life of many users, mainly youths. If Facebook use seems to be related to the need to belong, affiliate with others and for self-presentation, the beginning of excessive Facebook use and addiction could be associated to reward and gratification mechanisms as well as some personality traits. Studies from several countries indicate different Facebook addiction prevalence rates, mainly due to the use of a wide-range of evaluation instruments and to the lack of a clear and valid definition of this construct. Further investigations are needed to establish if excessive Facebook use can be considered as a specific online addiction disorder or an Internet addi...

Journal of applied physiology (Bethesda, Md. : 1985), Jan 15, 2016

The authors present an interesting analysis of the effect of moderate-intensity exercise-induced ... more The authors present an interesting analysis of the effect of moderate-intensity exercise-induced catecholamines on cognition speed (4). They summarize that moderate and catecholamine threshold (CT) exercise facilitates the speed of cognition and attribute it to activation of adrenergic neurons in the vagal/ NTS/LC pathway (4). Catecholamine release is also regulated by stress (1), in addition to other factors. Stress, and subsequent stress hormone release, may affect this pathway and the resulting speed of cognition. Even moderate-intensity exercise is a stressor, which requires adaptive responses of many body systems (3), including the vagal/NTS afferent pathway. Corticotropin-releasing hormone (CRH) neurons release CRH to the pituitary gland for subsequent release of ACTH, but they also possess axons that terminate in the LC/NE-sympathetic system neurons in the NTS (3). Physiological stressors have been shown to activate neurons in the NTS and induce ACTH release (5). Cortisol released by the adrenal cortex in response to ACTH can result in negative feedback effects on ACTH secretion, the hypothalamic CRH neurons, and the LC/ NE-sympathetic system (5). In this way, cortisol may cause disruptions in dopamine neurochemistry or alter regulation of dopamine release. Alterations in dopamine neurotransmission (excessive or insufficient) by cortisol can affect cognitive function (2), and individual responses to the stress of exercise may explain the lack of mean effect size differences for moderate vs. CT exercise. Conversely, moderate-intensity exercise-induced cortisol release may parallel the CT and positively affect dopaminecontaining neurons excitability and speed of cognition. HOW DOES ACUTE EXERCISE INFLUENCE COGNITION? TO THE EDITOR: McMorris (4) composed a well-written and interesting Viewpoint. The main hypothesis is that acute exercise changes the concentration of catecholamines in the brain, which leads to a higher speed of cognition. This adds

CNS & Neurological Disorders - Drug Targets, 2015

In the present study we examined the moderating effect of the power motive on salivary cortisol r... more In the present study we examined the moderating effect of the power motive on salivary cortisol responses to acute psychosocial stress and exercise in adolescents. Fifty-seven high school students aged M = 14.8 years participated in the study. The Operant Motive Test was applied to measure the implicit power motive and the Personality Research Fonn was used to measure the explicit power motive. Salivary cortisol levels were assessed before and after the stress stimuli. Participants were randomly assigned to three experimental groups. An exercise group ran 15 minutes at a defmed heart rate of 65-75% HRmax• A psychosocial stress group worked on a standard intelligence test for the same amount of time under the assumption, that their test scores will be made public in class after the test. The control group participated in a regular class session. The implicit power motive was significantly associated with increased cortisol levels in the psychosocial stress group. The explicit power motive was not associated with cortisol responses. Findings suggest that the implicit power motive moderates the cortisol responses to acute stress in an adolescent age group with higher responses to psychosocial stress in comparison to exercise or control conditions.

Medical Express, 2016

INTRODUCTION: Facebook is the world's most widely accessed social network, where millions of peop... more INTRODUCTION: Facebook is the world's most widely accessed social network, where millions of people intercommunicate. Behavioral and psychological changes relate to abusive and uncontrolled use creating severe impacts on users' life. METHOD: A critical revision was performed through MedLine, Lilacs, SciELO and Cochrane databases using the terms: "Facebook Addiction, " "Social Network Sites, " "Facebook Abuse. " The search covered the past 5 years up to January 2015. Articles that examine dependence on Facebook in the general population were included; we analyzed how this concept evolved over the last five years, and hope to contribute to the better understanding of the issue and its impacts. RESULTS: Although controversial, published reports correlate Facebook addiction to mechanisms of reward and gratification. Some users developed an abusive relationship stimulated by the false feeling of satisfaction or as a way to feel better or more self-assured (increased level of excitement or escape). Studies from several countries indicate different prevalence, probably due to lack of consensus, and the use of different denominations, giving rise to the adoption of different diagnostic criteria. CONCLUSION: Social Networks are modern communication tools; however, not only benefits, but also subsequent damage caused by its abusive use must be monitored. Many users with abusive usage and dependence recognize significant losses in their personal, professional, academic, social and family lives. Further investigation is needed to determine if abusive Facebook usage is a new psychiatric classification or merely the substrate of other disorders.

CNS & Neurological Disorders - Drug Targets, 2015

Mental practice is an internal reproduction of a motor act (whose intention is to promote learnin... more Mental practice is an internal reproduction of a motor act (whose intention is to promote learning and improving motor skills). Some studies have shown that other cognitive strategies also increase the strength and muscular resistance in healthy people by the enhancement of the performance during dynamic tasks. Mental training sessions may be primordial to improving muscle strength in different subjects. The aim of this study was to systematically review and meta-analiyze studies that assessed whether mental practice is effective in improving muscular strength. We conducted an electronic-computed search in Pub-Med/Medline and ISI Web of Knowledge, Scielo and manual searchs, searching papers written in English between 1991 and 2014. There were 44 studies in Pub-Med/Medline, 631 in ISI Web of Knowledge, 11 in Scielo and 3 in manual searchs databases. After exclusion of studies for duplicate, unrelated to the topic by title and summary, different samples and methodologies, a meta-analysis of 4 studies was carried out to identify the dose-response relationship. We did not find evidence that mental practice is effective in increasing strength in healthy individuals. There is no evidence that mental practice alone can be effective to induce strength gains or to optimize the training effects.

Journal of physical therapy science, 2015

Strength training is recommended for children with cerebral palsy. However, it is difficult for m... more Strength training is recommended for children with cerebral palsy. However, it is difficult for moderately impaired children with cerebral palsy, who require crutches for ambulation, to participate in this type of training. The purpose of this study was to investigate whether whole-body vibration training is an effective method of strengthening in a moderately impaired child with cerebral palsy. [Subject and Methods] This report describes an 8-year-old Japanese boy with cerebral palsy, who was ambulatory with crutches. The subject participated in physical therapy twice a week for 5 weeks. Whole-body vibration training was selected to complement the standing practice. The patient's crutch-walking ability, gross motor function, and spasticity were evaluated. [Results] The number of steps and walking duration were reduced in a 5-m walk test with crutches and gross motor function was improved. Further, the spasticity was reduced. [Conclusion] Whole-body vibration training is an effective physical therapy intervention in moderately impaired children with cerebral palsy, who are unable to walk without crutches.

Revista de neurologia, 2010

Sensorimotor integration is defined as the capability of the central nervous system to integrate ... more Sensorimotor integration is defined as the capability of the central nervous system to integrate different sources of stimuli, and parallelly, to transform such inputs in motor actions. To review the basic principles of sensorimotor integration, such as, its neural bases and its elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects, and the abnormalities reported in the most common movement disorders, such as, Parkinson' disease, dystonia and stroke, like the cortical reorganization-related mechanisms. Whether these disorders are associated with an abnormal peripheral sensory input or defective central processing is still unclear, but most of the data support a central mechanism. We found that the sensorimotor integration process plays a potential role in elementary mechanisms involved in specific goal-directed tasks performed by healthy subjects and in occurrence of abnormalities in most common movement disorders and, moreover, play a pote...

American Journal of Neuroscience, 2011

Problem statement: The visual analysis of Electroencephalogram (EEG) activity has shown useful as... more Problem statement: The visual analysis of Electroencephalogram (EEG) activity has shown useful as a complementary tool in Alzheimer Disease (AD diagnosis) when the diagnosis remains uncertain, in addition to be used in some clinical protocols. However, this analysis is subject to the inherent equipment imprecision, biological artifact, electrical records, and subjective physician interpretation of the visual analysis variation. The Artificial Neural Network (ANN) could be a helpful tool, appropriate to address problems such as prediction and pattern recognition. Approach: In this study, it was used a new class of ANN, namely the Paraconsistent Artificial Neural Network (PANN), which is capable of handling uncertain, inconsistent, and paracomplete information, for recognizing predetermined patterns of EEG activity and to assess its value as a possible complementary method for AD diagnosis. Thirty three AD patients and thirty four controls patients of EEG records were obtained during relaxed wakefulness. It was considered as normal patient pattern, the background EEG activity between 8.0 Hz and 12.0 Hz (with an average frequency of 10.0 Hz), allowing a range of 0.5 Hz. Results: The PANN was able to recognize waves that belonging to their respective bands of clinical use (theta, delta, alpha, and beta), leading to an agreement with the clinical diagnosis at 80% of sensitivity and at 73% of specificity. Conclusion: Supported by results, the PANN could be a promising tool to manipulate EEG analysis, bearing in mind the following considerations: the growing interest of specialists in EEG visual analysis and the ability of the PANN to deal in directly imprecise, inconsistent and paracomplete data, providing an interesting quantitative and qualitative analysis.

PLoS ONE, 2013

There is increasing evidence that hand immobilization is associated with various changes in the b... more There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter-and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter-and intra-hemispheric changes.

American Journal of Neuroscience, 2011

Problem statement: Amyotrophic Lateral Sclerosis (ALS) is a progressive and degenerative disease ... more Problem statement: Amyotrophic Lateral Sclerosis (ALS) is a progressive and degenerative disease that affects the anterior horn motor neurons of the spinal cord and pyramidal tracts. In Brazil, there are few epidemiological data on this disease. Recently, some important findings have been reported, allowing a better understanding on the underlying processes of neuronal death, as well as the characteristics of this population. To discuss the clinical and functional profile of a convenience sample of patients with ALS in Rio de Janeiro and Neurology Department-Federal Fluminense University to compare the data with studies of other regions and countries. Approach: We used the Severity and Functional Ability Scale (SFAS) as a clinical and functional indicator for ALS. The modified El Escorial criteria were used to establish the diagnosis. The participants underwent five quarterly assessments during the study period. The research took place at

Reviews in the Neurosciences, 2010

Some patients are no longer able to communicate effectively or even interact with the outside wor... more Some patients are no longer able to communicate effectively or even interact with the outside world in ways that most of us take for granted. In the most severe cases, tetraplegic or post-stroke patients are literally 'locked in' their bodies, unable to exert any motor control after, for example, a spinal cord injury or a brainstem stroke, requiring alternative methods of communication and control. But we suggest that, in the near future, their brains may offer them a way out. Non-invasive electroencephalogram (EEG)-based brain-computer interfaces (BCI) can be characterized by the technique used to measure brain activity and by the way that different brain signals are translated into commands that control an effector (e.g., controlling a computer cursor for word processing and accessing the internet). This review focuses on the basic concepts of EEG-based BCI, the main advances in communication, motor control restoration and the downregulation of cortical activity, and the mirror neuron system (MNS) in the context of BCI. The latter appears to be relevant for clinical applications in the coming years, particularly for severely limited patients. Hypothetically, MNS could provide a robust way to map neural activity to behavior, representing the high-level information about goals and intentions of these patients. Non-invasive EEG-based BCIs allow brain-derived communication in patients with amyotrophic lateral sclerosis and motor control restoration in patients after spinal cord injury and stroke. Epilepsy and attention deficit and hyperactive disorder patients were able to downregulate their cortical activity. Given the rapid progression of EEG-based BCI research over the last few years and the swift ascent of computer processing speeds and signal analysis techniques, we suggest that emerging ideas (e.g., MNS in the context of BCI) related to clinical neurorehabilitation of severely limited patients will generate viable clinical applications in the near future.

Neurological Sciences, 2012

Spinal cord injury (SCI) is a disease that affects millions of people worldwide, causing a tempor... more Spinal cord injury (SCI) is a disease that affects millions of people worldwide, causing a temporary or permanent impairment of neuromotor functions. Mostly associated to traumatic lesions, but also to other forms of disease, the appropriate treatment is still unsure. In this review, several ongoing studies are presented that aim to provide methods of prevention that ensure quality of life, and rehabilitation trends to patients who suffer from this injury. Stem cell research, highlighted in this review, seeks to reduce damage caused to the tissue, as also provide spinal cord regeneration through the application of several types of stem cells. On the other hand, research using brain-computer interface (BCI) technology proposes the development of interfaces based on the interaction of neural networks with artificial tools to restore motor control and full mobility of the injured area. PubMed, MED-LINE and SciELO data basis analyses were performed to identify studies published from 2000 to date, which describe the link between SCI with stem cells and BCI technology.

CNS & Neurological Disorders - Drug Targets, 2011

Clinical Practice & Epidemiology in Mental Health, 2010

Background: The impact of physical activity on brain metabolic functions has been investigated in... more Background: The impact of physical activity on brain metabolic functions has been investigated in different studies and there is growing evidence that exercise can be used as a preventive and rehabilitative intervention in the treatment of depressive disorders. However, the exact neuronal mechanisms underlying the latter phenomenon have not been clearly elucidated. The present article summarises key results derived from studies that focussed on the neurobiological impact of exercise on brain metabolic functions associated with depressive disorders. Since major depressive disorder (MDD) is a life threatening disease it is of great significance to find reliable strategies to prevent or to cure this illness. Therefore, the aim of this paper is to review (1) the physiological relationship between physical activity and depressive disorders and (2) the potential neurobiological alterations induced by exercise that might lead to the relief of mental disorders like depression. Methods: We searched electronic databases for literature concerning the relationship between exercise and depression from 1963 until 2009. Results: The data suggests an association between physical inactivity and higher levels of depressive symptoms. Properly designed studies could show that exercise training can be as effective as antidepressive medications. Conclusion: The exact mechanisms how exercise affects the brain are not fully understood and the literature lacks of well designed studies concerning the effects of exercise training on depressive disorders. But the observed antidepressant actions of exercise are strong enough that it already can be used as an alternative to current medications in the treatment of depressive disorders.

Brain Research Bulletin, 2012

Arquivos de Neuro-Psiquiatria, 2011

This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 health... more This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 healthy right-handed subjects had to catch a free falling object through quantitative electroencephalogram (qEEG). For this reason, we used coherence that represents a measurement of linear covariation between two signals in the frequency domain. In addition, we investigated gamma-band (30-100 Hz) activity that is related to cognitive and somatosensory processes. We hypothesized that gamma coherence will be increase in both parietal and occipital areas during moment after ball drop, due to their involvement in manipulation of objects, visuospatial processing, visual perception, stimuli identification and attention processes. We confirmed our hypothesis, an increase in gamma coherence on P3-P4 (t= -2.15; p=0.033) and PZ-OZ (t= -2.16; p=0.034) electrode pairs was verified for a paired t-test. We conclude that to execute tasks involving anticipatory movements (feedforward mechanisms), like our ow...

Revista Brasileira de Psiquiatria, 2013

Revista Brasileira de Psiquiatria, 2013

Clinical practice and epidemiology in mental health : CP & EMH, 2016

Facebook is notably the most widely known and used social network worldwide. It has been describe... more Facebook is notably the most widely known and used social network worldwide. It has been described as a valuable tool for leisure and communication between people all over the world. However, healthy and conscience Facebook use is contrasted by excessive use and lack of control, creating an addiction with severely impacts the everyday life of many users, mainly youths. If Facebook use seems to be related to the need to belong, affiliate with others and for self-presentation, the beginning of excessive Facebook use and addiction could be associated to reward and gratification mechanisms as well as some personality traits. Studies from several countries indicate different Facebook addiction prevalence rates, mainly due to the use of a wide-range of evaluation instruments and to the lack of a clear and valid definition of this construct. Further investigations are needed to establish if excessive Facebook use can be considered as a specific online addiction disorder or an Internet addi...