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Journal of Neuroengineering and... Aug 2022This systematic review and meta-analysis aim to summarize and analyze the available evidence of non-invasive brain stimulation/spinal cord stimulation on gait, balance... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
This systematic review and meta-analysis aim to summarize and analyze the available evidence of non-invasive brain stimulation/spinal cord stimulation on gait, balance and/or lower limb motor recovery in stroke patients.
METHODS
The PubMed database was searched from its inception through to 31/03/2021 for randomized controlled trials investigating repetitive transcranial magnetic stimulation or transcranial/trans-spinal direct current/alternating current stimulation for improving gait, balance and/or lower limb motor function in stroke patients.
RESULTS
Overall, 25 appropriate studies (including 657 stroke subjects) were found. The data indicates that non-invasive brain stimulation/spinal cord stimulation is effective in supporting recovery. However, the effects are inhomogeneous across studies: (1) transcranial/trans-spinal direct current/alternating current stimulation induce greater effects than repetitive transcranial magnetic stimulation, and (2) bilateral application of non-invasive brain stimulation is superior to unilateral stimulation.
CONCLUSIONS
The current evidence encourages further research and suggests that more individualized approaches are necessary for increasing effect sizes in stroke patients.
Topics: Brain; Gait; Humans; Lower Extremity; Stroke; Stroke Rehabilitation; Transcranial Direct Current Stimulation; Transcranial Magnetic Stimulation
PubMed: 35922846
DOI: 10.1186/s12984-022-01062-y -
Medicine and Science in Sports and... Jun 2016The relationship among physical activity (PA), fitness, cognitive function, and academic achievement in children is receiving considerable attention. The utility of PA... (Review)
Review
BACKGROUND
The relationship among physical activity (PA), fitness, cognitive function, and academic achievement in children is receiving considerable attention. The utility of PA to improve cognition and academic achievement is promising but uncertain; thus, this position stand will provide clarity from the available science.
OBJECTIVE
The purpose of this study was to answer the following questions: 1) among children age 5-13 yr, do PA and physical fitness influence cognition, learning, brain structure, and brain function? 2) Among children age 5-13 yr, do PA, physical education (PE), and sports programs influence standardized achievement test performance and concentration/attention?
STUDY ELIGIBILITY CRITERIA
This study used primary source articles published in English in peer-reviewed journals. Articles that presented data on, PA, fitness, or PE/sport participation and cognition, learning, brain function/structure, academic achievement, or concentration/attention were included.
DATA SOURCES
Two separate searches were performed to identify studies that focused on 1) cognition, learning, brain structure, and brain function and 2) standardized achievement test performance and concentration/attention. PubMed, ERIC, PsychInfo, SportDiscus, Scopus, Web of Science, Academic Search Premier, and Embase were searched (January 1990-September 2014) for studies that met inclusion criteria. Sixty-four studies met inclusion criteria for the first search (cognition/learning/brain), and 73 studies met inclusion criteria for the second search (academic achievement/concentration).
STUDY APPRAISAL AND SYNTHESIS METHODS
Articles were grouped by study design as cross-sectional, longitudinal, acute, or intervention trials. Considerable heterogeneity existed for several important study parameters; therefore, results were synthesized and presented by study design.
RESULTS
A majority of the research supports the view that physical fitness, single bouts of PA, and PA interventions benefit children's cognitive functioning. Limited evidence was available concerning the effects of PA on learning, with only one cross-sectional study meeting the inclusion criteria. Evidence indicates that PA has a relationship to areas of the brain that support complex cognitive processes during laboratory tasks. Although favorable results have been obtained from cross-sectional and longitudinal studies related to academic achievement, the results obtained from controlled experiments evaluating the benefits of PA on academic performance are mixed, and additional, well-designed studies are needed.
LIMITATIONS
Limitations in evidence meeting inclusion criteria for this review include lack of randomized controlled trials, limited studies that are adequately powered, lack of information on participant characteristics, failure to blind for outcome measures, proximity of PA to measurement outcomes, and lack of accountability for known confounders. Therefore, many studies were ranked as high risk for bias because of multiple design limitations.
CONCLUSIONS
The present systematic review found evidence to suggest that there are positive associations among PA, fitness, cognition, and academic achievement. However, the findings are inconsistent, and the effects of numerous elements of PA on cognition remain to be explored, such as type, amount, frequency, and timing. Many questions remain regarding how to best incorporate PA within schools, such as activity breaks versus active lessons in relation to improved academic achievement. Regardless, the literature suggests no indication that increases in PA negatively affect cognition or academic achievement and PA is important for growth and development and general health. On the basis of the evidence available, the authors concluded that PA has a positive influence on cognition as well as brain structure and function; however, more research is necessary to determine mechanisms and long-term effect as well as strategies to translate laboratory findings to the school environment. Therefore, the evidence category rating is B. The literature suggests that PA and PE have a neutral effect on academic achievement. Thus, because of the limitations in the literature and the current information available, the evidence category rating for academic achievement is C.
Topics: Achievement; Adolescent; Brain; Child; Child, Preschool; Cognition; Exercise; Humans; Learning; Physical Fitness
PubMed: 27182986
DOI: 10.1249/MSS.0000000000000901 -
The Lancet. Neurology Mar 2014Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments, affect millions of children... (Review)
Review
Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments, affect millions of children worldwide, and some diagnoses seem to be increasing in frequency. Industrial chemicals that injure the developing brain are among the known causes for this rise in prevalence. In 2006, we did a systematic review and identified five industrial chemicals as developmental neurotoxicants: lead, methylmercury, polychlorinated biphenyls, arsenic, and toluene. Since 2006, epidemiological studies have documented six additional developmental neurotoxicants-manganese, fluoride, chlorpyrifos, dichlorodiphenyltrichloroethane, tetrachloroethylene, and the polybrominated diphenyl ethers. We postulate that even more neurotoxicants remain undiscovered. To control the pandemic of developmental neurotoxicity, we propose a global prevention strategy. Untested chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity. To coordinate these efforts and to accelerate translation of science into prevention, we propose the urgent formation of a new international clearinghouse.
Topics: Animals; Brain; Developmental Disabilities; Environmental Exposure; Humans; Methylmercury Compounds; Neurotoxicity Syndromes; Polychlorinated Biphenyls
PubMed: 24556010
DOI: 10.1016/S1474-4422(13)70278-3 -
Alzheimer's Research & Therapy Jan 2019Alcohol use has been identified as a risk factor for dementia and cognitive decline. However, some patterns of drinking have been associated with beneficial effects.
BACKGROUND
Alcohol use has been identified as a risk factor for dementia and cognitive decline. However, some patterns of drinking have been associated with beneficial effects.
METHODS AND RESULTS
To clarify the relationship between alcohol use and dementia, we conducted a scoping review based on a systematic search of systematic reviews published from January 2000 to October 2017 by using Medline, Embase, and PsycINFO. Overall, 28 systematic reviews were identified: 20 on the associations between the level of alcohol use and the incidence of cognitive impairment/dementia, six on the associations between dimensions of alcohol use and specific brain functions, and two on induced dementias. Although causality could not be established, light to moderate alcohol use in middle to late adulthood was associated with a decreased risk of cognitive impairment and dementia. Heavy alcohol use was associated with changes in brain structures, cognitive impairments, and an increased risk of all types of dementia.
CONCLUSION
Reducing heavy alcohol use may be an effective dementia prevention strategy.
Topics: Alcohol Drinking; Brain; Cognitive Dysfunction; Dementia; Humans; Meta-Analysis as Topic; Systematic Reviews as Topic
PubMed: 30611304
DOI: 10.1186/s13195-018-0453-0 -
Accelerated Brain Volume Loss Caused by Anti-β-Amyloid Drugs: A Systematic Review and Meta-analysis.Neurology May 2023To evaluate brain volume changes caused by different subclasses of anti-β-amyloid (Aβ) drugs trailed in patients with Alzheimer disease. (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
To evaluate brain volume changes caused by different subclasses of anti-β-amyloid (Aβ) drugs trailed in patients with Alzheimer disease.
METHODS
PubMed, Embase, and ClinicalTrials.gov databases were searched for clinical trials of anti-Aβ drugs. This systematic review and meta-analysis included adults enrolled in randomized controlled trials of anti-Aβ drugs (n = 8,062-10,279). The inclusion criteria were as follows: (1) randomized controlled trials of patients treated with anti-Aβ drugs that have demonstrated to favorably change at least one biomarker of pathologic Aβ and (2) detailed MRI data sufficient to assess the volumetric changes in at least one brain region. MRI brain volumes were used as the primary outcome measure; brain regions commonly reported include hippocampus, lateral ventricle, and whole brain. Amyloid-related imaging abnormalities (ARIAs) were investigated when reported in clinical trials. Of the 145 trials reviewed, 31 were included in the final analyses.
RESULTS
A meta-analysis on the highest dose of each trial on hippocampus, ventricle, and whole brain revealed drug-induced acceleration of volume changes that varied by anti-Aβ drug class. Secretase inhibitors accelerated atrophy to the hippocampus (Δ placebo - Δ drug: -37.1 µL [19.6% more than placebo]; 95% CI -47.0 to -27.1) and whole brain (Δ placebo - Δ drug: -3.3 mL [21.8% more than placebo]; 95% CI -4.1 to 2.5). Conversely, ARIA-inducing monoclonal antibodies accelerated ventricular enlargement (Δ placebo - Δ drug: +2.1 mL [38.7% more than placebo]; 95% CI 1.5-2.8) where a striking correlation between ventricular volume and ARIA frequency was observed ( = 0.86, = 6.22 × 10). Mild cognitively impaired participants treated with anti-Aβ drugs were projected to have a material regression toward brain volumes typical of Alzheimer dementia ∼8 months earlier than if they were untreated.
DISCUSSION
These findings reveal the potential for anti-Aβ therapies to compromise long-term brain health by accelerating brain atrophy and provide new insight into the adverse impact of ARIA. Six recommendations emerge from these findings.
Topics: Adult; Humans; Amyloid beta-Peptides; Alzheimer Disease; Antibodies, Monoclonal; Brain; Atrophy
PubMed: 36973044
DOI: 10.1212/WNL.0000000000207156 -
Sleep Medicine Reviews Feb 2022Current theories of the glymphatic system (GS) hypothesize that it relies on cerebrospinal fluid (CSF) circulation to disseminate growth factors and remove metabolic... (Review)
Review
Current theories of the glymphatic system (GS) hypothesize that it relies on cerebrospinal fluid (CSF) circulation to disseminate growth factors and remove metabolic waste from the brain with increased CSF production and circulation during sleep; thereby, linking sleep disturbance with elements of CSF circulation and GS exchange. However, our growing knowledge of the relations between sleep, CSF, and the GS are plagued by variability in sleep and CSF measures across a wide array of pathologies. Hence, this review aims to summarize the dynamic relationships between sleep, CSF-, and GS-related features in samples of typically developing individuals and those with autoimmune/inflammatory, neurodegenerative, neurodevelopmental, sleep-related, neurotraumatic, neuropsychiatric, and skull atypicalities. One hundred and ninety articles (total n = 19,129 participants) were identified and reviewed for pathology, CSF circulation and related metrics, GS function, and sleep. Numerous associations were documented between sleep problems and CSF metabolite concentrations (e.g., amyloid-beta, orexin, tau proteins) and increased CSF volumes or pressure. However, these relations were not universal, with marked differences across pathologies. It is clear that elements of CSF circulation/composition and GS exchange represent pathways influenced by sleep; however, carefully designed studies and advances in GS measurement are needed to delineate the nuanced relationships.
Topics: Amyloid beta-Peptides; Brain; Glymphatic System; Humans; Sleep; Sleep Wake Disorders
PubMed: 34902819
DOI: 10.1016/j.smrv.2021.101572 -
European Archives of Psychiatry and... Feb 2021Transcranial alternating current stimulation (tACS) is a unique form of non-invasive brain stimulation. Sinusoidal alternating electric currents are delivered to the... (Review)
Review
Transcranial alternating current stimulation (tACS) is a unique form of non-invasive brain stimulation. Sinusoidal alternating electric currents are delivered to the scalp to affect mostly cortical neurons. tACS is supposed to modulate brain function and, in turn, cognitive processes by entraining brain oscillations and inducing long-term synaptic plasticity. Therefore, tACS has been investigated in cognitive neuroscience, but only recently, it has been also introduced in psychiatric clinical trials. This review describes current concepts and first findings of applying tACS as a potential therapeutic tool in the field of psychiatry. The current understanding of its mechanisms of action is explained, bridging cellular neuronal activity and the brain network mechanism. Revisiting the relevance of altered brain oscillations found in six major psychiatric disorders, putative targets for the management of mental disorders using tACS are discussed. A systematic literature search on PubMed was conducted to report findings of the clinical studies applying tACS in patients with psychiatric conditions. In conclusion, the initial results may support the feasibility of tACS in clinical psychiatric populations without serious adverse events. Moreover, these results showed the ability of tACS to reset disturbed brain oscillations, and thus to improve behavioural outcomes. In addition to its potential therapeutic role, the reactivity of the brain circuits to tACS could serve as a possible tool to determine the diagnosis, classification or prognosis of psychiatric disorders. Future double-blind randomised controlled trials are necessary to answer currently unresolved questions. They may aim to detect response predictors and control for various confounding factors.
Topics: Brain; Humans; Neuronal Plasticity; Neurons; Psychiatry; Transcranial Direct Current Stimulation
PubMed: 33211157
DOI: 10.1007/s00406-020-01209-9 -
Nutrients Aug 2019Anorexia nervosa (AN) is an eating disorder often occurring in adolescence. AN has one of the highest mortality rates amongst psychiatric illnesses and is associated...
Anorexia nervosa (AN) is an eating disorder often occurring in adolescence. AN has one of the highest mortality rates amongst psychiatric illnesses and is associated with medical complications and high risk for psychiatric comorbidities, persisting after treatment. Remission rates range from 23% to 33%. Moreover, weight recovery does not necessarily reflect cognitive recovery. This issue is of particular interest in adolescence, characterized by progressive changes in brain structure and functional circuitries, and fast cognitive development. We reviewed existing literature on fMRI studies in adolescents diagnosed with AN, following PRISMA guidelines. Eligible studies had to: (1) be written in English; (2) include only adolescent participants; and (3) use block-design fMRI. We propose a pathogenic model based on normal and AN-related neural and cognitive maturation during adolescence. We propose that underweight and delayed puberty-caused by genetic, environmental, and neurobehavioral factors-can affect brain and cognitive development and lead to impaired cognitive flexibility, which in turn sustains the perpetuation of aberrant behaviors in a vicious cycle. Moreover, greater punishment sensitivity causes a shift toward punishment-based learning, leading to greater anxiety and ultimately to excessive reappraisal over emotions. Treatments combining physiological and neurobehavioral rationales must be adopted to improve outcomes and prevent relapses.
Topics: Adolescent; Adolescent Behavior; Adolescent Development; Age Factors; Anorexia Nervosa; Brain; Cognition; Cognition Disorders; Feeding Behavior; Female; Humans; Magnetic Resonance Imaging; Mental Health; Puberty, Delayed; Recovery of Function; Risk Factors; Sex Factors; Treatment Outcome
PubMed: 31443192
DOI: 10.3390/nu11081907 -
Nutrients Jun 2020The foundations of neurodevelopment across an individual's lifespan are established in the first 1000 days of life (2 years). During this period an adequate supply of...
The foundations of neurodevelopment across an individual's lifespan are established in the first 1000 days of life (2 years). During this period an adequate supply of nutrients are essential for proper neurodevelopment and lifelong brain function. Of these, evidence for choline has been building but has not been widely collated using systematic approaches. Therefore, a systematic review was performed to identify the animal and human studies looking at inter-relationships between choline, neurological development, and brain function during the first 1000 days of life. The database PubMed was used, and reference lists were searched. In total, 813 publications were subject to the title/abstract review, and 38 animal and 16 human studies were included after evaluation. Findings suggest that supplementing the maternal or child's diet with choline over the first 1000 days of life could subsequently: (1) support normal brain development (animal and human evidence), (2) protect against neural and metabolic insults, particularly when the fetus is exposed to alcohol (animal and human evidence), and (3) improve neural and cognitive functioning (animal evidence). Overall, most offspring would benefit from increased choline supply during the first 1000 days of life, particularly in relation to helping facilitate normal brain development. Health policies and guidelines should consider re-evaluation to help communicate and impart potential choline benefits through diet and/or supplementation approaches across this critical life stage.
Topics: Age Factors; Animals; Brain; Choline; Cognition; Dietary Supplements; Female; Humans; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Male; Maternal Nutritional Physiological Phenomena; Maternal-Fetal Exchange; Pregnancy
PubMed: 32531929
DOI: 10.3390/nu12061731 -
Pediatric Research Jan 2020Neonatal intensive care practices have resulted in marked improvements in the survival of premature infants; however, they remain at significant risk for adverse...
BACKGROUND
Neonatal intensive care practices have resulted in marked improvements in the survival of premature infants; however, they remain at significant risk for adverse neurodevelopmental outcomes. The impact of current nutritional practices on brain development following early extra-uterine exposure in premature infants is not well known.
METHODS
We performed a systematic review to investigate nutritional effects on postnatal brain development in healthy term and prematurely born infants utilizing advanced magnetic resonance imaging tools.
RESULTS
Systematic screen yielded 595 studies for appraisal. Of these, 22 total studies were selected for inclusion in the review, with findings summarized in a qualitative, descriptive fashion.
CONCLUSION
Fat and energy intake are associated with improved brain volume and development in premature infants. While breast milk intake and long-chain polyunsaturated fatty acid supplementation has been proven beneficial in term infants, the impact in preterm infants is less well understood.
Topics: Age Factors; Bottle Feeding; Brain; Breast Feeding; Child Development; Gestational Age; Humans; Infant Formula; Infant Nutritional Physiological Phenomena; Infant, Newborn; Infant, Premature; Magnetic Resonance Imaging; Neurogenesis; Nutritional Status; Premature Birth
PubMed: 31349359
DOI: 10.1038/s41390-019-0508-3