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Ageing Research Reviews Aug 2022Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique. When stimulation is applied over the primary motor cortex and coupled with... (Meta-Analysis)
Meta-Analysis Review
Cortical excitability and plasticity in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis of transcranial magnetic stimulation studies.
BACKGROUND
Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique. When stimulation is applied over the primary motor cortex and coupled with electromyography measures, TMS can probe functions of cortical excitability and plasticity in vivo. The purpose of this meta-analysis is to evaluate the utility of TMS-derived measures for differentiating patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) from cognitively normal older adults (CN).
METHODS
Databases searched included PubMed, Embase, APA PsycInfo, Medline, and CINAHL Plus from inception to July 2021.
RESULTS
Sixty-one studies with a total of 2728 participants (1454 patients with AD, 163 patients with MCI, and 1111 CN) were included. Patients with AD showed significantly higher cortical excitability, lower cortical inhibition, and impaired cortical plasticity compared to the CN cohorts. Patients with MCI exhibited increased cortical excitability and reduced plasticity compared to the CN cohort. Additionally, lower cognitive performance was significantly associated with higher cortical excitability and lower inhibition. No seizure events due to TMS were reported, and the mild adverse response rate is approximately 3/1000 (i.e., 9/2728).
CONCLUSIONS
Findings of our meta-analysis demonstrate the potential of using TMS-derived cortical excitability and plasticity measures as diagnostic biomarkers and therapeutic targets for AD and MCI.
Topics: Aged; Alzheimer Disease; Cognitive Dysfunction; Cortical Excitability; Humans; Neuronal Plasticity; Transcranial Magnetic Stimulation
PubMed: 35680080
DOI: 10.1016/j.arr.2022.101660 -
Ageing Research Reviews Sep 2022To determine the effects of low- vs. high-intensity aerobic and resistance training on motor and cognitive function, brain activation, brain structure, and neurochemical... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To determine the effects of low- vs. high-intensity aerobic and resistance training on motor and cognitive function, brain activation, brain structure, and neurochemical markers of neuroplasticity and the association thereof in healthy young and older adults and in patients with multiple sclerosis, Parkinson's disease, and stroke.
DESIGN
Systematic review and robust variance estimation meta-analysis with meta-regression.
DATA SOURCES
Systematic search of MEDLINE, Web of Science, and CINAHL databases.
RESULTS
Fifty studies with 60 intervention arms and 2283 in-analyses participants were included. Due to the low number of studies, the three patient groups were combined and analyzed as a single group. Overall, low- (g=0.19, p = 0.024) and high-intensity exercise (g=0.40, p = 0.001) improved neuroplasticity. Exercise intensity scaled with neuroplasticity only in healthy young adults but not in healthy older adults or patient groups. Exercise-induced improvements in neuroplasticity were associated with changes in motor but not cognitive outcomes.
CONCLUSION
Exercise intensity is an important variable to dose and individualize the exercise stimulus for healthy young individuals but not necessarily for healthy older adults and neurological patients. This conclusion warrants caution because studies are needed that directly compare the effects of low- vs. high-intensity exercise on neuroplasticity to determine if such changes are mechanistically and incrementally linked to improved cognition and motor function.
Topics: Aged; Biomarkers; Cognition; Exercise; Humans; Multiple Sclerosis; Neuronal Plasticity; Resistance Training
PubMed: 35853549
DOI: 10.1016/j.arr.2022.101698 -
Arquivos de Neuro-psiquiatria Sep 2021Stroke is among the leading causes of death and disability worldwide. Interventions for stroke rehabilitation aim to minimize sequelae, promote individuals' independence...
BACKGROUND
Stroke is among the leading causes of death and disability worldwide. Interventions for stroke rehabilitation aim to minimize sequelae, promote individuals' independence and potentially recover functional damage. The role of aerobic exercise as a facilitator of post-stroke neuroplasticity in humans is still questionable.
OBJECTIVE
To investigate the impact of aerobic exercise on neuroplasticity in patients with stroke sequelae.
METHODS
A systematic review of randomized clinical trials and crossover studies was performed, with searches for human studies in the following databases: PUBMED, EMBASE, LILACS and PeDRO, only in English, following the PRISMA protocol. The keywords used for selecting articles were defined based on the PICO strategy.
RESULTS
This systematic review evaluated the impacts of aerobic exercise on neuroplasticity through assessment of neural networks and neuronal excitability, neurotrophic factors, or cognitive and functional assessment. Studies that evaluated the effects of aerobic exercise on neuroplasticity after stroke measured through functional resonance (fMRI) or cortical excitability have shown divergent results, but aerobic exercise potentially can modify the neural network, as measured through fMRI. Additionally, aerobic exercise combined with cognitive training improves certain cognitive domains linked to motor learning. Studies that involved analysis of neurotrophic factors to assess neuroplasticity had conflicting results.
CONCLUSIONS
Physical exercise is a therapeutic intervention in rehabilitation programs that, beyond the known benefits relating to physical conditioning, functionality, mood and cardiovascular health, may also potentiate the neuroplasticity process. Neuroplasticity responses seem more robust in moderate to high-intensity exercise training programs, but dose-response heterogeneity and non-uniform neuroplasticity assessments limit generalizability.
Topics: Exercise; Exercise Therapy; Humans; Neuronal Plasticity; Stroke; Stroke Rehabilitation
PubMed: 34669820
DOI: 10.1590/0004-282X-ANP-2020-0551 -
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 -
Frontiers in Psychiatry 2021Clinical studies suggest the therapeutic potential of psychedelics, including ayahuasca, DMT, psilocybin, and LSD, in stress-related disorders. These substances induce...
Clinical studies suggest the therapeutic potential of psychedelics, including ayahuasca, DMT, psilocybin, and LSD, in stress-related disorders. These substances induce cognitive, antidepressant, anxiolytic, and antiaddictive effects suggested to arise from biological changes similar to conventional antidepressants or the rapid-acting substance ketamine. The proposed route is by inducing brain neuroplasticity. This review attempts to summarize the evidence that psychedelics induce neuroplasticity by focusing on psychedelics' cellular and molecular neuroplasticity effects after single and repeated administration. When behavioral parameters are encountered in the selected studies, the biological pathways will be linked to the behavioral effects. Additionally, knowledge gaps in the underlying biology of clinical outcomes of psychedelics are highlighted. The literature searched yielded 344 results. Title and abstract screening reduced the sample to 35; eight were included from other sources, and full-text screening resulted in the final selection of 16 preclinical and four clinical studies. Studies ( = 20) show that a single administration of a psychedelic produces rapid changes in plasticity mechanisms on a molecular, neuronal, synaptic, and dendritic level. The expression of plasticity-related genes and proteins, including Brain-Derived Neurotrophic Factor (BDNF), is changed after a single administration of psychedelics, resulting in changed neuroplasticity. The latter included more dendritic complexity, which outlasted the acute effects of the psychedelic. Repeated administration of a psychedelic directly stimulated neurogenesis and increased BDNF mRNA levels up to a month after treatment. Findings from the current review demonstrate that psychedelics induce molecular and cellular adaptations related to neuroplasticity and suggest those run parallel to the clinical effects of psychedelics, potentially underlying them. Future (pre)clinical research might focus on deciphering the specific cellular mechanism activated by different psychedelics and related to long-term clinical and biological effects to increase our understanding of the therapeutic potential of these compounds.
PubMed: 34566723
DOI: 10.3389/fpsyt.2021.724606 -
Archives of Rehabilitation Research and... Mar 2021To investigate the effect of action observation therapy (AOT) in the rehabilitation of neurologic and musculoskeletal conditions. (Review)
Review
OBJECTIVE
To investigate the effect of action observation therapy (AOT) in the rehabilitation of neurologic and musculoskeletal conditions.
DATA SOURCES
Searches were completed until July 2020 from the electronic databases Allied and Complementary Medicine Database (via OVID SP), Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, EMBASE, MEDLINE, and the Physiotherapy Evidence Database.
STUDY SELECTION
Randomized controlled trials comparing AOT with standard care were assessed. Musculoskeletal (amputee, orthopedic) and neurologic (dementia, cerebral palsy, multiple sclerosis, Parkinson disease, stroke) conditions were included. There were no age limitations. Articles had to be available in English.
DATA EXTRACTION
Two reviewers independently screened titles, abstracts and full extracts of studies for eligibility and assessed the risk of bias of each study using the Cochrane Risk of Bias Tool. Data extraction included participant characteristics and intervention duration, frequency, and type.
RESULTS
The effect of AOT in different outcome measures (OMs) was referenced in terms of body structures and functions, activities and participation, and environmental factors as outlined by the International Classification of Functioning, Disability, and Health (ICF). Of the 3448 articles identified, 36 articles with 1405 patients met the inclusion criteria. Seven of the 11 meta-analyses revealed a significant effect of intervention, with results presented using the mean difference and 95% CI. A best evidence synthesis was used across all OMs. Strong evidence supports the use of AOT in the rehabilitation of individuals with stroke and Parkinson disease; moderate evidence supports AOT in the rehabilitation of populations with orthopedic and multiple sclerosis diagnoses. However, moderate evidence is provided for and against the effect of AOT in persons with Parkinson disease and cerebral palsy.
CONCLUSIONS
This review suggests that AOT is advantageous in the rehabilitation of certain conditions in improving ICF domains. No conclusions can be drawn regarding treatment parameters because of the heterogeneity of the intervention. AOT has been considerably less explored in musculoskeletal conditions.
PubMed: 33778479
DOI: 10.1016/j.arrct.2021.100106 -
The Cochrane Database of Systematic... Feb 2016Complex regional pain syndrome (CRPS) is a painful and disabling condition that usually manifests in response to trauma or surgery. When it occurs, it is associated with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Complex regional pain syndrome (CRPS) is a painful and disabling condition that usually manifests in response to trauma or surgery. When it occurs, it is associated with significant pain and disability. It is thought to arise and persist as a consequence of a maladaptive pro-inflammatory response and disturbances in sympathetically-mediated vasomotor control, together with maladaptive peripheral and central neuronal plasticity. CRPS can be classified into two types: type I (CRPS I) in which a specific nerve lesion has not been identified, and type II (CRPS II) where there is an identifiable nerve lesion. Guidelines recommend the inclusion of a variety of physiotherapy interventions as part of the multimodal treatment of people with CRPS, although their effectiveness is not known.
OBJECTIVES
To determine the effectiveness of physiotherapy interventions for treating the pain and disability associated with CRPS types I and II.
SEARCH METHODS
We searched the following databases from inception up to 12 February 2015: CENTRAL (the Cochrane Library), MEDLINE, EMBASE, CINAHL, PsycINFO, LILACS, PEDro, Web of Science, DARE and Health Technology Assessments, without language restrictions, for randomised controlled trials (RCTs) of physiotherapy interventions for treating pain and disability in people CRPS. We also searched additional online sources for unpublished trials and trials in progress.
SELECTION CRITERIA
We included RCTs of physiotherapy interventions (including manual therapy, therapeutic exercise, electrotherapy, physiotherapist-administered education and cortically directed sensory-motor rehabilitation strategies) employed in either a stand-alone fashion or in combination, compared with placebo, no treatment, another intervention or usual care, or of varying physiotherapy interventions compared with each other in adults with CRPS I and II. Our primary outcomes of interest were patient-centred outcomes of pain intensity and functional disability.
DATA COLLECTION AND ANALYSIS
Two review authors independently evaluated those studies identified through the electronic searches for eligibility and subsequently extracted all relevant data from the included RCTs. Two review authors independently performed 'Risk of bias' assessments and rated the quality of the body of evidence for the main outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.
MAIN RESULTS
We included 18 RCTs (739 participants) that tested the effectiveness of a broad range of physiotherapy-based interventions. Overall, there was a paucity of high quality evidence concerning physiotherapy treatment for pain and disability in people with CRPS I. Most included trials were at 'high' risk of bias (15 trials) and the remainder were at 'unclear' risk of bias (three trials). The quality of the evidence was very low or low for all comparisons, according to the GRADE approach.We found very low quality evidence that graded motor imagery (GMI; two trials, 49 participants) may be useful for improving pain (0 to 100 VAS) (mean difference (MD) -21.00, 95% CI -31.17 to -10.83) and functional disability (11-point numerical rating scale) (MD 2.30, 95% CI 1.12 to 3.48), at long-term (six months) follow-up, in people with CRPS I compared to usual care plus physiotherapy; very low quality evidence that multimodal physiotherapy (one trial, 135 participants) may be useful for improving 'impairment' at long-term (12 month) follow-up compared to a minimal 'social work' intervention; and very low quality evidence that mirror therapy (two trials, 72 participants) provides clinically meaningful improvements in pain (0 to 10 VAS) (MD 3.4, 95% CI -4.71 to -2.09) and function (0 to 5 functional ability subscale of the Wolf Motor Function Test) (MD -2.3, 95% CI -2.88 to -1.72) at long-term (six month) follow-up in people with CRPS I post stroke compared to placebo (covered mirror).There was low to very low quality evidence that tactile discrimination training, stellate ganglion block via ultrasound and pulsed electromagnetic field therapy compared to placebo, and manual lymphatic drainage combined with and compared to either anti-inflammatories and physical therapy or exercise are not effective for treating pain in the short-term in people with CRPS I. Laser therapy may provide small clinically insignificant, short-term, improvements in pain compared to interferential current therapy in people with CRPS I.Adverse events were only rarely reported in the included trials. No trials including participants with CRPS II met the inclusion criteria of this review.
AUTHORS' CONCLUSIONS
The best available data show that GMI and mirror therapy may provide clinically meaningful improvements in pain and function in people with CRPS I although the quality of the supporting evidence is very low. Evidence of the effectiveness of multimodal physiotherapy, electrotherapy and manual lymphatic drainage for treating people with CRPS types I and II is generally absent or unclear. Large scale, high quality RCTs are required to test the effectiveness of physiotherapy-based interventions for treating pain and disability of people with CRPS I and II. Implications for clinical practice and future research are considered.
Topics: Adult; Complex Regional Pain Syndromes; Humans; Pain Measurement; Physical Therapy Modalities; Randomized Controlled Trials as Topic
PubMed: 26905470
DOI: 10.1002/14651858.CD010853.pub2 -
Neural Plasticity 2020Parkinson's disease (PD) is a neurodegenerative disorder for which there is currently only symptomatic treatment. During the last decade, there has been an increased... (Meta-Analysis)
Meta-Analysis
Parkinson's disease (PD) is a neurodegenerative disorder for which there is currently only symptomatic treatment. During the last decade, there has been an increased interest in investigating physical exercise as a neuroprotective mechanism in PD. Animal studies have suggested that exercise may in fact induce neuroplastic changes, but evidence in humans is still scarce. A handful of reviews have previously reported on exercise-induced neuroplasticity in humans with PD, but few have been systematic, or have mixed studies on both animals and humans, or focused on one neuroplastic outcome only. Here, we provide a systematic review and metasynthesis of the published studies on humans in this research field where we have also included different methods of evaluating neuroplasticity. Our results indicate that various forms of physical exercise may lead to changes in various markers of neuroplasticity. A narrative synthesis suggests that brain function and structure can be altered in a positive direction after an exercise period, whereas a meta-analysis on neurochemical adaptations after exercise points in disparate directions. Finally, a GRADE analysis showed that the current overall level of evidence for exercise-induced neuroplasticity in people with PD is very low. Our results demonstrate that even though the results in this area point in a positive direction, researchers need to provide studies of higher quality using more rigorous methodology.
Topics: Brain; Exercise; Exercise Therapy; Humans; Neuronal Plasticity; Parkinson Disease; Treatment Outcome
PubMed: 32256559
DOI: 10.1155/2020/8961493 -
Neural Plasticity 2020Physical exercise (PE) has been associated with increase neuroplasticity, neurotrophic factors, and improvements in brain function.
BACKGROUND
Physical exercise (PE) has been associated with increase neuroplasticity, neurotrophic factors, and improvements in brain function.
OBJECTIVE
To evaluate the effects of different PE protocols on neuroplasticity components and brain function in a human and animal model.
METHODS
We conducted a systematic review process from November 2019 to January 2020 of the following databases: PubMed, ScienceDirect, SciELO, LILACS, and Scopus. A keyword combination referring to PE and neuroplasticity was included as part of a more thorough search process. From an initial number of 20,782 original articles, after reading the titles and abstracts, twenty-one original articles were included. Two investigators evaluated the abstract, the data of the study, the design, the sample size, the participant characteristics, and the PE protocol.
RESULTS
PE increases neuroplasticity via neurotrophic factors (BDNF, GDNF, and NGF) and receptor (TrkB and P75NTR) production providing improvements in neuroplasticity, and cognitive function (learning and memory) in human and animal models.
CONCLUSION
PE was effective for increasing the production of neurotrophic factors, cell growth, and proliferation, as well as for improving brain functionality.
Topics: Animals; Brain; Cognition; Exercise; Humans; Learning; Memory; Neuronal Plasticity
PubMed: 33414823
DOI: 10.1155/2020/8856621 -
Sports Health 2022Only 55% of the athletes return to competitive sports after an anterior cruciate ligament (ACL) injury. Athletes younger than 25 years who return to sports have a second...
CONTEXT
Only 55% of the athletes return to competitive sports after an anterior cruciate ligament (ACL) injury. Athletes younger than 25 years who return to sports have a second injury rate of 23%. There may be a mismatch between rehabilitation contents and the demands an athlete faces after returning to sports. Current return-to-sports (RTS) tests utilize closed and predictable motor skills; however, demands on the field are different. Neurocognitive functions are essential to manage dynamic sport situations and may fluctuate after peripheral injuries. Most RTS and rehabilitation paradigms appear to lack this aspect, which might be linked to increased risk of second injury.
OBJECTIVE
This systematic and scoping review aims to map existing evidence about neurocognitive and neurophysiological functions in athletes, which could be linked to ACL injury in an integrated fashion and bring an extensive perspective to assessment and rehabilitation approaches.
DATA SOURCES
PubMed and Cochrane databases were searched to identify relevant studies published between 2005 and 2020 using the keywords , , , , , , , and .
STUDY SELECTION
Studies investigating either neurocognitive or neurophysiological functions in athletes and linking these to ACL injury regardless of their design and technique were included.
STUDY DESIGN
Systematic review.
LEVEL OF EVIDENCE
Level 3.
DATA EXTRACTION
The demographic, temporal, neurological, and behavioral data revealing possible injury-related aspects were extracted and summarized.
RESULTS
A total of 16 studies were included in this review. Deficits in different neurocognitive domains and changes in neurophysiological functions could be a predisposing risk factor for, or a consequence caused by, ACL injuries.
CONCLUSION
Clinicians should view ACL injuries not only as a musculoskeletal but also as a neural lesion with neurocognitive and neurophysiological aspects. Rehabilitation and RTS paradigms should consider these changes for assessment and interventions after injury.
Topics: Anterior Cruciate Ligament Injuries; Anterior Cruciate Ligament Reconstruction; Athletes; Humans; Reinjuries; Return to Sport
PubMed: 34236003
DOI: 10.1177/19417381211029265