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The Cochrane Database of Systematic... Dec 2017Stroke is a major health issue and cause of long-term disability and has a major emotional and socioeconomic impact. There is a need to explore options for long-term... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Stroke is a major health issue and cause of long-term disability and has a major emotional and socioeconomic impact. There is a need to explore options for long-term sustainable interventions that support stroke survivors to engage in meaningful activities to address life challenges after stroke. Rehabilitation focuses on recovery of function and cognition to the maximum level achievable, and may include a wide range of complementary strategies including yoga.Yoga is a mind-body practice that originated in India, and which has become increasingly widespread in the Western world. Recent evidence highlights the positive effects of yoga for people with a range of physical and psychological health conditions. A recent non-Cochrane systematic review concluded that yoga can be used as self-administered practice in stroke rehabilitation.
OBJECTIVES
To assess the effectiveness of yoga, as a stroke rehabilitation intervention, on recovery of function and quality of life (QoL).
SEARCH METHODS
We searched the Cochrane Stroke Group Trials Register (last searched July 2017), Cochrane Central Register of Controlled Trials (CENTRAL) (last searched July 2017), MEDLINE (to July 2017), Embase (to July 2017), CINAHL (to July 2017), AMED (to July 2017), PsycINFO (to July 2017), LILACS (to July 2017), SciELO (to July 2017), IndMED (to July 2017), OTseeker (to July 2017) and PEDro (to July 2017). We also searched four trials registers, and one conference abstracts database. We screened reference lists of relevant publications and contacted authors for additional information.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) that compared yoga with a waiting-list control or no intervention control in stroke survivors.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data from the included studies. We performed all analyses using Review Manager (RevMan). One review author entered the data into RevMan; another checked the entries. We discussed disagreements with a third review author until consensus was reached. We used the Cochrane 'Risk of bias' tool. Where we considered studies to be sufficiently similar, we conducted a meta-analysis by pooling the appropriate data. For outcomes for which it was inappropriate or impossible to pool quantitatively, we conducted a descriptive analysis and provided a narrative summary.
MAIN RESULTS
We included two RCTs involving 72 participants. Sixty-nine participants were included in one meta-analysis (balance). Both trials assessed QoL, along with secondary outcomes measures relating to movement and psychological outcomes; one also measured disability.In one study the Stroke Impact Scale was used to measure QoL across six domains, at baseline and post-intervention. The effect of yoga on five domains (physical, emotion, communication, social participation, stroke recovery) was not significant; however, the effect of yoga on the memory domain was significant (mean difference (MD) 15.30, 95% confidence interval (CI) 1.29 to 29.31, P = 0.03), the evidence for this finding was very low grade. In the second study, QoL was assessed using the Stroke-Specifc QoL Scale; no significant effect was found.Secondary outcomes included movement, strength and endurance, and psychological variables, pain, and disability.Balance was measured in both studies using the Berg Balance Scale; the effect of intervention was not significant (MD 2.38, 95% CI -1.41 to 6.17, P = 0.22). Sensititivy analysis did not alter the direction of effect. One study measured balance self-efficacy, using the Activities-specific Balance Confidence Scale (MD 10.60, 95% CI -7.08,= to 28.28, P = 0.24); the effect of intervention was not significant; the evidence for this finding was very low grade.One study measured gait using the Comfortable Speed Gait Test (MD 1.32, 95% CI -1.35 to 3.99, P = 0.33), and motor function using the Motor Assessment Scale (MD -4.00, 95% CI -12.42 to 4.42, P = 0.35); no significant effect was found based on very low-grade evidence.One study measured disability using the modified Rankin Scale (mRS) but reported only whether participants were independent or dependent. No significant effect was found: (odds ratio (OR) 2.08, 95% CI 0.50 to 8.60, P = 0.31); the evidence for this finding was very low grade.Anxiety and depression were measured in one study. Three measures were used: the Geriatric Depression Scale-Short Form (GCDS15), and two forms of State Trait Anxiety Inventory (STAI, Form Y) to measure state anxiety (i.e. anxiety experienced in response to stressful situations) and trait anxiety (i.e. anxiety associated with chronic psychological disorders). No significant effect was found for depression (GDS15, MD -2.10, 95% CI -4.70 to 0.50, P = 0.11) or for trait anxiety (STAI-Y2, MD -6.70, 95% CI -15.35 to 1.95, P = 0.13), based on very low-grade evidence. However, a significant effect was found for state anxiety: STAI-Y1 (MD -8.40, 95% CI -16.74 to -0.06, P = 0.05); the evidence for this finding was very low grade.No adverse events were reported.Quality of the evidenceWe assessed the quality of the evidence using GRADE. Overall, the quality of the evidence was very low, due to the small number of trials included in the review both of which were judged to be at high risk of bias, particularly in relation to incompleteness of data and selective reporting, and especially regarding the representative nature of the sample in one study.
AUTHORS' CONCLUSIONS
Yoga has the potential for being included as part of patient-centred stroke rehabilitation. However, this review has identified insufficient information to confirm or refute the effectiveness or safety of yoga as a stroke rehabilitation treatment. Further large-scale methodologically robust trials are required to establish the effectiveness of yoga as a stroke rehabilitation treatment.
Topics: Anxiety; Communication; Depression; Emotions; Gait; Humans; Memory; Postural Balance; Quality of Life; Randomized Controlled Trials as Topic; Recovery of Function; Social Participation; Stroke Rehabilitation; Yoga
PubMed: 29220541
DOI: 10.1002/14651858.CD011483.pub2 -
Biomedicines Jun 2023Fibromyalgia is a common disease syndrome characterized by chronic pain and fatigue in conjunction with cognitive dysfunction such as memory difficulties. Patients... (Review)
Review
Fibromyalgia is a common disease syndrome characterized by chronic pain and fatigue in conjunction with cognitive dysfunction such as memory difficulties. Patients currently face a difficult prognosis with limited treatment options and a diminished quality of life. Given its widespread use and potential efficacy in treating other types of pain, cannabis may prove to be an effective treatment for fibromyalgia. This review aims to examine and discuss current clinical evidence regarding the use of cannabis for the treatment of fibromyalgia. An electronic search was conducted on MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus using Medical Subject Heading (MeSH) terms on all literature published up to October 2022. A follow-up manual search included a complete verification of relevant studies. The results of four randomized controlled trials (RCTs) and five observational studies (a total of 564 patients) that investigated the effects of cannabis on fibromyalgia symptoms were included in this review. Of the RCTs, only one demonstrated that cannabinoids did not have a different effect than placebo on pain responses. Overall, this analysis shows low-quality evidence supporting short-term pain reduction in people with fibromyalgia treated with cannabinoid therapeutics. Although current evidence is limited, medical cannabis appears to be a safe alternative for treating fibromyalgia.
PubMed: 37371716
DOI: 10.3390/biomedicines11061621 -
Experimental Gerontology Jul 2018Creatine is a supplement used by sportsmen to increase athletic performance by improving energy supply to muscle tissues. It is also an essential brain compound and some...
BACKGROUND AND AIMS
Creatine is a supplement used by sportsmen to increase athletic performance by improving energy supply to muscle tissues. It is also an essential brain compound and some hypothesize that it aids cognition by improving energy supply and neuroprotection. The aim of this systematic review is to investigate the effects of oral creatine administration on cognitive function in healthy individuals.
METHODS
A search of multiple electronic databases was performed for the identification of randomized clinical trials (RCTs) examining the cognitive effects of oral creatine supplementation in healthy individuals.
RESULTS
Six studies (281 individuals) met our inclusion criteria. Generally, there was evidence that short term memory and intelligence/reasoning may be improved by creatine administration. Regarding other cognitive domains, such as long-term memory, spatial memory, memory scanning, attention, executive function, response inhibition, word fluency, reaction time and mental fatigue, the results were conflicting. Performance on cognitive tasks stayed unchanged in young individuals. Vegetarians responded better than meat-eaters in memory tasks but for other cognitive domains no differences were observed.
CONCLUSIONS
Oral creatine administration may improve short-term memory and intelligence/reasoning of healthy individuals but its effect on other cognitive domains remains unclear. Findings suggest potential benefit for aging and stressed individuals. Since creatine is safe, future studies should include larger sample sizes. It is imperative that creatine should be tested on patients with dementias or cognitive impairment.
Topics: Cognition; Creatine; Dietary Supplements; Healthy Volunteers; Humans; Intelligence; Memory, Short-Term; Randomized Controlled Trials as Topic
PubMed: 29704637
DOI: 10.1016/j.exger.2018.04.013 -
Journal of Psychopharmacology (Oxford,... Feb 2016The effects of propranolol in the treatment of anxiety disorders have not been systematically evaluated previously. The aim was to conduct a systematic review and... (Comparative Study)
Comparative Study Meta-Analysis Review
The effects of propranolol in the treatment of anxiety disorders have not been systematically evaluated previously. The aim was to conduct a systematic review and meta-analysis of randomised controlled trials, addressing the efficacy of oral propranolol versus placebo or other medication as a treatment for alleviating either state or trait anxiety in patients suffering from anxiety disorders. Eight studies met the inclusion criteria. These studies concerned panic disorder with or without agoraphobia (four studies, total n = 130), specific phobia (two studies, total n = 37), social phobia (one study, n = 16), and posttraumatic stress disorder (PTSD) (one study, n = 19). Three out of four panic disorder trials qualified for pooled analyses. These meta-analyses found no statistically significant differences between the efficacy of propranolol and benzodiazepines regarding the short-term treatment of panic disorder with or without agoraphobia. Also, no evidence was found for effects of propranolol on PTSD symptom severity through inhibition of memory reconsolidation. In conclusion, the quality of evidence for the efficacy of propranolol at present is insufficient to support the routine use of propranolol in the treatment of any of the anxiety disorders.
Topics: Administration, Oral; Adrenergic beta-Antagonists; Anti-Anxiety Agents; Anxiety Disorders; Humans; Propranolol; Randomized Controlled Trials as Topic; Severity of Illness Index
PubMed: 26487439
DOI: 10.1177/0269881115612236 -
Advances in Nutrition (Bethesda, Md.) May 2016Breakfast is thought to be beneficial for cognitive and academic performance in school children. However, breakfast is the most frequently skipped meal, especially among... (Review)
Review
Breakfast is thought to be beneficial for cognitive and academic performance in school children. However, breakfast is the most frequently skipped meal, especially among adolescents. The aim of the current article was to systematically review the evidence from intervention studies for the effects of breakfast on cognitive performance in children and adolescents. The effects of breakfast were evaluated by cognitive domain and breakfast manipulation. A total of 45 studies reported in 43 articles were included in the review. Most studies considered the acute effect of a single breakfast (n = 34). The acute studies looked at breakfast compared with no breakfast (n = 24) and/or comparisons of breakfast type (n = 15). The effects of chronic school breakfast program interventions were evaluated in 11 studies. The findings suggest that breakfast consumption relative to fasting has a short-term (same morning) positive domain-specific effect on cognition. Tasks requiring attention, executive function, and memory were facilitated more reliably by breakfast consumption relative to fasting, with effects more apparent in undernourished children. Firm conclusions cannot be made about the acute effects of breakfast composition and the effects of chronic breakfast interventions because there are too few studies and these largely report inconsistent findings. This review also highlights methodologic limitations of the existing research. These include a lack of research on adolescents, few naturalistic breakfast manipulations or testing environments, small samples, and insensitive cognitive tests.
Topics: Adolescent; Attention; Breakfast; Child; Cognition; Diet; Executive Function; Humans; Language; Memory; Psychomotor Performance; Randomized Controlled Trials as Topic
PubMed: 27184287
DOI: 10.3945/an.115.010256 -
Journal of Parkinson's Disease 2018Cognitive dysfunction is one of the most prevalent non-motor symptoms in Parkinson's disease (PD), often experienced as more debilitating for patients and caregivers...
BACKGROUND
Cognitive dysfunction is one of the most prevalent non-motor symptoms in Parkinson's disease (PD), often experienced as more debilitating for patients and caregivers than motor problems. Therefore, a deeper understanding of the course of cognitive decline and the identification of valid progression markers for Parkinson's disease dementia (PDD) is essential.
OBJECTIVE
This systematic review summarizes the current state of knowledge on cognitive decline over time by reporting effect sizes of cognitive changes in neuropsychological tests.
METHODS
1368 studies were identified by a PubMed database search and 25 studies by additionally scanning previous literature. After screening all records, including 69 full-text article reviews, 12 longitudinal studies on the progression of cognitive decline in PD met our criteria (e.g., sample size ≥50 patients).
RESULTS
Only a few studies monitored cognitive decline over a longer period (>4 years). Most studies focused on the evaluation of change in global cognitive state by use of the Mini-Mental State Examination, whereas the use of neuropsychological tests was highly heterogenic among studies. Only one study evaluated patients' cognitive performance in all specified domains (executive function, attention & working memory, memory, language, and visual-spatial function) allowing for diagnosis of cognitive impairment according to consensus guidelines. Medium to strong effect sizes could only be observed in studies with follow-up intervals of four years or longer.
CONCLUSIONS
The results emphasize the need for the assessment of larger PD cohorts over longer periods of follow-up with a comprehensive neuropsychological battery.
Topics: Attention; Cognition; Cognition Disorders; Disease Progression; Executive Function; Humans; Language; Memory, Short-Term; Neuropsychological Tests; Parkinson Disease
PubMed: 29914040
DOI: 10.3233/JPD-181306 -
Frontiers in Public Health 2022As brain function declines and cognitive ability declines, the benefits of resistance exercise to the brain of older people are gradually gaining attention.
BACKGROUND
As brain function declines and cognitive ability declines, the benefits of resistance exercise to the brain of older people are gradually gaining attention.
OBJECTIVE
The purpose of this review is to explore the mechanism and relationship between physiological factors such as vascular and neuronal degeneration and cognitive decline, and to categorize the differences in the effects of an acute and chronic resistance exercise intervention on cognitive function in healthy elderly people and the possible regulators of cognitive effects.
METHODS
Using PubMed, Elsevier, Web of Science, X-MOL, CNKI, and Taiwan academic literature database, the research papers published in relevant journals at home and abroad until April 2022 were searched with Chinese and English keywords such as Resistance exercise, the elderly, hippocampus, memory performance, neurons, cognitive function. Pedro scale was used to check the quality of various documents, and the relevant research documents were obtained with the resistance exercise elements as the main axis for comprehensive analysis.
RESULTS AND CONCLUSION
(1) Resistance exercise can have a beneficial effect on the brain function of the elderly through blood flow changes, stimulate nerve conduction substances and endocrine metabolism, promote cerebrovascular regeneration and gray matter volume of the brain, and prevent or delay the cognitive function degradation such as memory and attention of the elderly; (2) Acute resistance can temporarily stimulate hormone secretion and significantly improve the effect of short-term memory test, but it has little effect on the cognitive performance of the elderly; (3) Moderate-high intensity resistance exercise (50-80%1RM, 1-3 times/week, 2-3 groups/time) lasting for at least 6 months is more prominent for the improvement of cognitive function of the elderly, while the parameters such as resistance exercise intensity, exercise amount, duration, evaluation test time and differences of subjects may have different degrees of influence on cognitive benefits.
Topics: Humans; Aged; Resistance Training; Exercise; Health Status; Cognition; Taiwan
PubMed: 36483263
DOI: 10.3389/fpubh.2022.1013734 -
The Cochrane Database of Systematic... Apr 2017Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance, headaches and impaired concentration and short-term memory. CFS presents as a common, debilitating and serious health problem. Treatment may include physical interventions, such as exercise therapy, which was last reviewed in 2004.
OBJECTIVES
The objective of this review was to determine the effects of exercise therapy (ET) for patients with CFS as compared with any other intervention or control.• Exercise therapy versus 'passive control' (e.g. treatment as usual, waiting-list control, relaxation, flexibility).• Exercise therapy versus other active treatment (e.g. cognitive-behavioural therapy (CBT), cognitive treatment, supportive therapy, pacing, pharmacological therapy such as antidepressants).• Exercise therapy in combination with other specified treatment strategies versus other specified treatment strategies (e.g. exercise combined with pharmacological treatment vs pharmacological treatment alone).
SEARCH METHODS
We searched The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR), the Cochrane Central Register of Controlled Trials (CENTRAL) and SPORTDiscus up to May 2014 using a comprehensive list of free-text terms for CFS and exercise. We located unpublished or ongoing trials through the World Health Organization (WHO) International Clinical Trials Registry Platform (to May 2014). We screened reference lists of retrieved articles and contacted experts in the field for additional studies SELECTION CRITERIA: Randomised controlled trials involving adults with a primary diagnosis of CFS who were able to participate in exercise therapy. Studies had to compare exercise therapy with passive control, psychological therapies, adaptive pacing therapy or pharmacological therapy.
DATA COLLECTION AND ANALYSIS
Two review authors independently performed study selection, risk of bias assessments and data extraction. We combined continuous measures of outcomes using mean differences (MDs) and standardised mean differences (SMDs). We combined serious adverse reactions and drop-outs using risk ratios (RRs). We calculated an overall effect size with 95% confidence intervals (CIs) for each outcome.
MAIN RESULTS
We have included eight randomised controlled studies and have reported data from 1518 participants in this review. Three studies diagnosed individuals with CFS using the 1994 criteria of the Centers for Disease Control and Prevention (CDC); five used the Oxford criteria. Exercise therapy lasted from 12 to 26 weeks. Seven studies used variations of aerobic exercise therapy such as walking, swimming, cycling or dancing provided at mixed levels in terms of intensity of the aerobic exercise from very low to quite rigorous, whilst one study used anaerobic exercise. Control groups consisted of passive control (eight studies; e.g. treatment as usual, relaxation, flexibility) or CBT (two studies), cognitive therapy (one study), supportive listening (one study), pacing (one study), pharmacological treatment (one study) and combination treatment (one study). Risk of bias varied across studies, but within each study, little variation was found in the risk of bias across our primary and secondary outcome measures.Investigators compared exercise therapy with 'passive' control in eight trials, which enrolled 971 participants. Seven studies consistently showed a reduction in fatigue following exercise therapy at end of treatment, even though the fatigue scales used different scoring systems: an 11-item scale with a scoring system of 0 to 11 points (MD -6.06, 95% CI -6.95 to -5.17; one study, 148 participants; low-quality evidence); the same 11-item scale with a scoring system of 0 to 33 points (MD -2.82, 95% CI -4.07 to -1.57; three studies, 540 participants; moderate-quality evidence); and a 14-item scale with a scoring system of 0 to 42 points (MD -6.80, 95% CI -10.31 to -3.28; three studies, 152 participants; moderate-quality evidence). Serious adverse reactions were rare in both groups (RR 0.99, 95% CI 0.14 to 6.97; one study, 319 participants; moderate-quality evidence), but sparse data made it impossible for review authors to draw conclusions. Study authors reported a positive effect of exercise therapy at end of treatment with respect to sleep (MD -1.49, 95% CI -2.95 to -0.02; two studies, 323 participants), physical functioning (MD 13.10, 95% CI 1.98 to 24.22; five studies, 725 participants) and self-perceived changes in overall health (RR 1.83, 95% CI 1.39 to 2.40; four studies, 489 participants). It was not possible for review authors to draw conclusions regarding the remaining outcomes.Investigators compared exercise therapy with CBT in two trials (351 participants). One trial (298 participants) reported little or no difference in fatigue at end of treatment between the two groups using an 11-item scale with a scoring system of 0 to 33 points (MD 0.20, 95% CI -1.49 to 1.89). Both studies measured differences in fatigue at follow-up, but neither found differences between the two groups using an 11-item fatigue scale with a scoring system of 0 to 33 points (MD 0.30, 95% CI -1.45 to 2.05) and a nine-item Fatigue Severity Scale with a scoring system of 1 to 7 points (MD 0.40, 95% CI -0.34 to 1.14). Serious adverse reactions were rare in both groups (RR 0.67, 95% CI 0.11 to 3.96). We observed little or no difference in physical functioning, depression, anxiety and sleep, and we were not able to draw any conclusions with regard to pain, self-perceived changes in overall health, use of health service resources and drop-out rate.With regard to other comparisons, one study (320 participants) suggested a general benefit of exercise over adaptive pacing, and another study (183 participants) a benefit of exercise over supportive listening. The available evidence was too sparse to draw conclusions about the effect of pharmaceutical interventions.
AUTHORS' CONCLUSIONS
Patients with CFS may generally benefit and feel less fatigued following exercise therapy, and no evidence suggests that exercise therapy may worsen outcomes. A positive effect with respect to sleep, physical function and self-perceived general health has been observed, but no conclusions for the outcomes of pain, quality of life, anxiety, depression, drop-out rate and health service resources were possible. The effectiveness of exercise therapy seems greater than that of pacing but similar to that of CBT. Randomised trials with low risk of bias are needed to investigate the type, duration and intensity of the most beneficial exercise intervention.
Topics: Adult; Cognitive Behavioral Therapy; Depression; Exercise; Exercise Therapy; Fatigue Syndrome, Chronic; Health Status; Humans; Patient Dropouts; Quality of Life; Randomized Controlled Trials as Topic; Sleep Wake Disorders
PubMed: 28444695
DOI: 10.1002/14651858.CD003200.pub7 -
Neuroscience and Biobehavioral Reviews Aug 2021Endogenous melatonin levels are inversely associated with age and cognitive deficits. Although melatonin can improve psychopathological behavior disturbances in clinical... (Meta-Analysis)
Meta-Analysis Review
Neurocognitive effects of melatonin treatment in healthy adults and individuals with Alzheimer's disease and insomnia: A systematic review and meta-analysis of randomized controlled trials.
Endogenous melatonin levels are inversely associated with age and cognitive deficits. Although melatonin can improve psychopathological behavior disturbances in clinical trials, whether melatonin may also enhance cognitive function remains elusive. This study examined cognitive outcomes from randomized trials of melatonin treatment for Alzheimer's disease (AD), insomnia, and healthy-subjects. Twenty-two studies met the inclusion criteria (AD = 9, insomnia = 2, healthy-subjects = 11). AD patients receiving >12 weeks of melatonin treatment improved mini-mental state examination (MMSE) score [MD: 1.82 (1.01; 2.63) p < 0.0001]. Importantly, melatonin significantly improved MMSE score in mild stage of AD [MD: 1.89 (0.96; 2.82) p < 0.0001]. In healthy-subjects, although daytime melatonin treatment notably decreased in accuracy by correct responses [SMD: -0.74 (-1.03; -0.45) p < 0.00001], the reaction-time score on different stimuli (p = 0.37) did not increased. Additionally, by pooling of short-term, spatial, and visual memory scores, melatonin did not reduce memory function (p = 0.08). Meta-analysis of MMSE score suggested that melatonin is effective in treatment for mild stage of AD. Additionally, we propose that melatonin may be preferable to traditional hypnotics in management of insomnia.
Topics: Adult; Alzheimer Disease; Cognition Disorders; Humans; Melatonin; Randomized Controlled Trials as Topic; Sleep Initiation and Maintenance Disorders
PubMed: 33957167
DOI: 10.1016/j.neubiorev.2021.04.034 -
Journal of Athletic Training Feb 2020Sport-related concussions (SRCs) are known to have short-term effects on cognitive processes, which can result in diverse clinical presentations. The long-term effects...
BACKGROUND
Sport-related concussions (SRCs) are known to have short-term effects on cognitive processes, which can result in diverse clinical presentations. The long-term effects of SRC and repeated exposure to head impacts that do not result in SRC on specific cognitive health outcomes remain unclear.
OBJECTIVES
To synthesize and appraise the evidence base regarding cognitive health in living retired athletes with a history of head-impact exposure or SRC.
DATA SOURCES
A systematic search of the EMBASE, PsycINFO, MEDLINE/PubMed, CINAHL, Cochrane Central Register of Controlled Trials, and Web of Science databases was conducted from inception to April 2018 using common key words and medical subject headings related to 3 components: (1) the participant (eg, retired athlete), (2) the primary outcome measure (eg, cognitive test used), and (3) the secondary outcome measure (eg, history of sport concussion).
STUDY SELECTION
Cross-sectional studies of living retired male or female athletes in which at least 1 cognitive test was used as an outcome measure were included. Two reviewers independently screened studies.
DATA EXTRACTION
Data extraction was performed using Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Methodologic quality was assessed independently by 2 reviewers using the Downs and Black tool.
DATA SYNTHESIS
The search yielded 46 cross-sectional observational studies that were included in a qualitative synthesis. Most included studies (80%, n = 37) were published in the 5 years before our review. A large proportion of these studies (n = 20) included retired American National Football League players. The other research investigated professional, university, high school, and amateur retired athletes participating in sports such as American and Australian football, boxing, field and ice hockey, rugby, and soccer. The total sample consisted of 13 975 participants: 7387 collision-sport athletes, 662 contact-sport athletes, 3346 noncontact-sport athletes, and 2580 participants classified as controls. Compared with control participants or normative data, retired athletes displayed worse performance in 17 of 31 studies (55%) of memory, 6 of 11 studies (55%) of executive function, and 4 of 6 studies (67%) of psychomotor function and increased subjective concerns about cognitive function in 11 of 14 studies (79%). The authors of 13 of 46 investigations (28%) reported a frequency-response relationship, with poorer cognitive outcomes in athletes who had greater levels of exposure to head impacts or concussions. However, these results must be interpreted in light of the lack of methodologic rigor and moderate quality assessment of the included studies.
CONCLUSIONS
Evidence of poorer cognitive health among retired athletes with a history of concussion and head-impact exposure is evolving. Our results suggest that a history of SRC may more greatly affect the cognitive domains of memory, executive function, and psychomotor function. Retired athletes appeared to have increased self-reported cognitive difficulties, but the paucity of high-quality, prospective studies limited the conclusions that could be drawn regarding a cause-and-effect relationship between concussion and long-term health outcomes. Future researchers should consider a range of cognitive health outcomes, as well as premorbid ability, in diverse samples of athletes with or without a history of concussion or head-impact exposure to delineate the long-term effects of sport participation on cognitive functioning.
Topics: Athletic Injuries; Australia; Boxing; Brain Concussion; Cognition; Executive Function; Football; Hockey; Humans; Memory; Psychomotor Performance; Retirement; Soccer
PubMed: 31935139
DOI: 10.4085/1062-6050-297-18