Children's shyness and frontal electroencephalogram delta-beta correlation in the pediatric surgical setting.

The prospect of surgery is a unique psychologically threatening context for children, often leading to experiences of preoperative anxiety. Recent research suggests that individual differences in children's temperament may influence responses to the surgical setting. In the present study, we examined whether individual differences in shyness were related to differences in frontal electroencephalogram (EEG) delta-beta correlation, a proposed neural correlate of emotion regulation and dysregulation, among children anticipating surgery. Seventy-one children (36 boys, Mage  = 10.3 years, SDage  = 1.7 years) undergoing elective surgery self-reported on their own shyness, and their parents also reported on their child's shyness. Using a mobile, dry sensor EEG headband, frontal EEG measures were collected and self- and observer-reported measures of state anxiety were obtained at the children's preoperative visit (Time 1) and on the day of surgery (Time 2). A latent cluster analysis derived classes of low shy (n = 37) and high shy (n = 34) children using the child- and parent-reported shyness measures. We then compared the two classes on frontal EEG delta-beta correlation using between- and within-subjects analyses. Although children classified as high versus low in shyness had higher self- and observer-reported state anxiety across both time periods, frontal EEG delta-beta correlation increased from T1 to T2 only among low shy children using a between-subjects delta-beta correlation measure. We discuss the interpretation of a relatively higher delta-beta correlation as a correlate of emotion regulatory versus dysregulatory strategies for some children in a "real-world," surgical context.

Systematic Review: Audiovisual Interventions for Reducing Preoperative Anxiety in Children Undergoing Elective Surgery.

OBJECTIVE: To examine the effectiveness of Audiovisual (AV) interventions at reducing preoperative anxiety and its associated outcomes in children undergoing elective surgery. METHODS: A systematic review of randomized controlled trials (RCTs) and nonrandomized studies where the primary outcome was children's preoperative anxiety was conducted. Secondary outcomes included postoperative pain, behavioral changes, recovery, induction compliance, satisfaction, and cost-effectiveness. The risk of bias of each study was assessed. RESULTS: In all, 18 studies were identified. A meta-analytic approach and narrative synthesis of findings were used to summarize the results of the studies. CONCLUSIONS: This systematic review suggests that AV interventions can be effective in reducing children's preoperative anxiety. Videos, multi-faceted programs, and interactive games appear to be most effective, whereas music therapy and Internet programs are less effective. While AV interventions appear potentially useful, adequately powered RCTs are required to conclusively pinpoint the components and mechanisms of the most effective AV interventions and guide practice.

Risk and protective factors in predicting pediatric acute postsurgical pain: A systematic review and meta-analysis.

OBJECTIVE: Acute postsurgical pain (APSP), defined as pain within 3 months after surgery, is reported in most surgical pediatric patients, and a significant number of patients experience pain interfering with their daily life activities. We aimed to identify perioperative and psychosocial factors associated with APSP severity in pediatric patients undergoing surgery. METHOD: MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, and CENTRAL were searched from database inception to October 2021. Studies that reported an association between risk or protective factors and acute pain in children were included. The primary outcome was the magnitude of association between identified factors and APSP, as measured by standardized effect sizes. RESULTS: Thirty-eight studies (7,936 participants aged 1-18 years) were included. Meta-analysis of 12 studies (1,192 participants) revealed child preoperative pain, pain immediately after surgery, anticipated pain, temperament, pain catastrophizing, age, preoperative anxiety, parent pain catastrophizing, and parent preoperative anxiety were positively associated with APSP. Child pain coping efficacy was protective against APSP. We identified several modifiable child and parent psychosocial factors as predictors of APSP severity. CONCLUSION: Given the small degree of association between identified factors and postsurgical pain, there is value in pursuing other factors that may better explain the variability in pain. Recognizing patients at risk for moderate to severe APSP enables early implementation of interventions to minimize pain burden. Interventions to enhance coping, an adaptive characteristic, may also help to reduce APSP. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Parents' physiological reactivity to child distress and associations with parenting behaviour: A systematic review.

This systematic review and narrative synthesis characterized parents' physiological stress responses to child distress and how parents' physiological and behavioural responses relate. The review was pre-registered with PROSPERO (#CRD42021252852). In total, 3607 unique records were identified through Medline, Embase, PsycINFO, and CINAHL. Fifty-five studies reported on parents' physiological stress responses during their young child's (0-3 years) distress and were included in the review. Results were synthesized based on the biological outcome and distress context used and risk of bias was evaluated. Most studies examined cortisol or heart rate variability (HRV). Small to moderate decreases in parents' cortisol levels from baseline to post-stressor were reported across studies. Studies of salivary alpha amylase, electrodermal activity, HRV, and other cardiac outcomes reflected weak or inconsistent physiological responses or a paucity of relevant studies. Among the studies that examined associations between parents' physiological and behavioural responses, stronger associations emerged for insensitive parenting behaviours and during dyadic frustration tasks. Risk of bias was a significant limitation across studies and recommendations for future research are discussed.

Children's Shyness, Frontal Brain Activity, and Anxiety in the Perioperative Context.

Although preoperative anxiety affects up to 75% of children undergoing surgery each year and is associated with many adverse outcomes, we know relatively little about individual differences in how children respond to impending surgery. We examined whether patterns of anterior brain electrical activity (i.e., a neural correlate of anxious arousal) moderated the relation between children's shyness and preoperative anxiety on the day of surgery in 70 children (36 girls, Mage = 10.4 years, SDage = 1.7, years, range 8 to 13 years) undergoing elective surgery. Shyness was assessed using self-report approximately 1 week prior to surgery during a preoperative visit (Time 1), preoperative anxiety was assessed using self-report, and regional EEG (left and right frontal and temporal sites) was assessed using a dry sensory EEG headband on the day of surgery (Time 2). We found that overall frontal EEG alpha power moderated the relation between shyness and self-reported preoperative anxiety. Shyness was related to higher levels of self-reported anxiety on the day of surgery for children with lower average overall frontal alpha EEG power (i.e., higher cortical activity) but not for children with higher average overall frontal alpha EEG power (i.e., lower cortical activity). These results suggest that the pattern of frontal brain activity might amplify some shy children's affective responses to impending surgery. Findings also extend prior results linking children's shyness, frontal brain activity, and anxiety observed in the laboratory to a real-world, ecologically salient environment.

The role of anxiety and related states in pediatric postsurgical pain.

Background: Nearly 20% of children and adolescents have pain with disability 1 year after surgery, and they experience poor sleep, school absence, and decreased activities. Negative clinical, psychological, and developmental effects include greater pain medication use, longer recovery, and fear of future medical care. Research has found psychological and family influences (i.e., child and parental anxiety) on pediatric chronic postsurgical pain (CPSP), but a better understanding of the role of perioperative anxiety and its related states in predicting pediatric postsurgical pain is needed. The poor understanding of the causes of child CPSP can lead to misdiagnosis and inadequate treatment, with significant short- and long-term effects. Objectives: The aim of this review was to summarize the literature on children's perioperative anxiety and parental anxiety in relation to acute postsurgical pain, CPSP, and pain trajectories. We also examined other related psychological factors (i.e., anxiety sensitivity, catastrophizing, pain anxiety, and fear of pain) in relation to pediatric acute and chronic postsurgical pain. Lastly, we discuss the interventions that may be effective in reducing children's and parents' preoperative anxiety. Conclusions: Our findings may improve the understanding of the causes of CPSP and highlight the gaps in research and need for further study.

Contexte: Près de 20 % des enfants et adolescents ont des douleurs avec incapacité un après la chirurgie, et ils ont un mauvais sommeil, des absences scolaires et une diminution de leurs activités. Les effets cliniques, psychologiques et développementaux négatifs comprennent une utilisation accrue des analgésiques, une récupération plus longue et la peur des soins médicaux futurs. La recherche a révélé des influences psychologiques et familiales (c.-à-d. de l'anxiété chez les enfants et les parents) sur la douleur chronique postchirurgicale pédiatrique, mais une meilleure compréhension du rôle de l'anxiété périopératoire et ses états associés pour prédire la douleur postchirurgicale pédiatrique est nécessaire. Une mauvaise compréhension des causes de la douleur chronique postchirurgicale pédiatrique peut entraîner un diagnostic erroné et un traitement inadéquat, avec des effets importants à court et à long terme.Objectifs: Le but de cette revue était de résumer la littérature sur l'anxiété périopératoire des enfants et l'anxiété parentale en lien avec la douleur postchirurgicale aiguë, la douleur chronique postchirurgicale et les trajectoires de la douleur. Nous avons aussi examiné d'autres facteurs psychologiques connexes (ex. : sensibilité à l'anxiété, catastrophisme, anxiété de la douleur, et peur de la douleur) en lien avec la douleur chronique postchirurgicale pédiatrique aigue. Enfin, nous discutons des interventions qui peuvent être efficaces pour réduire l'anxiété préopératoire des enfants et des parents.Conclusions: Nos résultats peuvent améliorer la compréhension des causes de la douleur chronique postchirurgicale et mettre en évidence les lacunes dans la recherche, ainsi que la nécessité d'études plus poussées.

Association of Temperament With Preoperative Anxiety in Pediatric Patients Undergoing Surgery: A Systematic Review and Meta-analysis.

Importance: Preoperative anxiety is associated with poor behavioral adherence during anesthetic induction and adverse postoperative outcomes. Research suggests that temperament can affect preoperative anxiety and influence its short- and long-term effects, but these associations have not been systematically examined. Objective: To examine the associations of temperament with preoperative anxiety in young patients undergoing surgery. Data Sources: Studies from MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, and the Cochrane Central Register of Controlled Trials databases were searched from database inception to June 2018. Study Selection: All prospective studies reporting associations of temperament with preoperative anxiety were included. Overall, 43 of 5451 identified studies met selection criteria. Data Extraction and Synthesis: Using the PRISMA guidelines, reviewers independently read 43 full-text articles, extracted data on eligible studies, and assessed the quality of each study. Data were pooled using the Lipsey and Wilson random-effects model. Main Outcomes and Measures: Primary outcome was the association of temperament with preoperative anxiety in patients undergoing surgery. Results: A total of 23 studies, with 4527 participants aged 1 to 18 years, were included in this review. Meta-analysis of 12 studies including 1064 participants revealed that emotionality (r = 0.11; 95% CI, 0.04 to 0.19), intensity of reaction (r = 0.29; 95% CI, 0.11 to 0.46), and withdrawal (r = 0.40; 95% CI, 0.23 to 0.55) were positively associated with preoperative anxiety, whereas activity level (r = -0.23; 95% CI, -0.31 to -0.16) was negatively correlated with preoperative anxiety. Impulsivity was not significantly associated with preoperative anxiety. Conclusions and Relevance: This systematic review and meta-analysis provided evidence suggesting that temperament may help identify pediatric patients at risk of preoperative anxiety and guide the design of prevention and intervention strategies. Future studies should continue to explore temperament and other factors influencing preoperative anxiety and their transactional effects to guide the development of precision treatment approaches and to optimize perioperative care.

Audiovisual interventions for parental preoperative anxiety: A systematic review and meta-analysis.

OBJECTIVE: To systematically review and meta-analyze studies assessing the effectiveness of audiovisual (AV) interventions aimed at reducing anxiety in parents whose children are undergoing elective surgery. METHODS: A comprehensive search of multiple electronic databases was performed. A narrative synthesis of findings and random-effects meta-analyses were used to summarize the results. Our primary outcome was parental anxiety. Secondary outcomes included children's preoperative anxiety and postoperative outcomes; parental satisfaction, knowledge, and need for anesthesia information. Risk of bias was appraised within and across studies. RESULTS: Our search yielded 723 studies and 11 were included. A Standardized Mean Difference (SMD) of -0.53 (95% CI [-0.91, -0.15], p < .01) was found between parental anxiety scores in AV interventions and control groups. In terms of children's preoperative anxiety, there was a SMD of -0.59 (95% CI [-1.11, -0.07], p < .05) between children's anxiety scores in AV intervention and nonintervention participants. Furthermore, AV interventions were shown to shorten the recovery time for children undergoing surgery (SMD = -0.21; 95% CI [-0.39, -0.02], p = .03) but did not lead to improvements on other postoperative outcomes. CONCLUSIONS: These findings suggest that AV interventions have modest, positive effects on both parental and children's preoperative anxiety. Although a statistically significant medium size effect was detected, the clinical significance of this finding requires further exploration. Further research aimed at developing better AV interventions to help guide future practice is warranted. (PsycINFO Database Record

Risk factors of new onset anxiety and anxiety exacerbation in the perinatal period: A systematic review and meta-analysis.

BACKGROUND: Even though more than 20% of women meet diagnostic criteria for an anxiety disorder during the perinatal period, very little is known about the predictors of these problems. As a result, we systematically reviewed the literature on risk factors for new onset anxiety and maternal anxiety exacerbation in the perinatal period. METHODS: PubMed, MEDLINE, PsycINFO, CINAHL, Ovid, ProQuest Portal, and Web of Science were searched for studies assessing risk factors for the development of new onset anxiety or anxiety worsening in women during pregnancy and the postpartum period. RESULTS: 11,759 citations were identified, with 11 studies meeting eligibility criteria. New onset anxiety was assessed in 7 studies, anxiety worsening in 3, and 1 assessed both. Lower educational attainment, living with extended family members, multiparity, a family history of psychiatric disorders, hyperemesis gravidarum, comorbid sleep disorders, and prenatal oxytocin exposure were risk factors for new onset perinatal anxiety, while presence of comorbid psychiatric disorders and prenatal oxytocin were risk factors for anxiety worsening. LIMITATIONS: Studies not explicitly stating whether participants had pre-existing anxiety disorders were excluded. As a result, meta-analysis was not possible for several risk factors. CONCLUSIONS: Risk factors for new onset anxiety and anxiety worsening during the perinatal period include psychological, social, and biological exposures. Given the lack of studies differentiating women with and without pre-existing anxiety disorders, additional research is required in order to determine whether these factors differ from the non-puerperal population, as well as from each other.

Non-pharmacological interventions for improving postpartum maternal sleep: A systematic review and meta-analysis.

Evidence suggests that poor postpartum sleep quality is a risk factor for the development of postpartum depression. As such, non-pharmacological interventions have been developed to help improve sleep in the postpartum period. The primary aims of this systematic review and meta-analysis were to determine if non-pharmacological interventions improved maternal sleep and to compare the effectiveness of different intervention types. Secondary aims included examining effects on maternal mood and infant sleep. We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and Web of Science from their inceptions to September 2017 and found 15 eligible studies. Non-pharmacological sleep interventions were found to improve subjective reports of maternal sleep (Cohen's d = -0.54, 95%CI = -0.88 to -0.19). Massage (Cohen's d = -1.07 95%CI = -1.34 to -0.79) and exercise (Cohen's d = -0.82 95%CI = -1.28 to -0.37) interventions had the largest impact on maternal sleep quality. Positive effects on nocturnal infant sleep were found for interventions overall (Cohen's d = -0.27 95%CI = -0.52 to -0.02) but not for maternal depression (Cohen's d = -0.08 95%CI = -0.28 to 0.12). Despite evidence suggesting improvements in subjective maternal sleep, more research must be conducted on the durability of effects of non-pharmacological interventions using objective measures of sleep quality.

Children's Shyness in a Surgical Setting.

OBJECTIVE: We examined the relation between temperament and preoperative anxiety in 40 children (aged 8-13) who were undergoing elective surgery one week prior to surgery Time 1 (T1) and on the day of surgery Time 2 (T2). METHOD: Children's temperamental shyness was examined using the Colorado Childhood Temperament Inventory at T1, and preoperative anxiety was assessed using the Children's Perioperative Multidimensional Anxiety Scale at T1 and T2. RESULTS: We found that temperamental shyness predicted lower preoperative anxiety at T1 (ß = -10.78; p = .03) and at T2 (ß = -12.31; p = .03). CONCLUSION: We speculate that temperamentally shy children although seemingly paradoxical, our findings suggest that temperamentally shy children may have developed coping strategies from dealing with persistent anxiety in their everyday environments, and they may use these coping skills in the surgical context. These findings are discussed in terms of their theoretical and practical implications for understanding person by context interactions and managing children's preoperative anxiety.

OBJECTIF: Nous avons examiné la relation entre le tempérament et l'anxiété préopératoire chez 40 enfants (de 8 à 13 ans) qui allaient subir une chirurgie élective une semaine avant l'opération, Temps 1 (T1), et le jour de l'opération Temps 2 (T2). MÉTHODE: La timidité caractérielle des enfants a été examinée à l'aide de l'inventaire du tempérament des enfants du Colorado au T1, et l'anxiété préopératoire a été évaluée à l'aide de l'échelle d'anxiété multidimensionnelle périopératoire des enfants aux T1 et T2. RÉSULTATS: Nous avons constaté que la timidité caractérielle prédisait une anxiété préopératoire plus faible au T1 (ß = −10,78; p = 0,03) et au T2 (ß = −12,31; p = 0.03). CONCLUSION: Nous déduisons que les enfants caractériellement timides peuvent avoir développé des stratégies d'adaptation du fait de vivre avec une anxiété persistante dans leur environnement quotidien, et qu'ils peuvent utiliser ces habiletés d'adaptation dans le contexte chirurgical. Ces résultats sont discutés sous l'angle de leurs implications théoriques et pratiques pour comprendre la personne par les interactions contextuelles et prendre en charge l'anxiété préopératoire des enfants.

Tablet-Based Intervention for Reducing Children's Preoperative Anxiety: A Pilot Study.

OBJECTIVES: To examine the feasibility, acceptability, and effects of a novel tablet-based application, Story-Telling Medicine (STM), in reducing children's preoperative anxiety. METHODS: Children (N = 100) aged 7 to 13 years who were undergoing outpatient surgery were recruited from a local children's hospital. This study comprised 3 waves: Waves 1 (n = 30) and 2 (n = 30) examined feasibility, and Wave 3 (n = 40) examined the acceptability of STM and compared its effect on preoperative anxiety to Usual Care (UC). In Wave 3, children were randomly allocated to receive STM+UC or UC. A change in preoperative anxiety was measured using the Children's Perioperative Multidimensional Anxiety Scale (CPMAS) 7 to 14 days before surgery (T1), on the day of surgery (T2), and 1 month postoperatively (T3). RESULTS: Wave 1 demonstrated the feasibility of participant recruitment and data collection procedures but identified challenges with attrition at T2 and T3. Wave 2 piloted a modified protocol that addressed attrition and increased the feasibility of follow-up. In Wave 3, children in the STM+UC demonstrated greater reductions in CPMAS compared with the UC group (ΔM = 119.90, SE = 46.36, t(27) = 2.59, p = .015; 95% confidence interval = 24.78-215.02). CONCLUSION: This pilot study provides preliminary evidence that STM is a feasible and acceptable intervention for reducing children's preoperative anxiety in a busy pediatric operative setting and supports the investigation of a full-scale randomized controlled trial.

Associations Between Childhood Cognition and Cardiovascular Events in Adulthood: A Systematic Review and Meta-analysis.

BACKGROUND: The success of behavioural interventions to optimize cardiovascular health is dependent on adequate cognitive functioning beginning in early life. In this study we aimed to systematically review studies that examined associations between childhood cognition and cardiovascular disease (CVD) events in adulthood. METHODS: This study followed the Meta-analysis Of Observational Studies in Epidemiology guidelines to systematically examine associations between childhood cognition and adult CVD, coronary heart disease, and stroke hospitalization or mortality events. Literature was retrieved from EMBASE, MEDLINE, PsycInfo, and CINAHL. RESULTS: Five longitudinal studies that examined links between childhood cognition and CVD in adulthood were included. Pooled estimates of unadjusted CVD events indicated a relative risk of 1.23 (95% confidence interval, 1.12-1.34) per standard deviation decrease in childhood IQ, whereas the pooled estimate adjusted for biopsychosocial confounding factors indicated an overall relative risk of 1.16 (95% confidence interval, 1.07-1.26). CONCLUSIONS: Lower childhood IQ is associated with an increased risk of cardiovascular events in adulthood, even after adjustment for confounding variables. Future research should examine the behavioural mechanisms by which these risks are mediated to optimize cardiovascular health.

Mental health of extremely low birth weight survivors: A systematic review and meta-analysis.

Although individuals born at extremely low birth weight (ELBW; < 1,000 g) are the most vulnerable of all preterm survivors, their risk for mental health problems across the life span has not been systematically reviewed. The primary objective of this systematic review and meta-analysis was to ascertain whether the risk for mental health problems is greater for ELBW survivors than their normal birth weight (NBW) peers in childhood, adolescence, and adulthood. Forty-one studies assessing 2,712 ELBW children, adolescents, and adults and 11,127 NBW controls were reviewed. Group differences in mental health outcomes were assessed using random effects meta-analyses. The impacts of birthplace, birth era, and neurosensory impairment on mental health outcomes were assessed in subgroup analyses. Children born at ELBW were reported by parents and teachers to be at significantly greater risk than NBW controls for inattention and hyperactivity, internalizing, and externalizing symptoms. ELBW children were also at greater risk for conduct and oppositional disorders, autistic symptoms, and social difficulties. Risks for parent-reported inattention and hyperactivity, internalizing, and social problems were greater in adolescents born at ELBW. In contrast, ELBW teens self-reported lower inattention, hyperactivity, and oppositional behavior levels than their NBW peers. Depression, anxiety, and social difficulties were elevated in ELBW survivors in adulthood. Group differences were robust to region of birth, era of birth, and the presence of neurosensory impairments. The complex needs faced by children born at ELBW continue throughout development, with long-term consequences for psychological and social well-being. (PsycINFO Database Record

Children's Perioperative Multidimensional Anxiety Scale (CPMAS): Development and validation.

Up to 5 million children are affected by perioperative anxiety in North America each year. High perioperative anxiety is predictive of numerous adverse emotional and behavioral outcomes in youth. We developed the Children's Perioperative Multidimensional Anxiety Scale (CPMAS) to address the need for a simple, age-appropriate self-report measure of pediatric perioperative anxiety in busy hospital settings. The CPMAS is a visual analog scale composed of 5 items, each of which is scored from 0-100. The objective of this study was to assess the psychometric properties of the CPMAS in children undergoing surgery. Eighty children aged 7 to 13 years who were undergoing elective surgery at a university-affiliated children's hospital were recruited. Children self-completed the CPMAS and the Screen for Childhood Anxiety Related Disorders (SCARED-C) at 3 time points: at preoperative assessment (T1), on the day of the operation (T2), and 1 month postoperatively (T3). Internal consistency, test-retest reliability, and the convergent validity of the CPMAS were assessed across all 3 visits. The CPMAS demonstrated good internal consistency (Cronbach's alpha ≥ .80) and stability (ICC = 0.71) across all 3 visits. CPMAS scores were moderately correlated with total SCARED-C scores (r values = .35 to .54, p values < .05 to .01) and SCARED-C state-related anxiety scores (r values = .29 to .71, p values < .05 to .01) at all 3 time points, suggesting the CPMAS and SCARED-C measures tap similar but not identical phenomena. These results suggest that the CPMAS has the potential to be a useful tool for evaluating perioperative anxiety in children undergoing surgery. (PsycINFO Database Record

Differential effects of low versus high amounts of weight supported treadmill training in spinally transected rats.

Intensive weight-supported treadmill training (WSTT) improves locomotor function following spinal cord injury. Because of a number of factors, undergoing intensive sessions of training may not be feasible. Whether reduced amounts of training are sufficient to enhance spinal plasticity to a level that is necessary for improving function is not known. The focus of the present study was to assess differences in recovery of locomotor function and spinal plasticity as a function of the amount of steps taken during WSTT in a rodent model of spinal cord injury. Rats were spinally transected at 5 days of age. When they reached 28 days of age, a robotic system was used to implement a weight-supported treadmill training program of either 100 or 1000 steps/training session daily for 4 weeks. Antibodies for brain-derived neurotrophic factor (BDNF), TrkB, and the pre-synaptic marker, synaptophysin, were used to examine the expression of these proteins in the ventral horn of the lumbar spinal cord. Rats that received weight-supported treadmill training performed better stepping relative to untrained rats, but only the rats that received 1000 steps/training session recovered locomotor function that resembled normal patterns. Only the rats that received 1000 steps/training session recovered normal levels of synaptophysin immunoreactivity around motor neurons. Weight-supported treadmill training consisting of either 100 or 1000 steps/training session increased BDNF immunoreactivity in the ventral horn of the lumbar spinal cord. TrkB expression in the ventral horn was not affected by spinal cord transection or weight-supported treadmill training. Synaptophysin expression, but not BDNF or TrkB expression was correlated with the recovery of stepping function. These findings suggested that a large amount of weight-supported treadmill training was necessary for restoring synaptic connections to motor neurons within the locomotor generating circuitry. Although a large amount of training was best for recovery, small amounts of training were associated with incremental gains in function and increased BDNF levels.