A randomized double-blind placebo-controlled trial of the effectiveness of melatonin on neurocognition and sleep in survivors of childhood cancer.

BACKGROUND: Adult survivors of childhood cancer are at risk of developing sleep and neurocognitive problems, yet few efficacious interventions exist targeting these prevalent late effects. Melatonin has known sleep-promoting effects; however, it has not been well studied among childhood cancer survivors. METHOD: Survivors (n = 580; mean age = 33.5 years; 26 years post-diagnosis) from the St. Jude Lifetime Cohort were randomized (1:1) to a six-month double-blind placebo-controlled trial of 3 mg time-release melatonin within three strata (stratum 1: neurocognitive impairment only; stratum 2: neurocognitive and sleep impairment; stratum 3: sleep impairment only). Neurocognitive performance was assessed at baseline and post-intervention using standardized measures. Sleep was assessed via self-report and actigraphy. Independent sample t tests compared mean change scores from baseline to six months. Post-hoc analyses compared the prevalence of clinically significant treatment responders among melatonin and placebo conditions within and across strata. RESULTS: Intent-to-treat analyses revealed no statistically significant differences in neurocognitive performance or sleep from baseline to post-intervention. However, among survivors with neurocognitive impairment only, a larger proportion randomized to melatonin versus placebo demonstrated a treatment response for visuomotor speed (63% vs 41%, P = 0.02) and nonverbal reasoning (46% vs 28%, P = 0.04). Among survivors with sleep impairment only, a larger proportion treated with melatonin demonstrated a treatment response for shifting attention (44% vs 28%, P = 0.05), short-term memory (39% vs 19%, P = 0.01), and actigraphy-assessed sleep duration (47% vs 29%, P = 0.05). CONCLUSION: Melatonin was not associated with improved neurocognitive performance or sleep in our intent-to-treat analyses; however, a subset of survivors demonstrated a clinically significant treatment response.

Predictors of health care utilization in adult survivors of childhood cancer exposed to central nervous system-directed therapy.

BACKGROUND: Survivors of childhood cancer treated with central nervous system (CNS)-directed therapy may be at risk for poor health care utilization because of neurocognitive deficits. This study examined associations between neurocognitive function and adherence to routine and risk-based medical evaluations in adult survivors exposed to CNS-directed therapy. METHODS: Neurocognitive function and health care utilization were assessed in 1304 adult survivors of childhood cancer enrolled in the St. Jude Lifetime Cohort Study. Adherence to recommended care was defined as meeting guidelines published by the Children's Oncology Group. Multivariate models were used to evaluate associations between neurocognitive function and health screenings. Established predictors of health care utilization were included as covariates. Odds ratios (ORs) or prevalence ratios (PRs) and 95% confidence intervals (CIs) were calculated for variables maintained in the final models. RESULTS: Adherence to recommended medical care was higher for routine care (general physician care, 57.6%; dental care, 49.1%) versus specialized care (survivor-focused care, 21.9%; echocardiogram, 19.9%). Higher intelligence was predictive of general physician care (OR, 1.74; 95% CI, 1.41-2.15) and survivor-focused care (OR, 1.44; 95% CI, 1.13-1.83) in comparison with no care, whereas better executive function skills were associated with reduced dental care (PR, 0.94; 95% CI, 0.91-0.98). Echocardiogram monitoring was not associated with neurocognition. Possible late effects of cancer treatment (pain and reduced cardiorespiratory fitness) were associated with an increased likelihood of receiving specialized medical care. CONCLUSIONS: Survivors with reduced global cognition are at risk for poor health care utilization. Educational practices regarding recommended health care should be personalized to ensure comprehension by survivors with neurocognitive impairment.

Conceptualizing functional cognition in traumatic brain injury rehabilitation.

PRIMARY OBJECTIVE: To conceptualize functional cognitive constructs across the continuum of traumatic brain injury (TBI) recovery, to form the foundation for the Computer Adaptive Measure of Functional Cognition for TBI (CAMFC-TBI). BACKGROUND: TBI often has a profound impact on a survivor's ability to return to previous level of functioning and significantly reduces the overall quality of life for survivors and caregivers. Few assessments are designed to evaluate TBI's impact on cognitive functioning in everyday life. Neuropsychological tests are time consuming and may have questionable ecological validity for predicting functional outcomes. Global functional assessments contain few cognitive items and may lack psychometric rigour. Presently there is a lack of efficient, precise, ecologically valid functional cognitive measures. MAIN OUTCOME AND RESULTS: Studies that used neuropsychological and global functional assessments were reviewed to direct conceptualization of functional cognitive constructs across TBI recovery stages. An advisory panel reviewed study methodology and functional cognitive constructs development. They validated the need for the CAMFC-TBI and the six functional cognitive constructs: attention, memory, processing speed, executive functioning, social communication and emotional management. CONCLUSION: Conceptualizing functional cognitive constructs is the first step in CAMFC-TBI development. Future project stages include item pool development, qualitative testing, field-testing, psychometric analysis and computerized adaptive test programming.

Decreased static and dynamic postural control in children with autism spectrum disorders.

The purpose of this study was to investigate postural control in children with Autism Spectrum Disorders (ASD) during static and dynamic postural challenges. We evaluated postural sway during quiet stance and the center of pressure (COP) shift mechanism during gait initiation for 13 children with ASD and 12 age-matched typically developing (TD) children. Children with ASD produced 438% greater normalized mediolateral sway (p<0.05) and 104% greater normalized anteroposterior sway (p<0.05) than TD children. Consequently, normalized sway area was also significantly greater (p<0.05) in the group with ASD. Similarly, the maximum separation between the COP and center of mass (COM) during quiet stance was 100% greater in the anteroposterior direction (p<0.05) and 146% greater in the resultant direction (p<0.05) for children with ASD. No significant difference was observed in the mediolateral direction, in spite of the 123% greater separation detected in children with ASD. During gait initiation, no group differences were detected in the posterior COP shift mechanism, suggesting the mechanism for generating forward momentum is intact. However, significantly smaller lateral COP shifts (p<0.05) were observed in children with ASD, suggesting instability or an alternative strategy for generating momentum in the mediolateral direction. These results help to clarify some discrepancies in the literature, suggesting an impaired or immature control of posture, even under the most basic conditions when no afferent or sensory information have been removed or modified. Additionally, these findings provide new insight into dynamic balance in children with ASD.