Quantifying and Examining Reserve in Symptomatic Former National Football League Players.

BACKGROUND: Repetitive head impacts (RHI) from contact sports have been associated with cognitive and neuropsychiatric disorders. However, not all individuals exposed to RHI develop such disorders. This may be explained by the reserve hypothesis. It remains unclear if the reserve hypothesis accounts for the heterogenous symptom presentation in RHI-exposed individuals. Moreover, optimal measurement of reserve in this population is unclear and likely unique from non-athlete populations. OBJECTIVE: We examined the association between metrics of reserve and cognitive and neuropsychiatric functioning in 89 symptomatic former National Football League players. METHODS: Individual-level proxies (e.g., education) defined reserve. We additionally quantified reserve as remaining residual variance in 1) episodic memory and 2) executive functioning performance, after accounting for demographics and brain pathology. Associations between reserve metrics and cognitive and neuropsychiatric functioning were examined. RESULTS: Higher reading ability was associated with better attention/information processing (ß=0.25; 95% CI, 0.05-0.46), episodic memory (ß=0.27; 95% CI, 0.06-0.48), semantic and phonemic fluency (ß=0.24; 95% CI, 0.02-0.46; ß=0.38; 95% CI, 0.17-0.59), and behavioral regulation (ß=-0.26; 95% CI, -0.48, -0.03) performance. There were no effects for other individual-level proxies. Residual episodic memory variance was associated with better attention/information processing (ß=0.45; 95% CI, 0.25, 0.65), executive functioning (ß=0.36; 95% CI, 0.15, 0.57), and semantic fluency (ß=0.38; 95% CI, 0.17, 0.59) performance. Residual executive functioning variance was associated with better attention/information processing (ß=0.44; 95% CI, 0.24, 0.64) and episodic memory (ß=0.37; 95% CI, 0.16, 0.58) performance. CONCLUSION: Traditional reserve proxies (e.g., years of education, occupational attainment) have limitations and may be unsuitable for use in elite athlete samples. Alternative approaches of reserve quantification may prove more suitable for this population.

Systematic review of depression in mild traumatic brain injury: study protocol.

BACKGROUND: Of the over 1 million reported cases of traumatic brain injuries reported annually in the USA, a sizeable proportion are characterized as mild. Although it is generally well-accepted that most people who suffer a mild traumatic brain injury recover within 1 to 3 months, a proportion of individuals continue to experience physiological, psychological, and emotional symptoms beyond the expected window of recovery. Depression is commonly reported following mild traumatic brain injury; however, its course, consequences, and prognostic factors remain to be well understood. METHODS: A systematic review will be conducted of available prospective longitudinal studies of adult mild traumatic brain injury-related depression. The aim of the systematic review is to describe the course of mild traumatic brain injury-related depression, along with its prognostic factors and health consequences. The review will comply with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A thorough database search of peer-reviewed publications in English and French will be conducted in PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Embase, Scopus, Erudit, and Cairn. Independent investigators will perform study selection and data extraction. Risk of bias will be assessed using the Quality in Prognosis Studies tool, and methodological quality will be evaluated using a system inspired by the Scottish Intercollegiate Guidelines Network Methodology. Results will be presented through qualitative description and tabulation. DISCUSSION: This will be the first systematic review conducted with the aim of describing the course, prognostic factors, and health-related outcomes of depression in adults who have suffered a mild traumatic brain injury. The findings of the planned systematic review have the potential to guide research and clinical practice to effectively develop and implement evidence-based interventions aimed at preventing and alleviating mild traumatic brain injury-related depression. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015019214.

Comparative evaluation of group-based mindfulness-based stress reduction and cognitive behavioral therapy for the treatment and management of chronic pain disorders: protocol for a systematic review and meta-analysis with indirect comparisons.

BACKGROUND: Chronic pain disorders impact the physical, psychological, social, and financial well-being of between 10%-30% of Canadians. The primary aims of psychological interventions targeting chronic pain disorders are to reduce patients' pain-related disability and to improve their quality of life. Cognitive behavioral therapy (CBT) is the prevailing treatment for chronic pain, however mindfulness-based stress reduction (MBSR) has displayed promise as an alternative treatment option. The objective of this systematic review and meta-analysis is to compare MBSR to CBT in their relative ability to reduce pain-related disability and intensity, to alleviate emotional distress, and to improve global functioning in chronic pain patients. METHODS/DESIGN: We will conduct a systematic review with meta-analyses to compare MBSR to CBT in the treatment of chronic pain disorders in adults. We will report our review according to the recommendations provided by the PRISMA statement. Randomized studies will be included and the literature search will comprise Ovid MEDLINE®, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, Embase Classic+Embase, PsycINFO, the Cochrane Library on Wiley, including CENTRAL, Cochrane Database of Systematic Reviews, DARE, and HTA. Study selection and data extraction will be conducted by independent investigators and in duplicate. Outcomes of interest will include pain interference, pain intensity, emotional functioning, and patient global impression of change. The Cochrane risk of bias tool will be used to assess risk of bias of included studies. As we anticipate that scales used to measure participant responses will be related but varied from study to study, standardized mean differences will be used to compare effect sizes between treatment modalities. Given the possibility of little or no head-to-head evidence comparing MBSR with CBT, we will use indirect treatment comparison methodology to assess the relative effectiveness of these interventions. DISCUSSION: The findings from this study will assist patients and treatment providers to make informed decisions regarding evidence-based treatment selection for chronic pain disorders. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42014009356.

A prospective study of grey matter and cognitive function alterations in chemotherapy-treated breast cancer patients.

PURPOSE: Subsequent to chemotherapy treatment, breast cancer patients often report a decline in cognitive functioning that can adversely impact many aspects of their lives. Evidence has mounted in recent years indicating that a portion of breast cancer survivors who have undergone chemotherapy display reduced performance on objective measures of cognitive functioning relative to comparison groups. Neurophysiological support for chemotherapy-related cognitive impairment has been accumulating due to an increase in neuroimaging studies in this field; however, longitudinal studies are limited and have not examined the relationship between structural grey matter alterations and neuropsychological performance. The aim of this study was to extend the cancer-cognition literature by investigating the association between grey matter attenuation and objectively measured cognitive functioning in chemotherapy-treated breast cancer patients. METHODS: Female breast cancer patients (n = 19) underwent magnetic resonance imaging after surgery but before commencing chemotherapy, one month following treatment, and one year after treatment completion. Individually matched controls (n = 19) underwent imaging at similar intervals. All participants underwent a comprehensive neuropsychological battery comprising four cognitive domains at these same time points. Longitudinal grey matter changes were investigated using voxel-based morphometry. RESULTS: One month following chemotherapy, patients had distributed grey matter volume reductions. One year after treatment, a partial recovery was observed with alterations persisting predominantly in frontal and temporal regions. This course was not observed in the healthy comparison group. Processing speed followed a similar trajectory within the patient group, with poorest scores obtained one month following treatment and some improvement evident one year post-treatment. CONCLUSION: This study provides further credence to patient claims of altered cognitive functioning subsequent to chemotherapy treatment.