The cortical and subcortical substrates of quality of life through substrates of self-awareness and executive functions, in chronic moderate-to-severe TBI.

BACKGROUND: Moderate-to-severe traumatic brain injury (TBI) follows a chronic neuro-psychological sequelae, interfering with quality of life (QOL). OBJECTIVE: To investigate the chronic effects of moderate-to-severe TBI as expressed by greater atrophy in specific regions-of-interest relating to executive functions (EF) and self-awareness (SA); and whether this atrophy reflects on EF, SA deficits and QOL. METHODS: Thirty-one males with chronic moderate-to-severe TBI, aged 18-51, were compared to 24 non-injured males (age range = 21-49), matched on age and education. EF was assessed through a composite score. SA and QOL were assessed using generic and TBI-specific measures. Online masks were applied on magnetic resonance images to extract EF and SA - related regions-of-interest. RESULTS: Findings revealed that participants with TBI presented with less volume in fronto-temporal cortical and subcortical regions, than controls. An interrelation between EF and SA - related regions was revealed. Participants with TBI scored lower on neuropsychosocial measures, than controls. Differences in EF and SA were reflected on the related regions-of-interest. Satisfaction with QOL was predicted by these regions-of-interest. CONCLUSION: Chronic TBI effects on brain volume extend on EF, SA, and QOL; highlighting the role of SA between EF and QOL, and the need for personalized interventions in improving recovery outcome.

Whole brain and corpus callosum diffusion tensor metrics: How do they correlate with visual and verbal memory performance in chronic traumatic brain injury.

This research investigates the chronic effect of moderate to severe traumatic brain injury on brain white matter integrity, as reflected by diffusion tensor imaging metrics, and the assessment of their correlation to neuropsychological response. Thirteen male participants with traumatic brain injury (8.4 years average post-injury time) were compared to a matched group of neurologically healthy controls. None of the traumatic brain injury subjects had received post-acute neurocognitive and/or neuropsychological rehabilitation. Between-group comparison of fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity was performed for the whole brain and corpus callosum. An extensive battery of visual and verbal memory tasks was employed for the comparative assessment of neurocognitive performance. Between-group and within-group performance differences were correlated with fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity of corpus callosum. Significant changes in global fractional anisotropy, mean diffusivity, and radial diffusivity were associated with traumatic brain injury. Visual memory capacity was reduced in traumatic brain injury, and this deficit was correlated to white matter integrity loss at the corpus callosum. Participants with traumatic brain injury underperformed controls in verbal memory as well, but no correlation with corpus callosum diffusion tensor imaging properties was established. Between-group performance difference was correlated with corpus callosum diffusion metrics in several tasks. Significant correlations were found between corpus callosum diffusion tensor imaging metrics and neuropsychological response within the traumatic brain injury group. Changes in whole brain and corpus callosum diffusion tensor metrics inflicted by moderate to severe traumatic brain injury are still evident several years post-injury and relate to neurocognitive impairment, while loss of white matter integrity seems to correlate with episodic and working memory impairment.

The Association Between Brain Reserve, Cognitive Reserve, and Neuropsychological and Functional Outcomes in Males With Chronic Moderate-to-Severe Traumatic Brain Injury.

Purpose Moderate-to-severe traumatic brain injury (TBI) leads to significant neural and cognitive impairment, affecting functional outcome. This study investigated the chronic effects of moderate-to-severe TBI on brain reserve (BR), cognitive reserve (CR), and neuropsychological and functional outcome. Method The group with TBI consisted of 41 male participants with a primary diagnosis of moderate-to-severe closed head injury (time since injury [TSI], M = 6.12 years, range: 1-23, SD = 5.99, Mdn = 4). TBI survivors were compared to 24 neurotypical male participants, matched on age and education. Magnetic resonance imaging T1 anatomical images were used to calculate gray and white matter and cerebrospinal fluid volume. BR was calculated using the ventricle-to-brain ratio. CR was assessed using two hold measures: the Peabody Picture Vocabulary Test and the Pseudowords task. Functional outcome was measured using the Glasgow Outcome Scale-Extended. Results Neuropsychological performance of TBI survivors was significantly lower than their neurotypical controls, as measured by theoretically driven composites of verbal and visual memory, executive functions, attention, and CR. They presented greater ventricle-to-brain ratio volume, compared to noninjured controls, with higher scores indicating lower BR levels. Both BR and TSI were significantly associated with CR. Also, a median-split analysis revealed a TSI effect on CR. Significant associations were evident between the Glasgow Outcome Scale-Extended and the BR and CR measures. Conclusions Lingering neuropsychological deficits in chronic TBI support the role of BR and CR in functional outcome. Furthermore, TSI interferes with CR supporting the notion that TBI sets off a chronic neurodegenerative and progressive course that interferes with semantic knowledge. Supplemental Material https://doi.org/10.23641/asha.14049923.

Regional Brain Volume, Brain Reserve and MMSE Performance in Healthy Aging From the NEUROAGE Cohort: Contributions of Sex, Education, and Depression Symptoms.

Objective: The aim of this study was twofold. First, to investigate the relationship between age, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) volumes, brain reserve (BR), and specific regions of interest (ROIs) with global cognitive function in healthy older adults participating in a longitudinal study on aging in the island country of Cyprus. Second, to assess the contribution of important demographic and psychosocial factors on brain volume. Specifically, the effects of sex and years of education and the association between depression symptoms on brain volume were also explored in this Mediterranean cohort. Methods: Eighty-seven healthy older adults (males = 37, females = 50) scoring ≥24 on the Mini-Mental State Examination (MMSE) were included, with a mean age of 72.75 years and a mean educational level of 10.48 years. The Geriatric Depression Scale was used to assess depression. T1-weighted magnetic resonance images were used to calculate global and regional volumes. Results: Age was negatively correlated with GM, WM, BR, MMSE scores, and ROIs, including the hippocampus, amygdala, entorhinal cortex, prefrontal cortex, anterior cingulate gyrus, and positively with CSF. Higher MMSE scores positively correlated with GM volume. Women exhibited greater levels of depression than men. Depression was also negatively correlated with GM volume and MMSE scores. Men had greater ventricular size than women and participants with higher education had greater ventricular expansion than those with fewer years in education. Conclusions: The reported structural changes provide evidence on the overlap between age-related brain changes and healthy cognitive aging and suggest that these age changes affect certain regions. Furthermore, sex, depressive symptomatology, and education are significant predictors of the aging brain. Brain reserve and higher education accommodate these changes and works against the development of clinical symptoms.

Executive functions, self-awareness and quality of life in chronic moderate-to-severe TBI.

BACKGROUND: Moderate-to-severe traumatic brain injury (TBI) leads to significant neuropsychological impairment, further affecting quality of life (QOL). OBJECTIVE: Investigate the effects of chronic moderate-to-severe TBI on Executive Functions (EF), Self-awareness (SA), QOL, and the associations between them. METHODS: 33 males with moderate-to-severe TBI (ages 18-51; time since injury 1-19 years) were compared to 24 non-injured males, matched on age and education. EF measures included the Rey Complex Figure Test (copy), the Trail Making Test A & B, the Symbol Digits Modalities Test, and the Control Oral Word Association Test. SA was assessed using the Dysexecutive Questionnaire Revised, and the Self-Regulation Skills Interview. QOL and health-realted QOL were assessed using the WHOQOL-BREF and the QOL after Brain Injury, respectively. RESULTS: TBI participants scored lower on EF, and SA, reported less satisfaction regarding physical health and greater satisfaction with environmental support, than controls. TBI survivors scoring lower on EF, exhibited lower SA. Lower SA correlated with greater satisfaction regarding cognitive skills, self-perception, and overall HRQOL. Lower EF performance correlated with greater satisfaction in social relationships. CONCLUSIONS: The long-term effects of TBI on EF, SA and QOL seem to support the role of EF and SA on QOL, and therefore, the need for personalized interventions in improving recovery outcome.

Altered Resting Functional Connectivity Is Related to Cognitive Outcome in Males With Moderate-Severe Traumatic Brain Injury.

TBI results in significant cognitive impairments and in altered brain functional connectivity. However, no studies explored so far, the relationship between global functional connectivity and cognitive outcome in chronic moderate-severe TBI. This proof of principle study employed the intrinsic connectivity contrast, an objective voxel-based metric of global functional connectivity, in a small sample of chronic moderate-severe TBI participants and a group of healthy controls matched on gender (males), age, and education. Cognitive tests assessing executive functions, verbal memory, visual memory, attention/organization, and cognitive reserve were administered. Group differences in terms of global functional connectivity maps were assessed and the association between performance on the cognitive measures and global functional connectivity was examined. Next, we investigated the spatial extent of functional connectivity in the brain regions found to be associated with cognitive performance, using traditional seed-based analyses. Global functional connectivity of the TBI group was altered, compared to the controls. Moreover, the strength of global functional connectivity in affected brain areas was associated with cognitive outcome. These findings indicate that impaired global functional connectivity is a significant consequence of TBI suggesting that cognitive impairments following TBI may be partly attributed to altered functional connectivity between brain areas involved in the specific cognitive functions.

Assessing the Relationship between Neurocognitive Performance and Brain Volume in Chronic Moderate-Severe Traumatic Brain Injury.

OBJECTIVES: Characterize the scale and pattern of long-term atrophy in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in chronic moderate-severe traumatic brain injury (TBI) and its relationship to neurocognitive outcomes. PARTICIPANTS: The TBI group consisted of 17 males with primary diagnosis of moderate-severe closed head injury. Participants had not received any systematic, post-acute rehabilitation and were recruited on average 8.36 years post-injury. The control group consisted of 15 males matched on age and education. MAIN MEASURES: Neurocognitive battery included widely used tests of verbal memory, visual memory, executive functioning, and attention/organization. GM, WM, and CSF volumes were calculated from segmented T1-weighted anatomical MR images. Voxel-based morphometry was employed to identify brain regions with differences in GM and WM between TBI and control groups. RESULTS: Chronic TBI results in significant neurocognitive impairments, and significant loss of GM and WM volume, and significant increase in CSF volume. Brain atrophy is not widespread, but it is rather distributed in a fronto-thalamic network. The extent of volume loss is predictive of performance on the neurocognitive tests. CONCLUSION: Significant brain atrophy and associated neurocognitive impairments during the chronic stages of TBI support the notion that TBI results in a chronic condition with lifelong implications.