Dynamic association between perfusion and white matter integrity across time since injury in Veterans with history of TBI.

ObjectiveCerebral blood flow (CBF) plays a critical role in the maintenance of neuronal integrity, and CBF alterations have been linked to deleterious white matter changes. Although both CBF and white matter microstructural alterations have been observed within the context of traumatic brain injury (TBI), the degree to which these pathological changes relate to one another and whether this association is altered by time since injury have not been examined. The current study therefore sought to clarify associations between resting CBF and white matter microstructure post-TBI.Methods37 veterans with history of mild or moderate TBI (mmTBI) underwent neuroimaging and completed health and psychiatric symptom questionnaires. Resting CBF was measured with multiphase pseudocontinuous arterial spin labeling (MPPCASL), and white matter microstructural integrity was measured with diffusion tensor imaging (DTI). The cingulate cortex and cingulum bundle were selected as a priori regions of interest for the ASL and DTI data, respectively, given the known vulnerability of these regions to TBI.ResultsRegression analyses controlling for age, sex, and posttraumatic stress disorder (PTSD) symptoms revealed a significant time since injury × resting CBF interaction for the left cingulum (p < 0.005). Decreased CBF was significantly associated with reduced cingulum fractional anisotropy (FA) in the chronic phase; however, no such association was observed for participants with less remote TBI.ConclusionsOur results showed that reduced CBF was associated with poorer white matter integrity in those who were further removed from their brain injury. Findings provide preliminary evidence of a possible dynamic association between CBF and white matter microstructure that warrants additional consideration within the context of the negative long-term clinical outcomes frequently observed in those with history of TBI. Additional cross-disciplinary studies integrating multiple imaging modalities (e.g., DTI, ASL) and refined neuropsychiatric assessment are needed to better understand the nature, temporal course, and dynamic association between brain changes and clinical outcomes post-injury

Blast-Exposed Veterans With Mild Traumatic Brain Injury Show Greater Frontal Cortical Thinning and Poorer Executive Functioning

Objective: Blast exposure (BE) and mild traumatic brain injury (mTBI) have been independently linked to pathological brain changes. However, the combined effects of BE and mTBI on brain structure have yet to be characterized. Therefore, we investigated whether regional differences in cortical thickness exist between mTBI Veterans with and without BE while on deployment. We also examined whether cortical thickness (CT) and cognitive performance differed among mTBI Veterans with low vs. high levels of cumulative BE.Methods: 80 Veterans with mTBI underwent neuroimaging and completed neuropsychological testing and self-report symptom rating scales. Analyses of covariance (ANCOVA) were used to compare blast-exposed Veterans (mTBI+BE, n = 51) to those without BE (mTBI-BE, n = 29) on CT of frontal and temporal a priori regions of interest (ROIs). Next, multiple regression analyses were used to examine whether CT and performance on an executive functions composite differed among mTBI Veterans with low (mTBI+BE Low, n = 22) vs. high (mTBI+BE High, n = 26) levels of cumulative BE.Results: Adjusting for age, numer of TBIs, and PTSD symptoms, the mTBI+BE group showed significant cortical thinning in frontal regions (i.e., left orbitofrontal cortex [p = 0.045], left middle frontal gyrus [p = 0.023], and right inferior frontal gyrus [p = 0.034]) compared to the mTBI-BE group. No significant group differences in CT were observed for temporal regions (p's > 0.05). Multiple regression analyses revealed a significant cumulative BE × CT interaction for the left orbitofrontal cortex (p = 0.001) and left middle frontal gyrus (p = 0.020); reduced CT was associated with worse cognitive performance in the mTBI+BE High group but not the mTBI+BE Low group.Conclusions: Findings show that Veterans with mTBI and BE may be at risk for cortical thinning post-deployment. Moreover, our results demonstrate that reductions in CT are associated with worse executive functioning among Veterans with high levels of cumulative BE. Future longitudinal studies are needed to determine whether BE exacerbates mTBI-related cortical thinning or independently negatively influences gray matter structure

Executive Functioning in Participants Over Age of 50 with Hoarding Disorder.

ObjectivesThe current investigation utilized mid-life and late-life participants diagnosed with hoarding disorder (HD) to explore the relationship between executive functioning and hoarding severity.DesignCorrelational analyses were used to investigate the associations between executive functioning and hoarding severity in nondemented participants. Multiple regression was used to determine if executive functioning had a unique association with HD severity when accounting for depressive symptoms.SettingParticipants were recruited from the San Diego area for HD intervention studies.ParticipantsParticipants were 113 nondemented adults aged 50-86 years who met DSM-5 criteria for HD. The mean age of the sample utilized in the analyses was 63.76 years (SD, 7.2; range, 51-85 years). The sample was mostly female (72%), Caucasian (81.4%), and unmarried (78%).MeasurementsHoarding severity was assessed using the Saving Inventory-Revised and the Clutter Image Rating and depression was assessed using the Hospital Anxiety and Depression Scale. Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST-128) and the Trail Making and Verbal Fluency subtests of the Delis-Kaplan Executive Function System.ResultsExecutive function (operationalized as perseveration on the WCST-128) was significantly associated with Clutter Image Ratings. In a multivariate context, executive function and depressive symptom severity were both significant predictors of variance in Clutter Image Rating.ConclusionsOur results suggest that executive function is related to severity of HD symptoms and should be considered as part of the conceptualization of HD

Executive Functioning in Participants Over Age of 50 with Hoarding Disorder.

ObjectivesThe current investigation utilized mid-life and late-life participants diagnosed with hoarding disorder (HD) to explore the relationship between executive functioning and hoarding severity.DesignCorrelational analyses were used to investigate the associations between executive functioning and hoarding severity in nondemented participants. Multiple regression was used to determine if executive functioning had a unique association with HD severity when accounting for depressive symptoms.SettingParticipants were recruited from the San Diego area for HD intervention studies.ParticipantsParticipants were 113 nondemented adults aged 50-86 years who met DSM-5 criteria for HD. The mean age of the sample utilized in the analyses was 63.76 years (SD, 7.2; range, 51-85 years). The sample was mostly female (72%), Caucasian (81.4%), and unmarried (78%).MeasurementsHoarding severity was assessed using the Saving Inventory-Revised and the Clutter Image Rating and depression was assessed using the Hospital Anxiety and Depression Scale. Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST-128) and the Trail Making and Verbal Fluency subtests of the Delis-Kaplan Executive Function System.ResultsExecutive function (operationalized as perseveration on the WCST-128) was significantly associated with Clutter Image Ratings. In a multivariate context, executive function and depressive symptom severity were both significant predictors of variance in Clutter Image Rating.ConclusionsOur results suggest that executive function is related to severity of HD symptoms and should be considered as part of the conceptualization of HD

Delineation of Apathy Subgroups in Parkinson's Disease: Differences in Clinical Presentation, Functional Ability, Health-related Quality of Life, and Caregiver Burden.

BackgroundApathy is a prevalent, multidimensional neuropsychiatric condition in Parkinson's disease (PD). Several authors have proposed apathy subtypes in PD, but no study has examined the classification of PD patients into distinct apathy subtypes, nor has any study examined the clinical utility of doing so.ObjectivesThe current study used a data-driven approach to explore the existence and associated clinical characteristics of apathy subtypes in PD.MethodThe Apathy Scale (AS) was administered to 157 non-demented individuals with PD. Participants were classified into apathy subgroups through cluster analysis. Differences among apathy subtypes on external clinical indicators were explored across apathy subgroups.ResultsIndividuals with PD were classified into three subgroups: a Non-Apathetic group with low levels of apathy symptoms, a Low Interest/Energy group, characterized by elevated symptoms of low interest/energy and minimal low initiation/emotional indifference symptoms, and a Low Initiation group, characterized by an absence of low interest/energy symptoms and elevated levels of low initiation/emotional indifference symptoms. Both Low Interest/Energy and Low Initiation groups exhibited worse depression, fatigue, anxiety, health-related quality of life, and caregiver burden than the Non-Apathetic subgroup. The Low Initiation group exhibited worse overall cognition, emotional well-being, state anxiety, communicative ability, and functional ability than the Low Interest/Energy group. Importantly, disease-related characteristics did not differ across apathy symptom subgroups.ConclusionsNon-demented PD patients can be separated into distinct apathy symptom subgroups, which are differentially associated with important clinical variables. Apathy subgroup membership may reflect disruption to different neural systems independent of disease progression

Factor Analysis of the Apathy Scale in Parkinson's Disease.

BackgroundThe Apathy Scale (AS), a popular measure of apathy in Parkinson's disease (PD), has been somewhat limited for failing to characterize dimensions of apathy, such as those involving cognitive, behavioral, and emotional apathy symptoms. This study sought to determine whether factors consistent with these apathy dimensions in PD could be identified on the AS, examine the associations between these factors and disease-related characteristics, and compare PD patients and healthy control (HCs) on identified factors.MethodsConfirmatory (CFA) and exploratory factor analysis (EFA) were conducted on AS scores of 157 nondemented PD patients to identify AS factors. These factors were then correlated with important disease-related characteristics, and PD and HC participants were compared across these factors.ResultsPreviously proposed AS models failed to achieve an adequate fit in CFA. A subsequent EFA revealed two factors on the AS reflecting joint cognitive-behavioral aspects of apathy (Motivation-Interest-Energy) and emotional apathy symptoms (Indifference). Both factors were associated with anxiety, depression, health-related quality of life, and independent activities of daily living, with Indifference associated more with the latter. In addition, only the Indifference factor was associated with cognitive functioning. PD patients reported higher levels of symptoms than HCs on both factors, with the group difference slightly larger on the Motivation-Interest-Energy factor.ConclusionThe AS can be decomposed into two factors reflecting Motivation-Interest-Energy and Indifference symptoms. These factors are differentially associated with clinical variables, including cognition and independent activities of daily living, indicating the importance of evaluating apathy from a multidimensional perspective

Evaluation of a hybrid treatment for Veterans with comorbid traumatic brain injury and posttraumatic stress disorder: Study protocol for a randomized controlled trial.

Comorbidity of posttraumatic stress disorder (PTSD) and history of traumatic brain injury (TBI) is high among Veterans of Operation Iraqi Freedom/Enduring Freedom/New Dawn (OIF/OEF/OND). Cognitive processing therapy (CPT) is empirically supported for the treatment of PTSD, but it is not specifically designed to accommodate the memory, attention, or problem solving deficits that are experienced by many Veterans with comorbid PTSD and TBI. Compensatory cognitive rehabilitation, including cognitive symptom management and rehabilitation therapy (CogSMART), is effective for cognitive deficits stemming from a variety of etiologies, including TBI. We have integrated components of CogSMART into CPT in order to address the unique challenges faced by Veterans with ongoing cognitive complaints related to PTSD and a history of mild TBI. Here we describe an ongoing randomized controlled trial investigating the efficacy of our novel hybrid treatment, SMART-CPT, as compared to standard CPT, for OIF/OEF/OND Veterans with PTSD and a history of mild to moderate TBI. We describe the development of this hybrid treatment as well as implementation of the randomized controlled trial