Robin E. Green

Deficits in facial emotion perception in adults with recent traumatic brain injury

UNLABELLED We examined whether facial emotion perception was compromised in adults with recent traumatic brain injury (TBI). Few studies have examined emotion perception in TBI; those that have, examined chronic patients only. Recent and chronic TBI populations differ according to degree of functional reorganization of the brain, use of compensatory strategies, and severity of cognitive impairments--any of which might differentially affect presentation of emotion perception deficits. A secondary aim of the study was to utilize the TBI population--in whom diffuse axonal injury (DAI) is a cardinal neurological feature--to examine the suggestion of Adolphs et al. [Journal of Neuroscience 20(7) (2000) 2683] that damage to white matter tracts should give rise to emotion perception deficits. METHODS Thirty TBI participants and 30 age-matched controls were tested. A 2 x 3 mixed design was employed. The dependent variable was accuracy on neutral and emotional face perception tests. RESULTS (1) The TBI group performed significantly less accurately than the matched controls on the facial emotion perception tasks, whereas the groups performed equivalently on a non-emotional face perception control task. (2) A sub-group of TBI participants without evidence of focal injury to areas of the brain most commonly implicated in facial emotion perception was as impaired on the emotion perception tasks as a second sub-group who had sustained focal lesions to these areas. This suggests an alternative neurological mechanism for deficits in the first sub-group, such as DAI. CONCLUSIONS Patients with recently acquired TBI are impaired in their ability to perceive emotions in faces. DAI alone may cause facial emotion perception deficits.

Influence of Continuous Positive Airway Pressure on Outcomes of Rehabilitation in Stroke Patients With Obstructive Sleep Apnea

Background and Purpose— In stroke patients, obstructive sleep apnea (OSA) is associated with poorer functional outcomes than in those without OSA. We hypothesized that treatment of OSA by continuous positive airway pressure (CPAP) in stroke patients would enhance motor, functional, and neurocognitive recovery. Methods— This was a randomized, open label, parallel group trial with blind assessment of outcomes performed in stroke patients with OSA in a stroke rehabilitation unit. Patients were assigned to standard rehabilitation alone (control group) or to CPAP (CPAP group). The primary outcomes were the Canadian Neurological scale, the 6-minute walk test distance, sustained attention response test, and the digit or spatial span-backward. Secondary outcomes included Epworth Sleepiness scale, Stanford Sleepiness scale, Functional Independence measure, Chedoke McMaster Stroke assessment, neurocognitive function, and Beck depression inventory. Tests were performed at baseline and 1 month later. Results— Patients assigned to CPAP (n=22) experienced no adverse events. Regarding primary outcomes, compared to the control group (n=22), the CPAP group experienced improvement in stroke-related impairment (Canadian Neurological scale score, P<0.001) but not in 6-minute walk test distance, sustained attention response test, or digit or spatial span-backward. Regarding secondary outcomes, the CPAP group experienced improvements in the Epworth Sleepiness scale (P<0.001), motor component of the Functional Independence measure (P=0.05), Chedoke-McMaster Stroke assessment of upper and lower limb motor recovery test of the leg (P=0.001), and the affective component of depression (P=0.006), but not neurocognitive function. Conclusions— Treatment of OSA by CPAP in stroke patients undergoing rehabilitation improved functional and motor, but not neurocognitive outcomes. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00221065.

Continuous-Flow Cell Saver Reduces Cognitive Decline in Elderly Patients After Coronary Bypass Surgery

Background— Cerebral microembolization during cardiopulmonary bypass may lead to cognitive decline after cardiac surgery. Transfusion of the unprocessed shed blood (major source of lipid microparticulates) into the patient during cardiopulmonary bypass is common practice to reduce blood loss and blood transfusion. Processing of shed blood with cell saver before transfusion may limit cerebral microembolization and reduce cognitive decline after surgery. Methods and Results— A total of 226 elderly patients were randomly allocated to either cell saver or control groups. Anesthesia and surgical management were standardized. Epiaortic scanning of the proximal thoracic aorta was performed in all patients. Transcranial Doppler was used to measure cerebral embolic rates. Standardized neuropsychological testing was conducted 1 week before and 6 weeks after surgery. The raw scores for each test were converted to Z scores, and then a combined Z score of 10 main variables was calculated for both study groups. The primary analysis was based on dichotomous composite cognitive outcome with a 1-SD rule. Cognitive dysfunction was present in 6% (95% confidence interval, 1.3% to 10.7%) of patients in the cell saver group and 15% (95% confidence interval, 8% to 22%) of patients in the control group 6 weeks after surgery (P=0.038). The severity of aortic atheroma and cerebral embolic count were similar between the 2 groups. Conclusions— The present report demonstrates that processing of shed blood with cell saver results in clinically significant reduction in postoperative cognitive dysfunction after cardiac surgery. These findings emphasize the clinical importance of lipid embolization in contributing to postoperative cognitive decline in patients exposed to cardiopulmonary bypass.

Long-term cognitive outcome in moderate to severe traumatic brain injury: a meta-analysis examining timed and untimed tests at 1 and 4.5 or more years after injury.

OBJECTIVES To examine long-term outcome of moderate to severe traumatic brain injury (TBI) on timed and untimed cognitive tests using meta-analysis. DESIGN Meta-analysis examining outcome at 2 epochs, 6 to 18 months postinjury (epoch 1) and 4.5 to 11 years postinjury (epoch 2). SETTING Data source was published articles (1966-2007) identified through electronic and manual search. PARTICIPANTS A total of 1380 subjects with moderate to severe TBI participated in the 16 studies meeting inclusion criteria. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Timed and untimed neuropsychologic tests with quantitative results (means, SDs, t, and df tests) from studies containing a healthy comparison group and a mean time since injury falling within 1 of the 2 epochs. RESULTS Patient versus control weighted effect sizes were medium to large at epoch 1 for both untimed tasks (r=-.46; confidence interval [CI], -.32 to -.65) and timed tasks (r=-.46; CI, -.35 to -.59). At epoch 2, effect sizes were slightly smaller for untimed tasks (r=-.38; CI, -.25 to -.60) and timed tasks (r=-.40; CI, -.32 to -.62). CONCLUSIONS Patients showed robust, persisting impairments on both timed and untimed tests at recovery plateau (ie, 6-18mo postinjury) and many years later. These findings converge with previous studies, though using an alternative approach that obviates some of the methodologic problems of longitudinal studies, such as selective attrition.

Measuring premorbid IQ in traumatic brain injury: An examination of the validity of the Wechsler Test of Adult Reading (WTAR)

Estimation of premorbid IQ in traumatic brain injury (TBI) is clinically and scientifically valuable because it permits the quantification of the cognitive impact of injury. This is achieved by comparing performances on tests of current ability to estimates of premorbid IQ, thereby enabling current capacity to be interpreted in light of preinjury ability. However, the validity of premorbid IQ tests that are commonly used for TBI has been questioned. In the present study, we examined the psychometric properties of a recently developed test, the Wechsler Test of Adult Reading (WTAR), which has yet to be examined for TBI. The cognitive performance of a group of 24 patients recovering from TBI (with a mean Glasgow Coma Scale score in the severely impaired range) was measured at 2 and 5 months postinjury. On both occasions, patients were administered three tests that have been used to measure premorbid IQ (the WTAR and the Vocabulary and Matrix Reasoning subtests of the Wechsler Adult Intelligence Scale 3rd Edition, WAIS-III) and three tests of current ability (Symbol Digit Modalities Test–Oral and Similarities and Block Design subtests of the WAIS-III). We found that performance significantly improved on tests of current cognitive ability, confirming recovery. In contrast, stable performance was observed on the WTAR from Assessment 1 (M = 34.25/50) to Assessment 2 (M = 34.21/50; r = .970, p < .001). Mean improvement across assessments was negligible (t = −0.086, p = .47; Cohens d = −0.005), and minimal individual participant change was observed (modal scaled score change = 0). WTAR scores were also highly similar to scores on a demographic estimate of premorbid IQ. Thus, converging evidence—high stability during recovery from TBI and similar IQ estimates to those of a demographic equation—suggests that the WTAR is a valid measure of premorbid IQ for TBI. Where word pronunciation tests are indicated (i.e., in patients for whom English is spoken and read fluently), these results endorse the use of the WTAR for patients with TBI.

Absence of chronic traumatic encephalopathy in retired football players with multiple concussions and neurological symptomatology

Background: Chronic traumatic encephalopathy (CTE) is the term coined for the neurodegenerative disease often suspected in athletes with histories of repeated concussion and progressive dementia. Histologically, CTE is defined as a tauopathy with a distribution of tau-positive neurofibrillary tangles (NFTs) that is distinct from other tauopathies, and usually shows an absence of beta-amyloid deposits, in contrast to Alzheimers disease (AD). Although the connection between repeated concussions and CTE-type neurodegeneration has been recently proposed, this causal relationship has not yet been firmly established. Also, the prevalence of CTE among athletes with multiple concussions is unknown. Methods: We performed a consecutive case series brain autopsy study on six retired professional football players from the Canadian Football League (CFL) with histories of multiple concussions and significant neurological decline. Results: All participants had progressive neurocognitive decline prior to death; however, only 3 cases had post-mortem neuropathological findings consistent with CTE. The other 3 participants had pathological diagnoses of AD, amyotrophic lateral sclerosis (ALS), and Parkinsons disease (PD). Moreover, the CTE cases showed co-morbid pathology of cancer, vascular disease, and AD. Discussion: Our case studies highlight that not all athletes with history of repeated concussions and neurological symptomology present neuropathological changes of CTE. These preliminary findings support the need for further research into the link between concussion and CTE as well as the need to expand the research to other possible causes of taupathy in athletes. They point to a critical need for prospective studies with good sampling methods to allow us to understand the relationship between multiple concussions and the development of CTE.

The Efficacy of Cognitive Behavior Therapy in the Treatment of Emotional Distress After Acquired Brain Injury

OBJECTIVE To evaluate the efficacy of cognitive behavior therapy (CBT), adapted to meet the unique needs of individuals with acquired brain injury (ABI), and modified for both group and telephone delivery. DESIGN Matched-controlled trial, with multiple measurements across participants, including pretreatment baseline assessment plus posttreatment and 1-month follow-up. SETTING Outpatient community brain injury center. PARTICIPANTS Participants (N=20) with chronic ABI. Ten were assigned to the CBT treatment group and 10 to education control. All were experiencing significant emotional distress at the onset of the study. INTERVENTION Eleven sessions of CBT (or education control), including 1 introductory individual session plus 10 further sessions administered in either group format or by telephone. The CBT was designed to decrease psychologic distress and improve coping. Specific adaptations were made to the CBT in order to better accommodate individuals with cognitive difficulties. MAIN OUTCOME MEASURES Primary outcome measures included the Symptom Checklist-90-Revised (SCL-90-R) and the Depression Anxiety Stress Scales (DASS-21). Secondary outcome measures included the Community Integration Questionnaire (CIQ) and the Ways of Coping Scale, Revised. RESULTS Significant CBT treatment effects (in both group and telephone formats) were observed on the SCL-90-R and the DASS-21, whereas no significant effects were observed in the education control group. No significant effects of treatment were observed on the CIQ or Ways of Coping Scale, Revised. CONCLUSIONS Results suggest that adapted CBT-administered by telephone or in a face-to-face group setting-can significantly improve emotional well-being in chronic ABI.

Magnetic Resonance Imaging Evidence of Progression of Subacute Brain Atrophy in Moderate to Severe Traumatic Brain Injury

OBJECTIVE To demonstrate subacute progression of brain atrophy (from 4.5-29mo postinjury) in moderate to severe traumatic brain injury (TBI) using structural magnetic resonance imaging (MRI). DESIGN Within-subjects, repeated-measures design. SETTING Inpatient neurorehabilitation program and teaching hospital (MRI department). PARTICIPANTS Adults (N=14) with moderate to severe TBI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Neuroradiologist readings and volumetric measurements (total brain cerebrospinal fluid and hippocampus) at 4.5 months and 2.5 years postinjury. RESULTS Ten of 14 patients showed visible atrophy progression. Significant increase in cerebrospinal fluid (CSF) volume (t(13)=-4.073, P<.001) and decrease in right and left hippocampal volumes (t(13)=4.221, P<.001 and t(13)=3.078, P<.005, respectively) were observed from 4.5 months to 2.5 years. Compared with published normative data, patients with TBI showed significantly more pathologic percent annual volume change for the hippocampi (t(26)=-3.864, P<.001, right; and t(26)=-2.737, P<.01, left), and a trend for CSF (t(26)=1.655, P=.059). CONCLUSIONS This study provides strong MRI evidence for subacute progression of atrophy, as distinct from early, acute neurologic changes observed.

Prediction of Return to Productivity After Severe Traumatic Brain Injury: Investigations of Optimal Neuropsychological Tests and Timing of Assessment

OBJECTIVES (1) To examine predictive validity of global neuropsychological performance, and performance on timed tests (controlling for manual motor function) and untimed tests, including attention, memory, executive function, on return to productivity at 1 year after traumatic brain injury (TBI). (2) To compare predictive validity at 8 weeks versus 5 months postinjury. (3) To examine predictive validity of early degree of recovery (8wk-5mo postinjury) for return to productivity. DESIGN Longitudinal, within subjects. SETTING Inpatient neurorehabilitation and community. PARTICIPANTS Patients (N=63) with moderate to severe TBI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES PRIMARY OUTCOME return to productivity at 1 year postinjury. Primary predictors: neuropsychological composite scores. Control variables: posttraumatic amnesia, acute care length of stay (LOS), Glasgow Coma Scale score, age, and estimated premorbid intelligence quotient. RESULTS Return to productivity was significantly correlated with global neuropsychological performance at 5 months postinjury (P<.05) and showed a trend toward significance at 8 weeks. Performance on the untimed composite score, and more specifically executive and memory functions, mirrored this pattern. Logical Memory performance significantly predicted return to productivity, but not other memory tests. Timed tests showed no significance or trend at either time point. Early degree of recovery did not predict return to productivity. Among control variables, only acute care LOS was predictive of return to productivity. CONCLUSIONS Findings validate utility of early neuropsychological assessment for predicting later return to productivity. They also provide more precise information regarding the optimal timing and test type: results support testing at 5 months postinjury on untimed tests (memory and executive function), but not simple attention or speed of mental processing. Findings are discussed with reference to previous literature.

Examining Moderators of Cognitive Recovery Trajectories After Moderate to Severe Traumatic Brain Injury

OBJECTIVES To examine the influence of cognitive reserve-related moderator variables on recovery trajectories during the first year after traumatic brain injury (TBI). Using mixed effects models, we measured (1) the level of cognitive function at 2 and 12 months postinjury and (2) the trajectories of cognitive recovery during the first 12 months postinjury. DESIGN Repeated-measures design with neuropsychological testing at 2, 5, and 12 months postinjury. SETTING Large, urban inpatient neurorehabilitation program. PARTICIPANTS Patients (N=75) with moderate-to-severe TBI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES PRIMARY OUTCOMES neuropsychological composite scores including simple speed of processing, complex speed of processing, memory, untimed executive functions, and attention span. Primary predictors: age, estimated premorbid intelligence quotient (IQ), and years of education. RESULTS Only age significantly moderated trajectories. Decreasing age significantly enhanced recovery of speed of processing, both simple (2-12mo postinjury, P<.001) and complex (2-12mo postinjury, P<.05; 5-12mo postinjury, P<.005). Decreasing age and increasing estimated premorbid IQ were associated with higher performance at 2 and 12mo postinjury for simple speed of processing (premorbid IQ, 2 and 12mo), complex speed of processing (age, 2 and 12mo), untimed executive functions (premorbid IQ, 2 and 12mo), and memory (premorbid IQ, 2 and 12mo). CONCLUSIONS Recovery of speed of processing (both simple and complex) was favorably moderated by younger age. Older age is associated with more neuronal loss and less integrity of white matter, and speed of processing is associated with white matter networks. The recuperative effects of younger age may therefore be attributable to greater reserve capacity (as indexed by white matter integrity). Lower age and higher estimated premorbid IQ were associated with higher functioning on a variety of cognitive outcomes. This may reflect the buffering effects of reserve capacity or premorbid differences in age and IQ-related cognitive functioning. Implications for rehabilitation and recovery mechanisms are discussed.