Intellectual enrichment lessens the effect of brain atrophy on learning and memory in multiple sclerosis

OBJECTIVE

Learning and memory impairments are prevalent among persons with multiple sclerosis (MS); however, such deficits are only weakly associated with MS disease severity (brain atrophy). The cognitive reserve hypothesis states that greater lifetime intellectual enrichment lessens the negative impact of brain disease on cognition, thereby helping to explain the incomplete relationship between brain disease and cognitive status in neurologic populations. The literature on cognitive reserve has focused mainly on Alzheimer disease. The current research examines whether greater intellectual enrichment lessens the negative effect of brain atrophy on learning and memory in patients with MS.

METHODS

Forty-four persons with MS completed neuropsychological measures of verbal learning and memory, and a vocabulary-based estimate of lifetime intellectual enrichment. Brain atrophy was estimated with third ventricle width measured from 3-T magnetization-prepared rapid gradient echo MRIs. Hierarchical regression was used to predict learning and memory with brain atrophy, intellectual enrichment, and the interaction between brain atrophy and intellectual enrichment.

RESULTS

Brain atrophy predicted worse learning and memory, and intellectual enrichment predicted better learning; however, these effects were moderated by interactions between brain atrophy and intellectual enrichment. Specifically, higher intellectual enrichment lessened the negative impact of brain atrophy on both learning and memory.

CONCLUSION

These findings help to explain the incomplete relationship between multiple sclerosis disease severity and cognition, as the effect of disease on cognition is attenuated among patients with higher intellectual enrichment. As such, intellectual enrichment is supported as a protective factor against disease-related cognitive impairment in persons with multiple sclerosis.

Increased functional connectivity within memory networks following memory rehabilitation in multiple sclerosis

Identifying effective behavioral treatments to improve memory in persons with learning and memory impairment is a primary goal for neurorehabilitation researchers. Memory deficits are the most common cognitive symptom in multiple sclerosis (MS), and hold negative professional and personal consequences for people who are often in the prime of their lives when diagnosed. A 10-session behavioral treatment, the modified Story Memory Technique (mSMT), was studied in a randomized, placebo-controlled clinical trial. Behavioral improvements and increased fMRI activation were shown after treatment. Here, connectivity within the neural networks underlying memory function was examined with resting-state functional connectivity (RSFC) in a subset of participants from the clinical trial. We hypothesized that the treatment would result in increased integrity of connections within two primary memory networks of the brain, the hippocampal memory network, and the default network (DN). Seeds were placed in left and right hippocampus, and the posterior cingulate cortex. Increased connectivity was found between left hippocampus and cortical regions specifically involved in memory for visual imagery, as well as among critical hubs of the DN. These results represent the first evidence for efficacy of a behavioral intervention to impact the integrity of neural networks subserving memory functions in persons with MS.

Assessing somatization disorder in the chronic fatigue syndrome

This study was conducted to examine the rates of somatization disorder (SD) in the chronic fatigue syndrome (CFS) relative to other fatiguing illness groups. It further addressed the arbitrary nature of the judgments made in assigning psychiatric vs. physical etiology to symptoms in controversial illnesses such as CFS. Patients with CFS (N = 42), multiple sclerosis (MS) (N = 18), and depression (N = 21) were compared with healthy individuals (N = 32) on a structured psychiatric interview. The SD section of the Diagnostic Interview Schedule (DIS) III-R was reanalyzed using different criteria sets to diagnose SD. All subjects received a thorough medical history, physical examination, and DIS interview. CFS patients received diagnostic laboratory testing to rule out other causes of fatigue. This study revealed that changing the attribution of SD symptoms from psychiatric to physical dramatically affected the rates of diagnosing SD in the CFS group. Both the CFS and depressed subjects endorsed a higher percentage of SD symptoms than either the MS or healthy groups, but very few met the strict DSM-III-R criteria for SD. The present study illustrates that the terminology used to interpret the symptoms (ie, psychiatric or physical) will determine which category CFS falls into. The diagnosis of SD is of limited use in populations in which the etiology of the illness has not been established.

Relationship of the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) to functional, emotional, and neuropsychological outcomes

OBJECTIVE

To explore the relationship of the Multiple Sclerosis Neuropsychology Questionnaire (MSNQ; [Benedict, R. H. B., Cox, D., Thompson, L. L., Foley, F., Weinstock-Guttman, B., & Munschauer, F. (2004). Reliable screening for neuropsychological impairment in multiple sclerosis. Multiple Sclerosis, 10, 675-678; Benedict, R. H. B., Munschauer, F., Linn, R., Miller, C., Murphy, E., Foley, F., et al. (2003). Screening for multiple sclerosis cognitive impairment using a self-administered 15-item questionnaire. Multiple Sclerosis, 9, 95-101]), a self-report screening measure of neuropsychological functioning in multiple sclerosis (MS), with everyday life functioning, neuropsychological functioning, and mood in MS. Additionally, to investigate the validity, sensitivity, and specificity of the MSNQ to predict cognitive impairment in persons with MS.

STUDY DESIGN

Cross-sectional, correlational analyses; analyses of sensitivity and specificity.

SETTING

Neuropsychology lab-based study with adults from the community including persons with MS (n=48) and healthy adults (n=40).

MAIN OUTCOME MEASURES

Subjective and objective measures of everyday life functioning, neuropsychological functioning, and mood; ROC curve of MSNQ-Self report and MSNQ-Informant report, sensitivity and specificity of MSNQ-S and MSNQ-I.

RESULTS

Correlational analyses indicate the MSNQ-S is significantly correlated with mood and self-reports of functioning, but not with objectively measures daily functioning and to only few neuropsychological tests. The MSNQ-I was not significantly correlated to mood, self-report of daily functioning or objectively measured daily functioning, but was significantly correlated with several measures of neuropsychological functioning.

CONCLUSION

The MSNQ-S was not supported as a sensitive screen for neuropsychological impairment in MS. However, the MSNQ-I was supported as a valid and sensitive screen of cognitive impairment in persons with MS, although further research is needed to determine an optimal cutoff score for this measure.

Differentiating simple versus complex processing speed: influence on new learning and memory performance

The current study was designed to examine how the construct of human information processing speed is conceptualized and measured, while also examining the influence of information processing speed on higher cognitive processes (i.e., learning). A mixed medical sample of 92 subjects participated in this study. Subjects underwent a broad-based neuropsychological evaluation, including measures of verbal and visuospatial new learning, spatial and verbal working memory, simple reaction time, choice reaction time, and information processing speed. Principal components factor analysis with varimax rotation resulted in a three-factor solution, comprised of: (1) simple speed/reaction time, (2) complex information processing and new learning, and (3) working memory. Notably, this factor solution identified 2 distinct forms of processing speed--simple and complex information processing speeds. In contrast to the abundance of literature grouping these two constructs together under one term (i.e., processing speed), these results indicate simple and complex speed to be distinct constructs assessed with different neuropsychological instruments. While the expected relationship between complex information processing capacities and working memory abilities was evident in this study, information processing speed also showed a significant relationship with new learning ability. The implications of this intriguing relationship are discussed.

Cerebral activation patterns during working memory performance in multiple sclerosis using FMRI

Working memory deficits are common in Multi Sclerosis (MS) and have been identified behaviourally in numerous studies. Despite recent advance in functional magnetic resonance imaging (fMRI), few published studies have examined cerebral activations associated with working memory dysfunction in MS. The present study examines brain activation patterns during performance of a working memory task in individual with clinically definite MS, compared to healthy controls (HC). fMRI was performed using a 1.5 Tesla GE scanner during a modified Paced Auditory Serial Addition Test (mPA-SAT). Participants were 6 individuals with MS with working memory impairment as evidenced on neuropsychological testing, 5 individuals with MS without working memory impairment, and 5 HC. Groups were demographically equivalent. Data were analyzed using Statistical Parametric Mapping (SPM99) software, with a stringent significance level (alpha < .005, voxel extent > or =8). Both MS groups and the HC group were able to perform the task, with comparable performance in terms of numbers of correct responses. Activation patterns within the HC and MS not-impaired groups were noted in similar brain regions, consistent with published observations in healthy samples That is, activations were lateralized to the left hemisphere, involving predominantly frontal regions. In contrast, the MS impaired group showed greater right frontal and right parietal lobe activation, when compared with the HC group. Thus, it appears that working memory dysfunction in MS is associated with altered patterns of cerebral activation that are related to the presence of cognitive impairement, and not solely a function of MS.

The relationship between neuropsychological measures and the Timed Instrumental Activities of Daily Living task in multiple sclerosis

Multiple sclerosis (MS) can result in cognitive deficits and a loss of functional independence. To date, little research has linked the observed cognitive and behavioral deficits in MS, especially those in the processing speed domain, to performance on tasks of everyday functioning. The present study examined the relationship between neuropsychological test performance and performance on the Timed Instrumental Activities of Daily Living task (TIADL) in individuals with MS, and in healthy controls (HCs). The TIADL is a functional measure, which assesses both accuracy and speed in one's performance of everyday activities. The MS group performed significantly worse on the TIADL relative to the HC group. Additionally, TIADL scores of individuals with MS were significantly correlated with neuropsychological measures of processing speed. TIADL scores were not, however, correlated with neuropsychological measures of verbal episodic memory or working memory. These results indicate that the impairments in processing speed may contribute to impairments in activities of everyday living in persons with MS. Multiple Sclerosis 2007; 13: 636-644. http://msj.sagepub.com

Unemployment in multiple sclerosis (MS): utility of the MS Functional Composite and cognitive testing

Unemployment is a significant concern among individuals with multiple sclerosis (MS). Determinations regarding ability to work are highly dependent on measurement tools used by neurologists and allied professionals. However, little is known of the usefulness of these tools when determining issues pertaining to employment status. The purpose of the present investigation was to examine the utility of the Multiple Sclerosis Functional Composite (MSFC) and a brief cognitive test battery when examining employment status in MS. Seventy-seven individuals with MS completed the MSFC and a brief cognitive test battery. On the MSFC, unemployed individuals demonstrated worse upper extremity functioning. There was no difference on the Paced Auditory Serial Addition Task (PASAT), the sole cognitive measure of the MSFC. On cognitive testing, unemployed individuals performed worse on measures of memory, information processing speed, and executive functioning. Through logistic regression analysis, the Symbol Digit Modalities Test (SDMT) was found to be the sole predictor of employment status among the significant disease, MSFC and cognitive variables. Consistent with previous findings, logistic regression found the SDMT to be a significant predictor of employment status. Given the lack of significant group differences on the PASAT, continued consideration of replacing the PASAT with the SDMT in the MSFC appears warranted.

Assessing the Behavioral Consequences of Multiple Sclerosis: An Application of the Frontal Systems Behavior Scale (FrSBe)

OBJECTIVE

The current study examines the utility of the Frontal Systems Behavior Scale (FrSBe) to document behavioral changes in people with multiple sclerosis (MS).

BACKGROUND

MS results in widespread central nervous system lesions that have a propensity for affecting frontal and parietal brain regions. As a result, behavioral symptoms may present, including disorders of executive functioning, apathy, and disinhibition.

METHOD

Twenty-six people with MS and 15 healthy controls (HC) underwent neuropsychological testing and completed the Frontal Systems Behavior Scale (FrSBe), and measures of emotional functioning.

RESULTS

Behavioral ratings for the MS group prior to illness were equivalent to those of the HC group. After illness however, a clinically and statistically significant increase was noted on two of three FrSBe scales, the apathy scale and the executive dysfunction scale. Relationships were also noted between the FrSBe family and self-report forms after illness and measures of neuropsychological performance, particularly information processing, working memory, and executive control. In contrast, physical disease progression was correlated with family ratings of behavior, but not self-ratings.

CONCLUSIONS

The FrSBe appears to be a sensitive measure of behavioral change in people with MS. Self-ratings and family ratings of behavioral changes are related to measures of neuropsychological performance. However, physical symptoms of MS are related only to the family ratings of behavior.

The relationship between self-awareness of neurobehavioral symptoms, cognitive functioning, and emotional symptoms in multiple sclerosis

OBJECTIVE

To examine self-awareness of neurobehavioral symptoms in multiple sclerosis (MS) across three domains of function (apathy, disinhibition, and executive control), and examine the relationship between self-awareness and cognitive functioning.

METHODS

Twenty-six individuals with MS completed neuropsychological testing, measures of emotional functioning, and self-ratings of neurobehavioral symptoms using the Frontal Systems Behavior Scale (FrSBe), a 46-item questionnaire with subscales assessing frequency of symptoms in executive dysfunction, disinhibition, and apathy. Informants' ratings of the FrSBe were also obtained. Decreasing differences between patient and informant reports on each subscale of the FrSBe (concordance) indicate higher levels of self-awareness.

RESULTS

Results showed significant positive correlations between cognitive abilities and self-awareness of executive dysfunction and disinhibition. In contrast, affect symptomatology (measures of anxiety and depression) were negatively correlated with self-awareness of executive dysfunction.

CONCLUSIONS

Level of self-awareness of neurobehavioral symptoms in MS is related to level of cognitive impairment In addition, symptoms of depression and anxiety reduced the accuracy of self-reporting. Thus, a clinician who relies on self-reports in creating an evaluation and treatment plan should consider the patient's cognitive and emotional states.

Functional neuroimaging of fatigue

Clearly, the use of functional neuroimaging for the study of fatigue is in its infancy. Relatively few studies focusing on fatigue using functional neuroimaging techniques have been published, and the few that exist focus primarily on persons with MS and CFS. The vast majority of these studies have examined self-reported fatigue, an approach that benefits from ease of administration but suffers from significant difficulties in interpretation. For example, we know that self-reported fatigue most often correlates with the degree of psychopathology.1 We also know that with more than 100 years of inquiry, self-reported fatigue does not correlate with objective measures of fatigue. As such, when functional imaging studies show a relationship between self-reported fatigue and activities in distinct areas of the brain, one must remain cautious about the interpretation of these results. A more recent approach in the functional imaging literature is to assess fatigue behaviorally during scanning and relate such objective measures of fatigue with cerebral activation. Although this is a new and novel approach, it remains unclear if this approach of operationally defining fatigue behaviorally will be a more valid paradigm in understanding the elusive construct of fatigue. Although fatigue is extraordinarily common as a symptom in many neurologic and psychiatric diseases, little is known about its precise mechanism. Chaudhuri and Behan hypothesized that the nonmotor functions of the basal ganglia play a key role in central fatigue. Specifically, they posit that fatigue is due to "alterations in the normal flow of sequential activation within the basal ganglia system affecting the neural integrator and the cortical feedback by the associated loop of the striato-thalamo-cortical fibers is a possible mechanism of central fatigue ." (p40). Therefore, other regions interacting with the basal ganglia may also contribute to fatigue, including the frontal cortex, thalamus, and the amygdala. In general, the functional imaging studies reviewed in this article tend to generally support the suggestion that damage to cortical-subcortical circuitry might be to blame for fatigue as well. If indeed fatigue is associated with functional impairment in a cortical-subcortical circuitry, it might be that studies that have examined structural damage (eg, total lesion load throughout the brain) may simply not provide the sensitivity required to detect a relationship between fatigue and pathology. After more than 100 years of frustration, it appears that functional neuroimaging techniques promise to provide an exciting potential for significant advances in our elusive understanding of the brain mechanisms associated with fatigue in clinical populations.

Divided attention and driving: a pilot study using virtual reality technology

BACKGROUND

Virtual reality (VR) was used to investigate the influence of divided attention (simple versus complex) on driving performance (speed control).

DESIGN

Three individuals with traumatic brain injury (TBI) and three healthy controls (HC), matched for age, education, and gender, were examined.

RESULTS

Preliminary results revealed no differences on driving speed between TBI and HC. In contrast, TBI subjects demonstrated a greater number of errors on a secondary task performed while driving.

CONCLUSION

The findings suggest that VR may provide an innovative medium for direct evaluation of basic cognitive functions (ie, divided attention) and its impact on everyday tasks (ie, driving) not previously available through traditional neuropsychological measures.

Memory and executive functions in amnesic and non-amnesic patients with aneurysms of the anterior communicating artery

Ruptured and repaired anterior communicating artery (ACoA) aneurysm can result in devastating impairments involving memory, executive function, confabulation and personality change. Importantly, traditional cerebral areas implicated in amnesia are not damaged, yet amnesia can still be manifested. While ACoA patients show normal visual-constructional skills (i.e. copy scores) on the Rey-Osterrieth complex figure test, recall is often impaired. What is unclear is whether impaired recall is attributable to problems in encoding, accelerated rates of forgetting, retrieval or some combination. To disentangle these issues, we examined 10 patients with ruptured aneurysms of the ACoA, using the Rey-organizational and extended memory procedure which uses an organizational procedure for enhancing immediate recall and provides added sensitivity by combining recall with non-recall measures (e.g. recognition, spatial discrimination and spatial assembly). The major findings were: (i) immediate recall in amnesics was improved by providing an organizational strategy; (ii) following the organization trials, amnesics and non-amnesics retained information to a comparable extent over a 30-min delay; (iii) two subgroups of amnesics emerged, those subjects impaired in acquisition and a second group with impaired retrieval; (iv) all subjects showed preserved memory on non-recall measures. These findings have important implications with respect to using organizational strategies in cognitive treatments and in using non-recall measures in improving the validity and reliability of patient assessment.

Clinicopathologic study of lacrimal sac and nasal mucosa in 44 patients with complete acquired nasolacrimal duct obstruction

We studied 44 patients who had dacryocystorhinostomy for primary acquired complete nasolacrimal duct obstruction. The lacrimal sac and nasal mucosa adjacent to the osteotomy were examined histologically. The lacrimal sac had chronic inflammatory changes in 33 of 37 patients with varying degrees of fibrosis in 34 of 37. Focal ulceration of the lacrimal sac epithelium was present in 15 cases. Goblet cells, present in 11 specimens, were not identified in 26 specimens. Moderate or severe chronic inflammation was found in 14 of 44 nasal mucosal specimens and marked fibrosis in 22. The pathology of the lacrimal sac and nasal mucosa is similar to that of the nasolacrimal duct in complete nasolacrimal duct obstruction. The nasal inflammation may have resulted from dacryocystitis or alternatively contributed to the dacryocystitis.

Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and performance of everyday life tasks: Actual Reality

BACKGROUND

Recently, a brief cognitive assessment (Brief International Cognitive Assessment for Multiple Sclerosis: BICAMS) has been recommended for use with patients diagnosed with multiple sclerosis (MS) to screen for cognitive impairments. However, the relationship between the BICAMS and everyday life activity has not been examined. The aim of this study was to examine whether the BICAMS can predict performance of activities of daily living using Actual Reality(TM) (AR) in persons with MS.

METHOD

A between-subjects design was utilized to compare 41 individuals with MS and 32 healthy controls (HC) performing BICAMS and an AR task. Participants were asked to access the internet to purchase a flight ticket or cookies, and were administered the BICAMS and questionnaires to assess quality of life (QOL), affect symptomatology, and prior internet experience.

RESULTS

Participants with MS performed significantly worse than HC on the BICAMS and the AR. Additionally, better BICAMS performance was associated with more independent AR performance. Self-reports of QOL were not correlated with AR or BICAMS performance.

CONCLUSIONS

Individuals with MS have greater problems with actual everyday life tasks as compared to HC. The BICAMS is a promising cognitive screening tool to predict actual functional performance in participants with MS.

The Relation Between Subjective and Objective Measures of Everyday Life Activities in Persons With Multiple Sclerosis

OBJECTIVES

To investigate the relation between subjective and objective performance-based measures of functional status in persons with multiple sclerosis (MS), and to compare their performance with healthy controls.

DESIGN

A between-groups design, using a correlational approach to examine the relation between objective and subjective measures of functional capacity.

SETTING

Outpatient rehabilitation research institution.

PARTICIPANTS

Seventy-four subjects with clinically definite MS and 35 healthy controls.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The Executive Function Performance Test (EFPT), Functional Assessment of Multiple Sclerosis (FAMS), and Functional Behavior Profile (FBP).

RESULTS

MS participants reported more difficulties performing functional tasks than did the healthy controls. MS participants also performed significantly worse on the EFPT than healthy controls. However, all correlations between subjective and objective functional measures were nonsignificant. After controlling for depressive symptomatology, EFPT performance was significantly associated with FBP scores, but not FAMS scores.

CONCLUSIONS

The lack of association between objective performance-based measures and subjective self-report measures of functional activities is a challenge to outcomes measurement and has implications for assessment of functional performance. Results are discussed in terms of the different dimensions that these tools are measuring and their respective strengths and limitations.

Exercise Training and Cognitive Rehabilitation

The current review develops a rationale and framework for examining the independent and combined effects of exercise training and cognitive rehabilitation on walking and cognitive functions in persons with multiple sclerosis (MS). To do so, we first review evidence for improvements in walking and cognitive outcomes with exercise training and cognitive rehabilitation in MS. We then review evidence regarding cognitive–motor coupling and possible cross-modality transfer effects of exercise training and cognitive rehabilitation. We lastly present a macro-level framework for considering mechanisms that might explain improvements in walking and cognitive dysfunction with exercise and cognitive rehabilitation individually and combined in MS. We conclude that researchers should consider examining the effects of exercise training and cognitive rehabilitation on walking, cognition, and cognitive–motor interactions in MS and the possible physiological and central mechanisms for improving these functions.

The relationship between executive functioning, processing speed, and white matter integrity in multiple sclerosis

The primary purpose of the current study was to examine the relationship between performance on executive tasks and white matter integrity, assessed by diffusion tensor imaging (DTI) in multiple sclerosis (MS). A second aim was to examine how processing speed affects the relationship between executive functioning and fractional anisotropy (FA). This relationship was examined in two executive tasks that rely heavily on processing speed: the Color-Word Interference Test and the Trail Making Test (Delis-Kaplan Executive Function System). It was hypothesized that reduced FA is related to poor performance on executive tasks in MS, but that this relationship would be affected by the statistical correction of processing speed from the executive tasks. A total of 15 healthy controls and 25 persons with MS participated. Regression analyses were used to examine the relationship between executive functioning and FA, both before and after processing speed was removed from the executive scores. Before processing speed was removed from the executive scores, reduced FA was associated with poor performance on the Color-Word Interference Test and Trail Making Test in a diffuse network including corpus callosum and superior longitudinal fasciculus. However, once processing speed was removed, the relationship between executive functions and FA was no longer significant on the Trail Making Test, and significantly reduced and more localized on the Color-Word Interference Test.

Prevalence of stimulant use for attentional dysfunction in children with phenylketonuria

Recent data suggest that children with phenylketonuria (PKU) and poor metabolic control may have an increased prevalence of attentional dysfunction. However, few formal studies have addressed this topic in detail. We reviewed the medical records of 38 school-aged children with early and continuously treated PKU to determine the prevalence of stimulant use for attentional dysfunction, and to determine the relationship between metabolic control and attentional symptoms. Twenty-six per cent of the PKU children used a stimulant medication for attentional dysfunction. This is significantly higher than in an age- and sex-matched control group consisting of children with type I diabetes mellitus (6.5%, p <0.006), and also considerably higher than population norms for attention deficit hyperactivity disorder (ADHD) (5%). We also found a significant relationship between phenylalanine levels and stimulant use or attentional symptoms. Mean plasma phenylalanine concentration was 486 micromol/L in the non-stimulant-using group and 792 micromol/L in the stimulant-using group (p <0.02). Mean phenylalanine concentration was 462 micromol/L in the group not reporting attentional symptoms, and was 702 micromol/L in the symptomatic group (p <0.05). Parents of the stimulant-using children felt that the stimulants were efficacious in treating their child's attentional symptoms. Stimulant use and parent reports of attentional dysfunction are quite common in our PKU patients and appear to be strongly related to higher phenylalanine concentrations.

Functionally activated brain imaging (O-15 PET and fMRI) in the study of learning and memory after traumatic brain injury

Advances in functional imaging technology and cognitive neuropsychology have resulted in paradigms in which participants can perform cognitive tasks during functional image acquisition. We will discuss the application of two approaches (oxygen-15 positron emission tomography and functional magnetic resonance imaging) that have recently been used to examine components of learning and memory following traumatic brain injury (TBI). Activated functional brain imaging findings that we will discuss may suggest possible functional reallocation and reorganization of brain substrates involved in verbal learning and memory following brain injury. The findings also are clearly in line with other research that indicates a prominent role for the frontal lobes in learning and memory functioning, and support the concept of distributed neural networks for memory-related functions, cognitive load, and the potential for examining brain re-organization after injury.

Cognitive dysfunction after aneurysm of the anterior communicating artery

The present study examined the nature of the amnestic syndrome following aneurysm of the anterior communicating artery (ACoA) in humans. Eleven ACoA and 13 subjects with intracranial hemorrhages (ICH) elsewhere in the brain were administered a battery of standard neuropsychological tests. The ACoA group performed significantly worse than the ICH controls on tests of delayed verbal memory and on the Wisconsin Card Sorting Test, despite significantly higher Full Scale IQ. No significant differences were observed between groups on tests of immediate recall, attention and concentration, and visuo-spatial functions, although the ACoA group tended to perform better on many of these tests. The results do not support the hypothesis that the cognitive impairments observed following ACoA aneurysm are the result of diffuse cortical damage. The role of specific anterior cerebral structures in defining the "ACOA syndrome" are discussed.

Education attenuates the negative impact of traumatic brain injury on cognitive status

OBJECTIVE

To investigate whether the cognitive reserve hypothesis helps to explain differential cognitive impairment among survivors of traumatic brain injury (TBI), whereby survivors with greater intellectual enrichment (estimated with education) are less vulnerable to cognitive impairment.

DESIGN

Cross-sectional study.

SETTING

Medical rehabilitation research center.

PARTICIPANTS

Survivors of moderate or severe TBI (n=44) and healthy controls (n=36).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Intellectual enrichment was estimated with educational attainment. Group was defined as TBI or healthy control. Current cognitive status (processing speed, working memory, episodic memory) was evaluated with neuropsychological tasks.

RESULTS

TBI survivors exhibited worse cognitive status than healthy persons (P<.001), and education was positively correlated with cognitive status in TBI survivors (r=.54, P<.001). Most importantly, regression analysis revealed an interaction between group and education (R(2) change=.036, P=.004), whereas higher education attenuated the negative impact of TBI on cognitive status. TBI survivors with lower education performed much worse than matched healthy persons, but this TBI-related performance discrepancy was attenuated at higher levels of education.

CONCLUSIONS

Higher intellectual enrichment (estimated with education) reduces the negative effect of TBI on cognitive outcomes, thereby supporting the cognitive reserve hypothesis in persons with TBI. Future work is necessary to investigate whether intellectual enrichment can build cognitive reserve as a rehabilitative intervention in survivors of TBI.

Driving behaviors following brain injury: self-report and motor vehicle records

BACKGROUND

This study examined both objective and subjective measures of driving behaviors occurring in the past 5 years for 47 individuals with traumatic brain injury (TBI) and 22 healthy controls (HC), matched for age, gender, education, and years of driving experience.

RESULTS

Overall, subtle descriptive differences in driving characteristics were observed between the two groups. However, comparison of self-reported and documented reports of aberrant driving behaviors did not reveal a significantly greater number of accidents or violations among TBI participants compared with HC drivers. The results suggest that individuals with TBI, who successfully complete a driving evaluation program, are able to reintegrate into the driving community with minimal difficulty.