The relationship between neuropsychological function and brain damage detected by neuroimaging after closed head injury

Association between mammillary body atrophy and memory impairment in retired athletes with a history of repetitive mild traumatic brain injury

Cognitive dysfunction, especially memory impairment, is a typical clinical feature of long-term symptoms caused by repetitive mild traumatic brain injury (rmTBI). The current study aims to investigate the relationship between regional brain atrophy and cognitive impairments in retired athletes with a long history of rmTBI. Overall, 27 retired athletes with a history of rmTBI (18 boxers, 3 kickboxers, 2 wrestlers, and 4 others; rmTBI group) and 23 age/sex-matched healthy participants (control group) were enrolled. MPRAGE on 3 T MRI was acquired and segmented. The TBV and TBV-adjusted regional brain volumes were compared between groups, and the relationship between the neuropsychological test scores and the regional brain volumes were evaluated. Total brain volume (TBV) and regional brain volumes of the mammillary bodies (MBs), hippocampi, amygdalae, thalami, caudate nuclei, and corpus callosum (CC) were estimated using the SPM12 and ITK-SNAP tools. In the rmTBI group, the regional brain volume/TBV ratio (rmTBI vs. control group, Mann-Whitney U test, p < 0.05) underwent partial correlation analysis, adjusting for age and sex, to assess its connection with neuropsychological test results. Compared with the control group, the rmTBI group showed significantly lower the MBs volume/TBV ratio (0.13 ± 0.05 vs. 0.19 ± 0.03 × 10-3, p < 0.001). The MBs volume/TBV ratio correlated with visual memory, as assessed, respectively, by the Rey-Osterrieth Complex Figure test delayed recall (ρ = 0.62, p < 0.001). In conclusion, retired athletes with rmTBI have MB atrophy, potentially contributing to memory impairment linked to the Papez circuit disconnection.

Spatiotemporal profile of atrophy in the first year following moderate-severe traumatic brain injury

Traumatic brain injury (TBI) triggers progressive neurodegeneration resulting in brain atrophy that continues months-to-years following injury. However, a comprehensive characterization of the spatial and temporal evolution of TBI-related brain atrophy remains incomplete. Utilizing a sensitive and unbiased morphometry analysis pipeline optimized for detecting longitudinal changes, we analyzed a sample consisting of 37 individuals with moderate-severe TBI who had primarily high-velocity and high-impact injury mechanisms. They were scanned up to three times during the first year after injury (3 months, 6 months, and 12 months post-injury) and compared with 33 demographically matched controls who were scanned once. Individuals with TBI already showed cortical thinning in frontal and temporal regions and reduced volume in the bilateral thalami at 3 months post-injury. Longitudinally, only a subset of cortical regions in the parietal and occipital lobes showed continued atrophy from 3 to 12 months post-injury. Additionally, cortical white matter volume and nearly all deep gray matter structures exhibited progressive atrophy over this period. Finally, we found that disproportionate atrophy of cortex along sulci relative to gyri, an emerging morphometric marker of chronic TBI, was present as early as 3 month post-injury. In parallel, neurocognitive functioning largely recovered during this period despite this pervasive atrophy. Our findings demonstrate msTBI results in characteristic progressive neurodegeneration patterns that are divergent across regions and scale with the severity of injury. Future clinical research using atrophy during the first year of TBI as a biomarker of neurodegeneration should consider the spatiotemporal profile of atrophy described in this study.

Volumetric MRI Findings in Mild Traumatic Brain Injury (mTBI) and Neuropsychological Outcome

Region of interest (ROI) volumetric assessment has become a standard technique in quantitative neuroimaging. ROI volume is thought to represent a coarse proxy for making inferences about the structural integrity of a brain region when compared to normative values representative of a healthy sample, adjusted for age and various demographic factors. This review focuses on structural volumetric analyses that have been performed in the study of neuropathological effects from mild traumatic brain injury (mTBI) in relation to neuropsychological outcome. From a ROI perspective, the probable candidate structures that are most likely affected in mTBI represent the target regions covered in this review. These include the corpus callosum, cingulate, thalamus, pituitary-hypothalamic area, basal ganglia, amygdala, and hippocampus and associated structures including the fornix and mammillary bodies, as well as whole brain and cerebral cortex along with the cerebellum. Ventricular volumetrics are also reviewed as an indirect assessment of parenchymal change in response to injury. This review demonstrates the potential role and limitations of examining structural changes in the ROIs mentioned above in relation to neuropsychological outcome. There is also discussion and review of the role that post-traumatic stress disorder (PTSD) may play in structural outcome in mTBI. As emphasized in the conclusions, structural volumetric findings in mTBI are likely just a single facet of what should be a multimodality approach to image analysis in mTBI, with an emphasis on how the injury damages or disrupts neural network integrity. The review provides an historical context to quantitative neuroimaging in neuropsychology along with commentary about future directions for volumetric neuroimaging research in mTBI.

Factors affecting cognition and emotion in patients with traumatic brain injury

BACKGROUND

Cognitive and emotional disturbances are common serious issues in patients with traumatic brain injury (TBI). However, predictors associated with neuropsychological functions were not consistent.

OBJECTIVE

To investigate factors affecting cognition and emotion in patients with TBI, we evaluated executive function, memory, and emotion based on injury severity and lesion location.

METHODS

Neuropsychological outcomes of 80 TBI patients were evaluated via Wisconsin Card Sorting Test (WCST), Color Trail Test (CTT), Controlled Oral Word Association Test (COWAT), Everyday Memory Questionnaire (EMQ), Geriatric Depression Scale (GDS), State-Trait Anxiety Inventory (STAI), and Agitated Behavior Scale (ABS). WCST, CTT, and COWAT assessed executive function; EMQ assessed everyday memory; and GDS, STAI, and ABS assessed emotion. Patients were categorized according to lateralization of lesion and existence of frontal lobe injury.

RESULTS

Patients with longer duration of loss of consciousness (LOC) showed more severe deficits in everyday memory and agitated behaviors. The frontal lesion group showed poorer performance in executive function and higher agitation than the non-frontal lesion group. Patients with bilateral frontal lesion showed greater deficits in executive function and were more depressed than unilateral frontal lesion groups. Especially in those unilateral frontal lesion groups, right side frontal lesion group was worse on executive function than left side frontal lesion group.

CONCLUSIONS

Duration of LOC and lesion location are main parameters affecting executive function, everyday memory, and emotion in neuropsychological outcomes following TBI, suggesting that these parameters need to be considered for cognitive rehabilitation interventions.

Functional Changes after Recombinant Human Growth Hormone Replacement in Patients with Chronic Traumatic Brain Injury and Abnormal Growth Hormone Secretion

We explored the effects of recombinant human growth hormone (rhGH) replacement on physical and cognitive functioning in subjects with a moderate-to-severe traumatic brain injury (TBI) with abnormal growth hormone (GH) secretion. Fifteen individuals who sustained a TBI at least 12 months prior to study enrollment were identified as having abnormal GH secretion by glucagon stimulation testing (maximum GH response less than 8 ng/mL). Peak cardiorespiratory capacity, body composition, and muscle force testing were assessed at baseline and one year after rhGH replacement. Additionally, standardized neuropsychological tests that assess memory, processing speed, and cognitive flexibility, as well as self-report inventories related to depression and fatigue, were administered at baseline and 1 year after rhGH replacement. Comparison tests were performed with proper post hoc analyses. All analyses were carried out at α < 0.05. Peak O₂ consumption, peak oxygen pulse (estimate of cardiac stroke volume), and peak ventilation all significantly increased (p < 0.05). Maximal isometric and isokinetic force production were not altered. Skeletal muscle fatigue did not change but the perceptual rating of fatigue was reduced by ∼25% (p = 0.06). Cognitive performance did not change significantly over time, whereas self-reported symptoms related to depression and fatigue significantly improved. The observed changes suggest that rhGH replacement has a positive impact on cardiorespiratory fitness and a positive impact on perceptual fatigue in survivors of TBI with altered GH secretion.

Prevalence and predictors of affective lability after paediatric traumatic brain injury

OBJECTIVE

Paediatric severe traumatic brain injury (TBI) is associated with significant post-injury affective and behavioural problems. Few studies have examined the prevalence and characteristics of affective lability after paediatric TBI.

METHODS

Ninety-seven children with severe TBI were evaluated 1 year post-injury for the presence of affective lability using the Children's Affective Lability Scale (CALS). Demographic, clinical and brain lesion characteristics were also assessed.

RESULTS

Affective lability significantly increased after injury. Eighty-six children had a pre-injury CALS score of 1 SD or less from the group pre-injury mean (M = 8.11, SD = 9.31), of which 35 and 15 children had a 1 SD and 2 SD increase in their CALS score from pre- to post-injury, respectively. A variety of affective shifts manifested post-injury including anxiety, silliness, dysphoria and irritability. The most severe symptoms were irritability and unpredictable temper outbursts. Risk factors for affective lability included elevated pre-injury affective lability and psychosocial adversity as well as greater damage to the orbitofrontal cortex. Post-injury affective lability was most frequently associated with a post-injury diagnosis of attention-deficit hyperactivity disorder.

CONCLUSIONS

Affective lability is common after paediatric TBI and frequently manifests as irritability and unpredictable outbursts. Early intervention is needed to improve psychiatric outcomes.

The impact of mild closed head injury on involuntary saccadic adaptation: Evidence for the preservation of implicit motor learning

OBJECTIVE

Mild closed head injury (CHI) can impair performance on volitional saccades (fast eye movements), with poorer saccade accuracy being one of the principal deficits. Assessing a patient group with known deficits of volitional saccades, the authors investigated whether mild CHI similarly impairs the implicit adaptation of visually-guided (reflexive) saccades, an important process which maintains saccadic accuracy.

METHODS

Within 2 weeks following mild CHI, 30 patients and 30 matched controls were compared on a computerized paradigm, which artificially induced saccadic adaptation. In response to an initial stimulus, subjects made a saccade during which the stimulus was displaced centripetally causing the initial (primary) saccade to be inaccurate. While these intra-saccadic changes remained unnoticed by the subjects, the displacements gradually caused adaptive saccadic hypometria.

RESULTS

No differences in adaptation were found between the CHI group and the controls (F(1, 29) = 0.51, p = 0.48). This finding indicates that mild CHI does not impair implicit reflexive saccade adaptation and suggests that cerebellar function and functions of deeper brain structures such as the thalamus, superior colliculus and the basal ganglia may be largely preserved following mild CHI. The current results support the notion that the profile of oculomotor function after mild CHI reflects a centripetal gradient of impairment and relates closely to the functional integrity of the injured brain.

Neuropsychological outcome and community re-integration following traumatic brain injury: The impact of frontal and non-frontal lesions

PRIMARY OBJECTIVE

To examine the relationship between cortical lesion location and brain injury outcome. It was hypothesized that focal frontal lesions after traumatic brain injury (TBI) would result in decreased executive and memory functioning and poor community participation outcome.

RESEARCH DESIGN

Three quasi-experimental, prospective studies employed a total of 643 patients with focal frontal, fronto-temporal, non-frontal or no lesions in CT scans.

METHODS AND PROCEDURES

CT scan analysis, neuropsychological assessment, the Neurobehavioural Functioning Inventory (NFI), the Community Integration Questionnaire (CIQ).

MAIN RESULTS

In study 1, frontal and fronto-temporal groups performed worse in executive functioning and better in constructional ability. Study 2 found no differences in neuropsychological and community re-integration measures at 1-year follow-up. Study 3 found comparable neuropsychological test score improvement across groups over 1 year.

CONCLUSIONS

Results are consistent with previous findings and document the potential for test score improvement with rehabilitation and suggest that lesion location needs to be considered when individual rehabilitation plans are being implemented in the post-acute stage of TBI.

Neurophysiological alterations during strategy-based verbal learning in traumatic brain injury

BACKGROUND

Verbal learning and strategic processing deficits are common sequelae of traumatic brain injury (TBI); however, the neurophysiological mechanisms underlying such deficits remain poorly understood.

METHODS

We performed functional magnetic resonance imaging (fMRI) in 25 individuals with chronic TBI (>1 year after injury) and 20 matched healthy controls. Subjects were scanned while encoding word lists, with free recall and recognition assessed after each scanning run. To vary the strategic processing load, participants learned semantically unrelated words (Unrelated condition), semantically related words under null instruction conditions (Spontaneous condition), and semantically related words following training on the use of a semantic clustering strategy (Directed condition).

RESULTS

Behavioral performance on recall, recognition, and semantic clustering improved significantly as follows: Unrelated < Spontaneous < Directed. Individuals with TBI exhibited impaired yet parallel behavioral performance relative to control participants. The fMRI measures of brain activity during verbal encoding revealed decreased activity in participants with TBI relative to controls in left dorsolateral prefrontal cortex (DLPFC; BA 9) and in a region spanning the left angular and supramarginal gyri (BA 39/40). Functional connectivity analysis revealed evidence of a functional-but not anatomical-breakdown in the connectivity between the DLPFC and other regions specifically when participants with TBI were directed to use the semantic encoding strategy.

CONCLUSION

After TBI, the DLPFC appears to be decoupled from other active brain regions specifically when strategic control is required. We hypothesize that approaches designed to help re-couple DLPFC under such conditions may aid TBI cognitive rehabilitation.

Intensive care unit variables and outcome after pediatric traumatic brain injury: a retrospective study of survivors

OBJECTIVE

Traumatic brain injury is a leading cause of death and disability in children. Hypotension has been associated with poor survival and outcome in children after traumatic brain injury, but the effect of acute hypertension is less certain. The objective was to obtain acute physiologic variables during the early hospitalization period in a cohort of children prospectively enrolled in another study.

DESIGN

Retrospective chart reviews.

SETTING

University-affiliated pediatric rehabilitation center.

PATIENTS

Fifty-seven survivors, 5-17 yrs of age, admitted for rehabilitation between 1992 and 1995 after sustaining a traumatic brain injury.

INTERVENTIONS

Standard of care.

MEASUREMENTS AND MAIN RESULTS

Outcomes were assessed at 1 yr postinjury through cognitive testing of the child and parent interview of the child's global functional skills. Cognitive outcome was measured using the Performance IQ from the Wechsler Intelligence Scale for Children, Third Edition. Overall functional outcome was assessed using the Disability Rating Scale.

CONCLUSIONS

This study suggests that early markers of secondary injury after moderate to severe traumatic brain injury in children may be predictive of long-term outcome. This study reinforces the need for longer term, systematic, and more precise measurements of outcomes in children with traumatic brain injury and prospective studies to examine the predictive value of acute management variables on multiple types of outcomes after traumatic brain injury in children.

Neuroanatomic correlates of CVLT-C performance following pediatric traumatic brain injury

Traumatic brain injury (TBI) frequently results in memory problems, and the degree of memory impairment is related to injury severity and is commonly associated with lesions in frontal and temporal brain areas. This study examined the relationship among injury severity, brain lesions, and memory in children with moderate to severe TBI using Donders' (1999) 5-factor model of performance on the California Verbal Learning Test-Children's Version (CVLT-C). Seventy-six children underwent magnetic resonance imaging (MRI) scans 3 months post-TBI and testing 1 year post-TBI. Results showed injury severity (Glasgow Coma Scale) was not predictive of performance on 4 of the 5 factors. Volume of frontal and/or temporal brain lesions was significantly predictive of performance on 3 of the 5 factors. Unexpectedly, lesion volume outside these areas (extra-frontotemporal) was predictive of performance on all 5 factors. In contrast, Verbal IQ at 1 year was most strongly associated with preinjury factors (socioeconomic status and special education involvement), although extra-frontotemporal lesions also contributed to the variability in this measure. Results suggest that in children with moderate to severe TBI, extra-frontal/temporal lesions are predictive of memory outcome 1 year postinjury above and beyond initial severity or frontal/temporal contusions. This finding may relate to widespread diffuse axonal injury, which potentially disconnects brain circuits mediating memory following moderate to severe TBI.

Dysarthria in traumatic brain injury: a breath group and intonational analysis

Prosodic abnormality is a common feature in the dysarthrias associated with traumatic brain injury (TBI), but very few analytic studies have been reported on the nature of the prosodic disturbances. This study, based on analyses of conversational and sentence speech samples, reports on breath group structure and its temporal and intonational components for 12 subjects with TBI and 8 healthy controls. It introduces the method of f0 close-copy stylization to the study of intonational patterns in dysarthria. The subjects with TBI had reduced mean length and variation of breath groups along with frequent inappropriate locations of breath pause and lengthy and variable breath pauses. Prosodic features that were preserved in the subjects with TBI were phrase final lengthening, f0 downtrend and a relatively normal f0 distribution. However, these subjects had reduced speaking and articulation rates, reduced f0 movement and reduced f0 slope. The phrase final lengthening and f0 downtrend phenomena, which can serve as prosodic cues of syntactic boundary, appear to be robust features of speech production, but the dynamic features of f0 control were more vulnerable to the neurological damage. This study indicates the importance of breath group management in TBI-induced dysarthria and the need to use methods such as those used in this study for large-scale investigations that examine cognitive, linguistic and motoric factors that conspire to reduce communicative efficiency.

Susceptibility weighted imaging: neuropsychologic outcome and pediatric head injury

Traumatic brain injury is among the most frequent pediatric neurologic disorders in the United States, affecting multiple aspects of neuropsychologic functioning. This study assessed the efficacy of susceptibility weighted imaging as a predictor of long-term neuropsychologic functioning after pediatric brain injury compared with magnetic resonance spectroscopic imaging. Susceptibility weighted imaging is a relatively new method that is considered superior to traditional magnetic resonance imaging sequences for detecting hemorrhagic diffuse axonal injury. In this study, imaging and spectroscopy were acquired 6 +/- 4 days after injury. Measures of neuropsychologic functioning were administered to 18 children and adolescents 1-4 years post injury. Negative correlations between lesion number and volume with neuropsychologic functioning were demonstrated. Lesion volume explained over 32% of the variance in cognitive performance, explaining at least an additional 20% beyond injury severity and age at injury alone and 19% beyond magnetic resonance spectroscopic metabolite variables. Exploratory analyses resulted in notable trends, with lesions in deeper brain regions more strongly associated with poorer neuropsychologic performance. Improved detection of the extent of diffuse axonal injury following a brain injury will allow for a better understanding of its association with long-term outcome, which in turn can improve prognostic efficacy for effective treatment planning.

Update of neuropathology and neurological recovery after traumatic brain injury

This review focuses on the potential for traumatic brain injury to evoke both focal and diffuse changes within the brain parenchyma, while considering the cellular constituents involved and the subcellular perturbations that contribute to their dysfunction. New insight is provided on the pathobiology of traumatically induced cell body injury and diffuse axonal damage. The consequences of axonal damage in terms of subsequent deafferentation and any potential retrograde cell death and atrophy are addressed. The regional and global metabolic sequelae are also considered. This detailed presentation of the neuropathological consequences of traumatic brain injury is used to set the stage for better appreciating the neurological recovery occurring after traumatic injury. Although the pathological and clinical effects of focal and diffuse damage are usually intermingled, the different clinical manifestations of recovery patterns associated with focal versus diffuse injuries are presented. The recognizable patterns of recovery, involving unconsciousness, posttraumatic confusion/amnesia, and postconfusional restoration, that typically occur across the full spectrum of diffuse injury are described, recognizing that the patient's long-term recovery may involve more idiosyncratic combinations of dysfunction. The review highlights the relationship of focal lesions to localizing syndromes that may be embedded in the evolving natural history of diffuse pathology. It is noted that injuries with primarily focal pathology do not necessarily follow a comparable pattern of recovery with distinct phases. Potential linkages of these recovery patterns to the known neuropathological sequelae of injury and various reparative mechanisms are considered and it is proposed that potential biological markers and newer imaging technologies will better define these linkages.

Saccade sequences as markers for cerebral dysfunction following mild closed head injury

Diffuse axonal injury caused by mild closed head injury (CHI) is likely to affect the neural networks concerned with the planning and execution of sequences of memory-guided saccades. Thirty subjects with mild CHI and thirty controls were tested on 2- and 3-step sequences of memory-guided saccades. CHI subjects showed more directional errors, larger position errors, and hypermetria of primary saccades and final eye position. No deficits were seen in temporal accuracy (timing and rhythm). These results suggest that computerized tests of saccade sequences can provide sensitive markers of cerebral dysfunction after mild CHI.

Is the spatial distribution of brain lesions associated with closed-head injury in children predictive of subsequent development of posttraumatic stress disorder?

PURPOSE

To determine whether there is an association between the spatial distributions of lesions detected at magnetic resonance (MR) imaging of the brain in children, adolescents, and young adults after closed-head injury (CHI) and development of the reexperiencing symptoms of posttraumatic stress disorder (PTSD).

MATERIALS AND METHODS

Data obtained in 94 subjects without a history of PTSD as determined by parental interview were analyzed. MR images were obtained 3 months after CHI. Lesions were manually delineated and registered to the Talairach coordinate system. Mann-Whitney analysis of lesion distribution and PTSD status at 1 year (again, as determined by parental interview) was performed, consisting of an analysis of lesion distribution versus the major symptoms of PTSD: reexperiencing, hyperarousal, and avoidance.

RESULTS

Of the 94 subjects, 41 met the PTSD reexperiencing criterion and nine met all three PTSD criteria. Subjects who met the reexperiencing criterion had fewer lesions in limbic system structures (eg, the cingulum) on the right than did subjects who did not meet this criterion (Mann-Whitney, P =.003).

CONCLUSION

Lesions induced by CHI in the limbic system on the right may inhibit subsequent manifestation of PTSD reexperiencing symptoms in children, adolescents, and young adults.

SPECT, MR and quantitative MR imaging: correlates with neuropsychological and psychological outcome in traumatic brain injury

This study examined the relative effectiveness of magnetic resonance (MR) imaging, single photon emission tomography (SPECT) and quantitative magnetic resonance (QMR) imaging in detecting brain abnormalities in 52 traumatically brain injured patients. The relationship between brain abnormalities and neuropsychological and psychological testing results was also investigated. Sixty-two per cent of patients had abnormal clinical MR findings, 57% had abnormal SPECT and 51% had abnormal QMR. Each neuroimaging modality detected brain abnormalities that the other two did not. Neuropsychological and psychological testing indicated significant memory impairments and subjective emotional distress even several years post-injury. Memory and intellectual impairments modestly but significantly correlated with the number of brain abnormalities indicated by all three imaging studies combined, as well as those detected individually by QMR and MR. SPECT abnormalities alone were not correlated with intellectual and memory outcome. Psychological distress was also related to the number of MR abnormalities, with most brain abnormalities being in the frontal areas.

Neuroimaging variables related to development of Secondary Attention Deficit Hyperactivity Disorder after closed head injury in children and adolescents

OBJECTIVE

To characterize children who develop Secondary Attention Deficit Hyperactivity Disorder (S-ADHD) after severe and moderate closed head injury (CHI) according to neuroimaging variables.

METHOD

Ninety-nine children from 4-19 years who suffered severe and moderate CHI were prospectively followed for a year after injury. Premorbid psychiatric status was determined by administration to the parent of a structured psychiatric interview. This interview was readministered 1 year after injury to determine the presence of post-closed head injury S-ADHD. An MRI was performed 3 months after injury to define lesion locations and volumes.

RESULTS

A set of multiple logistic regression models determined that the odds of developing S-ADHD were 3.64 times higher among children with thalamus injury, and 3.15 times higher among children with basal ganglia injury. There was no significant difference in lesion volumes in any of the locations of interest between the group who developed S-ADHD and the group who did not develop S-ADHD.

CONCLUSION

The data support an association between S-ADHD and injury in either or both the thalamus and basal ganglia, but they do not definitively demonstrate whether injury in either structure has an effect on S-ADHD in the absence of injury in the other.

Is the spatial distribution of brain lesions associated with closed-head injury predictive of subsequent development of attention-deficit/hyperactivity disorder? Analysis with brain-image database

PURPOSE

To determine whether there is an association between the spatial distribution of lesions detected at magnetic resonance (MR) imaging of the brain in children after closed-head injury and the development of secondary attention-deficit/hyperactivity disorder (ADHD).

MATERIALS AND METHODS

Data obtained from 76 children without prior history of ADHD were analyzed. MR images were obtained 3 months after closed-head injury. After manual delineation of lesions, images were registered to the Talairach coordinate system. For each subject, registered images and secondary ADHD status were integrated into a brain-image database, which contains depiction (visualization) and statistical analysis software. Using this database, we assessed visually the spatial distributions of lesions and performed statistical analysis of image and clinical variables.

RESULTS

Of the 76 children, 15 developed secondary ADHD. Depiction of the data suggested that children who developed secondary ADHD had more lesions in the right putamen than children who did not develop secondary ADHD; this impression was confirmed statistically. After Bonferroni correction, we could not demonstrate significant differences between secondary ADHD status and lesion burdens for the right caudate nucleus or the right globus pallidus.

CONCLUSION

Closed-head injury-induced lesions in the right putamen in children are associated with subsequent development of secondary ADHD. Depiction software is useful in guiding statistical analysis of image data.

Premorbid prevalence of ADHD and development of secondary ADHD after closed head injury

OBJECTIVE

To determine premorbid prevalence of attention-deficit hyperactivity disorder (ADHD) in children with moderate and severe closed head injury (CHI), to determine incidence of ADHD 1 year after injury, and to characterize children who develop ADHD by demographic, neuropsychiatric, and outcome variables.

METHOD

Ninety-nine children who had severe and moderate CHI were followed up for 1 year. Premorbid and 1-year postinjury psychiatric status were ascertained by parent and child structured interviews and questionnaires measuring affective lability, aggression, apathy, and social judgment.

RESULTS

Premorbid prevalence of ADHD was 0.20, significantly higher than in a reference population (0.045). Fifteen of the remaining 80 children (0.19) developed full ADHD criteria (except for age of onset) by the end of the first year. Children who developed secondary ADHD (S-ADHD) had significantly greater premorbid psychosocial adversity, posttraumatic affective lability and aggression, posttraumatic psychiatric comorbidity, and overall disability than children who did not develop S-ADHD.

CONCLUSIONS

There is an excess prevalence of premorbid ADHD among children who present with moderate and severe CHI. Children with high psychosocial adversity are more likely to develop S-ADHD after CHI. S-ADHD has criteria in common with personality change due to CHI, a deficit in behavioral inhibition being the major overlapping feature.

Are there any mild interhemispheric effects after moderately severe closed head injury?

Interhemispheric communication of motor, sensory and language information in parallel with information processing was investigated in four male patients (age range 22-37 years) 3 and 6 months after moderately severe closed head injury. Specific tasks of interhemispheric functions were given: linguistic tasks (tactile naming, writing and ideomotor praxis), motor tasks (graphaesthesia, tactile and finger localization) and sensory tasks (smell and colour vision). Information processing was evaluated by means of the Paced Auditory Serial Addition Task (PASAT). In comparison with age-matched controls (normals and paraplegics), post-injury findings indicated subtle motor, sensorimotor and language deficits in combinations suggesting mild interhemispheric disconnection. On most tasks, patients' performance improved over time along with gradual normalization of information processing. It is concluded that interhemispheric effects in the early phases after head injury may have a significant bearing on the process of recovery and functional restoration.

Evaluation of brain injury related behavioral disturbances in community mental health centers

As a result of improved emergency trauma services, more individuals suffering a traumatic brain injury are surviving. Unfortunately, most of these survivors suffer chronic neuropsychiatric sequelae related to both the brain damage and the psychosocial impact of the injury on self-esteem, self-image, primary role, and vocational function. Current community supports are often inadequate to deal with the complex array of neurologic and psychiatric difficulties. This article outlines common features of brain injury, explores the link between these features and the common neuropsychiatric sequelae of brain injury, and suggests some principles helpful in the evaluation of the behaviorally challenged brain injured patient.

Subpopulations in closed-head injury: preliminary results

The classification systems currently utilized to categorize closed-head injury (CHI) patients are all based on severity levels. However, these scales are unable to account for the wide variability among CHI patients. Another way to classify these patients is to use the clinical picture independent of the overall severity level. That approach is used with aphasic patients but not with the CHI population. These preliminary data indicate that there are distinct subgroups in the CHI population. These subgroups can be identified by their overall pattern of performance on a battery of tests covering language, memory, visuospatial, cognitive and discourse skills. The characteristics of the tentative subgroups are described, but a more extensive study is needed to confirm the robustness of this classification.

Cognitive flexibility and mental programming after closed head injuries and anterior or posterior cerebral excisions

Cognitive inflexibility and deficient mental programming are specifically related to frontal lobe lesions. The aim was to demonstrate that closed head injury (CHI) patients with brain lesions verified by computed tomography have such cognitive deficits, and are inferior in these respects to patients with posterior cerebral excisions mainly for tumours. This hypothesis was confirmed using a Category Identification and Sorting test as well as a measure of mental programming in a Spatial Learning task. Furthermore, CHI patients who had non-frontal parenchymal lesions were inferior by these measures to patients with posterior excisions. This result suggests that diffuse axonal lesion in CHI causes the deficits similar to those following frontal lobe excision.

Intercorrelation of lesions detected by magnetic resonance imaging after closed head injury

Forty-three patients with closed head injuries were followed up 5 to 12 months post-injury. Patients had magnetic resonance imaging (MRI) and performed a variety of neuropsychological tests. There were systematic relationships between lesions in different sites: depth of lesions in orbito-frontal regions, frontal regions, and temporal poles were particularly strongly intercorrelated. Depth of lesions in specific sites also correlated with an overall measure of brain damage: the number of areas with lesions present. After correcting for premorbid differences there were significant correlations between lesions in specific sites and scores on three out of five WAIS subtests. Scores on these three subtests also correlated significantly with overall brain damage. In general, hemispheric sites which were significantly related to neuropsychological measures also showed significant intercorrelations among themselves. The findings stress the importance of patterns of lesions in head injury, and emphasize the difficulty of showing differential localization of cerebral function in this population.

Cognitive test performances related to early and late computed tomography findings after closed-head injury

Computed tomography (CT) findings from early (less than 24 hours) and late scan (6 months) after closed-head injury (CHI) were compared to cognitive test scores obtained on an average of 4 months after injury in a consecutive series of 53 patients. The presence of parenchymal lesion was associated with poor test results, indicating cognitive inflexibility and disinhibition of routine response tendencies in novel tasks. These deficits have previously been found to be related in particular to frontal-lobe dysfunction, but the present study did not support the hypothesis that frontal lesion is the principal cause of this impairment in CHI. Parenchymal lesions in the right and left hemisphere were associated with spatial and verbal deficits, respectively. Ventricular enlargement in the late CT was related to cognitive inefficiency, both being strongly associated with age. The results suggest that parenchymal lesion in the early CT is an indicator of diffuse axonal injury, which results in cognitive inflexibility during recovery.