Sustained attention after severe closed head injury.

Sustained attention was assessed in 20 patients with severe closed head injury (CHI) and 20 normal matched controls. Participants were presented with a visual continuous performance task (CPT) with 3 levels of complexity. Performance was assessed by examining response latencies and error rates. Across all levels of complexity, the CHI patients demonstrated a vigilance decrement, whereas the performance of the matched controls was stable across time. The vigilance decrement was not differentially affected by the manipulation of task complexity in the CHI patients. However, findings suggest that the overall vigilance performance of CHI patients was differentially affected by increasing the complexity of the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual selective attention after severe closed head injury

This study investigated the nature of selective attention deficits after severe closed head injury (CHI). Twenty participants with severe CHI (greater than 1 year postinjury) and 20 matched controls completed search and nonsearch visual selective attention tasks under conditions of low (Experiment 1) and high (Experiment 2) target-distractor similarity. In the search situations, participants searched visual displays that contained 1, 4, or 8 items for the targets. In the nonsearch situations, the location of the targets was visually cued with a peripheral arrow. The results revealed that in both the low and high target-distractor similarity search conditions. CHI participants required a longer time than controls to locate and identify the target. In contrast, in the nonsearch condition, CHI participants were able to successfully ignore irrelevant task information when target-distractor similarity was low. However, when target-distractor similarity was high, CHI participants had more difficulty than controls ignoring the irrelevant information. These results suggest that, in comparison to controls, CHI participants may be at a disadvantage in selective attention situations when visual search is required and when the discriminability between targets and distractors is difficult.     

Automatic process development following severe closed head injury.

Automatic process development was investigated in a closed head injury (CHI) population. Ten severe CHI participants (>1 year postinjury) and 10 matched controls completed consistent mapping (CM) and varied mapping (VM) semantic-category memory search tasks. In VM search, despite a similar pattern of serial memory search, the CHI participants responded slower than controls and exhibited slower memory search rates throughout practice (1,800 trials). In CM search, after extensive practice (1,800 trials) both groups showed the performance characteristics indicative of automatic process development, that is, near-zero slopes and large reductions in response times. However, the CHI participants were slower to automatize the task. These results indicate that for memory-based search tasks the effects of a CHI may slow down the speed with which automatic processes develop but that CHI participants can acquire and use automatic processes in task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory remediation after severe closed head injury: Notebook training versus supportive therapy.

Evaluated the effectiveness of a 9-wk memory notebook treatment for closed-head injured (CHI) participants with documented memory deficits. Eight participants who had sustained a severe CHI more than 2 yrs earlier were allocated to receive either notebook training or supportive therapy. The notebook training group reported significantly fewer observed everyday memory (EMF) failures on a daily checklist measure than the supportive therapy group. Although in the same direction, this finding no longer reached significance at follow-up. No significant treatment effects were found for the laboratory-based memory measures at posttreatment or follow-up. Although the present results are to be considered preliminary because of the small sample size, they suggest that notebook training has the potential to help individuals compensate for everyday memory problems and that the methods used to measure training efficacy are important. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral changes after closed head injury in children.

This study provides a longitudinal follow-up of the behavioral adjustment of 45 children with mild, moderate, and severe closed head injuries. Two measures of behavioral adjustment, the Child Behavior Checklist (CBCL) and the Vineland Adaptive Behavior Scales (VABS), were obtained from a parent at the time of injury and at 6 and 12 months postinjury. The severely injured children obtained significantly poorer VABS scores than children with mild and moderate injuries over the year-long follow-up. In addition, on the CBCL, severely injured children had more school problems and engaged in fewer social activities than mild and moderately injured children. These results show that severe head injury in children was associated with declines in adaptive functioning, whereas scores for children with mild and moderate injuries did not differ, nor did they deviate from average levels at any follow-up interval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term psychosocial adjustment following very severe closed head injury.

Examined the cognitive, psychological, and social functioning of 18 community-dwelling male patients who had experienced a severe closed head injury (CHI) at least 18 mo previously and still required contact with rehabilitation services. Results from Ss with CHI were compared with those from 27 normal control Ss. Information on Ss' behavior was also obtained from their significant others. Results show that Ss with CHI exhibited deficits in their cognitive and social functioning but showed no signs of emotional or psychiatric disturbance. Attempts to find a relationship between the cognitive impairment and social functioning of Ss with CHI were partially successful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of verbal learning after closed head injury.

Cluster analysis of the learning trials and delayed free-recall trials of 70 patients with closed head injury on the California Verbal Learning Test (CVLT) revealed 3 distinct patterns of memory performance. The clusters differed in the amount and rate of learning, retroactive interference, and the level of delayed recall. There was a significant positive relationship between performance on the CVLT and performance on concurrent measures of attention, semantic memory, and intellectual ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Event-related potentials as an index of cognitive function during recovery from severe closed head injury

OBJECTIVE: To evaluate the utility and neuropsychological correlates of serially performed recordings of event-related potentials (ERPs) in patients recovering from a severe closed head injury (CHI). DESIGN: Prospective longitudinal study. SETTING: Brain injury rehabilitation unit based in a national rehabilitation hospital. SUBJECTS: Sixteen patients with severe CHI (significant degree of impaired consciousness greater than 24 hours) subclassified into two severity groups according to initial Glasgow Coma Scale (GCS) score: those with initial GCS score < 9, consistent with a more severe injury; and those with initial GCS score > 8, indicating a less severe injury. METHODS: ERPs were elicited using the standard auditory P300 "oddball" detection paradigm. ERP recordings were carried out three times: 2 months after injury, 1 month later, and 2.5 months or more after the initial study. Parameters analyzed included latencies and amplitudes of the P3, N2, P2, and N1 components of the ERPs. Correlations between changes in these ERP parameters and specific neuropsychological test results were evaluated. RESULTS: Initial P3 latencies in the more severely injured group were significantly longer (P < .05) than those recorded in the less severely injured patients. In subsequent recordings, P3 latency was found to be significantly shorter compared with the initial P3 latency, and the difference in P3 latency between the two patient groups was no longer statistically significant by the time of the third recording. For the group as a whole, P3 latency decreased significantly on each repeated recording. N2 latency was found to be significantly shorter (P < .05) between the first and third recordings. Cognitive performance significantly improved between the first and third recordings. P3 latency shortening was correlated with improvement in neuropsychological test scores for short-term and long-term story recall and for word recall. N2 latency shortening was correlated with improvement in the neuropsychological test scores for word recall only. CONCLUSION: ERP recordings performed in the subacute stage after CHI may assist in evaluating injury severity. Moreover, serially performed recordings of P3 latency may be used as a physiologic index of brain activity that correlates with recovery from CHI.     

Discourse after closed head injury in young children

This study examined narrative discourse in 23 children, ages 6 to 8 years, who sustained a severe closed head injury (CHI) at least 1 year prior to assessment. Narratives were analyzed at multiple levels using language and information structure measures. Results revealed significant discourse impairments in the CHI group on all measures of information structure, whereas differences in the linguistic domain failed to reach significance. In addition, effects of age at injury and lateralization of lesion on discourse were considered. Although no significant differences were found according to age at injury, a consistent pattern of generally poorer discourse scores was found for the early injured group (< 5 years). With regard to lesion focus, the group findings were unimpressive. However, preliminary examination of individual CHI cases with relatively large lateralized lesions suggested that the late injured children may show the language-brain patterns reported in brain-injured adults, whereas early injured children may not.     

Sagittal sinus thrombosis after closed head injury

We describe a patient with trisomy 8 mosaicism followed through a sixth pregnancy and discuss issues in phenotypic and genotypic variability, the risk for neoplasia, and reproductive risks.     

Hypnosis and attention deficits after closed head injury

In a controlled study of patients attending a concussion clinic because of ongoing postconcussion symptoms, attention deficits were recorded in the head-injured group for the aspects of alertness, assessed by the Continuous Performance Test (CPT), and processing capacity, assessed by a version of the Paced Auditory Serial Addition Test (PASAT). Selective attention was intact. Hypnotizability was assessed by the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), with normal means and standard deviations found in both the concussed and control groups. There was a significant correlation, however, between HGSHS:A scores and PASAT scores in the concussed group only. The results of this preliminary study suggest that slower processing capacity after a closed head injury may predict higher hypnotizability and that hypnosis could be an appropriate rehabilitation technique for these patients who present with postconcussion symptoms.     

Naturalistic action impairment in closed head injury.

The authors sought to determine whether errors of action committed by patients with closed head injury (CHI) would conform to predictions derived from frontal lobe theories. In Study 1, 30 CHI patients and 18 normal controls performed routine activities, such as wrapping a present, under conditions of graded complexity. CHI patients committed more errors even on the simplest condition; but, except for a higher proportion of omitted actions, their error profile was very similar to that of controls. Study 2 involved a subset of patients whose performance in Study 1 was within normal limits. When these high functioning patients were asked to perform the routine tasks under still more taxing conditions, they, too, committed errors in excess of the control group. Accounts based on frontal mechanisms have a difficult time explaining the overall pattern of findings. An alternative based on limited-capacity resources is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imaging of closed head injury

The endocrinology of late gestation and parturition in the mare has been described, but unlike other domestic animal species, the factors that initiate parturition in the mare have not been elucidated. In contrast to ruminant species, maternal estrogen and progesterone concentrations do not change markedly, and a well-defined fetal cortisol surge is not observed just prior to parturition in the mare. Parturition is associated with large increases in prostaglandin and oxytocin concentrations, which induce uterine contractions and delivery of the foal. There are many methods of inducing parturition in term mares, but the most popular and safest method is through the administration of low-dose oxytocin.     

Semantic priming after severe closed head trauma: Automatic and attentional processes.

The 2-process theory of semantic priming (J. H. Neely, 1977; M. I. Posner and C. R. Snyder, 1975) was used to determine the maintenance of automatic processes after severe closed head injury (CHI) and to determine whether processes that demand attention suffer a deficit. Ss with severe CHI (N?=?18,?>?2 yrs postinjury) and 18 matched control Ss completed a lexical decision task in which a category prime was followed by a target. Automatic and attentional priming were determined by orthogonally varying prime–target relatedness, expectancy, and stimulus onset asynchrony. Although the CHI Ss had slower reaction times (RTs) overall, there were no significant group differences in the magnitude of either the automatic or attentional component of semantic priming. The present results indicate the integrity of semantic processes and normal semantic priming in long-term patients with severe CHI. The results are discussed in relation to an attentional resource hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Actual versus self-reported scholastic achievement of litigating postconcussion and severe closed head injury claimants.

Psychologists typically rely on patients' self-report of premorbid status in litigated settings. The authors examined the fidelity between self-reported and actual scholastic performance in litigating head injury claimants. The data indicated late postconcussion syndrome (LPCS) and severe closed head injury litigants retrospectively inflated scholastic performance to a greater degree than nonlitigating control groups. The LPCS group showed the highest magnitude of grade inflation, but discrepancy scores did not significantly correlate with a battery of malingering measures or with objective cerebral dysfunction. These findings support previous studies, which showed self-report is not a reliable basis for estimation of preinjury cognitive status. Retrospective inflation may represent a response shift bias shaped by an adversarial context rather than a form of malingering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Major depression in patients with closed head injury.

Interviewed 120 patients with closed head injury (CHI) with regard to depressive symptoms at least 2 yrs after the date of injury. 92 Ss met Diagnostic and Statistical Manual of Mental Disorders (DSM-III) criteria for major depressive disorder. Half of the depressed CHI Ss did not manifest depressive symptoms until at least 6 mo after being injured. Bipolar affective disorder and schizophrenia were uncommon following CHI. CHI patients may be at increased risk for development of major depressive disorder. CHI patients should be screened for depressive symptoms after they appear to have made a "full" recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frontal lobe changes after severe diffuse closed head injury in children: a volumetric study of magnetic resonance imaging

In view of the pathophysiology and biomechanics of severe closed head injury (CHI) in children, we postulated that the frontal lobes sustain diffuse injury, even in the absence of focal brain lesions detected by magnetic resonance imaging (MRI). This study quantitated the morphological effects of CHI on the frontal lobes in children who sustained head trauma of varying severity. The MRI findings of 14 children who had sustained severe CHIs (Glasgow Coma Scale score of < or = 8) were compared with the findings in a matched group of 14 children having sustained mild head injuries (Glasgow Coma Scale score of 13-15). The patients ranged in age from 5 to 15 years at the time of their MRIs, which were acquired at least 3 months postinjury. MRI findings revealed no focal areas of abnormal signal in the frontal lobes. Volumetric analysis disclosed that the total prefrontal cerebrospinal fluid increased and the gray matter volume decreased in the patients with severe CHI, relative to the mildly injured comparison group. Gray matter volume was also reduced in the orbitofrontal and dorsolateral regions of the brains of children with severe CHI, relative to the children who sustained mild head trauma. These volumetric findings indicate that prefrontal tissue loss occurs after severe CHI in children, even in the absence of focal brain lesions in this area. Nearly two-thirds of the children who sustained severe CHIs were moderately disabled after an average postinjury interval of 3 years or more, whereas 12 of the 14 patients with mild CHIs attained a good recovery (2 were moderately disabled) by the time of study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of divided attention on implicit and explicit memory performance following severe closed head injury.

This study investigated the relation between attentional limitations and memory impairments in patients with closed head injuries (CHI). Twenty-seven CHI participants ( > 1 year postinjury) and 27 matched controls rated their liking of target words under conditions of full and divided attention. Participants then completed an implicit test of tachistoscopic identification (TI) and an explicit test of recognition for the target words As expected, the results revealed impaired explicit memory but preserved perceptually driven implicit memory performance following a CHI. Contrary to what was hypothesized, a reduction in attention available at encoding did not disproportionately impair the recognition performance of the CHI patients. Finally, unlike controls, the CHI participants' priming scores on the TI task were significantly affected by dividing attention at encoding. However, this finding interacted with CHI participants perceptual processing rates, suggesting that nonmemory cognitive factors may influence measured performances on implicit memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive recovery correlates with white-matter restitution after head injury

Longitudinal measurements of local cerebral perfusion (LCBF) and local partition coefficients (L lambda) using xenon-enhanced computed tomography were examined in six patients who had suffered from head injury at a mean age of 30 +/- 9.3 years. They were selected from a larger group with head injury because all were observed longitudinally to make excellent cognitive recovery some years after acute cerebral trauma. Results were compared with similar longitudinal measurements made in six age-matched neurologically normal volunteers. In the index group, cognitive test scores were reduced at the time of the first LCBP measurement but significantly improved to normal at the time of the second. The mean interval between measurements was 2.7 +/- 0.7 years. At the time of the first measurement, all six patients exhibited abnormal volumes of white matter with reduced Hounsfield numbers and LCBF and L lambda values. Abnormalities in volume of white matter and LCBF and L lambda values improved to normal at the time of the second measurement. Perfusion values for frontal cortex, putamen, and thalamus were still slightly reduced but also improved toward normal between measurements. Cognitive recovery correlated best with restoration of white matter integrity, suggesting that following head injury, cognitive impairments may be associated with temporary disconnections of corticothalamic projection systems.     

Affective state and awareness of sensory and cognitive effects after closed head injury.

Found that emotional dysphoria was significantly and positively correlated with awareness of sensory and cognitive change in 42 Ss with closed head injury (CHI). Compared with their rehabilitation therapists, Ss tended to underestimate the sensory and cognitive effects of their injury, but agreement between Ss and therapists was highest for those sensory and cognitive functions that Ss could accurately define. S awareness of the sensory and cognitive effects of CHI may be formed from an interaction among at least 4 variables: the assessment measure used, the S's preinjury awareness, motivational influences (e.g., denial), and damage to the frontal lobes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)