Vegetative state after closed-head injury. A Traumatic Coma Data Bank Report.

To elucidate the clinical course of the vegetative state after severe closed-head injury, the Traumatic Coma Data Bank was analyzed for outcome at the time of discharge from the hospital and after follow-up intervals ranging up to 3 years after injury. Of 650 patients with closed-head injury available for analysis, 93 (14%) were discharged in a vegetative state. In comparison with conscious survivors, patients in a vegetative state sustained more severe closed-head injury as reflected by the Glasgow Coma Scale scores and pupillary findings and more frequently had diffuse injury complicated by swelling or shift in midline structures. Of 84 patients in a vegetative state who provided follow-up data, 41% became conscious by 6 months, 52% regained consciousness by 1 year, and 58% recovered consciousness within the 3-year follow-up interval. A logistic regression failed to identify predictors of recovery from the vegetative state.

Deficits in auditory-spatial integration of sequentially presented patterns due to cortical lesions.

Groups of patients with cortical lesions were subjected to a uniquely developed procedure to test auditory-spatial perception. The stimuli were comprised of a sound source, which sequentially outlined a pattern within a 10 X 10 matrix of loudspeakers. Simple sound patterns, which "moved" across the loudspeaker array only once or twice, were equally well identified by the control group and the various patient groups. However, the more complex patterns, which outlined the contour of alphabetical letters, resulted in significantly lowered identification rates for the patient groups with lesions in the right posterior, left posterior and left temporal lobes. As a control measure, visual-spatial tasks were administered, and lower performance rates were found for the left and right posterior groups. The differences and similarities between auditory spatial and visual-spatial processing are discussed.

Parallel and serial visual search after closed head injury: electrophysiological evidence for perceptual dysfunctions.

Event-related potentials (ERPs) were recorded from closed head injury (CHI) patients at least 2 years postinjury and from controls in order to assess their parallel and serial processing abilities during visual search. In Experiment 1, stimuli consisted of arrays of eight triangles; half of the arrays contained a target item. In the "feature-present" condition, the target item was a triangle with an additional horizontal line that could be detected automatically and in parallel, while in the "feature-absent" condition all items except for the target triangle had an additional horizontal line, thus requiring a serial search. In Experiment 2, stimuli consisted of eight solid bars (50%), seven solid bars and a vertical open bar (25%), and seven solid bars and a horizontal open bar (25%): the array containing the horizontal bar served as a target. By recording ERPs to the arrays containing vertical open bars, which were similar to the target items, parallel processing of "pop-out" stimuli could be studied in the absence of any overt response. ERP data were compared with the results of neuropsychological and neuroimaging (MRI, CAT) examination. Patient exhibited a decreased behavioral performance both in the parallel and in the serial processing mode. Furthermore, abnormalities of early and intermediate ERP components (P1, N1, P2, N2) were found, whereas the late component (P3) was less affected by CHI. The results were interpreted as an index of CHI-induced dysfunctions in perceptual processes such as simple feature registration and early target discrimination. It was suggested that these dysfunctions contribute to impairments of parallel as well as serial processes in visual search.

Motivational effects on neuropsychological functioning: comparison of depressed versus nondepressed individuals.

The neuropsychology of depression was examined in terms of organic and motivational hypotheses. Thirty medication-free depressed outpatients (selected according to Diagnostic and Statistical Manual of Mental Disorders [American Psychiatric Association, 1980] criteria for major depression) and 30 nondepressed normal controls were evaluated with a variety of neuropsychology measures. Prior to testing, subjects were assigned randomly to either a motivated or nonmotivated condition. A task measuring level of motivation demonstrated efficacy of the two motivation conditions. A 2 x 2 (Diagnosis x Motivational Level) multivariate analysis of variance of all the dependent measures revealed a significant main effect for depression, but no effect for motivation and no interaction. Univariate analyses demonstrated that the depressed group was impaired on visuospatial short-term memory and learning and on verbal learning. The finding of neuropsychological deficit in depressed subjects was not attributable to motivational factors. The problems with conceptualizing depression as a right-hemisphere dysfunction are discussed.

Computer-assisted attention retraining in head-injured individuals: a controlled efficacy study of an outpatient program.

The efficacy of a computer-assisted attention retraining program was evaluated with 29 outpatients suffering from moderate to severe traumatic brain injury. Ss who were at least 12 months postinjury were randomly assigned either to the attention training program or a memory training program that served as a control condition. Training lasted 9 weeks with two 2-hr sessions per week for both groups. The experimental design evaluated outcome by juxtaposing a multiple baseline procedure for a 1st set of measures of attention and memory with a pre and post group comparison that relied on a 2nd set of neuropsychological tests. The experimental group improved significantly in comparison with the control group on measures of attention. The reversed pattern for the memory measures was not observed. None of the treatment effects generalized to the 2nd set of dependent variables.

Neuropsychological sequelae of arteriovenous malformations.

A total of 24 patients harboring arteriovenous malformations (AVMs) in either the dominant hemisphere (n = 12) or the nondominant hemisphere (n = 12) were examined neuropsychologically. When compared with 24 matched normal control subjects, the AVM patients demonstrated differential degrees of impairment in verbal or visuospatial processing, depending on whether the lesion involved the dominant or nondominant hemisphere. As predicted, most compelling were the findings of cognitive deficit associated with the hemisphere contralateral to the AVM relative to matched normal control subjects. Evidence of higher cortical dysfunction contralateral to the residing AVM is discussed in the context of cerebrovascular steal.

Preoperative versus postoperative neuropsychological sequelae of arteriovenous malformations.

In a cohort of 14 patients suffering from cerebral arteriovenous malformations (AVM), neuropsychological functioning was examined before and after AVM resection. Improvements after surgery were assumed to be due to enhanced neurocognitive functions associated with the hemisphere ipsilateral to the AVM, and to a lesser extent, with the contralateral hemisphere. Before surgical intervention, the performances of AVM patients were deficient relative to matched normals. Postoperatively, neuropsychological gains were observed particularly in the areas of learning, memory, and higher integrative thought, not only for ipsilateral, but also for contralateral functioning. Contralateral and ipsilateral improvement is consistent with the premise that cerebrovascular steal is lessened; thus, neurosurgical intervention to eliminate arteriovenous shunts was found to result in overall neurobehavioral gains.

Neurobehavioral outcome following minor head injury: a three-center study.

The majority of hospital admissions for head trauma are due to minor injuries; that is, no or only transient loss of consciousness without major complications and not requiring intracranial surgery. Despite the low mortality rate following minor head injury, there is controversy surrounding the extent of morbidity and the long-term sequelae. The authors postulated that consecutively admitted patients who fulfilled research diagnostic criteria for minor head injury and who were carefully screened for antecedent neuropsychiatric disorder and prior head injury would exhibit subacute cognitive and memory deficits that would resolve over a period of 1 to 3 months postinjury. To evaluate this hypothesis, the neurobehavioral functioning of 57 patients was compared within 1 week after minor head injury (baseline) and at 1 month postinjury with that of 56 selected control subjects at three medical centers. Quantified tests of memory, attention, and information-processing speed revealed that neurobehavioral impairment demonstrated at baseline by all means of measurement generally resolved during the first 3 months after minor head injury. Although nearly all patients initially reported cognitive problems, somatic complaints, and emotional malaise, these postconcussion symptoms had substantially resolved by the 3-month follow-up examination. The data suggest that a single uncomplicated minor head injury produces no permanent disabling neurobehavioral impairment in the great majority of patients who are free of preexisting neuropsychiatric disorder and substance abuse.

Neurobehavioral outcome 1 year after severe head injury. Experience of the Traumatic Coma Data Bank.

The outcome 1 year after they had sustained a severe head injury was investigated in patients who were admitted to the neurosurgery service at one of four centers participating in the Traumatic Coma Data Bank (TCDB). Of 300 eligible survivors, the quality of recovery 1 year after injury was assessed by at least the Glasgow Outcome Scale (GOS) in 263 patients (87%), whereas complete neuropsychological assessment was performed in 127 (42%) of the eligible survivors. The capacity of the patients to undergo neuropsychological testing 1 year after injury was a criterion of recovery as reflected by a significant relationship to neurological indices of acute injury and the GOS score at the time of hospital discharge. The neurobehavioral data at 1 year after injury were generally comparable across the four samples of patients and characterized by impairment of memory and slowed information processing. In contrast, language and visuospatial ability recovered to within the normal range. The lowest postresuscitation Glasgow Coma Scale (GCS) score and pupillary reactivity were predictive of the 1-year GOS score and neuropsychological performance. The lowest GCS score was especially predictive of neuropsychological performance 1 year postinjury in patients who had at least one nonreactive pupil following resuscitation. Notwithstanding limitations related to the scope of the TCDB and attrition in follow-up material, the results indicate a characteristic pattern of neurobehavioral recovery from severe head injury and encourage the use of neurobehavioral outcome measurements in clinical trials to evaluate interventions for head-injured patients.

Construct validity of the San Diego Neuropsychological Test Battery.

A group of 259 normal adults were administered the San Diego Neuropsychological Test Battery. Factor analysis of the SDNB supported the construct validity of the battery according to a Luria-based functional systems assessment approach. Using expert ratings to interpret the obtained factor loadings, the following factors were identified: (a) arousal, (b) mnestic processes, (c) complex intelligence, and (d) planning. A second factor analysis of the SDNB, using a sample of 100 schizophrenic and head injured cases, achieved a factor structure very similar to that of the normal sample, offering further empirical support for a functional assessment approach with clinical populations. The clinical factor analysis yielded slightly different proportions of variance contributed by the test measures and two planning factors. The results are discussed as they relate to Luria's qualitative analysis of cortical organization applied to a quantitative methodology.

The efficacy of structured memory retraining in a group comparison of head trauma patients.

Empirically proven mnemonic techniques from the literature were assembled into a comprehensive treatment program for brain injured clients. Twenty head injured subjects with mild to moderate neuropsychological impairments were matched on the variables of age, sex, years of formal premorbid education, and elapsed time since insult. These patients were then randomly assigned to either the control or experimental remediation group. Both groups attended a six-week program and were blind as to what type of treatment they were receiving. Each followed identical daily schedules where the experimental group received the formal memory remediation and the controls received treatment focusing on psychosocial issues. Both groups improved on the neuropsychological memory measures over the course of the study. The experimental group did not improve significantly more than did the control group; however, once the groups were subdivided according to the severity of neuropsychological functioning at intake, significant treatment effects were observed. More specifically, only those patients with mild residual impairments seemed to benefit from rehabilitative efforts, and those with more moderate deficits did not respond to treatment. Clinical implications and future research are discussed.

Neuropsychological sequelae of exposure to the chlorinated hydrocarbon solvents trichloroethylene and trichloroethane.

Reports in the literature concerning the acute neurobehavioral effects of trichloroethylene (TCE) and trichloroethane (TCA) conflict as to whether or not cognitive deficits ensue. Our study of two patients acutely exposed to low concentrations of TCE suggests that (a) acute, low-dose exposures are sufficient to produce the mild to moderate impairments in psychomotor speed, attention and memory also reported after chronic exposures; (b) these memory impairments may be characterized by storage and/or retrieval difficulties; (c) the neural damage produced by TCE exposure is likely to be diffuse, but temporal lobe structures supporting memory may be more sensitive to TCE exposure than other brain structures; and (d) even brief exposures can lead to prolonged, but not necessarily chronic mild to moderate cognitive impairment. In a third case, exposed to trichloroethane (TCA), the neuropsychological profile suggests that this substance has few, if any, neurobehavioral effects at low concentrations.

Impaired verbal and figural fluency after head injury.

Previous research has found that verbal fluency is reduced in head-injured patients and in patients with focal damage to the frontal lobes. The present study compares a task of verbal associative fluency with a new measure of nonverbal, or figural, fluency that focuses on speed of producing unique designs and accounting for perseverative tendencies. Using results from 35 head-injured patients and 50 normals, we found that both verbal and figural fluency are compromised following brain trauma. Consistent with previous research, patients with severe head injuries were more impaired than patients with moderate head injuries. The discussion focuses on those cognitive factors that might influence verbal or figural fluency.

Dementia as a neuropsychological consequence of chronic occupational exposure to polychlorinated biphenyls (PCBs).

Previous epidemiological and clinical studies of humans exposed to polychlorinated biphenyls (PCBs) indicate that the majority of patients have neurological complaints (e.g., headache, vertigo, paresthesias, poor memory and concentration, fatigue, depression). Since only a small minority of PCB-exposed patients demonstrate abnormalities on objective neurological measures (e.g., CT-scans, EEC, nerve conduction velocity), it is particularly unfortunate that objective neuropsychological data has not been published to substantiate patient complaints. The present study provides neuropsychological test data on two patients exposed to PCBs. In both cases, PCB exposure is documented by an analysis of PCB levels in the patients' work environments. Despite the absence of abnormalities on CT-scans and EEC, both patients displayed a variety of cognitive deficits and emotional disturbance. Serial assessment of one patient with high blood levels of PCBs revealed a dementia (sharing certain features with Alzheimer's disease) and an organic affective syndrome. Assessment of a second patient exposed to PCBs (but with no detectable blood levels of PCBs) suggested that his cognitive impairments were not due to PCB exposure. The present study provides data which points to the importance and sensitivity of neuropsychological examination in cases of PCB-exposure.

The use of significant others to enhance the detection of malingerers from traumatically brain-injured patients.

Cognitive and neurobehavioral symptoms are common following traumatic brain injuries (TBIs). Because malingerers are likely to complain of such symptoms and perform poorly on neuropsychological tests, clinicians may have considerable difficulty distinguishing malingerers from TBI patients. In this study, we compared the subjective complaints of malingerers to TBI patients and then compared both groups to the problems observed by their respective significant others. We tested the assumption whether significant others could add one more piece to the challenging puzzle of diagnosing malingering. Our results demonstrated that the malingerers complained of more problems than patients who had sustained moderate or severe TBI. However, the significant others of the malingerers observed fewer cognitive, emotional-behavioral, and total problems than did the significant others of patients with severe, moderate, and even mild TBI. These findings suggest that the detection of malingering can be enhanced by interviews with significant others.

Benton Controlled Oral Word Association Test: reliability and updated norms.

The aim of this paper is to update the over 20-year-old normative data for the Benton Controlled Word Association (COWA) Test. In a sample of 360 normal volunteers, the age ranged between 16-70 years, and the educational level ranged from 7-22 years. Care was taken to ensure that the population was heterogeneous, yet the two stratifications of gender, four age, and three educational groups led to 24 cells with 15 individuals in each. Test-retest reliability was established by testing 30% of the sample after a 6-month delay, which represents a typical follow up duration between testings in a clinical setting. The two forms of the COWA revealed significant test-retest reliability. Generally, our updated values fall above the original normative values, which were derived from a less well-educated and rural sample. No major gender or age trends were noted, but the COWA test performances were influenced by education, i.e., as the level of education increased, the performance on the COWA increased. The only gender differences that were found were for the women in the highest educational group ( > 16 years), who performed significantly better that men in the highest educational group. An error analysis of repetitions or perseverations is provided, with cut-off scores according to age levels. Finally, the updated COWA norms are compared to the original norms as well as to other measures of word fluency.

Figural fluency: differential impairment in patients with left versus right frontal lobe lesions.

Based on an experimental study, Jones-Gotman and Milner demonstrated that patients with right frontal lobe lesions were impaired on design fluency. We sought a clinical adaptation and developed a psychometrically sound technique for design fluency. The present study explores the validity of the Ruff Figural Fluency Test (RFFT) in discriminating patients with either right frontal or nonright frontal lobe lesions. In the first of two studies, six subjects with circumscribed focal lesions were given the RFFT and the Jones-Gotman and Milner figural fluency task. In the second study, we identified a larger sample of 30 patients with focal lesions in the right frontal, left frontal, right posterior, or left posterior cortex. The results from both studies support the validity of the RFFT as a measure which is sensitive to right anterior dysfunction.

The psychological construct of word fluency.

Measures of word fluency have been convincingly linked in the literature to damage in the left prefrontal lobe region. Yet, a reduction in word fluency has also been reported with diffuse, multifocal and nonfrontal lobe damage. Despite the undisputed neuropsychological application of multiple word fluency measures, the psychological construct underlying this measure is not well understood. In a sample of 360 normal adults stratified by age, gender, and level of education, we found that auditory attention and word knowledge were among the most important determinants. With respect to memory, short-term memory was not significantly correlated, but long-term memory was. Despite these three determinants, a large share of the variance of the multiple regression was still not accounted for, which underscores the partial independence of word fluency per se. Thus, we propose a distinction between (1) poor word fluency secondary to deficient verbal attention, word knowledge, and/or verbal long-term memory and (2) impaired word fluency without these three areas concurrently affected. Based on a review of the literature, it seems likely that in the latter condition, the profile is more associated with prefrontal lobe impairment, versus in the former condition, diffuse multifocal or nonfrontal lobe factors can play a role.

Estimation of premorbid functioning after traumatic brain injury.

Estimation of premorbid functioning in patients with traumatic brain injury (TBI) is a difficult but necessary step both in the assessment of neurological impairment and in planning treatment. Because the estimation process is almost always retrospective, its reliability is questionable. The use of multiple sources of information improves the likelihood of an accurate estimate. The effects of TBI cross a number of domains in the victim's life. Thus, premorbid functioning must be estimated in the physical, cognitive, emotional, social, financial and vocational spheres. Knowledge of baseline or premorbid functioning levels allows the clinician to appreciate the severity of injury, provide a prognosis, and shape treatment goals that are specific to the individual. In this article, we present the key questions to be addressed, suggest sources of information to obtain the answers, describe the processes through which answers should be obtained, and outline the uses for this important information in working with victims of TBI.

Factorial validation of the Ruff-Light Trail Learning Test (RULIT).

The factorial validity of the Ruff-Light Trail Learning Test (RULIT) was evaluated for its specificity as a test of visuospatial learning and memory. In a sample of 307 normal adults, principal components analyses (PCAs) were calculated on scores from the RULIT and selected neuropsychological tests. The PCAs revealed visuospatial learning and memory components, which included RULIT scores that were empirically distinct from verbal learning and memory components. These results provide support for the RULIT as a measure of visuospatial learning and memory.