Closed Head Injured Subjects Research Articles

Depth of Processing in Closed Head Injured Patients

Information processing problems in closed head injured (CHI) patients are well documented and manifest on both discourse and neuropsychological assessment. This article describes the use of a fable task with this population and argues that it is a particularly sensitive tool for exploring the communicative and cognitive deficits of such patients. The results of a group of 10 CHI subjects and 12 normal controls are presented on three fable tasks that tapped different levels of processing. Significant differences were found between the CHI subjects and the normal subjects on a rating scale that measured the appropriateness of overall response, as well as on individual operations performed. The results are interpreted in relation to a theory of resource allocation, and therapy implications for this population are highlighted.

Clinical Utility of Wechsler Memory Scale-Revised and Predicted IQ Discrepancies in Closed Head Injury

Comparisons between Wechsler Memory Scale-Revised (WMS-R) indexes and Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ scores have been proposed to identify severity of memory deficits. However, many neurologic conditions reduce both intellectual and memory functioning, and thus, examining differences between these scores may be of little value. Closed head injured subjects who completed the WMS-R were divided into either mild injury (MI, n = 41) or moderate/severe (SI, n = 41) injury groups based on trauma severity indicators and were matched on age and level of education. The Oklahoma Premorbid Intelligence Estimation (OPIE), a regression formula that takes into account demographic variables as well as IQ performance, was calculated for each subject. Discrepancy scores were calculated between predicted IQ scores and WAIS-R IQ and WMS-R indexes. SI head-injured subjects displayed significantly larger discrepancies (19 points) between OPIE scores and Delayed Recall Indexes from the WMS-R than the MI subjects (10 points). Significantly larger percentages of subjects in the SI group displayed significant (>SD) reductions in many of the WMS-R and WAIS-R scores from estimates than subjects in the MI group. Comparing current memory functioning to estimates of premorbid intellectual ability appears to be a sensitive indicator of presence and degree of intellectual and memory dysfunction in head trauma patients. Results also provide evidence that estimates of premorbid intellectual ability can serve as estimates of premorbid memory functioning. © 1997 National Academy of Neuropsychology. Published by Elsevier Science Ltd

Speech-language evaluation of closed head injured subjects in South Africa: Cultural applicability and ecological validity of a test battery

This paper addresses the communicative outcome of a group of closed head injured (CHI) subjects in South Africa. Communicative outcome is evaluated on one test battery currently used for medico-legal assessments in South Africa. It was found that a number of the tests were sensitive to breakdown in this sample, but that the demographic factors of first language and pre-injury education significantly affected performance on some tests. Many test performances were significantly related to return to work, thus confirming the importance of communicative skills in the workplace, and the speech-language pathologist's role in vocational assessment and rehabilitation.

Verbal rehearsal and memory in children with closed head injury: A quantitative and qualitative analysis

Nine closed head injured (CHI) children (mean age = 11.4 years) with post-onset intervals of seven months to eight years were studied. The CHI children ranged from mild-moderate to severely impaired. Nine normally developing children (mean age = 10.9 years) served as controls. An overt rehearsal free recall task was used. Subjects were instructed to “think aloud” following presentation of each item to-be-recalled. Quantitative analyses suggested impaired verbal recall and inefficient, passive rehearsal strategy use in severely injured subjects. Mild-moderate subjects performed similarly to controls and exhibited active rehearsal strategy use. Qualitative analysis revealed differences between CHI subjects and controls' range of rehearsal strategies, monitoring and metamemory. Implications for clinical assessment and intervention with respect to use of rehearsal strategies are discussed.

A physiological analysis of articulatory dysfunction in dysarthric speakers following severe closed-head injury.

A physiological analysis of the lip and tongue function of a group of 18 severely closed-head injured (CHI) subjects was performed using lip and tongue force transduction systems. Lip and tongue strength, endurance and rate of repetitive movements were assessed on four non-speech tasks: maximum strength, sustained maximum strength, repetition of 10 maximum strength compressions, and maximum repetition rate. The values recorded were compared to those achieved by a group of 18 non-neurologically impaired subjects, matched for age and sex, who served as the controls. The results of the study indicated that the CHI subjects demonstrated a significant impairment of lip and tongue function based on strength, endurance and rate of repetitive movements, compared to the controls. While lip function was found to be significantly impaired on several measures of strength and endurance, tongue function was noted to be more severely compromised. The CHI subjects were found to exhibit a significantly reduced rate of repetitive movements of the lips and tongue. The results are discussed in relation to the effects of CHI on neuromuscular function and differential subsystem impairment in dysarthria. The clinical implications of these findings are also discussed in relation to the treatment of articulatory disturbances following severe CHI.

Perceptual speech characteristics of dysarthric speakers following severe closed head injury.

The perceptual speech characteristics of a group of 20 severely closed head-injured (CHI) subjects were compared with those of a normal non-neurologically impaired control group matched for age and sex. The CHI subjects were found to be significantly less intelligible than the controls, and exhibited deficits in the prosodic, resonatory, articulatory, respiratory and phonatory aspects of speech production. The most frequently occurring deviant speech dimensions related to disturbances of prosody, resonance, articulation and respiration, with those deviant speech dimensions pertaining to phonation being less apparent in the speech of the CHI subjects. The findings are discussed in relation to the heterogeneity of the CHI population and the effects of CHI on neuromuscular function. The study highlights the need for accurate, instrumental physiological evaluation of the motor subsystems involved in speech production.

Hypernasality in dysarthric speakers following severe closed head injury: a perceptual and instrumental analysis.

Hypernasality in the dysarthric speech of 20 severely closed-head-injured (CHI) subjects was investigated using both perceptual and instrumental techniques. A perceptual analysis of the speech of the CHI subjects was performed using a four-point rating scale for hypernasality. Instrumental assessment was carried out using a computerized accelerometric technique yielding a nasal coupling index. Results revealed a high incidence of perceived hypernasality (95%) in the speech of subjects in the CHI group. More than half of these subjects exhibited hypernasality of speech to a moderate to severe degree. When compared with a control group matched for age and sex the severely CHI subjects were perceived as being significantly more hypernasal. Instrumental assessment revealed that the functioning of the velopharyngeal valve in the group of CHI subjects was significantly impaired compared to the control group. The study highlighted the need to evaluate the perceptual and instrumental assessment results for the severely CHI subjects on an individual basis. The clinical implications of these findings are discussed.

Differential pragmatic language loss after closed head injury: Ability to comprehend conversational implicature

AbstractTwo experiments in which 2 closed-head-injured (CHI) subjects and 12 non-brain-damaged control subjects took part investigated the capacity to comprehend indirect speech acts. In the first experiment, the subjects were required to interpret conventional indirect speech acts. One CHI subject, but not the other, had trouble rejecting the literal meaning. In the second experiment, the subjects were required to interpret the meaning behind two literally conflicting sentences. While the control subjects interpreted these as representing a sarcastic exchange, the CHI subjects were unable to provide an adequate explanation. The results were interpreted in terms of common cognitive deficits after closed head injury.

Analysis of conversational discourse in head-injured adults

In the study discussed In this article, appropriateness In conversations with a research assistant was examined in closed head Injured (CHI) adults and compared with normal subjects. Utterances of a speakerinitiator were designated as obliges (those that clearly summon or demand a response) or comments (those that do not). A differential response to these initiatives described whether the speaker was appropriately extending the conversation. Utterances of a speaker-responder were evaluated on a scale of appropriateness (adequate plus, adequate, inadequate, ambiguous). Results indicated that the two subject groups could be distinguished on the basis of (1) the CHI subjects' greater number of turns per conversation, (2) the research assistant's higher percentage of obliges in conversations with the CHI subjects, and (3) the quality of speaker responses.

Narrative and procedural discourse after closed head injury

Aspects of productivity, content, and cohesion in the narrative and procedural discourse of 11 closed head-injured (CHI) adults and 21 normal adults were examined. Two narrative tasks, one involving retelling a story heard and the other formulating a story based on a comic strip, and one procedural task of telling how to buy groceries were administered to each subject. CHI subjects consistently produced fewer words, spoke slower, used more mazes (dysfluencies), produced fewer target content units, and used fewer cohesive ties per utterance, as compared to the normal subjects. Other significant differences in discourse occurred between the two groups, but these varied from task to task. Normal subjects varied characteristics of their discourse performance according to the discourse task. Significant differences across tasks occurred on seven of the 13 discourse measures. The CHI subjects, however, showed more limited variation in that their performance varied on only three of the 13 measures. Correlations among discourse, language, and memory measures were examined and discussed. The results of this study indicate that analysis of CHI narrative and procedural discourse has important clinical and theoretical implications.

Effects of elicitation procedures on the narratives of normal and closed head-injured adults.

Stories were elicited under two conditions--story retelling and story generation--from a group of 23 normal young adults and 4 closed head-injured (CHI) adults who had reached a high level of language recovery. Sentence production, intersentential cohesion, and story grammar were analyzed. The results demonstrated that the two elicitation tasks differentially influenced the performance of both normal and CHI subjects at all levels of analysis, and the two groups differed in the cohesive and story grammar measures only in the story generation task. It is concluded that comparing performance across tasks of story retelling and story generation is a useful procedure for characterizing the discourse problems of CHI subjects with recovery of high-level language skills.

Evaluation of communication competence in patients with closed head injury

Twenty closed head injured (CHI) and 15 control subjects (non-CHI) were selected from a hospital population and evaluated after all CHI subjects were alert and conscious. The test battery included an audiometric evaluation and 21 subtests of intelligence, verbal expressive and receptive language, articulation, auditory and visual short-term memory, oral agility, automatic speech, writing, reading, and simple mathematics. The CHI subjects performed significantly less well than the control group on all subtests except articulation and five of the subtests of reading, writing, and mathematics. Additionally, the less severely involved CHI subjects performed significantly better than the more severely involved CHI subjects on the subtest, Automatized Sequences, and, to a lesser degree, Oral Agility. The implications are that CHI has an immediate generalized effect upon the cerebral mechanisms subserving intelligence, speech, language, memory, and specific writing, reading, and arithmetic skills and that the differences seen in automatic speech and oral-motor skills appear to be dependent upon the severity of the traumatic head injury. I recommend that all CHI patients undergo assessment for communication competence regardless of the level of severity of the trauma.