Biomedical subjects

W M High

Publications and source records attributed to W M High.

35 records · Page 2Linked to original sources

PubMed1989

Magnetic resonance imaging after closed head injury in children.

Magnetic resonance imaging (MRI) was performed in a series of 21 children and adolescents who had been hospitalized after sustaining closed head injuries of varying severity at least 6 months previously. Areas of high intensity in the parenchyma were present in 8 of the 11 severely injured patients, whereas MRI findings were normal in all 10 patients with mild-to-moderate head injuries. Lesions involving the subcortical white matter were confined to severely injured patients whose clinical features were compatible with diffuse axonal injury. Neuropsychological assessment disclosed deficits primarily in the severely injured patients; these deficits were significantly associated with persistent lesions visualized by MRI. Serial MRI and neurobehavioral assessment following early injury may be useful in documenting cognitive impairment in relation to structural alterations of the young brain.

Adolescent↗

PubMed1988

Automatic and effortful processing after severe closed head injury.

To investigate the automatic versus effortful distinction following severe closed head injury (CHI), we administered free recall and frequency of occurrence tasks to patients and controls. In Experiment 1 we found that both free recall (an effortful task) and judgment of relative frequency of occurrence (an automatic task) were impaired in 15 CHI patients as compared to 14 controls. In Experiment 2 we corroborated this finding and showed that absolute estimates of frequency were also impaired in new samples of 16 patients and 16 controls. We infer that cognitive tasks which normal individuals can perform without practice, feedback, or instructions may demand more effortful strategies following severe CHI.

Adult↗

PubMed1988

Learning and forgetting during posttraumatic amnesia in head injured patients.

To investigate forgetting during recovery from head injury, colour slides were initially projected for long durations to ensure acquisition on a recognition test given 10 minutes later. Patients tested during posttraumatic amnesia (PTA) exhibited accelerated forgetting over 32 hours as compared with head trauma patients studied after the period of PTA and normal controls.

Adult↗

PubMed1988

Disproportionately severe memory deficit in relation to normal intellectual functioning after closed head injury.

The presence of disproportionate memory impairment with relatively preserved intellectual functioning was examined in 87 survivors of moderate or severe closed head injury. Approximately one-fourth of the patients tested at 5 to 15 and/or 16 to 42 months after injury manifested defective memory on both auditory and pictorial measures despite obtaining Wechsler Verbal and Performance Intelligence Quotients within the average range. The findings indicate that disproportionately severe memory deficit persists in a subgroup of closed head injured survivors which is reminiscent in some cases of the amnesic disturbance arising from other causes. Evaluation of long term memory in relation to cognitive ability could potentially identify important distinctions for prognosis and rehabilitation in head injured patients.

Adult↗

PubMed1988

Memory functioning during the first year after closed head injury in children and adolescents.

Effects of the severity of closed head injury (CHI) on verbal learning and memory and visual recognition memory were studied at base line and on a 1-year follow-up examination in 58 pediatric admissions sampled from three age ranges, 6-8, 9-12, and 13-15 years. Within each age range, recovery of memory was compared in patients with mild to moderate CHI and survivors of severe injury. Consistent with previous findings obtained in head-injured children sampled from a wide age range, the present study confirms that memory deficit persists at least 1 year after severe CHI. Impairment of visual recognition memory was directly related to severity of CHI in all three age ranges. The severity of CHI was directly related to initial and residual verbal memory deficit in adolescents, but this effect was inconsistent in children. We suggest that the cerebral substrate for visual recognition memory was well established in all three age ranges and thus was vulnerable to the effects of injury. In contrast, verbal memory skills were undergoing rapid development in the adolescents, but were still immature in children. Extended follow-up could conceivably demonstrate the late appearance of verbal memory deficit in the children who had apparent sparing of function.

Adolescent↗

PubMed1988

Relationship of depth of brain lesions to consciousness and outcome after closed head injury.

Magnetic resonance (MR) imaging was performed in 94 patients who sustained closed head injury of varying severity. Results of MR studies obtained after the intensive care phase of treatment disclosed that intracranial lesions were present in about 88% of the patients. Consistent with the centripetal model of progressive brain injury proposed in 1974 by Ommaya and Gennarelli, the depth of brain lesion was positively related to the degree and duration of impaired consciousness. Further analysis indicated that the relationship between depth of brain lesion and impaired consciousness could not be attributed to secondary effects of raised intracranial pressure or to the size of intracranial lesion(s).

Adolescent↗

PubMed1988

Sustained attention and information processing speed in chronic survivors of severe closed head injury.

Sustained attention and information processing speed in 15 long-term survivors of severe closed head injury and 14 demographically matched controls have been examined. The average time between head injury and testing was 3.6 years. The performance of patients on all tasks was impaired relative to controls, thus documenting persistent deficits in attention. Of particular interest was the finding that controls were capable of redirecting and improving their sustained attention during a test session versus the steady decline in patient performance. The findings are discussed within the framework of controlled attentional processes.

Adult↗

PubMed1987

The neurobehavioural rating scale: assessment of the behavioural sequelae of head injury by the clinician.

To investigate the inter-rater reliability and validity of the Neurobehavioural Rating Scale at various stages of recovery after hospitalisation for closed head injury, we studied 101 head trauma patients who had no antecedent neuropsychiatric disorder. The results demonstrated satisfactory inter-rater reliability and showed that the Neurobehavioural Rating Scale reflects both the severity and chronicity of closed head injury. A principal components analysis revealed four factors which were differentially related to severity of head injury and the presence of a frontal lobe mass lesion. Although our findings provide support for utilising clinical ratings of behaviour to investigate sequelae of head injury, extension of this technique to other settings is necessary to evaluate the distinctiveness of the neurobehavioural profile of closed head injury as compared with other aetiologies of brain damage.

Adolescent↗

PubMed1987

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.

Adolescent↗

PubMed1987

Magnetic resonance imaging and computerized tomography in relation to the neurobehavioral sequelae of mild and moderate head injuries.

Twenty patients admitted for minor or moderate closed-head injury were studied to investigate the relationship between magnetic resonance imaging (MRI) and neurobehavioral sequelae. The MRI scans demonstrated 44 more intracranial lesions than did concurrent computerized tomography (CT) scans in 17 patients (85%); most of these lesions were located in the frontal and temporal regions. Estimates of lesion volume based on MRI were frequently greater than with CT; however, MRI disclosed no additional lesions that required surgical evacuation. Neuropsychological assessment during the initial hospitalization revealed deficits in frontal lobe functioning and memory that were related to the size and localization of the lesions as defined by MRI. Follow-up MRI and neuropsychological testing at 1 month (13 cases) and 3 months (six cases) disclosed marked reduction of lesion size paralleled by improvement in cognition and memory. These findings encourage further investigation of the prognostic utility of MRI for the clinical management and rehabilitation of mild or moderate head injury.

Adolescent↗

PubMed1987

Neurobehavioral functioning and magnetic resonance imaging findings in young boxers.

In a prospective investigation of neurobehavioral functioning in young boxers, 13 pugilists and 13 matched control subjects underwent tests of attention, information-processing rate, memory, and visuomotor coordination and speed. The results disclosed more proficient verbal learning in the control subjects, whereas delayed recall and other measurements of memory did not differ between the two groups. Reaction time was faster in the boxers than in the control subjects, but no other differences were significant. Ten subjects in each group were retested 6 months later and exhibited improvement in their neuropsychological performance as compared to baseline measurements. However, there were no differences in scores between the boxers and the control subjects at the follow-up examination or in the magnitude of improvement from baseline values. Magnetic resonance imaging, which was performed in nine of the boxers, disclosed normal findings.

Adult↗

PubMed1986

Effects of oral physostigmine and lecithin on memory and attention in closed head-injured patients.

In view of the evidence for the role of the central cholinergic pathways in memory and preliminary studies suggesting alteration of neurotransmitters after severe head injury, we completed a double-blind, placebo-controlled study of combined oral physostigmine and lecithin. Sixteen survivors of moderate to severe closed head injury who had unequivocal memory deficit were studied during the course of inpatient rehabilitation. Although the results generally indicated no difference in the effects of the physostigmine-lecithin combination as compared to lecithin alone, sustained attention on the continuous performance test was more efficient under physostigmine than placebo when the drug condition occurred first in the crossover design. Further investigation of neurotransmitter manipulation is warranted in patients with traumatic brain injury.

Administration, Oral↗

PubMed1985

Impairment of olfactory recognition after closed head injury.

To investigate the effects of closed head injury (CHI) on olfactory identification, we administered a test of olfactory naming and forced choice recognition to 52 CHI patients who had no evidence of anosmia. The Olfactory Identification Test consisted of 'scratch and sniff' labels of familiar nonirritant odorants. In comparison with a normal control group (n = 19) of similar age, olfactory naming and recognition were impaired in the CHI series, particularly in patients with moderate or severe head injury. The presence of a haematoma or contusion in the frontal/temporal region was also related to impaired olfactory recognition. We suggest that nonmissile head injury can produce at least a partial impairment of olfactory recognition despite relatively preserved olfactory detection.

Adolescent↗

PubMed1985

Impairment of remote memory after closed head injury.

Evidence of partial retrograde amnesia for episodic memories of no personal salience was found in head injured patients (n = 10) tested during posttraumatic amnesia or shortly after its resolution (n = 10), but there was no selective preservation of the earliest memories. In contrast, head injured patients tested during posttraumatic amnesia exhibited relatively preserved retention of early autobiographical memories which they recalled as accurately as oriented head injured patients. It is suggested that reminiscence of salient, early events increases their resistance to partial retrograde amnesia and contributes to the observed temporal gradient.

Adolescent↗

PubMed1985

Neurobehavioral outcome after gunshot wounds to the head in adult civilians and children.

To assess the quality of long term outcome of civilian gunshot wounds to the head after intensive neurosurgical management, particularly with regard to the possibility of subtle problems due to diffuse injury, we administered neuropsychological tests to six survivors (four adults and two children) at about 1 year after injury. Five patients were moderately disabled, and one patient achieved a good recovery. Residual neurobehavioral sequelae were present in all cases. Defects in long term memory for new information were the most common sequelae, whereas the persistence of linguistic and visuospatial deficits was related to the hemispheric lateralization of injury. In comparison with the outcome reported for patients with closed head injuries who had similar Glasgow coma scale scores, our patients exhibited more severe impairment due to significant focal brain injuries and less evidence of diffuse damage.

Adult↗

PubMed1984

Evoked potential correlates of posttraumatic amnesia after closed head injury.

The P-300 component of evoked potentials to a rare tone was measured in normal volunteers and in patients with closed head injuries who either were confused (in posttraumatic amnesia) or had recovered from posttraumatic amnesia and were oriented at the time of recording. The latency of this component, which reflects cortical processing of stimuli, varied reliably, with the degree of orientation being longest for confused patients and shortest for normal subjects. On the basis of these data, we suggest that the P-300 latency can be used as a physiological index of cognitive function in patients with closed head injury.

Adolescent↗

PubMedDate not supplied

Functional outcome from traumatic brain injury: unidimensional or multidimensional?

This study compared multidimensional and unidimensional measures of functional outcome from traumatic brain injury in a referred sample of 67 persons with moderate to severe traumatic brain injury who resided in the community or in a nonhospital facility. Four outcome indicators (independence in self-care, independence in travel, paid employment, and friendship) were correlated with the patients' ratings on two unidimensional outcome measures, the Disability Rating Scale (DRS) and Glasgow Outcome Scale (GOS), and on a multidimensional outcome measure, the Craig Handicap Assessment and Reporting Technique (CHART). The results showed that the CHART Occupation and Social Integration scales were associated with different outcome indicators, controlling for overall outcome as measured by the DRS and GOS. DRS and GOS ratings were associated more strongly with the self-care and travel indicators than with the employment or friendship indicators. The results support a multidimensional model of functional outcome from brain injury, suggest that the CHART may measure some outcome dimensions more specifically than do the DRS and GOS, and point to limitations of unidimensional outcome scales.

Adult↗