Amnesia following severe head injury.

This report concerns some aspects of the problem of establishing valid and reliable criteria for post-traumatic amnesia, and of relating this to other cognitive functions in the post-injury period. Of specific interest are the variability of the duration of retrograde and anterograde amnesia on attempts at repeated assessment, and the relationship between the time of return of full orientation and the end of the period of anterograde amnesia. A prospective study was undertaken of sixty consecutive patients who had suffered severe head injuries and had been admitted to the neurosurgical service of the Winnipeg General Hospital. The object of this study was to obtain information regarding organic, psychological and social indices of the future clinical course.     

Impaired emotional recognition following severe head injury

Four tests of emotional recognition from facial expression and posture cues were administered to 15 male closed head injury patients who had previously shown no impairment on a visual perception task. An equivalent number of controls matched for sex, age and verbal IQ were administered the same tests. Only those stimuli which validly depicted the stated emotion, identified by the controls performance, were included in the final analyses. Head injury patients were impaired on emotional recognition across all four tests compared to controls. No relationship between age, verbal IQ and emotional recognition could be found in either subject group. Similarly, no significant correlation between head injured and control performance across the 31 affective stimuli was found. Results indicated that the head injured were more impaired on the recognition of negative emotions than positive emotions. These findings are discussed with reference to the psychosocial difficulties encountered by the severely head injured.     

Conceptual encoding following severe closed head injury

This investigation examined whether survivors of severe closed head injury encode semantic properties of to-be-remembered words and the relationship of such processing to frontal lobe functioning. Fourteen patients enrolled in rehabilitation and 12 controls were administered the Release from Proactive Inhibition paradigm involving trials of recalling words from the same category followed by a shift to a new category or continued presentation of identical material. Similar to the controls, patients demonstrated a facilitation in recall when the category shifted. An association between the amount of release and frontal lobe functioning (as evaluated by neuropsychological tests and magnetic resonance imaging) was not compelling and depended upon the particular measure of release that was utilized. Pending replication in a larger, more representative sample, we suggest that conceptual encoding is relatively preserved in long-term survivors. The failure to find a robust relationship between frontal lobe pathology and semantic encoding is discussed in light of other investigations suggesting an association.     

Social recovery during the year following severe head injury.

A group of 54 patients who had suffered severe closed head injury (PTA >24 hours) were followed from the time of their injury for a period of two years. Relatives were interviewed within the first four weeks to assess the patient's previous personality and social adjustment. Patients and relatives were then assessed personally six and 12 months later and by postal questionnaires after two years. Only six patients were still not back at work after two years but more had not resumed all their leisure activities. Family relationships appeared to have settled down again by this stage but social contacts were still less frequent. Personality changes were associated with prior family relationships, cognitive changes with diminished social contacts whilst premorbid personality and physical deficits were associated with time taken to return to work.     

Pathophysiology, treatment and outcome following severe head injury in children.

The pathophysiology and outcome following severe head injury in 85 children are presented. The commonest initial CT diagnosis was of acute brain swelling. This swelling was associated with an increased white matter density on the CT scan which decreased to normal concomitant with recovery and increased ventricular size. CBF measurements in 6 of these patients revealed an increased blood flow despite a decreased CMRO2 and clinical coma. This CT pattern of diffuse swelling is believed to be due to acute cerebrovascular congestion and hyperemia and not to edema. Because of this, all children were treated with endotracheal intubation and controlled hyperventilation as part of the initial management. Mass lesions were uncommon, 20%. ICP was monitored in 40 children. The ICP rose above 20 Torr despite therapy in 80% of children with decerebrate or flaccid coma and in only 20% of children with spontaneous motor function. The ICP was at its highest between the second and fifth day. Aggressive therapy to control the ICP, with barbiturates if necessary, was successful in 80% of the patients. The overall results were useful recovery in 87.5% of the children, 3.5% were left vegetative or severely disabled and 9% died.     

Maternal reporting of behaviour following very severe blunt head injury.

Mothers of 40 very severely head injured male subjects rated their son's behaviour on the Current Behaviour Scale and their ratings were compared with mothers' ratings of 40 control male subjects. The scale was able to discriminate the two groups, by utilising two factors--loss of emotional control and loss of motivation. The mothers' level of emotional distress was closely related to their reporting of loss of emotional control in their sons, but reporting of loss of motivation, or lowered arousal, was strongly predicted by the functional disability of the son. The utility of refining the measurement of post-trauma behaviour is discussed.     

Carotid and vertebral artery injury following severe head or cervical spine trauma.

In order to determine the frequency of neck vessel injuries, Doppler investigations were performed in 60 patients following either severe head injury (n = 29), cervical spine injury (n = 26), or combined head and cervical spine injury (n = 5). The majority of patients were referred to our hospital for early rehabilitation; before admission Doppler investigations had been performed in only 2 patients. Clinically, 3 patients sustained severe cerebral ischemia due to neck vessel trauma: 1 patient with left-sided ICA dissection after head trauma revealed Doppler abnormalities only in the early phase of the disease; the second patient demonstrated persistent Doppler abnormalities due to traumatic right-sided ICA and VA occlusion. The third patient sustained a fatal vertebral and basilar artery thrombosis following cervical spine injury. In 57 patients without clinical signs suspicious of neck vessel trauma, sonography revealed abnormalities in 3 patients (11%) with severe head injury and in 6 patients (20%) with cervical spine or combined head and spine injury, in both groups mainly related to the vertebrobasilar system. Neck vessel injury is probably an underdiagnosed complication of severe head or cervical spine trauma. Although interpretation of Doppler findings may be difficult, particularly in the vertebrobasilar system, Doppler investigations can be recommended as a screening method to exclude neck vessel injuries.     

Behavioral assessment of social competence following severe head injury

Eighteen community-dwelling adults who had suffered a very severe closed-head injury more than 18 months previously and required long-term rehabilitative support were compared with a closely matched control group on a number of behavioral measures of skill during social interaction. Results showed that during social interactions the head-injured patients exhibited impaired communication skills. They appeared disinterested, and their speech was characterized as lacking in fluency and clarity due to their difficulty in finding appropriate words, use of inappropriate expressions and inability to express ideas clearly. Attempts to find a relationship between the patients' cognitive deficits and their impaired communication skills were unsuccessful. It is suggested that the often reported poor social adjustment of some head-injured patients is in part related to their inappropriate behavior during social interactions. This is particularly manifest in their poor language skills and speech delivery style.     

Memory failures in everyday life following severe head injury

Abstract

Questionnaires concerning the incidence of memory failures in everyday life were used in a postal survey of the aftereffects of severe head injury. Several years after a severe injury, 50 patients were compared to 33 patients a similar period after a very mild injury. A questionnaire completed on behalf of each patient by someone living in daily contact with him appeared to have some validity as a memory measure. The pattern of memory failures reported was similar to that found in a previous study and this may primarily reflect the ease with which certain forms of memory failure can be observed. A questionnaire completed by the patients themselves had little validity, possibly because severely injured patients could not recall their own memory failures. Only a minority of severely injured patients were reported to be significantly handicapped by memory failures at this stage in their recovery.     

Behavioral assessment of social competence following severe head injury

Abstract

The utility of the concept of «subcortical dementia» was investigated by comparing the verbal learning and memory abilities of Parkinson's disease (PD) patients with those of Huntington's disease (HD) patients. Many similarities between the PD and HD groups emerged, including impaired immediate memory spans, inconsistency of recall across learning trials, deficient use of a semantic clustering learning strategy, elevated intrusion rates on delayed recall, impaired recognition memory performance, normal retention of information over delay periods, normal vulnerability to proactive or retroactive interference, and normal types of intrusion errors. The HD subjects, however, displayed inferior free recall, deficient improvement across learning trials, abnormal serial position recall effects, higher perseveration rates, and supranormal improvement on recognition testing compared with free recall. Implications of these results for characterizing memory deficits associated with subcortical system dysfunction are discussed.     

Midbrain deafness following head injury.

A patient is described who became deaf following a head injury. Postmortem examination revealed bilateral lesions of the lateral lemnisci and inferior colliculi. The clinical pattern of midbrain deafness is examined and compared with syndromes of cortical and peripheral auditory impairment.     

Severe head injury: effect upon cellular immune function.

Infection is a major cause of morbidity following severe head injury. Although investigations have demonstrated central nervous system modulation of immune function, the effects of severe head injury on immune activity have not been well documented. This study prospectively investigated cellular immune function in 20 patients with isolated severe head injury. In vivo cellular immune status was determined by responses to delayed-type hypersensitivity (DTH) skin tests. In vitro studies included the effect of the lymphocyte mitogen, phytohaemagglutinin (PHA), on peripheral blood lymphocyte (PBL) phenotype expression and PBL blastogenesis. DTH skin testing demonstrated anergy to all antigens used during the first two weeks following head injury. Analysis of PBLs incubated with PHA demonstrated a decrease in the percent of PBL blastogenesis (p = 0.002), the percentage of cells marking as T-cells (p = 0.018), helper T-cells (p less than 0.001) and those expressing interleukin-2 receptors (p less than 0.001). There was a significant increase in the percentage of cells that marked as monocytes (p = 0.030), whereas there was no significant change in the percentage of B-cells, suppressor/cytotoxic T-cells, natural killer cells or in cells expressing the HLA-DR antigen. The infection rate was 55% with most occurring within 5 days of injury. The results of this study suggest that isolated severe head injury causes suppression of cellular immunity. The decrease in PHA stimulated PBL blastogenesis, helper T-cell phenotypic and interleukin-2 receptor expression, suggests suppression in early helper T-cell activation may be responsible for the high incidence of infection following severe head injury. The possible significance of increased monocyte phenotypic expression is discussed.     

Influence of cerebral oxygenation following severe head injury on neuropsychological testing

Abstract

Despite recent advances in the management of severe head injury the mortality and morbidity remains high. Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are crucial parameters for the correct management at the intensive care unit, due to their therapeutic and prognostic importance. In addition, regional brain tissue oxygenation (p_tiO₂) seems to be of importance. While different studies demonstrated the impact of cerebral hypoxia on outcome (mortality), no data are available focusing on morbidity (neuropsychological deficits). Therefore, our study is carried out to demonstrate a possible relationship between amount of cerebral oxygenation during acute stage after severe head injury and neuropsychological outcome. Besides ICP and CPP, p_tiO₂ was monitored in 40 severely head injured patients during the ICU stay from the day of admission until day 10. Monitoring data were stored and amount of hypoxic episodes were calculated. Besides outcome using the Glasgow Outcome Scale neuropsychological testing was performed 2–3 years after injury. Analysing the quality of brain tissue oxygenation, a relationship to the performance in neuropsychological tests could be found. Patients with low brain tissue oxygenation had a worse outcome in neuropsychological testing, especially concerning intelligence and memory. Associated with these deficits patients showed a reduced performance in their profession. Our data suggest a possible predictive value of brain tissue oxygen on morbidity analysing neurocognitive function after head injury. This may implicate monitoring and treatment of cerebral hypoxia.     

Frontal lobe dysfunction following closed head injury. A review of the literature

This review of the relationship between frontal lobe pathology and sequelae of closed head injury (CHI) emphasizes the variety of neuropsychological disturbances that may be present and factors that influence symptom presentation. First, the mechanisms of injury in CHI are briefly summarized with an emphasis on frontal involvement. This summary is followed by an overview of frontal lobe structure and function including behavioral and cognitive sequelae associated with frontal damage in other patient populations. Next, findings specifically related to frontal dysfunction in CHI patients are presented. These studies, although few in number, indicate that CHI patients frequently exhibit deficits indicative of frontal damage. The clinical implications of frontal dysfunction following CHI and potential avenues for future research are discussed.     

Influence of cerebral oxygenation following severe head injury on neuropsychological testing

Despite recent advances in the management of severe head injury the mortality and morbidity remains high. Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are crucial parameters for the correct management at the intensive care unit, due to their therapeutic and prognostic importance. In addition, regional brain tissue oxygenation (ptiO2) seems to be of importance. While different studies demonstrated the impact of cerebral hypoxia on outcome (mortality), no data are available focusing on morbidity (neuropsychological deficits). Therefore, our study is carried out to demonstrate a possible relationship between amount of cerebral oxygenation during acute stage after severe head injury and neuropsychological outcome. Besides ICP and CPP, ptiO2 was monitored in 40 severely head injured patients during the ICU stay from the day of admission until day 10. Monitoring data were stored and amount of hypoxic episodes were calculated. Besides outcome using the Glasgow Outcome Scale neuropsychological testing was performed 2-3 years after injury. Analysing the quality of brain tissue oxygenation, a relationship to the performance in neuropsychological tests could be found. Patients with low brain tissue oxygenation had a worse outcome in neuropsychological testing, especially concerning intelligence and memory. Associated with these deficits patients showed a reduced performance in their profession. Our data suggest a possible predictive value of brain tissue oxygen on morbidity analysing neurocognitive function after head injury. This may implicate monitoring and treatment of cerebral hypoxia.     

Patient outcome in the year following severe head injury and relatives'' psychiatric and social functioning.

Fifty-seven consecutive severe male head injury patients together with a defined female relative were assessed at home 3, 6 and 12 months after injury in order to measure the psychiatric and social impact of the injury on the relative. Relatives were found to have significant and persistent psychiatric and social dysfunction and they considered themselves to have a high burden in caring for the relative throughout the year. No particular relationship was found to be the more vulnerable. The most frequent predictor of the relatives' psychiatric and social status was the level of symptomatic complaints voiced by the patients. The findings suggest the need for comprehensive rehabilitation of head injury patients and their relatives.     

Cognitive impairment following closed head injury.

Cognitive impairments are usually the most disabling sequelae of CHI. The earliest stage of recovery from moderate to severe closed head injury is a period of PTA that typically includes memory loss for events preceding and surrounding the injury and memory loss for events occurring since the injury. Following resolution of PTA, deficits may be present in a number of cognitive domains. Memory and attention/information processing speed and efficiency are typically the cognitive domains most severely affected by head injury. Intellectual, language, and perceptual skills tend to be relatively preserved. Neurologic variables such as pupillary reactivity and worst GCS score are prognostic of cognitive impairment at 1 to 2 years postinjury. Following mild head injury, impairments of memory and information processing may be apparent within the first week of recovery. These deficits usually resolve in 1 to 3 months, although chronic complaints persist in a minority of individuals. The long-term cognitive effects of CHI are typically more severe for younger children than older children. Neuropsychologic assessment provides an objective way to measure the presence and severity of cognitive impairment.     

A comparison between electroencephalography and somatosensory evoked potentials for outcome prediction following severe head injury.

The value of somatosensory evoked potentials (SEPs) for the prediction of outcome following severe head injury (HI) is established. The role of the electroencephalogram (EEG) in this setting is uncertain. In this comparative study, SEPs and EEGs were recorded within 3 days of severe HI in 90 patients, and the results related to outcome at 6 months. Patients with an isoelectric EEG or an EEG with repeated isoelectric intervals died. Reactivity of the EEG to external stimulation tended to be associated with favorable outcome. Grading of the EEGs on the basis of frequency composition otherwise provided no prognostic information. The presence of SEP scalp potentials bilaterally predicted favorable outcome, particularly if the central conduction times were normal. Conversely, the absence of one of both scalp potentials was associated with unfavorable outcome. EEGs thus provided useful prognostic information in only a minority of patients. By comparison, SEPs allowed prediction of both favorable and unfavorable outcomes in a much larger number of patients, and were therefore prognostically superior.