Alvin McLean

Neuropsychological and psychosocial consequences of minor head injury.

Twenty subjects with minor head injury were compared to an uninjured group at 1 and 12 months after injury on a battery of neuropsychological and psychosocial measures. The results indicate that single minor head injury in persons with no prior compromising condition is associated with mild but probably clinically non-significant difficulties at 1 month after injury. Disruptions of everyday activities, however, are extensive with other system injuries significantly contributing to these problems. Recent reports in the literature may represent overestimation of head injury related losses due to lack of control for the effects of pre-injury characteristics and other system injuries.

The behavioral sequelae of head injury

Twenty patients with mild and, in a few cases, moderately severe head injuries were examined 3 days and 1 month postinjury. The results indicate that these patients, as compared to appropriate controls, show significant neuropsychological difficulties at 3 days, but not at 1 month postinjury. Postconcussional symptoms are endorsed, on the other hand, at both 3 days and 1 month. Absence of significant neuropsychological findings at 1 month is contrary to some of the previous reports. A number of reasons for this discrepancy were discussed. Some of these included: (a) inappropriate controls used in previous research; (2) failure to screen for pre-existing conditions in prior studies, therefore confounding the effects of the injury with pre-injury factors; (3) possible practice effects in our research; and (4) differences in the neuropsychological measures used across different studies.

Neuropsychological recovery in patients with moderate to severe head injury: 2 year follow-up

Neuropsychological outcome and recovery of a group of 31 consecutive adult patients with moderate to severe head injuries were prospectively investigated over a 2-year period. A friend control group was used for comparison purposes. Based on the results we conclude: (1) there is marked impairment of a broad spectrum of neuropsychological functions at 1, 12, and 24 months postinjury; (2) coma length is significantly related to neuropsychological status at all three time periods, although the relationship is weaker at 12 and 24 months; (3) marked improvement in all functions occurs in the first year, while recovery in the second year appears more specific and may depend on the severity of the injury and type of function; (4) practice effects and variability over repeated measures cause difficulties in determining recovery and need to be addressed with larger samples.

Psychosocial recovery after head injury

Psychosocial recovery after head injury was prospectively examined at 1 and 12 months postinjury in a group of 102 hospitalized adult head-injured patients representing a broad range of head injury severity. For comparison purposes, 102 friend controls were used. Outcome was assessed with a battery of psychosocial measures including the Sickness Impact Profile, the Head Injury Symptom Checklist, and the Modified Function Status Index. The results indicate that head-injury patients experience significant psychosocial problems (eg, ability to return to work, resume leisure activity, concentrate and remember information, feelings of irritability) at both 1 and 12 months postinjury but these difficulties improve over time. Whereas improvements occur in both psychosocial and physical areas of functioning, improvements are greater in the physical area. The nature and extent of difficulties seen vary as a function of head injury severity, and time from injury to observation. Finally, the results suggest that not all problems reported by head-injured patients are solely related to the injury (eg, irritability, anxiety, fatigue, or headaches).

Memory and head injury severity.

One hundred and two consecutive head injured patients were studied at 1 and 12 months after injury. Their performances were compared with a group of uninjured friends. The results indicate that impairment in memory depends on the type of task used, time from injury to testing, and on the severity of head injury (that is, degree of impaired consciousness). Head injury severity indices are more closely related to behavioural outcome early as compared with later after injury. At 1 year, only those with deep or prolonged impaired consciousness (as represented by greater than 1 day of coma, Glasgow Coma Scale of 8 or less, and post traumatic amnesia of 2 weeks or greater) are performing significantly worse than comparison subjects.

Psychosocial functioning at 1 month after head injury.

The authors examined the psychosocial sequelae of head trauma at 1 month after injury in a group of 102 adult head-injured patients representing a broad range of severity of trauma. One hundred two control subjects selected from friends of the head-injured patients were used for comparison purposes. Outcome was determined with a battery of psychosocial measures assessing a number of different areas of daily functioning. The results support the following conclusions: (a) at 1 month after injury, head-injured patients experience difficulties in a number of areas of psychosocial functioning, especially the resumption of major role activities (i.e., work, school, and home management) and leisure/recreational activities; (b) the relationship between head injury severity level and the adequacy of psychosocial functional differs for the various measures; and (c) in determining the psychosocial consequences of head trauma, the use of an appropriate control group is essential.

Development and evaluation of modifications to the sickness impact profile for head injury

Three modifications were made to the Sickness Impact Profile, a behavior-based measure of health status, to improve its sensitivity to the effects of head injury. (1) Additional items were included to capture head injury sequelae and behaviors typical of young adults, the age group to which head injury most frequently occurs. (2) Subjects individually excluded behaviors irrelevant to them, thus allowing the score to better reflect injury-related changes. (3) The different areas of functioning on the Sickness Impact Profile were reweighted to reflect global judgments of the constructs contribution to overall functioning rather than the sum of the item contributions. Only the first modification is head-injury specific. The others, are relevant to any disease or injury. The performance of the modifications was evaluated in a longitudinal study of 102 head injured and 102 comparison subjects tested at 1 and 12 months after injury. The evaluation of the modifications was based on their ability to distinguish head injury from comparison subjects and on the strength of their relationship with measures of brain dysfunction. Despite a few statistically significant improvements in discrimination, differences of a practical degree were not obtained. The standard Sickness Impact Profile performed well and is recommended for evaluation of day-to-day functioning in head injury studies.

Head Injury in the Pacific Northwest

This report describes 451 consecutive patients admitted to a regional trauma center with head injury over 1 years time. Our results replicate findings from other hospital- and population-based studies of head trauma. Males exceeded females by 3 to 1; the most frequent age of patients was between 15 and 24 years; and motor vehicles were the most common cause of injuries. Mortality was related inversely to Glasgow coma scale (GCS) scores and directly to age. This study also points out two current problems in head trauma research. One is the difficulty in using the GCS in a community with highly sophisticated emergency medical services. In 38% of the patients, one or more GCS components could not be assessed directly. In 17% of cases, GCS scores could not be confidently assigned. This was principally because endotracheal tubes were in place before arrival at the hospital, precluding determination of the verbal response. A second problem is the influence of chronic pre-existing central nervous system conditions on head outcome. Twenty-nine per cent of our patients had one or more such conditions at the time of their injury. Minimal estimates of prevalence ranged from 1% (mental retardation) to 18% (alcoholism).

General versus disease-specific measures. Further work on the Sickness Impact Profile for head injury.

Three modifications devised to make the Sickness Impact Profile more sensitive to head injury are evaluated in 202 head-injured and 132 general trauma patients 1 month and 12 months after injury. The modifications consist of adding items, deleting nonapplicable items, and reweighting areas of function. Each of the modifications, and especially all three combined, slightly but significantly improve discrimination of head-injured and comparison subjects and increase correlations with neurologic and neuropsychologic severity indexes. These slight improvements occur more often at 12 months than at 1 month and among those without rather than with pre-existing conditions. No improvements are found in the ability to classify patients into subgroups. The modifications fail to make improvements sufficiently large or consistent to provide a practical advantage over the SIP. The standard SIP provides a reasonable measure of psychosocial functioning following head injury. It relates to head injury and other system injury severity and reflects recovery with time. The SIP score relates to emotional functioning even after injury severity has been taken into account. Until other factors, such as emotional status and responses style, are better controlled, little benefit is likely to be obtained from creating disease-specific psychosocial measures.

Memory training combined with the use of oral physostigmine.

Impaired memory function is one of the most frequent and disabling symptoms observed after brain injury. A number of studies have examined the efficacy of using cholinergic agonists, such as physostigmine, in treating memory impairment resulting from various neurologic conditions. Few studies, however, have either combined the drug treatment with a memory training programme or monitored serum cholinesterase levels to increase the likelihood of achieving a therapeutic dose of the medication. The current study addresses both of these issues. Two single-case studies are reported in this investigation. In each case, a double-blind, placebo-controlled, single-subject, A-B-A design was used with A representing the base-line phases, B constituting the memory training combined with medication phase and A representing the return to base-line condition. Both patients sustained anoxia as a result of carbon monoxide poisoning. In the first case, a clinically significant improvement was seen in the patients performance of both standardized and non-standardized measures of memory function as a result of the combined treatment regimen. No significant changes, however, were seen in the patients performance on measures of attention and concentration, cognitive flexibility or motor speed. These findings were then replicated with the second anoxic patient. The results from this study point out the potential benefit of combining cholinergic agonists with specific memory training strategies in improving memory function after brain injury.