It has been shown that awareness of deficits following Traumatic Brain Injury (TBI) is often impaired, and that adequate rehabilitation programs have not yet been developed to treat this phenomenon (Prigatano, 1990). There is no consensus as to which brain region, when damaged, is responsible for self-awareness deficits as well as the degree to which deficits exists. The origin of the impairment, whether it be psychological or organic in nature, is also debated.
This article summarizes the current research and theories encompassing the issue of awareness after TBI and introduces existing models of treatment. Implications for future research are also discussed.
Awareness of deficits following Traumatic Brain Injury (TBI) is often impaired. It is repeatedly shown that TBI patients grossly overestimate their competencies as a result of the reduced amount of insight they have into their abilities. Awareness deficits have been related to both right hemisphere brain injuries and frontal lobe damage. There is also strong evidence that awareness deficits have an organic component as opposed to purely psychological. The implications for these deficits include greatly diminished vocational potential as well as strained interpersonal relationships.
This article addresses the issues surrounding awareness of deficit after TBI. It includes a review of the recent literature, a discussion of psychological versus organic origins of awareness deficits, brain regions presumed to be associated with such deficits, existing treatment models, implications for future research, and summary and conclusions.
It has been suggested in the literature that awareness of deficits following Traumatic Brain Injury (TBI) is often impaired (Prigatano, 1991). This impairment of awareness is demonstrated in a number of maladaptive ways, yet a clear understanding of its nature has yet to be developed. Prigatano and Schacter (1991) define self-awareness as the capacity to "perceive a situation, object, or interaction in a manner similar to others' perceptions, while at the same time maintaining the sense of a private, subjective, or unique interpretation of an experience." pg. 12. The state of self-awareness is a higher cerebral function and some authors (Stuss and Benson, 1986) go so far as to say that it is the highest of all integrated functions.
In the clinical arena, deficits in self-awareness are manifested by TBI patients in a variety of ways. Many patients underestimate the extent of their deficits, claim that their family members over-exaggerate their impairments, and/or demonstrate unrealistic ideation about the future. Decreased self awareness has also been described as an inability to understand the implications of one's own actions, a limited capacity to self-monitor, and a dissociation between actions and thoughts (Stuss, 1991). We would like to thank Cognitive Rehabilitaion Institute for their support during the process of this research.
TBI patients demonstrating limited awareness fail to recover maximally due to outright denial of their deficits. Often, they return to work prematurely with out realizing the postmorbid behavioral limitations they possess. (Gobble, Henry, Pfalhl, and Smith, 1987). Not recognizing these behavioral difficulties, TBI patients continue to function in maladaptive ways, and are confused when vocational goals fail. Hurt (1990) states that premature return to work often results in the patient's inability to meet prior work performance standards which leads to decreased self-esteem and lowered confidence in work competence. Also, deficits in awareness contribute to the patient's inability to evaluate himself objectively and set realistic work goals.
This continued lack of awareness culminates in financial hardship, decreased self-esteem, and eventual social isolation. Despite the vast amount of research in this area, there continues to be relatively few assessment measures and treatment techniques designed to address this phenomenon. Yet awareness deficits pose such a problem that adequate rehabilitation programs addressing this difficulty are desperately needed.
However, there is still much to understand before these treatment regimens can be developed. The literature presents conflicting ideas on many of the issues involving awareness of deficits associated with TBI. There has been disagreement as to which brain region, when damaged, is responsible for such deficits (Stuss, 1991; Gilmore, Heilman, and Schmidt, 1992). Also, the origin of the impairment, whether it be psychological or organic in nature, is debated (Weinstein and Kahn, 1955; Goldberg and Barr, 1991).
This article summarizes the current research relating awareness deficits with TBI, discusses the current controversy surrounding psychological versus organic origins of self-awareness deficits, and provides support for the organic view of why deficits occur by examining the different brain regions cited to be responsible for impaired awarenes. Existing models of treatment will also be examined as well as implications for future research.
Many articles have revealed that self-awareness deficits are definitely associated with traumatic brain injury. (Oddy, Coughlan, Tyerman, and Jenkins, 1985; Prigatano, Altman, and O'Brien, 1990; Prigatano and Leathem, 1993; Prigatano and Altman, 1990). Prigatano (1986, 1987, 1989, 1990, 1991, 1993) deserves much of the credit for the research advancements made in this area. He and Altman (1990) conducted a study to determine if the level of self-awareness in a brain-injured individual was related to other areas of cognitive functioning. Sixty four TBI patients were divided into the following three groups: Group 1 overestimated their behavioral competencies, Group 2 rated their behavior as consistent with family and friends' ratings of them, and Group 3 underestimated their behavior competencies. The results revealed that the groups did not differ in long-term verbal memory, verbal learning, or basic speed of new learning. In fact, the only difference between the groups was that Group 1 had slower speed of left-hand finger tapping, although no differences were found among right-hand finger tapping scores. Therefore, it is unlikely that self-awareness is related to other cognitive areas, but that it is in a class by itself. The authors suggest that lack of awareness of behavioral deficits is associated with neuropsychological changes not yet measured by existing standardized tests.
In research by Oddy, Coughlan, Tyerman, and Jenkins' (1985), patients and their family members were asked to describe the behavioral limitations experienced by the patient 7 years after her/his brain injury. Again, the patients underestimated the severity of their problems in comparison to their respective family members. Some family members even noted problems that the patients did not report at all. These results provide further support that TBI patients have reduced awareness of deficits. The authors suggest that this lack of awareness may not be psychological denial, but that it may have an organic component instead.
Prigatano and Leathem (1993) conducted a study with 41 New Zealand TBI patients to determine if cultural factors influenced self-awareness of deficits after brain insult. The New Zealand group was divided into those with Maori ancestry and those with English ancestry. Family members and the patients of each group were given the Patient Competency Rating Scale (PCRS), a scale developed by Prigatano and colleagues (Prigatano et al., 1986) that asks patients and families to judge subjectively the degree of competency the patient exhibits when performing activities of daily living. The patients' ratings tended to be higher than the family ratings which were consistent with patients' neuropsychological test performance, however, Maori TBI patients reported less behavioral competency than did their non-Maori counterparts. This finding implies that cultural factors as well as brain damage contribute to overall awareness deficits.
Prigatano and Altman (1990) looked at the degree to which TBI patients underestimate their deficits. They gave 64 TBI patients and their relatives the Patient Competency Rating Scale. Consistent with their predictions, the results showed that TBI patients underestimated their behavioral limitations on 10 out of the 30 items. Another interesting finding revealed that the problems most underestimated were those involving emotional control and social interaction. For example, the patients' relatives reported that these patients typically overestimated their ability to manage arguments, control their temper, and recognize when they have upset others. However, there was no discrepancy between patient and family ratings in terms of their ability to carry out basic every day tasks such as getting dressed in the morning or preparing meals. This finding suggests that it is only when TBI patients have to judge tasks involving a high degree of insight do they demonstrate self-awareness deficits. These results also imply the reverse, when an activity involves relatively little insight, and can be judged almost objectively, patients demonstrate very little impairments of awareness.
Other authors contend that family members as well as patients tend to overestimate patients' abilities (Sunderland, Harris, and Gleave, 1984). The authors asked TBI patients in the acute phase, who also suffered from a period of posttraumatic amnesia for at least 24 hours, and their families to rate the patients' memory abilities. The patients were then tested on 9 various memory measures. Both the families and the patients greatly underestimated the degree of behavioral limitations, with patients ratings being accurate on only three of the 9 measures and the families ratings accurate on 5 of the 9 ratings. According to these findings, it appears that inferences can not be made about the aforementioned article because family ratings may not be accurate. Therefore, it can not be presumed that there are no awareness deficits present when performing such fundamental tasks such as getting dressed in the morning.
There is a convincing psychological view that attempts to account for self-awareness deficits. Traditionally, the terms denial and self-awareness deficits have been used interchangeably in the literature (Deaton, 1986). This paper will use the term self-awareness, however, for the purpose of presenting the following theory, the term denial will be used. Denial has been conceived of as a psychological defense mechanism that appears when one is unable to deal with the pain associated with reality. Levine and Zigler's (1975) research revealed that stroke patients demonstrated more denial than patients with other medical diagnoses (i.e. cancer). These results imply that the reason stroke patients deny the existance of cognitive or motor deficits accompanying their condition is because these impairments tend to threaten their "sense of self". The authors maintain that this is an effective use of denial due to the anxiety reduction it produces. This view presents denial in psychoanalytic terms rather than as a result of organic damage which is characteristic of stroke patients.
Weinstein and Kahn (1955) further support the psychological view to account for awareness deficits. These authors postulate that when patients demonstrate a lack of awareness of their hemiplegia (one-sided paralysis), it is essentially denial, the unconscious defense mechanism. They studied patients with and without anosognosia (verbal denial of hemiplegia) to determine which group more frequently demonstrated the use of denial. The results revealed that patients exhibiting anosognosia were more likely use denial as a coping mechanism in other areas of their lives than did their non-anosognostic counterparts. These findings strengthen the notion that awareness of deficits may indeed have a psychological origin.
However, Gilmore et al. (1992) suggested that anosognosia may not be attributed to psychological denial or emotional changes arising from hemiplegia (Gilmore et. al 1992). In this study, eight consecutive patients undergoing intracarotid barbiturate (methohexitol) injections were assessed for anosognosia after their hemiplegia and aphasia had cleared. Anesthesia was administered to both left and right internal carotid arteries sequentially. After the left-hemisphere anesthesia, all the patients were able to recall their motor and language deficits. After the right-hemisphere anesthesia, however, not one of the patients were able to recall their hemiplegia. These results not only question the psychological origin of anosognosia, but also suggest that awareness deficits are more often associated with right hemisphere brain injuries than left sided brain injuries.
A number of researchers support this organic view (Geschwind, 1965; Lezak, 1983; Goldberg and Barr, 1991; Zaidel, 1987), and provide evidence that awareness deficits are organically caused. Goldberg and Barr (1991) discuss three different types of organic awareness impairments in terms of a tripartite error-monitoring system. First, a brain lesion might disrupt the mechanism of awareness. This type explains deficits in terms of an "awareness mechanism" breaking down as a direct result of some brain disease. Second, there may be a possibility that one may have a selectivity of awareness deficit that mirrors the selectivity in an intact brain. This type of impaired awareness implies that there were already existing premorbid awareness limitations. The third type of impaired awareness is post-morbid, and implies one's present inability to recognize feedback. These authors maintain that there are three types may play a role in determining the level of awareness in a person, yet a single cause to any of these three types of impaired awareness is unlikely to be identified.
Stuss's research has found that self-awareness deficits are related to frontal lobe injuries (1991). He discusses two frameworks in an attempt to characterize the relationship between the frontal lobes and the concept of awareness. The first is a model that emphasizes the structure of the brain as a way to understand the behavioral observations made by clinicians after insult to the frontal lobe (Stuss and Benson, 1986). The second framework is a psychological theory encompassing self and consciousness that facilitates the understanding of impairments in perceptions after frontal system damage (James, 1890). Such theoretical structures in which behavioral observations can be made is necessary when attempting to extract characteristics typical of patients exhibiting awareness deficits following frontal lobe damage. Using these frameworks, Stuss proposes seven characteristics of frontal lobe disorders of awareness including (1) Frontal disorders of awareness are related to self; (2) Disorders of self awareness can be present with normal sensorium and normal or even superior IQ, memory, and so on; (3) Fractionation of disturbed self-awareness appears possible; (4) Judgement and selectivity are important; (5) Knowledge is a phenomenon distinct from awareness; (6) Immediacy and warmth are essential; and (7) Certain aspects of awareness also appear to imply the future. Stuss provides three clinical examples to support his assertion that self-awareness deficits are a result of disturbance to the frontal lobes, yet whether or not self-awareness deficits are unique to frontal lobe damage has yet to be determined.
Other authors have also held specific brain activity responsible for self-awareness deficits (Geschwind, 1965; Heilman, 1991). Heilman (1991) proposed a "feed forward" or intentional theory of anosognosia in which there is a mismatch between expectations and sensory feedback that would make the patient aware of the deficits. Geschwind (1965) posited a disconnection hypothesis to explain anosognosia related to right hemisphere disease.
Hurt (1990) proposed a systematic model for delivery of vocational rehabilitation services which encompasses cognitive, psychosocial, and physical problems associated with mild brain injuries. She identifies six critical factors in vocational rehabilitation including the patient remediating cognitive deficits, being aware of vocational limitations, feeling a reduced degree of fatigue, participating in a trial work experience, tolerating frustration and controlling emotional responses, and having follow up services implemented throughout adjustment process and beyond. The Mild Brain Injury Program involves intensive therapies three to five days a week for six to ten months. The therapies provided are cognitive retraining, individual counseling, group, vocational counseling, and participating in a "work station". The three key components of Hurt's vocational rehabilitation model specific to developing self awareness are formal vocational testing to identify strengths and limitations, group therapy to confront behavioral limitations through interacting in a social environment, and finally, participation in an appropriate trial work experience dsigned to utilize newly learned compensatory strategies while rebuilding confidence level and self-esteem. The first three months are targeted toward increasing self-awareness while months four through six concentrate on identifying vocational alternatives and developing job-seeking skills. Finally, a rigorous follow up plan is implemented to ensure vocational success. In terms of success rate, of the twenty participants involved in the program trial, 90% managed to remain employed at competitive levels.
Another model of treatment was introduced by Wesolowski and Zencius (1994), and included such elements as TBI education, personal adjustment groups, team integration, goal and journal group, the utilization of "natural consequences", and video therapy. These authors report that the most frequently used method of assessing self-awareness deficits is through observations made by the rehabilitation staff, family members and friends. The most common assessment measure is the Competency Rating Scale, a self-report measure given to clients to evaluate themselves on such items as memory, grooming, social skills, etc. The client and the staff member both complete the scale, and the greater the discrepancy between scores, the greater the awareness deficit. This review covers only some of the many issues involved in vocationally assessing TBI patients experiencing awareness deficits.
The literature cited in this article clearly supports the idea that awareness of deficits following TBI is often impaired. It is repeatedly shown that TBI patients grossly overestimate their competencies, especially in the areas of social and emotional control.Vocational potential is greatly affected partly due to the lowered degree of insight TBI patients have into their abilities. It has also been shown that awareness deficits have been definitely related to both right brain injuries and frontal lobe damage. There appears to be strong evidence in the literature supporting the idea that awareness deficits have a significant organic component.
The issue of whether awareness deficits are psychological or organic in nature may be looked at in a broader scope than the black and white perspective covered in the previous discussion. Instead of approaching this matter in either/or terms, Prigatano (1990) suggests looking at both psychological and neurological factors. It is feasible that psychological problems can interact with organic factors to produce problems in awareness. Therefore, it might be more appropriate to look at the degree to which each element plays a role in contributing to awareness impairments. Supporting this idea, the works of Weinstein and Kahn (1955) and Stuss (1991) together reveal that awareness deficits may have organic underpinnings as well as anxiety reduction components.
Again, a broader perspective is needed when considering the brain region responsible for problems in awareness. Perhaps there is no one brain region at fault for such deficits. The possibility that multiple lesions might be accountable for impairments in awareness can certainly be entertained. Prigatano and Altman (1991) noted that TBI patients who consistently underestimated their behavioral problems were shown to have a larger number of lesions reported by CT or MRI findings. They did not, however, show worse performance on many standard neuropsychological tests further indicating the need for tests measuring such deficits. There is also burgeoning evidence that an area deemed the heterodermal cortex may eventually be shown to contribute to inaccurate self-appraisal of behavioral limitations (Mesulam, 1985).
Despite the vast amount of research found in this area, several issues have yet to be resolved before adequate rehabilitation strategies can be developed. A clear understanding of awareness deficits after TBI needs to be cultivated before clinical implications can be addressed thoroughly, and appropriate rehabilitation programs developed. The most apparent need in the research arena is a standardized test that measures impaired awareness in this population. Prigatano and Altman (1990) reported that neuropsychological test scores failed to predict ratings on the items sampling emotional control and social interaction. In fact, it is repeatedly suggested that traditional neuropsychological measures currently existing do not adequately reflect impaired awareness of certain behavioral limitations. Once this is developed, an effective treatment model targeted specifically for rehabilitating self-awareness deficits can be implemented for TBI patients.
Paige A. Murphy