Awareness of Behavioral, Cognitive, and Physical Deficits in Acute Traumatic Brain Injury

Transcription

1 1450 Awareness of Behavioral, Cognitive, and Physical Deficits in Acute Traumatic Brain Injury Tessa Hart, PhD, Mark Sherer, PhD, John Whyte, MD, PhD, Marcia Polansky, ScD, Thomas A. Novack, PhD ABSTRACT. Hart T, Sherer M, Whyte J, Polansky M, IMPAIRED AWARENESS OF deficit, sometimes termed Novack TA. Awareness of behavioral, cognitive, and physical impaired self-awareness (ISA), has been observed in several deficits in acute traumatic brain injury. Arch Phys Med Rehabil neurologic disorders (see reviews by McGlynn and Schacter ;85: and Prigatano and Schacter 2 ). Impaired self-awareness has been identified as a common problem in traumatic brain injury Objective: To compare awareness of deficit in 3 domains of (TBI), especially for people with moderate to severe injuries. function (physical, cognitive, behavioral/emotional) in acute 3 Understanding ISA is important for both clinical and theoretical reasons. It may have a negative effect on rehabilitation traumatic brain injury (TBI), controlling for severity of impairment in the different domains. efforts because people who do not perceive that they have Design: Inception cohort. deficits may refuse or resist treatment. In addition, ISA predicts Setting: Three inpatient rehabilitation programs. poor productivity outcomes in both the acute Participants: People with acute TBI (N 161), tested as 4 and postacute 5 stages of recovery. From a theoretical perspective, patterns of soon as feasible after posttraumatic amnesia. ISA may help us understand how the process of monitoring and Interventions: Not applicable. adjusting one s performance is organized under normal conditions and why certain facets of performance may elude con- Main Outcome Measures: Awareness Questionnaire (AQ) completed by the person with TBI and the treating neuropsychologist; and self- and clinician-rating scores calculated in the ISA may be measured using questionnaires or interviews scious awareness. 3 domains. designed to elicit quantitative or qualitative information about Results: For participants who were rated by clinicians as self-perceived abilities. To make an inference about impaired more impaired in at least 1 domain (ie, scored lower on the self-awareness, this self-report must differ from some external AQ), self-ratings differed significantly from one another in all standard, such as performance on neuropsychologic tests. 6 3 domains, with behavioral self-ratings highest, physical selfratings lowest, and cognitive self-ratings intermediate. In sub- ratings by another party, such as a relative or therapist, with the More commonly, the self-rating is compared with collateral groups of participants rated at the same level by clinicians in all assumption that a discrepancy (in the direction of another party 3 domains, physical self-ratings were also lowest, that is, more reporting more severe problems) indicates ISA. Potential drawbacks to the collateral rating method include the possibility that consonant with clinician ratings. Participants tended to rate themselves as relatively unchanged in cognitive and behavioral raters are biased, either in the direction of under- or overreporting problems, or that raters may not have enough informa- domains regardless of the level of clinician ratings on these factors. tion to make accurate judgments. 7,8 Nonetheless, calculating Conclusions: Patterns of discrepant awareness of deficit in discrepancies between self- and other-ratings is probably the most common quantitative method of estimating ISA. different functional areas seen in postacute TBI also appear to ISA is not uniform across all types of deficits, but it affects be present acutely and are not entirely related to differential cognitive and behavioral deficits more than it does physical severity of deficit. We discuss several possible reasons for problems, or difficulties with functional activities such as activities of daily living (ADLs). This pattern is all the more discrepant awareness of deficit, including differences in internal and external feedback, cultural and psychologic factors, and striking because cognitive and behavioral deficits may be more different levels of ambiguity inherent in causal explanations for relevant than physical or functional deficits to long-term social different types of problems. and vocational outcomes after TBI. 9,10 The implication is that Key Words: Awareness; Brain injuries; Rehabilitation. people with TBI may be less aware of their more salient 2004 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and awareness of physical versus cognitive and emotional difficul- problems. Several studies have reported greater apparent Rehabilitation ties in postacute TBI patients. Investigations by Tepper 11 and Cusick 12 and colleagues found that level of physical disability was reported with greater agreement between people with TBI and their family members, compared with levels of cognitive disability. Similarly in a study by Hendryx, 13 family members From Moss Rehabilitation Research Institute and Department of Rehabilitation reported more emotional changes in subjects with TBI than the Medicine, Jefferson Medical College, Philadelphia, PA (Hart, Whyte); Methodist Rehabilitation Center, Jackson, MS (Sherer); MCP-Hahnemann School of Public subjects reported in themselves. However, family members and Health, Philadelphia, PA (Polansky); and University of Alabama, Birmingham, AL TBI subjects reported about equal degrees of change for cognitive and physical functioning. Sherer et al 3 found that people (Novack). Supported by National Institute on Disability and Rehabilitation Research (grant with postacute TBI, as a group, reported a higher degree of nos. H133A980067, H133A980035, H133A97033). No commercial party having a direct financial interest in the results of the research physical than nonphysical (cognitive, behavioral) impairment. supporting this article has or will confer a benefit upon the author(s) or upon any In contrast, their relatives reported more nonphysical than organization with which the author(s) is/are associated. physical impairments when asked to rate the patients on the Reprint requests to Tessa Hart, PhD, Moss Rehabilitation Research Institute, 1200 same items. W Tabor Rd, Philadelphia, PA 19141, thart@einstein.edu /04/ $30.00/0 Other studies in postacute samples have reported similar doi: /j.apmr findings when ADLs (rather than physical symptoms) have

2 DEFICIT AWARENESS IN ACUTE TBI, Hart 1451 been compared with cognitive and emotional sequelae. Prigatano 14,15 and colleagues contrasted patient self-ratings with relatives ratings on the Patient Competency Rating Scale 16 (PCRS), which includes self- and other-ratings in basic ADLs, emotional and interpersonal function, and cognitive abilities. The self-ratings of subjects with TBI were reportedly discrepant from relatives ratings (ie, relatives rated the subjects as less competent) in the areas of social interaction and emotional control, whereas self-ratings and other-ratings did not differ significantly for ADL items. Hart et al 17 compared discrepancies between self- and other-reports of frequency of problematic symptoms in 6 domains of function using the Neurobehavioral Functioning Inventory Revised 18 at 1 year post-tbi. Of the items that were discrepant, the majority were in the direction of the person with TBI reporting fewer problems, and this pattern occurred more in subscales measuring emotional, behavioral, and cognitive function compared with scales measuring motor and somatic symptoms. Most investigations of ISA after TBI, including the comparisons of self-awareness in the different areas of function cited above, have focused on postacute stages of recovery. Several recent investigations 4,19 have explored ISA in the acute phase of TBI. However, to our knowledge, previous research on acute ISA compared across domains of function has been limited. McKinlay and Brooks 20 studied TBI patients at 3, 6, and 12 months postinjury. At each interval, patients and family members showed good agreement on ratings of patients sensory and motor functioning but poor agreement on ratings of patients cognitive and behavioral functioning. In the latter areas, family members consistently reported greater impairments. As part of a later longitudinal study of ISA, Fleming and Strong 21 administered the PCRS to subjects with TBI and their therapists at 3 months post-tbi. TBI patients rated themselves as significantly more competent than did therapists in social and emotional function, instrumental ADLs such as laundry, and certain cognitive areas (eg, items related to prospective memory). As in the studies by Prigatano, patient and therapist ratings did not differ significantly for basic ADLs such as self-care. These findings, taken together, offer several possible interpretations. One is that people with TBI are better able to detect, and/or are more willing to report, deficits in physical function or basic ADL compared with deficits in cognition or emotional and interpersonal behavior. This could be because the former problems are easier to perceive, more socially acceptable to acknowledge, or both. However, another possibility is that self-awareness of interpersonal and, in some studies, cognitive difficulties appears to be more impaired because these abilities are themselves differentially impaired in the samples studied. We have discussed this issue previously 4,17 as it relates to the use of discrepancy score methods to estimate the magnitude of ISA. The magnitude of a discrepancy score is constrained mathematically by the magnitude of the scores that comprise it. Thus, for domains or items rated worse by the collateral rater, there is a bigger range of possible ISA scores because there is more room for disagreement between the self- and other-rating. As an example of how this could affect the comparison of ISA across different domains of function, consider a study in which patient self-ratings are compared with therapist ratings in basic self-care and behavioral control. Behavioral control is more problematic than performance of basic ADLs for many TBI patients, particularly in the postacute phases of recovery. To the extent that therapist ratings are related to true levels of ability or impairment in these areas,* therapist ratings on average will be lower (worse) for behavioral control than for ADLs, and discrepancy scores would have a larger possible range in the former domain than the latter. In this study, we compared self-awareness of deficit after TBI in 3 major domains of function physical, cognitive, and behavioral using a study design that differed in several ways from previous work. Our purpose was 3-fold. Our first objective was to determine whether differences in ISA across different domains of function, as noted in previous literature, would be replicated in a design controlling for the effects of the constraints on discrepancy scores. The current design controlled for these effects by stratifying levels of impairment within domains, and studying subgroups of participants with deficits at an approximately comparable level of severity across multiple domains. Our second objective was to clarify the relative impact of ISA on 3 important functional domains (cognitive, physical, behavioral/interpersonal). These domains were measured on a single scale using clusters of items derived from factor analysis, rather than groupings based on face content alone. Moreover, cognitive and behavioral items were treated as belonging to distinct domains rather than combining them into a nonphysical domain, as some previous studies have done. Based on previous findings, we hypothesized that ISA would affect behavioral/interpersonal functions more than it would physical functions, but the relative impact on cognition was more difficult to predict. Our third objective was to investigate ISA across domains of function in the acute stages of recovery after TBI, which has been relatively neglected in previous research. An acute sample was considered particularly relevant to our objectives in this study because of the greater likelihood of observing multiple deficits in the same subjects, as well as observing subjects across a range of severity levels in each domain. METHODS Participants Participants were 161 people with moderate to severe TBI, recruited from consecutive admissions to the inpatient units of 3 participating rehabilitation centers. The participating centers were all Traumatic Brain Injury Model Systems (TBIMS) sites. The majority of participants (n 118) were also enrolled in the TBIMS national database. 23 The other 43, all enrolled at 1 of the centers, were not TBIMS participants, but met the System s eligibility criteria related to injury type, acuity, and severity. According to these criteria, all participants were aged 16 or older and were diagnosed with acute mechanical (penetrating, nonpenetrating) TBI with an initial Glasgow Coma Scale (GCS) score of less than 13, and/or positive findings on neuroimaging studies consistent with acute traumatic injury. All participants who were also TBIMS participants had been admitted for level I trauma care within 24 hours of injury and transferred to inpatient rehabilitation within 72 hours of discharge from acute care. A few of the non-tbims participants had been sent home or to subacute rehabilitation for brief periods between their discharge from acute care and their admission to acute rehabilitation. * The discrepancy score method of estimating ISA is based on the assumption that the collateral rating is a more accurate measure of the true level of ability/ impairment than the self-rating. This assumption is controversial, but may be justified by studies reporting that collateral ratings are more strongly related to one another and to objective measures of function, such as neuropsychologic test scores, than are patient self-ratings. 3,22

3 1452 DEFICIT AWARENESS IN ACUTE TBI, Hart Table 1: Injury Severity and Functional Status on Rehabilitation Admission Across the Sample (N 161) Index n Mean SD Range GCS score Time to follow commands (d) Duration of PTA (d) FIM score* Cognitive Motor Total DRS score *Lower scores indicate more disability; higher scores indicate more disability. Our participants were required to meet TBIMS criteria as above and were also required to: (1) speak and understand English; (2) be alert, oriented, and out of posttraumatic amnesia (PTA) according to criteria described below; (3) have no prior or concurrent conditions that would significantly affect mental status (eg, mental retardation, schizophrenia, Alzheimer s disease); (4) demonstrate receptive and expressive language function adequate to complete a Likert-type self-report questionnaire; and (5) provide informed consent. One hundred thirtyseven participants had also been participants in a previous study of ISA in acute TBI. 4 As is typical for moderate to severe TBI patients, the majority (81%) of participants were men. Sixty-seven percent were white and 28% were African American. Ages ranged from 16 to 82 years (mean standard deviation [SD], y). Approximately one third (33%) of the sample had a high school diploma or General Educational Development certificate; 32% had less than 12 years of education; and 35% had some college education. More than half of the participants (52%) were single. About two thirds (66%) were competitively employed at the time of injury, and another 12% were classified as students. In terms of injury etiology, 58% of participants were injured in motor vehicle collisions, 16% in assaults, and 16% in falls; the remainder were injured by other causes, such as sports events and pedestrian accidents. Injury severity was estimated with several commonly used indices of altered consciousness, data from which are displayed in table 1. Not all measures were available for all participants. The GCS score 24 was measured on admission to emergency care. Time to follow commands was the number of days between the injury date and the day on which simple motor commands were followed on at least 2 occasions within a 24-hour period. Duration of PTA was defined as the number of days between the injury date and the second day within 72 hours that the patient scored greater than 75 on the Galveston Orientation and Amnesia Test 25 (GOAT), or was noted to be fully oriented in acute care progress records. These indices confirmed that the sample was composed of people with primarily moderate to severe brain injuries, as would be expected of any sample admitted for inpatient rehabilitation. Additional clinical indices were used to assess the cognitive, physical, and functional characteristics of the sample on admission to rehabilitation. These included the FIM instrument 26 and the Disability Rating Scale 27 (DRS). As shown in table 1, participants on average fell between the minimal and moderate assistance levels (ie, average score across items, 3.5) for the cognitive abilities assessed by the FIM (expressive and receptive language, problem solving, memory and social interaction), and between moderate and maximal assistance levels (average item score, 2.6) for FIM motor skills (physical function, basic ADLs). The mean DRS score for the sample corresponds to the low end of the range of scores, indicating severe disability. Measures The primary measure we used was the Awareness Questionnaire 28 (AQ). This instrument has 17 items covering different types of abilities that are rated on a1to5scale that compares the current level of functioning to the level of functioning before injury. For each item the respondent is asked, How is your ability to, as compared with before your injury? Response options are: 1, much worse (than before injury); 2, a little worse; 3, about the same; 4, a little better; and 5, much better. A parallel version with appropriately modified wording allows therapists or other collateral raters to rate the patient on the same items. The AQ has demonstrated good internal consistency in both patient and family samples 28 and has been validated in multiple studies of self-awareness of deficit after TBI. 3-5 Procedure On enrollment into the study (or on enrollment into the TBIMS, whichever came first), participants were administered the GOAT until they were deemed to be out of PTA, as defined above. They were then given the AQ as soon as feasible after clearing PTA or after being recruited for the study for those out of PTA on rehabilitation admission. The AQ was administered individually, with items being read and explained as necessary. Because administration of the questionnaire was linked to clearance from PTA and admission to inpatient rehabilitation, subjects were tested over a substantial range of time from 5 to 166 days postinjury. However, the majority had remained hospitalized since injury and all were participating in comparable levels of inpatient TBI rehabilitation when tested. The median injury-to-test interval was 32 days. Within 3 working days of each subject s completion of the AQ, the same instrument with parallel wording was completed about the subject by his/her treating neuropsychologist. These raters were not involved in obtaining the participant selfratings. Data Analysis The main dependent variables of interest were participants self-ratings in the 3 factors, or domains of function, addressed in the AQ: physical, cognitive, and behavioral. For each domain, the average self-rating was calculated across items that had loaded on each factor as established in previous factor analytic research. 28 Thus, physical, cognitive, and behavioral self-rating scores were calculated for each participant. The items comprising each factor are presented in table 2. Internal consistencies for these factors were adequate in previous research, considering the small number of items, ranging from.68 to.80 in a client sample and.57 to.80 in a family sample. 28 For each participant, average clinician rating scores for each factor were calculated in similar fashion. These scores were then used to create 2 severity groups on each factor, corresponding to the 2 scoring options on the AQ that pertain to impairment relative to preinjury status. On each factor, mean clinician ratings of 1 to 1.99 were designated as relatively more impaired, and mean clinician ratings of 2 to 2.99 were

4 DEFICIT AWARENESS IN ACUTE TBI, Hart 1453 Table 2: Item Content in the Physical, Cognitive, and Behavioral Factors of the AQ Physical (4 items) Cognitive (7 items) Behavioral (6 items) Movement of arms and legs Vision Hearing Coordination Memory for recent events Orientation Concentration Expression of thoughts Thinking Organization Overall ability to live independently Emotional adjustment Planning Control of feelings Getting along with others Money management Overall ability to do the things you want to do in life designated as less impaired. * The severity groups were generated so that we could compare self-ratings across domains in people who were comparable in objective levels of impairment, that is, the levels of impairment judged by the clinician raters. Because the AQ is scored on an ordinal scale and because self-ratings were not expected to be normally distributed, we used nonparametric significance tests (Kruskal-Wallis tests for comparing the 3 domains, and then Mann-Whitney U tests for pairwise comparisons). These analyses were performed on all 161 participants, meaning that, in each severity group, scores in the 3 domains were derived from overlapping sets of participants (ie, a participant could be in the more impaired group for the cognitive domain but in the less impaired group for the behavioral domain). Additional analyses were performed on smaller subgroups of subjects who scored at the same severity level in all 3 domain, that is, more impaired (n 18) in physical, cognitive, and behavioral function or less impaired (n 37). For these analyses, we performed Friedman tests for matched samples, with follow-up Wilcoxon signedrank tests, to compare self-ratings across domains for participants who were rated at the same level by clinicians in each domain. An level of.05 was used throughout to determine statistical significance. RESULTS Table 3 shows the range, means, and SDs of self-ratings and clinician ratings on the AQ across the full sample, for the scale as a whole, and for the items comprising the 3 functional domains. Self-ratings across domain by severity group are shown in figure 1, with results of significance tests reported in table 4. Among the participants rated as more impaired in at least 1 domain, self-ratings across the 3 domains all differed significantly from one another. Behavioral self-ratings were highest (ie, least impaired), cognitive self-ratings were intermediate, Table 3: Patient Self-Ratings and Clinician Ratings on the AQ Across the Sample (N 161) Portion of Scale Self-Ratings Range of Average Scores Mean SD Clinician Ratings Range of Average Scores Mean SD All items Physical factor items Cognitive factor items Behavioral factor items NOTE. 1, much worse than before injury; 2, a little worse; 3, same as before injury; 4, a little better than before; 5, much better. and physical self-ratings were lowest that is, most aligned with the clinician ratings. In the less impaired group, the behavioral self-ratings were, again, significantly higher than the physical self-ratings. However, the cognitive self-ratings, again in the intermediate position, did not differ significantly from either of the others. While the planned statistical contrasts of primary interest involved comparing self-ratings across these 3 domains within severity groups, we were also intrigued by patterns of selfratings observed across severity levels. As shown in table 4, physical self-ratings were lower in the more impaired group than in the less impaired group a pattern consistent with clinician ratings and also statistically significant (Mann-Whitney U 1333, P.03). However, self-ratings in the behavioral domain were significantly higher in the more impaired than in the less impaired group (Mann-Whitney U , P.05), a pattern opposite to that of the clinician ratings. Self-ratings in the cognitive domain did not differ significantly between clinician-rating severity groups. Results of analyses comparing self-ratings across the 3 domains for participants who received the same clinician-rating level in each of the 3 domains are shown in figure 2. This figure also shows the average clinician-rating score for each domain. Only 18 participants were rated as more impaired in all 3 domains, but a group about twice that size (n 37) received less impaired clinician ratings in all 3. As shown in figure 2, the order of the mean self-ratings across domains was consistent *Clinician mean factor ratings of 3 or above, indicating very mild to no impairment, did not occur at all for the cognitive or behavioral factors. Nine participants received ratings in this range on the physical factor and were excluded from all analyses involving that factor. Fig 1. Mean self-ratings across 3 domains of function by clinicianrating score.

5 1454 DEFICIT AWARENESS IN ACUTE TBI, Hart Group Table 4: Significance Tests Comparing Self-Ratings Across Domains and Severity Levels Physical Self-Rating (mean SD) Cognitive Self-Rating (mean SD) Behavioral Self-Rating (mean SD) Mann-Whitney/Kruskal-Wallis Test Results More impaired (clinician rating, ) , P.001 All 3 domain self-ratings significantly different from one another, P.001 Less impaired (clinician rating, ) , P.001 Behavioral physical self-rating, P.001 Other 2-way domain comparisons (NS) Abbreviation: NS, not significant. with the results obtained in the whole sample, that is, behavioral greater than cognitive greater than physical. In the more impaired group, the Friedman test comparing self-ratings across domains did not reach significance ( 2 test 4.1, P.13). In the larger sample comprising the less impaired group, the Friedman test was highly significant ( 2 test 26.5, P.001). Pairwise Wilcoxon tests revealed that the physical self-ratings were significantly lower than self-ratings in both cognitive (z 4.3, P.001) and behavioral (z 4.6, P.001) domains, which did not differ significantly from one another (z 1.4, P.18). Validation of Clinician Ratings Using clinician ratings to group participants by severity level is based on the assumption that these ratings are accurate reflections of participants true levels of ability on the rated items. To verify that clinician ratings were related to other measures of participants ability, the average clinician ratings across all 17 items of the AQ were correlated with the total FIM and DRS scores at rehabilitation admission. Both the AQ correlations with FIM (r.35) and DRS (r.46) were in the expected direction. Although these correlations were only moderately strong, both were significant at P less than.01. In contrast, participants average self-ratings across all 17 AQ items did not correlate significantly with either score (selfrating with FIM, r.08; self-rating with DRS, r.13). DISCUSSION To our knowledge, this is the first investigation into selfawareness of deficit in TBI that directly compares deficit awareness across physical, cognitive, and behavioral domains in the acute stages of recovery. We also believe this to be the first study to use factor-analyzed item clusters to define these domains, rather than the more limited and potentially less reliable sets of items grouped on face content alone. Our results suggest that even when severity of deficit is roughly equated across domains (a step not taken in previous work in this area), physical deficits appear to be acknowledged significantly more than cognitive or behavioral problems. Cognitive difficulties are, in turn, acknowledged more than are problems related to interpersonal difficulties or loss of emotional control. This pattern is generally consistent with previous work. 4,11,12,15 However, previous studies have tended to combine various nonphysical domains with one another rather than to directly compare awareness of cognitive versus behavioral and emotional difficulties, as we have done in this study. By analyzing participants actual level of self-rating rather than discrepancy scores (ie, differences between self- and clinician ratings), we were able to draw comparisons in selfratings across groups of participants at different levels of objective severity (ie, severity as established by clinician rating). It was notable that in the behavioral domain, more Fig 2. Mean self-ratings across 3 domains of function for participants receiving same clinician rating of more impaired (A) or less impaired (B) in all 3 domains.

6 DEFICIT AWARENESS IN ACUTE TBI, Hart 1455 impaired participants rated themselves as functioning significantly better than did participants who were judged by clinicians to be less impaired. Our method of analysis also permitted direct observation of the relation between self- and clinician rating at different levels of severity. As seen most strikingly in the subgroup analyses (fig 2), participants self-ratings were relatively independent of severity of deficit as established by clinician rating. That is, the average self-ratings in each domain were nearly identical across groups, despite 1 group having received a much lower clinician rating in all 3 domains. It appeared that at least in the cognitive and behavioral domains, participants tended to rate themselves as being close to the same as before injury, regardless of deficits that made them appear to others to be impaired, to some degree. Use of the discrepancy score approach to estimate the magnitude of ISA in this case might have led to the interpretation that the more impaired group s self-awareness was worse than that of the less impaired. It is not clear what this interpretation would add to the observation that both groups perceive their cognitive and behavioral function as relatively unchanged by injury. A similar point was noted by Newman et al 19 in the context of interpreting apparent longitudinal changes in ISA after TBI. They pointed out that self- versus other-rating discrepancies declined from rehabilitation admission to discharge. However, the change was not due to changes in patient self-ratings but to improvements in therapist ratings, presumably reflecting true improvements in patient function during the rehabilitation stay. Several study limitations should be noted that could affect the generalizability of these findings. The sample included only people enrolled in inpatient TBI rehabilitation, and only those who cleared PTA before hospital discharge. It is possible that findings would differ for people who are more impaired, or less impaired, than the participants in this study. In addition, different means of measuring ISA might be more appropriate for more impaired patients, beyond the paper-and-pencil method we used. Another limitation of this study is the lack of objective verification of clinician judgments about patients levels of impairment in the 3 domains. It would be valuable in future research to include measures of different domains of function that are not solely dependent on clinician ratings. Notwithstanding these limitations, the question remains why our participants would more readily acknowledge or show awareness of physical limitations, as opposed to acknowledging cognitive and (especially) behavioral and emotional difficulties. Because our sample was comprised of people undergoing acute rehabilitation, one possibility is that the people interacting with patients (therapists, family members), or the activities that patients are engaged in, place greater emphasis on physical deficits in this stage of rehabilitation. There is no particular evidence to support this, however, and in fact the distribution of clinician ratings across domains suggests that in this sample, cognitive and behavioral abilities were seen by clinicians as more severely compromised overall. For example, figure 1 shows that the majority of participants (123/154) were rated as less impaired in physical function, but more impaired in cognitive function (102/159). In the treatment settings of the specialized TBI rehabilitation hospitals that participated in this research, there is ample treatment and feedback geared toward cognitive and interpersonal deficits. Furthermore, even if there were a domain imbalance in the focus of acute rehabilitation, this would not explain the differential awareness of deficit in different domains of function in postacute samples. 11 It is also possible that physical deficits offer stronger or more consistent evidence of their existence to the actor, compared with difficulties with cognition or behavioral control. For instance, physical deficits may be more consistently displayed than cognitive deficits (which may come to the fore or recede, depending on environmental demands and supports that are not always visible), thus offering greater opportunity to be noticed and recalled by the TBI patient. Or, physical impairments could provide more consistent internal feedback compared with nonphysical impairments. Again, however, this would not entirely explain awareness discrepancy in the long-term picture, as it is quite common for people with TBI to exhibit more severe cognitive, emotional, and behavioral problems than physical problems in later years after the injury A related possibility is that physical and nonphysical impairments could differ not only in the clarity of internal feedback they provide, but also in the certainty or ambiguity surrounding events related to these problem areas as they are expressed in the real world. For instance, if you attempt to walk across the room by yourself and you fall down, there may be few potential interpretations of this event, the most obvious being that your legs were too weak to support your body. However, if you have a fight with your spouse, several explanations are possible: it could be your fault or your spouse s fault, or the dispute could be induced by some extreme external circumstance, or some combination of many circumstances. Thus, it may be inherently more difficult to sort out one s own contribution to complex interpersonal events compared with physical events, and harder still for those with reasoning and memory impairments from TBI. Another possible explanation may be that it is psychologically or culturally more acceptable to acknowledge physical deficits than to acknowledge cognitive or behavioral deficits. Cross-cultural studies suggest that general underreporting of deficits is common in TBI patients, but that the specific deficits most prone to underreporting may vary according to cultural values. 32,33 However, it is not intuitively clear that a sample of mostly young, mostly male Americans would prefer to acknowledge physical weakness rather than problems in other areas of function. Further research might help to clarify this possibility. A more organically based explanation of the variability in awareness observed in neurologic disorders was proposed by Schacter, 34 who hypothesized the existence of a modular Conscious Awareness System (CAS). The CAS, in this view, depends on information provided by knowledge modules (including facial, spatial, lexical, and self modules). Disruption of the CAS would result in globally poor awareness of deficits in all domains, whereas disruption of a knowledge module (or the connections between the module and the CAS) would result in a more circumscribed awareness problem. Assuming there is a module addressing information about self, it may be reasonable to hypothesize subcomponents of that system focusing on such abilities as physical skills, cognitive skills, and behavior, all with separate or overlapping brain representations, as hypothesized by Prigatano and Schacter. 2 It is possible that the cerebral injuries common to TBI, particularly involving anterior frontotemporal regions, have a greater impact on the CAS subcomponents involving cognitive and behavior information than information about physical abilities. Thus, for a person with TBI, the CAS may have greater access to information about physical abilities than about cognition and behavior. This would also help to explain why problems with awareness can persist in the face of experience and deliberate feedback, because a damaged CAS module would still not be able to interpret the domain-specific information in a normal fashion. Further research is needed to uncover the various potential causes of impaired awareness of deficit in different domains of human behavior, and to apply this knowledge to development of appropriate interventions for a disorder that can be intractable in current rehabilitation efforts. 35

7 1456 DEFICIT AWARENESS IN ACUTE TBI, Hart CONCLUSIONS This study yielded new information relevant to its 3 objectives. Consistent with previous findings, self-awareness of deficit differed markedly across different types of function in the acute stages of recovery after TBI. Physical deficits were recognized more than behavioral/interpersonal deficits, with self-awareness of cognitive deficits occupying an intermediate position, even when differential severity of deficit was controlled as a potential confounding factor. Further research is needed to determine the underlying causes of this and other intriguing aspects of disorders of self-awareness in TBI. Acknowledgments: We thank Caron Morita for assistance with subject recruitment and data collection, and Rebecca Fidler-Sheppard for database management and assistance with data analysis. References 1. McGlynn SM, Schacter DL. Unawareness of deficits in neuropsychological syndromes. J Clin Exp Neuropsychol 1989;11: Prigatano GP, Schacter DL. Awareness of deficit after brain injury: clinical and theoretical issues. New York: Oxford Univ Pr; Sherer M, Boake C, Levin E, Silver BV, Ringholz GM, High WM. Characteristics of impaired awareness after traumatic brain injury. J Int Neuropsychol Soc 1998;4: Sherer M, Hart T, Nick TG, Whyte J, Thompson RN, Yablon SA. Early impaired self- awareness after traumatic brain injury. Arch Phys Med Rehabil 2003;84: Sherer M, Bergloff P, Levin E, High WJ, Oden KE, Nick TG. Impaired awareness and employment outcome after traumatic brain injury. J Head Trauma Rehabil 1998;13(5): Anderson SW, Tranel D. Awareness of disease states following cerebral infarction, dementia, and head trauma: standardized assessment. Clin Neuropsychologist 1989;3: Fleming J, Strong J, Ashton R. Self-awareness of deficits after brain injury: how best to measure? Brain Inj 1996;10: Bogod NM, Mateer CA, MacDonald SW. Self-awareness after traumatic brain injury: a comparison of measures and their relationship to executive functions. J Int Neuropsychol Soc 2003;9: Brooks DN, Campsie L, Symington C, Beattie A, McKinlay W. The five year outcome of severe blunt head injury: a relative s view. J Neurol Neurosurg Psychiatry 1986;49: Novack TA, Bush BA, Meythaler JM, Canupp K. Outcome after traumatic brain injury: pathway analysis of contributions from premorbid, injury severity, and recovery variables. Arch Phys Med Rehabil 2001;82: Tepper S, Beatty P, DeJong G. Outcomes in traumatic brain injury: self-report versus report of significant others. Brain Inj 1996;10: Cusick CP, Gerhart KA, Mellick DC. Participant-proxy reliability in traumatic brain injury outcome research. J Head Trauma Rehabil 2000;15: Hendryx PM. Psychosocial changes perceived by closed-headinjured adults and their families. Arch Phys Med Rehabil 1989; 70: Prigatano GP, Altman IM. Impaired awareness of behavioral limitations after traumatic brain injury. Arch Phys Med Rehabil 1990;71: Prigatano GP. Behavioral limitations TBI patients tend to underestimate: a replication and extension to patients with lateralized cerebral dysfunction. Clin Neuropsychologist 1996;10: Prigatano G, Fordyce DJ, Zeiner HK, Roueche JR, Pepping M, Wood BC. Neuropsychological rehabilitation after brain injury. Baltimore: Johns Hopkins Univ Pr; Hart T, Whyte J, Polansky M, et al. Concordance of patient and family report of neurobehavioral symptoms at 1 year after traumatic brain injury. Arch Phys Med Rehabil 2003;84: Kreutzer JS, Seel RT, Marwitz JH. Neurobehavioral functioning inventory. San Antonio: Harcourt Brace; Newman A, Garmoe W, Beatty P, Ziccardi M. Self-awareness of traumatically brain injured patients in the acute inpatient rehabilitation setting. Brain Inj 2000;14: McKinlay WW, Brooks DN. Methodological problems in assessing psychosocial recovery following severe head injury. J Clin Neuropsychol 1984;6: Fleming J, Strong J. A longitudinal study of self-awareness: functional deficits underestimated by persons with brain injury. Occup Ther J Res 1999;19: Fordyce DJ, Rouche JR. Changes in perspectives of disability among patients, staff, and relatives during rehabilitation of brain injury. Rehabil Psychol 1986;31: Dabmer ER, Shilling MA, Hamilton BB, et al. A model systems database for traumatic brain injury. J Head Trauma Rehabil 1993; 8(2): Teasdale G, Jennett B. Assessment of coma and impaired consciousness. Lancet 1974;2: Levin HS, O Donnell VM, Grossman RG. The Galveston Orientation and Amnesia Test: a practical scale to assess cognition after head injury. J Nerv Ment Dis 1979;167: Hamilton BB, Granger CV, Sherwin FS, Zielezny M, Tashman JS. A uniform national data system for medical rehabilitation. In: Fuhrer MJ, editor. Rehabilitation outcomes: analysis and measurement. Baltimore: Brooks; p Rappaport M, Hall KM, Hopkins K, Belleza T, Cope DN. Disability rating scale for severe head trauma: coma to community. Arch Phys Med Rehabil 1982;63: Sherer M, Bergloff P, Boake C, High W, Levin E. The awareness questionnaire: factor structure and internal consistency. Brain Inj 1998;12: Jacobs H. The Los Angeles Head Injury Survey: procedures and initial findings. Arch Phys Med Rehabil 1988;69: Rappaport M, Herrero-Backe C, Rappaport ML, Winterfield KM. Head injury outcome up to ten years later. Arch Phys Med Rehabil 1989;70: Oliver JH, Ponsford JL, Curran CA. Outcome following traumatic brain injury: a comparison between 2 and 5 years after injury. Brain Inj 1996;10: Prigatano GP, Leathem JM. Awareness of behavioral limitations after traumatic brain injury: a cross-cultural study of New Zealand Maoris and Non-Maoris. Clin Neuropsychologist 1993;7: Prigatano GP, Ogano M, Amakusa B. A cross-cultural study of impaired self-awareness in Japanese patients with brain dysfunction. Neuropsychiatry Neuropsychol Behav Neurol 1997;10: Schacter DL. Toward a cognitive neuropsychology of awareness: implicit knowledge and agnosia. J Clin Exp Neuropsychol 1990; 12: Prigatano GP. Principles of neuropsychological rehabilitation. New York: Oxford Univ Pr; 1999.