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Home > RNJ > 2005 > November/December > Predictors of Disorientation Among Brain Injury and Stroke Patients During Rehabilitation

Predictors of Disorientation Among Brain Injury and Stroke Patients During Rehabilitation
Joan P. Alverzo, PhD RN CRRN

Predictors of temporal disorientation among brain injury and stroke patients undergoing rehabilitation were explored in this descriptive study. Cognitive orientation is a construct of consciousness, and the Parallel Distributed Processing model provided a framework for conceptualizing consciousness in this study. Data were collected by a retrospective chart review of a convenience sample of stroke and brain injury patients admitted to an acute rehabilitation hospital over 4 months. The dependent variable in the study was the Temporal Orientation Test used as a daily measure in the study hospital. A total of 167 patients were admitted during the time frame, and of those, 114 patients met the study criteria and were included in the data analysis. The independent variables were defined as age, gender, years of education, number of comorbidities, patient diagnosis, orientation status on admission, and use of narcotic/sedative medications. A logistical regression was performed using SPSS Release 11.01. Only one of the six variables—orientation status on admission—reliably predicted the onset of disorientation during the rehabilitation stay with an odds ratio of 0.217, p < .001. This indicates that the risk of becoming disoriented after a period of orientation during the rehabilitation stay increased by 78% among patients who are disoriented on admission to rehabilitation, compared with those who are oriented on admission. These findings confirm that temporal orientation is unstable during the period of rehabilitation following a brain injury or stroke.

Impaired consciousness is one of the earliest and most reliable indicators of neurological compromise. During the period immediately following neurological injury, level of consciousness (LOC) may fluctuate (Crosby & Parsons, 1989; Neatherlin, 1999). Any change in LOC, both immediately after the injury and in the hours, days, or weeks that follow, is often clinically important (Feske, 1998; McNair, 1999; Plum & Posner, 1980). Early determination that a patient’s LOC is deteriorating affords an opportunity for clinicians to intervene with treatment and potentially avert further brain damage. Orientation as an indicator of a change in LOC fluctuating in either a positive or negative direction or a pattern of change in orientation has not been investigated.

Patients who sustain brain injuries because of trauma or stroke are at risk for altered consciousness because of both the initial area of brain damage and extended areas of damage from secondary changes, such as increased intracranial pressure (Feske, 1998; McNair, 1999; Neatherlin, 1999; Yamamoto, Bogousslavsky, & van Melle, 1998). For this reason, nurses continue to monitor for neurological changes by assessing LOC of patients throughout their acute hospitalization as well as during rehabilitation (Le, Venti, & Levin, 1994). However, there is no consistent practice for how a nurse evaluates changes in LOC that can be subtle in nature (Alverzo & Galski, 1999; Crosby & Parsons, 1989; Way & Segatore, 1994). The purpose of this study was to determine whether the onset of disorientation during the rehabilitation stay of stroke and brain injury patients was associated with any predictive factors.

Significance of the Study

Traumatic brain injury (TBI) and stroke are significant healthcare issues in the United States. TBIs affect a total of 7 million adults a year (McNair, 1999) and are credited with about one-third of all traumatic deaths in the United States (Thurman & Guerrero, 1999). The highest incidence is among young men and older adults. Stroke is the third leading cause of death in the United States (Rhys, Jiang, Matchar, David, & Samsa, 1999), affecting a total of 730,000 persons each year (Williams, Yilmaz, & Lopez-Yunez, 2000).

Because of improvements in medical technology over the past 20 years, more patients are surviving brain injuries and strokes (Hock, 1999; McNair, 1999). Mortality associated with TBI declined by 22% between 1979 and 1992 (Sosin, Sniezek, & Waxweiler, 1995). From 1980 to 1991, stroke mortality declined between 10.5% and 27.1% based on gender and age (Derby, Lapane, Feldman, & Carleton, 2000). The improved survival rates from both TBI and stroke have increased the need for reliable assessment methods to monitor a patient’s neurological status and potential neurological deterioration more closely. Early detection of a worsening neurological status can lead to earlier interventions, decreased morbidity, decreased resource consumption, and a shortened hospital stay (Feske, 1998). The management of patients who sustain a TBI or stroke has evolved both in the accuracy of diagnostic testing (Stein, Spettell, Young, & Ross, 1993) and in treatment options. Although diagnostic testing of TBI and stroke patients is standard practice in most emergency rooms (Feske, 1998), follow-up testing is generally performed only when there are observable changes in a patient’s neurological status (Ross, Pitts, & Kobayashi, 1992; Yamamoto et al., 1998). The most important indicator of neurological deterioration is a change in LOC (Feske, 1998; Neatherlin, 1999). In spite of the importance of a change in LOC, recognizing it remains a largely subjective process (Benner & Tanner, 1987; Ingram, 1994; Yamamoto et al.).

Review of the Literature

Consciousness and orientation are interwoven. In general, research on consciousness, including scales that are designed to measure LOCs, uses some measure of orientation. The same, however, cannot be said of the research and literature on orientation. Persons are known to be disoriented, from both diminished consciousness and conditions with no associated loss of consciousness, such as dementia or psychiatric illness. This review focuses on both research on consciousness and research on orientation, identifying areas of overlap and areas in which the concepts digress.

Nurses in hospital settings assess altered LOC for several days, weeks, or months to screen for potential neurological deficits. In some cases, a change in LOC determined by repeated assessments of a patient’s neurological status may be the first indication of neurological complications (Neatherlin, 1999; Plum & Posner, 1980). Healthcare providers use the Glasgow Coma Scale (GCS) to evaluate patients in a coma (Teasdale & Jennett, 1974), which is considered the international standard for determining coma level (Way & Segatore, 1992).

There is no standardized test for determining changes in LOC for patients who are not in a coma. Descriptors such as confused, obtunded, stuporous, lethargic, or delirious are common (Feske, 1998), but these terms are confusing and tend to be unreliable. Nurses have frequently monitored orientation as an indicator of altered LOC (Grant & Kinney, 1990; Johnson, Maas, & Moorhead, 2000); however, there is no standardized method for its measurement (Alverzo & Galski, 1999; Williams et al., 2000) nor any research to support the value of such testing.

A number of nursing scholars have investigated LOC. Several qualitative studies have explored the concept of LOC (Lusardi & Schwartz-Barcott, 1996; Schorr, 1983; Tosch, 1988), focused on the meaning of altered consciousness following coma, and concluded that a patients’ awareness of the state of altered consciousness varies with their LOC and acuity and is associated with themes of death and imprisonment. Ingram (1994) reviewed nurses’ knowledge of LOC from both empirical and aesthetic frameworks and determined that nurses use intuition when assessing altered consciousness rather than relying only on tests such as the GCS.

Several quantitative studies in the nursing literature have focused on the measurement of LOC, proposing new instruments to replace the GCS with more sensitive brain stem indicators (Crosby & Parsons, 1989; Segatore & Way, 1992; Way & Segatore, 1994). One study investigated what indicators nurses report they rely on to assess altered LOC, concluding that orientation is the most frequent and important indicator of altered LOC in a patient who is awake (Grant & Kinney, 1990). Although this study demonstrated that orientation is thought to be an important indicator of altered LOC among nurses, there has been no research to determine whether there is a relationship between orientation and a change in neurological status.

Orientation can be measured alone or in combination with other related cognitive constructs. A wide range of instruments that have been designed to measure phenomena such as cognition, delirium, and dementia include orientation among their critical elements. One study concluded that a single measure of orientation does not capture the scope of cognition problems following TBI (Nakase-Thompson, Sherer, Yablon, Nick, & Trzepacz, 2004). Benton, Van Allen, and Fogel (1964) developed the Temporal Orientation Test (TOT) as one of the first standardized tests for time orientation. Over the past 35 years, the TOT has been used in the formulation of a number of instruments including the Galveston Orientation and Amnesia Test (GOAT; Levin, O’Donnell, & Grossman, 1979), and the Orientation Log (O-Log; Jackson, Novack, & Dowler, 1998). The TOT is designed to measure only one sphere of orientation—orientation to time. Several studies have determined that time or temporal orientation is the most fragile of the three categories of orientation—person, place, and time (Benton, Van Allen, & Fogel, 1964; Daniel, Crovitz, & Weiner, 1987; High, Levin, & Gary, 1989). It is the first category of orientation to show error when a patient is deteriorating, and it is the last category of orientation to return when a patient is improving.

Nursing practice evolves based on both traditions and research. To date, the practice of assessing orientation changes to determine whether a patient’s neurological status is altered has been a tradition that has not been validated by scientific inquiry. This study contributes to nursing scholarship by exploring changes in orientation and the predictive factors associated with those changes, thus contributing to the body of evidence-based practice. The study does not, however, provide sufficient evidence to determine whether testing patient’s orientation is useful as a means of determining a change in LOC. Further research is needed.

Theoretical Rationale—Parallel Distributed Processing

Plum and Posner (1980) performed some of the early theoretical work on coma and altered consciousness. They differentiated various coma states including clouding of consciousness, delirium, obtundation, and stupor. In the early 1970s, Plum and Posner proposed a continuum model of consciousness, with the lower end of the continuum being a person’s state of arousal and the upper end being content of thought. This model has been used by a number of researchers and has served as the basis for several scales to measure LOC (Crosby & Parsons, 1989; Way & Segatore, 1994).

Building on the framework proposed by Plum and Posner, a number of researchers have pursued a model for consciousness. Attempts to identify a focal region for consciousness have largely been unsuccessful (Anderson & Rosenfeld, 1998). Devinsky (1988) suggested that a model for consciousness requires a unification between various cortical and subcortical regions beyond simple association. The Parallel Distributed Processing (PDP) model developed by Rumelhart and McClelland with the PDP Research Group (1986) builds on artificial intelligence research and basic science research on neural networks and provides a framework for information processing in the brain, including consciousness.

Consciousness in this model is the result of many different modules at the cortical and the subcortical levels of the brain that are linked through a parallel structure (Rumelhart & McClelland, 1986). Alterations in consciousness can result from failure of individual modules or the connections between modules. This supports the early work of Plum and Posner (1980) that consciousness reflects whole brain function rather than the function of any specific region of the brain. Using the same model, orientation to time, place, and person requires the integration of current sensory input with memory in a dynamic manner.

Both alterations in consciousness and disruptions in orientation are the result of an inability to integrate information from various neural networks in the brain into a steady state of awareness or arousal (Devinsky, 1988). Conversely, full consciousness and orientation rely, at a minimum, on the activation of the reticular activation system, creating a wakeful state. Further research is needed to test the relationship between orientation as an indicator of consciousness and changes in a patient’s neurological status. Establishing the relationship between these constructs will validate orientation as a key component of consciousness within this integrated model. Further, it will determine the usefulness of orientation as a clinical measure of altered consciousness and support more objective assessment of patients’ neurological status.

Method

The purpose of this descriptive research was to determine the factors associated with a change in temporal orientation among stroke and brain injury patients during rehabilitation. A change in orientation was defined in this study as a score of 4 or more error points following a period of 3 days when the patient scored within the normal range of 0–3 error points on the total TOT (Levin & Benton, 1975; Natelson, Haupt, Fleischer, & Grey, 1979) and is a dichotomous variable. This instrument has been adopted as part of the standard assessment of stroke and brain injury patients at the facility where the research was conducted (see Figure 1). A nurse administers the test verbally and records the results on a daily neurological assessment flowsheet. The test requires 5 minutes or less to administer and assigns a negative numerical value to errors in the day, month, year, day of week, and present clock time.

The independent variables that were examined included several demographic variables such as age, years of education, gender, number of comorbidities, traumatic versus nontraumatic diagnoses, orientation on admission to rehabilitation, and sedative/narcotic medications. The research question was “What are the variables associated with temporal disorientation among stroke and brain injury patients during their stay in rehabilitation?” A logistic regression analysis was performed on temporal orientation (oriented or disoriented during the stay) as the outcome measure. Analysis was performed using SPSS Release 11.01.

Sample

Sample inclusion criteria involved first the assignment of patients on admission to the rehabilitation impairment categories of stroke, TBI, or nontraumatic brain injury (NTBI). In addition, the sample patients needed to have a rehabilitation stay of 4 days or longer to have baseline scores on the TOT. Sample patients also were required to have a score on the TOT of 3 or less error points on admission, or for 3 days or longer before the development of a neurological complication. This allowed a normal baseline score on the TOT to be established so that a change could be detected.

Exclusion criteria were as follows: (a) persons with a history of dementia or mental illness based on the confounding effect of these diagnoses and (b) patients who were unable to respond correctly to yes–no questions because this would interfere with reliable testing. The convenience sample was chosen by retrospective chart review of consecutively admitted stroke and brain injury patients who met the study criteria. The sample for this study comprised patients with either a diagnosis of brain injury or stroke.

Results

The final study sample was drawn from 177 consecutively admitted brain injury and stroke patients. A total of 114 patients met the inclusion criteria, with an average age of 59.96 years (range, 19–87). Out of the 114 patients in the sample, 55 (48%) were older than 65 years. The gender distribution was 51% male (n = 58) and 49% female (n = 56). The rehabilitation admission diagnoses of the study patients, otherwise known as rehabilitation impairment categories (RIC), were 66 strokes, 22 TBI, and 26 NTBI. The gender varied in relation to the patients’ RICs (see Table 1). The incidence of TBI by gender was 19% of the males and 19.6% of the females. The incidence of NTBI by gender was 32.8% of the males and 12.5% of the females.

Age groupings were used to analyze differences in discharge disposition, orientation status on admission, and disorientation during the stay. Orientation status differed by age group, with those 66 years and older having a higher percentage of disorientation on admission, during the stay, and on discharge (see Table 2). In the sample, a total of 56% of patients had 12 years of education, and 19.3% had 16 years of education. The sample varied in the number of comorbidities that existed at the time of admission (Table 3). The greatest number of comorbidities were present among stroke patients, with 58% of all the comorbidities for the three groups.

At the time of admission to rehabilitation a total of 76 (66.7%) of patients were oriented to time. Of the other 38 (33.3%) patients not oriented on admission, the range of the number of days before they achieved orientation was 1–33, with a mean of 8.11 days. The group with the highest percentage of disorientation on admission was the TBI group (n = 9), representing 40.9% of those who were disoriented.

Medications were tracked in three categories for the study: narcotic medications, hypnotic/sedative medications, and anticholinergic medications. The frequency of use for each medication group in the study group is listed in Table 4.

A logistic regression analysis was performed on temporal orientation (oriented or disoriented during the stay) as the outcome measure. The variables in the model were age, gender, years of education, number of comorbidities, traumatic or nontraumatic diagnosis, orientation status on admission to rehabilitation, and use of sedative/hypnotic medications. Analysis was performed using SPSS Release 11.01.

A test of the full model with all seven variables loaded as a block against a constant only model was statistically reliable; likelihood ratio χ2 (7, N = 114) = 17. 509, p < .014. This indicates that the predictors as a set reliably distinguish between those who became disoriented during their stay and those who did not.

The model appeared to be well-calibrated. The Hosmer-Lemeshow test was performed and the results were nonsignificant; χ2 (8, N = 114) = 2.319, p < .970. However, the variance in temporal orientation accounted for by this model was small, with Nagelkerke r2 = .196. This suggested that the variable of orientation on admission to rehabilitation accounts for only 19% of the variance in orientation and that 81% of the variation is because of other factors not tested in this model. Therefore, there are important predictor variables for disorientation that need to be identified and included in future models.

Table 5 contains the parameter estimates, Wald test, odds ratios, and associated 95% confidence intervals for each of the six predictors. Only one of the seven predictors, orientation status on admission, reliably predicted the onset of disorientation during the rehabilitation stay. This variable had an odds ratio of 0.217. The odds ratio indicates that the risk of becoming disoriented is 78% higher in persons having a history of disorientation at admission to rehabilitation.

The residuals were examined for outliers and influential points. There were no extreme outliers, with a range of standardized residuals of –1.73, t = 2.11, with a mean of –0.01. There did not appear to be any overly influential points. No Cook’s Ds exceeded 1, and no leverage values exceeded .35. All these tests indicate that the data were not affected by outliers or by any data points that were overly influential, supporting the validity of the results. Multicollinearity was assessed to determine whether there was any overlap between the variables that might be measuring the same thing. If the square root of the VIF is equal to or greater than 2, then multicollinearity may be a problem. In this case, all the VIFs were well below 2. Therefore, each variable measured a unique aspect of the total model.

Discussion

Research on the variability of temporal orientation is quite limited (Desmond et al., 1994; Sweet et al., 1999). This study was unique in its exploration of the longitudinal changes in temporal orientation among brain injury and stroke patients. The degree to which temporal orientation varied among the sample patients was surprising given the assumptions of other studies on orientation that often stopped once a period of orientation was achieved. The single predictor variable of a patient becoming disoriented during his or her stay was the presence of disorientation at the time of admission to rehabilitation. Out of 38 patients who were disoriented on admission and achieved 3 days of orientation during their stays, 22 (57.8%) became disoriented once again during their stay, and 4 (10%) remained disoriented at discharge. The preponderance of literature on posttraumatic amnesia (PTA) following TBI is predicated on the assumption that once a patient has achieved 3 days of orientation, the period of PTA is over. Further testing of orientation has not extended beyond the end of PTA in most studies (Ellenberg, Levin, & Saydjari, 1996; Wilson et al., 1994).

The method by which clinicians measure orientation over time is not standardized. In a study of 52 rehabilitation nurses, there was no consistency in how orientation was measured during a patient’s rehabilitation stay, and one of the more commonly reported methods to determine whether a patient was oriented was general conversation (Alverzo & Galski, 1999). This is consistent with other studies (Benton, Van Allen, & Fogel, 1964; Natelson et al., 1979), identifying the same variability among neurologists testing orientation. Jackson, Novack, and Dowler (1998) proposed a brief bedside orientation instrument for this very reason. To date, however, methods for tracking orientation change over time and are not well established in the hospital setting nor in rehabilitation. The two methods that are reported to be consistently used are the Mini-Mental Status Examination (Folstein, Folstein, & McHugh, 1975) by psychologists, physicians, nurses, and other therapists generally limited to a baseline test of new patients in the in- and outpatient settings (Smith, Breitbart, & Platt, 1995), and the use of GOAT (Levin, O’Donnell, & Grossman, 1979) among TBI patients only during the period of PTA (Schacter & Crovitz, 1977).

Sample patients included those who had sustained strokes, TBIs, and NTBIs, but for the purpose of the data analysis, these three categories were collapsed into two—TBIs and NTBIs including stroke. The groups included many more patients with NTBIs (80.7%) than TBIs (19.3%). Although the bulk of patients fit into the NTBI group, this cluster did not undermine the data analysis of the diagnostic group as a predictor in the study. Unequal group numbers is not an assumption in logistical regression.

The repeated measure design was an important component of this study, tracking disorientation across time. Patient tolerance for testing once per day was relatively high, based on anecdotal evidence. An increase in frequency of testing to more than once a day may have not been tolerated as well. There also may have been more interference with the validity of the test, given possible contamination of one test upon another. That being said, there remain many unanswered questions regarding how orientation varies over a 24-hour cycle. This study was limited to the inpatient stay and did not test patients after discharge. Variability of orientation as the patient gets further from the initial injury or illness event is also an open question.

The model for predicting the onset of disorientation during the rehabilitation stay identified only one predictor for disorientation: disorientation on admission to rehabilitation. This finding is important because it confirms that orientation is unstable during the period following a stroke or brain injury. Further, the result that TBI versus NTBI was not predictive of the onset of disorientation during the patient stay was also important. The pattern of disorientation among TBI patients raises many questions about the assumptions in previous research.

Disorientation is a persistent phenomenon during rehabilitation for both TBI and NTBI patients. In the stroke population, a few studies have explored orientation changes over time. Desmond et al. (1994) looked at orientation at two intervals following stroke, concluding that orientation is both common and persistent following stroke. Hochstenback (2003) looked at the cognitive effect of stroke and noted that, of all the cognitive domains, improvements in attention including orientation were the most significant at 2 years after stroke. Predictors for disorientation based on previous research, including age, years of education, and medications, were not found to be statistically significant in this study. The incidence of disorientation that occurred following 3 days of orientation was much higher than anticipated, and disorientation on admission to rehabilitation was a statistically significant predictor of a patient becoming disoriented during his or her stay. These findings suggest that disorientation among patients with brain injuries is a persistent issue, and longitudinal testing of orientation may provide important assessment information to assist in tracking a patient’s recovery.

Conclusion

Given the paucity of research on orientation, the opportunity for further inquiry into this important concept is wide open (Desmond et al., 1994; Schneider, von Daniken, & Gutbrod, K., 1996). The frequent use of orientation in clinical assessment emphasizes the need for a greater understanding regarding its measurement (Grant & Kinney, 1990). Exploring the meaning and usefulness of testing a patient for orientation is also important so that it can be properly understood and interpreted within a clinical context. Trending data on changes in orientation are missing in many patient populations, with the greater majority of research focusing on “snapshots” of orientation at various time intervals. In addition, the need for a better understanding of orientation within theoretical frameworks of brain function is evident, since there are very few hypotheses regarding how the brain synthesizes information to arrive at the correct answers to orientation questions.

Nursing research on orientation is in its infancy. This study was one of the first to methodically test temporal orientation over time in hospitalized patients. A previous nursing study on orientation (Alverzo & Galski, 1999) laid important groundwork to confirm that the measurement of orientation by nurses in a rehabilitation hospital varies tremendously, further concluding that the interpretation of whether a patient is oriented based on their testing is equally variable. Without a standard method for nurses to test orientation, it is difficult to draw any conclusions about changes in orientation.

Further research into the phenomena of orientation is needed, both from a clinical perspective to create an empirical foundation for practice, and from a theoretical perspective to establish a working model based on brain function. Descriptive nursing research that focuses on clinical studies of varying patient populations and trends in orientation related to patient outcomes is needed first. The next step would be experimental nursing research directed at establishing nursing interventions that either directly affect disorientation or complement the recovery of disoriented patients, mitigating adverse outcomes. Research focusing on links between changes in patient orientation and a nurse’s aesthetic knowledge of a patient would provide an important insight into how intuition can complement empirical knowledge. Finally, research that explores orientation within a theoretical model of brain function is needed to further illuminate the role of orientation in consciousness.

Acknowledgment

This research was funded by the Rehabilitation Nursing Foundation New Investigator Grant (2001).

The author extends special thanks to nurse data collectors Nadia Bogovic, Virginia Dizon, Terrence Englis, Maria Levy, and Aud Lynch from the Kessler Institute for Rehabilitation.

About the Author

Joan P. Alverzo, PhD RN CRRN, is chief clinical officer at the Kessler Institute for Rehabilitation in West Orange, NJ.

Direct correspondence to Joan P. Alverzo, PhD RN CRRN, 1199 Pleasant Valley Way, West Orange, NJ 07052, or via e-mail to jalverzo@kessler-rehab.com

References

Alverzo, J. P., & Galski, T. (1999). Nurses assessment of orientation in a rehabilitation setting. Rehabilitation Nursing, 24(1), 7–23.

Anderson, J. A., & Rosenfeld, E. (Eds.). (1998). Talking nets: An oral history of neural networks. Cambridge: MIT Press.

Benner, P., & Tanner, C. (1987). How expert nurses use intuition. American Journal of Nursing, 87, 23–26.

Benton, A. L., Van Allen, M. W., & Fogel, M. L. (1964). Temporal orientation in cerebral disease. The Journal of Nervous and Mental Disease, 139, 110–119.

Crosby, L., & Parsons, C. (1989). Clinical neurologic assessment tool: Development and testing of an instrument to index neurologic status. Heart and Lung, 18, 121–129.

Daniel, W. F., Crovitz, H. F., & Weiner, R. D. (1987). Neuropsychological aspects of disorientation. Cortex, 23, 169–183.

Derby, C. A., Lapane, K. L., Feldman, H. A., & Carleton R. A. (2000). Trends in validated cases of fatal and nonfatal stroke, stroke classification, and risk factors in southeastern New England, 1980 to 1991: Data from the Pawtucket Heart Health Program. Stroke, 31(4), 875–881.

Desmond, D. W., Tatemichi, T. K., Figueroa, M., Gropen, T. I., & Stern, Y. (1994). Disorientation following stroke: Frequency, course, and clinical correlates. Journal of Neurology, 241, 585–591.

Devinsky, O. (1988). Neurological aspects of the conscious and unconscious mind. Contemporary Neurology Series, 29, 321–372.

Ellenberg, J. H., Levin, H. S., & Saydjari, C. (1996). Posttraumatic amnesia as a predictor of outcome after severe closed head injury. Archives of Neurology, 53, 782–791.

Feske, S. (1998). Coma and confusional states: Emergency diagnosis and management. Neurologic Clinics of North America, 16(2), 237–256.

Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). Mini mental state: A practical method of grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189–198.

Grant, J. S., & Kinney, M. (1990). Altered LOC: Validity of a nursing diagnosis. Research in Nursing and Health, 13, 403–410.

High, W. M., Levin, H. S., & Gary, H. E. (1989). Recovery of orientation following closed head injury. Journal of Clinical and Experimental Neuropsychology, 12, 703–714.

Hochstenback, J. B., den Otter, R., & Mulder, T. W. (2003). Cognitive recovery after stroke: A 2-year follow-up. Archives of Physical and Medical Rehabilitation, 84(10), 1499–1504.

Hock, N. H. (1999). Brain attack: The stroke continuum. Neuroscience Nursing for a New Millennium, 3(3), 689–723.

Ingram, N. (1994). Knowledge and level of consciousness: Application to nursing practice. Journal of Advanced Nursing, 20, 881–884.

Jackson, W. T., Novack T. A., & Dowler, R. N. (1998). Effective serial measurement of cognitive orientation in rehabilitation: The orientation log. Archives of Physical Medicine and Rehabilitation, 79, 718–720.

Le, N., Venti, C., & Levin, E. (1994). Initial assessment of patient cognition in a rehabilitation hospital. Rehabilitation Nursing, 19, 293–297.

Levin, H. S., & Benton, A. L. (1975). Temporal orientation in patients with brain disease. Applied Neurophysiology, 38, 56–60.

Levin, H. S., O’Donnell, V. M., & Grossman, R. (1979). The Galveston orientation and amnesia test. The Journal of Nervous and Mental Disease, 167(11), 675–684.

Lusardi , P. T. & Schwartz-Barcott, D. (1996). Making sense of it: A neuro-interactional model of meaning emergence in critically ill ventilated patients. Journal of Advanced Nursing, 23, 896–903.

McNair, N. D. (1999). Traumatic brain injury. Neuroscience Nursing for a New Millennium, 34(3), 637–661.

Nakase-Thompson, R., Sherer, M., Yablon, S. A., Nick, T. G., & Trzepacz, P. T. (2004). Acute confusion following traumatic brain injury. Brain Injury, 18(2), 131–142

Natelson, B. H., Haupt, E. J., Fleischer, E. J., & Grey, L. (1979). Temporal orientation and education. Archives of Neurology, 36, 444–446.

Neatherlin, J. S. (1999). Foundation for practice: Neuroassessment for neuroscience nurses. Neuroscience Nursing for a New Millennium, 34(3), 573–592.

Plum, F., & Posner, J. (1980). Diagnosis of stupor and coma (3rd ed. ). Philadelphia: F. A. Davis.

Rhys, W. G., Jiang, J. G., Matchar, D. B., & Samsa, G. P. (1999). Incidence and occurrence of total (first ever and recurrent) stroke. Stroke, 30(12), 2523–2528.

Ross, A. M., Pitts, L. H., & Kobayashi, S. (1992). Prognosticators of outcome after major head injury in the elderly. Journal of Neuroscience Nursing, 24(2), 88–93.

Rumelhart, D. E., McClelland, J. L., & PDP Research Group. (1986). Parallel Distributed Processing: Explorations in the microstructures of cognition. Cambridge: MIT Press.

Schacter, D. L., & Crovitz, H. F. (1977). Memory function after closed head injury: A review of the quantitative research. Cortex, 13, 150–176.

Schneider, A., von Daniken, C., & Gutbrod, K. (1996). Disorientation in amnesia: A confusion of memory traces. Brain, 119, 1627–1632.

Schorr, J. A. (1983). Manifestations of consciousness and the developmental phenomenon of death. Advances in Nursing Science, October, 26–35.

Segatore, M., & Way, C. (1992). The Glasgow coma scale: Time for change. Heart and Lung, 21(6), 548–557.

Smith, M. J., Breitbart, W. S., & Platt, M. M. (1995). A critique of instruments and methods to detect, diagnose, and rate delirium. Journal of Pain and Symptom Management, 10(1), 35–77.

Sosin, D. M., Sniezek, J. E., & Waxweiler, R. J. (1995). Trends in death associated with traumatic brain injury. 1979–1992. Journal of the American Medical Association, 273, 1778–1780.

Stein, S. C., Spettell, C., Young, G., & Ross, S. E. (1993). Limitations of neurological assessment in mild head injury. Brain Injury, 7(5), 425–430.

Sweet, J. J, Such, Y., Leahy, B., Abramowitz, C., & Nowinski, C. J. (1999). Normative clinical relationships between orientation and memory: Age as an important moderator variable. The Clinical Neuropsychologist, 13(4), 495–508.

Teasdale, B., & Jeanett, B. (1974). Assessment of coma and impaired consciousness. Lancet, 2(7872), 81–84.

Thurman, D., & Guerrero, J. (1999). Trends in hospitalization associated with traumatic brain injury. Journal of the American Medical Association, 282(10), 954–957.

Tosch, P. (1988). Patients’ recollections of their posttraumatic coma. Journal of Neuroscience Nursing, 20(4), 223–228.

Way, C., & Segatore, M. (1994). Development and preliminary testing of the neurological assessment instrument. Journal of Neuroscience Nursing, 26(5), 278–287.

Williams, L. S., Yilmaz, E. Y., & Lopez-Yunez, A. M. (2000). Retrospective assessment of initial stroke severity with the NIH stroke scale. 2000 American Heart Association, 31(4), 858–862.

Wilson, J. T., Teasdale, G. M., Hadley, D. M., Wiedman, K. D., & Lang, D. (1994). Post-traumatic amnesia: Still a valuable yardstick. Journal of Neurology, Neurosurgery, and Psychiatry, 57, 198–201.

Yamamoto, H., Bogousslavsky, J., & van Melle, G. (1998). Different predictors of neurological worsening in different causes of stroke. American Medical Association, 55(4), 481–486.