Biomedical subjects

S R Millis

Publications and source records attributed to S R Millis.

At least 19 recordsLinked to original sources

PubMed2001

Severe penetrating head injury: a study of outcomes.

OBJECTIVE: To determine and describe the demographics and functional outcomes of persons who require inpatient rehabilitation for severe penetrating head injury resulting from a gunshot wound to the head. DESIGN: Data were collected prospectively from the time of admission to acute care through discharge from inpatient rehabilitation. SETTING: Two sites: an urban, level I, acute care, trauma center and an inpatient rehabilitation hospital with a specialized brain injury unit. PARTICIPANTS: Twenty-seven persons with severe penetrating head injury. MAIN OUTCOME MEASURES: The FIM instrument, the Disability Rating Scale (DRS), and the length of stay (LOS). RESULTS: Demographic data showed our population to be similar to other groups of persons at high risk for violent injury. Eighty-five percent of the subjects were men with a mean age of 34 years. The majority were African American (93%), reflective of our general patient population. Average acute care LOS was 31 days and average rehabilitation LOS was 44 days. Average FIM gain was 40.2 and, on average, DRS scores improved 7.6 points from rehabilitation admission to discharge. All study participants made enough progress to be discharged to private residences. CONCLUSION: Although the mortality rate is high among patients with penetrating head injury, those who survive to receive inpatient rehabilitation can achieve functional improvement.

Activities of Daily Living↗

PubMed2001

Using early neuropsychologic testing to predict long-term productivity outcome from traumatic brain injury.

OBJECTIVE: To evaluate whether early neuropsychologic testing is useful in predicting long-term productivity outcome after traumatic brain injury (TBI). DESIGN: Validation cohort prediction study. SETTING: Four inpatient brain injury rehabilitation programs participating in the Traumatic Brain Injury Model Systems project. PARTICIPANTS: A total of 293 adults with nonpenetrating TBI. MAIN OUTCOME MEASURES: Fifteen neuropsychologic tests were administered to patients who emerged from posttraumatic amnesia before rehabilitation discharge. Test scores were classified in the normal range or impaired range, using objective criteria. Outcome was defined as productive if the patient was competitively employed or enrolled full time in regular education. RESULTS: Productivity at follow-up was predicted by completion of at least 1 neuropsychologic test before discharge, by an injury-test interval of less than 2 months, and by normal range scores on 10 of the 15 neuropsychologic tests. Normal range scores on these tests increased the probability of a productive outcome by 40% to 130%. CONCLUSIONS: Neuropsychologic testing can help predict long-term productivity even when performed before discharge from inpatient rehabilitation and at variable injury-test intervals. Early testing should be interpreted in relation to injury-test interval. Because tests of multiple neuropsychologic domains predicted outcome, comprehensive evaluations might be more useful in predicting outcome.

Adult↗

PubMed2001

Verbal recall and recognition following traumatic brain injury: a [0-15]-water positron emission tomography study.

Although several studies exist which have examined static functional neuroimaging following traumatic brain injury (TBI), controlled cognitive activation studies of episodic memory in this population have not been published. The present investigation studied verbal recall using [O-15]-water positron emission tomography (PET) in 5 individuals who sustained severe TBI (M GCS=6.8; M years post-injury=3.18), and 4 non-injured control participants. Statistical image analysis demonstrated changes in frontoparietal regional cerebral blood flow (rCBF) in both groups, but there were interesting differences between groups and across conditions. Frontal lobe rCBF changes in TBI patients were reduced during free recall but enhanced during recognition, when compared to controls. Changes in cerebellar rCBF were observed in the control group during free recall, but not in the TBI sample. In both groups, bifrontal rCBF increases were noted on recognition tasks. The present findings provide evidence of alterations in specific substrates involved in verbal recall following brain injury.

Adult↗

PubMed2000

Factors associated with insomnia among post-acute traumatic brain injury survivors.

This study investigated the relationships between insomnia and select demographic, injury and psychosocial variables in post-acute, traumatic brain injury. Clinical assessment of sleep and mood was undertaken via objective measures and a diagnostic interview among 91 consecutive brain injury admissions to an outpatient neurorehabilitation clinic. No associations between insomnia and gender, education, age, and time since injury were found. A logistic regression model of insomnia prediction based upon the Beck Depression Inventory (BDI), self-reported pain disturbance, litigation and Glasgow Coma Score (GCS) correctly classified 87% of the sample with respect to the presence or absence of insomnia; however, depression and injury severity were the only variables that made a significant unique contribution to the prediction of insomnia. It is concluded that among post-acute traumatic brain injury patients, insomnia is linked with both the presence of depression and a history of milder brain injuries. This suggests that the determinants of insomnia may differ from the acute to the post-acute phase, with neurological factors playing a primary role early in the recovery process and psychosocial factors ascending later. Therefore, assessment and treatment of insomnia must give careful attention to the larger psychosocial context in which the sleep disorder emerges, particularly to role of emotional disturbance.

Adolescent↗

PubMed1999

Measures of executive functioning as predictors of functional ability and social integration in a rehabilitation sample.

OBJECTIVE: To examine the utility of executive function tests in predicting rehabilitation outcome. DESIGN: A prospective, descriptive study of the value of neuropsychologic and motor functioning measures in the prediction of functional outcome 6 months after acute rehabilitation. SETTING: A Midwestern, urban, university-affiliated rehabilitation hospital. PATIENTS: Ninety consecutive admissions to traumatic brain injury, orthopedic, and spinal cord injury units. Age of the participants ranged from 17 to 73. MAIN OUTCOME MEASURES: Community Integration Questionnaire (CIQ), Disability Rating Scale (DRS), SF-36 Health Survey. RESULTS: Canonical correlation analyses indicated that measures of executive functioning and verbal memory were strongly related to measures of functional outcome 6 months after rehabilitation, as measured by the DRS and the CIQ. In contrast, perceived health status as measured by the SF-36 was highly related to estimated premorbid IQ and modestly related to visuospatial impairment. CONCLUSIONS: Executive functioning, verbal memory, and estimated premorbid intelligence predict functional dependence after discharge from rehabilitation beyond information regarding basic sensory and motor skills. Moreover, there is a dissociation between measures of functional outcome, such that objective and behaviorally oriented measures of disability (CIQ and DRS) are strongly related to each other; however, they are not related to perceptions of general health status (SF-36).

Adolescent↗

PubMed1999

Confirmatory factor analysis of the Wechsler Memory Scale-III.

The latent structure of the Wechsler Memory Scale-III was analyzed by confirmatory factor analysis using the covariance matrix based on the 11 primary subtests from the standardization sample. Omnibus fit indexes and individual parameter estimates were examined. Of the five models evaluated, a three-factor model (working memory, auditory memory, and visual memory) provided the best fit for the standardization sample (NNFI = .98, RMSEA = .05, GFI = .98, BIC = 429.42). Models that proposed separate immediate and delayed memory constructs were hampered by inadmissible parameter estimates that signaled model specification errors. R2 values for the Faces subtests were uniformly low for all five models that suggested that this subtest has insufficient commonality with the visual memory construct.

Factor Analysis, Statistical↗

PubMed1999

The effect of cocaine on traumatic brain injury outcome: a preliminary evaluation.

The effect of acute cocaine use on the functional and neuropsychological outcome of persons with traumatic brain injury, (TBI) was examined by comparing persons with TBI who tested positive for cocaine at the time of admission with persons with negative drug and alcohol screens. Subjects were matched for age, admission GCS score, level of education, and aetiology of injury (closed vs penetrating head injury). Dependent measures were: the Disability Rating Scale, the Functional Independence Measure, and selected neuropsychological tests. No group differences were found in DRS, FIM, FIM subsets, or FIM change. However, the cocaine group scored significantly lower than the no-drug group on the Rey Auditory Verbal Learning Test, but did not differ on any of the other neuropsychological tests.

Adolescent↗

PubMed1998

Executive functioning and predictors of falls in the rehabilitation setting.

OBJECTIVE: To examine the incremental utility of executive function tests in the prediction of inpatient falls. DESIGN: Evaluation of neuropsychologic and medical risk factors for fall was completed at admission. Inpatient falls were tabulated following discharge. SETTING: A freestanding, urban rehabilitation hospital. PATIENTS: Ninety consecutive admissions to traumatic brain injury, orthopedic, and spinal cord injury wards. Age of the participants ranged from 17 to 73 years old. MAIN OUTCOME MEASURE: Incident reports of inpatient falls. RESULTS: Standard multiple regression analyses indicated that measures of executive functioning sensitive to self-monitoring accounted for unique variance in falls beyond that explained by age and functional motor ability as assessed by the Functional Independence Measure. Visuospatial functioning, although not directly related to falls, was a significant predictor in combination with measures of executive functioning. Together, these variables accounted for 30.3% of the variance in inpatient falls (multiple r = .55; p < .001). CONCLUSION: The findings suggest that the influence of motor and sensory impairments on falls are moderated, in part, by executive functioning. Patients with intact executive functioning are less likely to act in ways that could result in a fall; thus, aggressive fall prevention measures may be unnecessary. In contrast, executive dysfunction may signal the need for intervention, even among patients whose profiles are unremarkable with regard to traditional risk factors for fall.

Accidental Falls↗

PubMed1998

Detection of incomplete effort on the Wechsler Adult Intelligence Scale-Revised: a cross-validation.

This study determined whether the Vocabulary-Digit Span difference score and discriminant function based on subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) developed by Mittenberg et al. (1995) could differentiate patients with moderate and severe traumatic brain injuries (n = 50) from persons with financially compensable mild head injuries who were giving incomplete effort (n = 50). Employing modified cutoff scores, the discriminant function and Vocabulary-Digit Span difference score accurately classified 90% and 79% of the cases, respectively. Persons with traumatic brain injuries may produce WAIS-R subtest patterns that can be differentiated from individuals showing incomplete effort. These WAIS-R algorithms appear useful in making that distinction.

Adult↗

PubMed1998

Effects of coaching on detection of malingering on the California Verbal Learning Test.

The diagnostic accuracy of California Verbal Learning Test (CVLT) indices to detect malingered head injury was examined using a simulation paradigm that included naive malingerers, malingerers provided with information about head injury, and normal controls (N = 90). The application of diagnostic cutoff scores for Recognition Discriminability and Recognition Hits derived from populations of individuals with bona fide head injury and individuals suspected of malingering (Millis et al., 1995) proved highly sensitive and modestly specific in detecting feigned head injury among both simulation groups. Results of analyses of variance and logistic regression support previous findings that malingerers overestimate memory impairment associated with mild head injury; however, they indicate that exposure to a simple instructional set may render insensitive many indices of malingering. In contrast, indices based on more subtle principles of learning theory hold promise in the detection of malingering, even in the presence of an instructional set.

Adolescent↗

PubMed1998

Validation of the Warrington theory of visual processing and the Visual Object and Space Perception Battery.

Competing hypotheses regarding the nature of visual processing were examined using the performance of 111 healthy older persons on the Warrington and James (1990) Visual Object and Space Perception Battery (VOSP). Confirmatory factor analysis indicated that a two-factor model corresponding to the Warrington theory of object and space perception as discrete domains showed excellent congruence with the data, despite limitations in the VOSP space perception tests that may have resulted in underestimation of model fit. Moreover, compared to a unidimensional model of visual processing, the Warrington model demonstrated a superior fit to the data. These findings add to the bodies of evidence supporting a dissociation between object- and space-perception abilities and defining the construct validity of the VOSP battery.

Aged↗

PubMed1998

Do calendars enhance posttraumatic temporal orientation?: a pilot study.

The purpose of this study was to determine the effectiveness of an in-room calendar to correct temporal disorientation in a brain-injured population. Thirty consecutive brain injured patients (16 traumatic, 14 non-traumatic) admitted to a brain injury rehabilitation unit were randomly assigned to either a group with in-room calendars (n = 14) or a group without calendars (n = 16). A baseline Temporal Orientation Test (TOT) score was obtained. Daily TOT scores were obtained for patients throughout their rehabilitation stay or until two consecutive normal scores were obtained. When orientation errors were made, they were corrected and the attention of the patient was drawn to the calendar. There were no statistically significant associations between group and age, gender or mean GCS (for patients with traumatic etiology). Only baseline length of post-traumatic amnesia (PTA) had a significant association with eventual emergence from PTA (as defined by a normal score on the TOT). Age and presence of calendar were not significant. In-room calendars have been espoused as orientation aides. The data from this pilot study suggest that calendars do not hasten re-orientation. This finding suggests that other widely held but not rigorously tested beliefs regarding cognitive rehabilitation may need to be examined.

Age Factors↗

PubMed1998

Internal consistency of the Warrington Recognition Memory Test.

The Recognition Memory Test is frequently used to assess memory; however, one of the commonly cited limitations is a lack of data on reliability. The current study was undertaken to estimate the internal consistency reliability of the test with a sample of 72 persons with traumatic brain injury. Acceptable estimates of internal consistency for both subtests were obtained.

Adolescent↗

PubMed1997

Posttraumatic amnesia: its relation to functional outcome.

OBJECTIVE: To investigate the relation between duration of posttraumatic amnesia (PTA) and functional outcome in a traumatically brain injured population. PATIENTS: Two hundred seventy-six patients with traumatic brain injury (TBI) who were admitted to a Level I university trauma center and required inpatient rehabilitation. MEASURES: Duration of PTA was assessed by serial administrations of the Galveston Orientation Amnesia Test (GOAT). Functional Independence Measure (FIM) total scores, FIM cognitive and motor subscores, and Disability Rating Scale (DRS) scores were obtained at admission and discharge from inpatient rehabilitation. RESULTS: Duration of PTA was a significant predictor of all admission and discharge DRS and FIM scores. Duration of PTA and age at the time of injury, in combination, contributed significantly to the prediction of the DRS score and FIM total, cognitive, and motor scores at discharge. CONCLUSION: Duration of PTA appears to be a useful variable in predicting specific functional outcome in the TBI population receiving inpatient rehabilitation services. The use of age as a factor in addition to duration of PTA enhances the prediction of functional outcome.

Adolescent↗

PubMed1997

Risk factors for acute care transfer among traumatic brain injury patients.

OBJECTIVE: Acute inpatient traumatic brain injury (TBI) rehabilitation has seen a jump in complexity of medical patient care over the past several years, often necessitating transfer back to an acute care facility. The purpose of this study was to determine the association between selected clinical variables and transfer from inpatient rehabilitation to an acute care facility. DESIGN: A retrospective review of cases from 1992 to 1994. SETTING: A TBI unit in a freestanding rehabilitation hospital. PATIENTS: Twenty-two patients were identified as having received acute care transfer. This group was compared with 78 patients, admitted in the same interval, who did not require acute care transfer. The variables evaluated included recent surgery, pneumonia, fracture, intracranial blood, tracheostomy use, percutaneous feeding tube use, deep venous thrombosis, focal neurological examination, following simple commands, serum sodium level of < 135 mmol/L, serum white blood cell count of > 11,000 cells/microL, and serum hemoglobin level of < 10.0 g/dl. ANALYSIS: Chi-square analysis was performed on the association between acute care transfer and the noted variables. RESULTS: History of pneumonia (p < .03) and history of recent surgery (p < .02) were both associated with acute care transfer, and serum hemoglobin of < 10.0 g/dL had a trend towards association (p < .10). CONCLUSION: Physiatrists caring for the TBI patient may warrant more acute observation of individuals with these parameters to prevent the problems necessitating acute care transfer.

Brain Injuries↗

PubMed1997

Functional outcome after violence related traumatic brain injury.

Violent injuries have become an increasingly prevalent cause of traumatic brain injury (TBI). These injuries can be classified as either penetrating or non-penetrating in nature. While much of the research on violence has been within a military population, there exists a marked difference between military and civilian injuries. Prior work has reported relatively poor outcomes for those individuals who have suffered penetrating TBIs, but little has been done to assess specific functional outcome parameters in survivors. We examined 25 subjects that had sustained blunt injuries and 25 cases with penetrating injuries as a result of a violent act. Cases were matched by initial Glasgow Coma Scale (GCS), age and educational level. Mean GCS for this study sample was 8.8. The following outcome variables were assessed at rehabilitation admission and discharge and at 1 year post injury: Disability Rating Scale (DRS), Rancho Los Amigos Scale (LCFS), Functional Independence Measure (FIM) (ambulation, expression items), length of stay, and cost of care. Student's t-tests were performed to assess for differences between the two groups. No significant differences were noted between the groups for any of the outcome variables. Although penetrating injuries may have a higher initial mortality, those who survive to come to rehabilitation appear to have similar outcomes to those patients with non-penetrating violence related injuries.

Adult↗

PubMed1996

Verbal learning subtypes in traumatic brain injury: a replication.

Traumatic brain injury (TBI) has been associated with memory impairments, but the severity and qualitative aspects of such impairment do not appear homogeneous across patients. This study sought to replicate an earlier investigation that found distinct verbal learning subtypes in TBI using the California Verbal Learning Test (CVLT). CVLT data from 88 acute rehabilitation inpatients with mild, moderate, and severe traumatic brain injuries were analyzed with multiple cluster analytic techniques. Cluster analyses yielded five learning subtypes, three of which appeared similar to the subtypes previously identified as Active, Disorganized, and Passive subtypes, and two that appeared similar to the Deficient subgroup. Traumatic brain injury appears to be characterized by heterogeneous, but fairly reliable, verbal learning subtypes that can be detected early postinjury.

Adolescent↗

PubMed1996

Differential visuospatial dysfunction following striatal, frontal white matter, or posterior thalamic infarction.

The present study investigated visuospatial functioning in 35 right-hand dominant patients with striatal, frontal white matter, or posterior thalamic infarction, in the right cerebral hemisphere. On tasks of visual detection and discrimination, the groups performed within normal limits and comparable to one another. On tasks of visual synthesis and spatial analysis, each group was significantly impaired, with greatest impairment following infarction of deep grey structures. Correlational analyses indicated that in the striatal and frontal white matter groups, visual synthesis and spatial analysis task performance were strongly correlated with performance on neuropsychological tests of executive control. This relationship was not observed in the posterior thalamic group. The results support the hypothesis of differential patterns of visuospatial performance depending on the anatomical locus of subcortical lesions. The findings are explained in terms of differing subcortical circuitry and suggest that multiple substrates mediate the sequelae of subcortical lesions.

Aged↗