Life satisfaction after traumatic brain injury

OBJECTIVE

To investigate correlates of life satisfaction after traumatic brain injury (TBI).

DESIGN

Prospective, longitudinal study of patients with TBI studied 1 and 2 years after injury.

SETTING

A specialized inpatient TBI rehabilitation unit in a midwestern academic medical center.

SUBJECTS

Two hundred eighteen consecutive patients admitted for rehabilitation, at least 14 years of age, with a primary diagnosis of TBI, consented to participate, and interviewed 1 and/or 2 years after injury (112 interviewed both years, 58 at year 1 only, 48 at year 2 only).

MAIN OUTCOME MEASURES

Satisfaction With Life Scale.

RESULTS

Stepwise multiple regressions accounted for statistically significant, but small, proportions of variance. Not having a preinjury history of substance abuse and having gainful employment at the time of follow-up were associated with higher life satisfaction both 1 and 2 years after injury. Motor independence at rehabilitation discharge was also associated at 1 year. Current social integration and the absence of depressed mood were associated at 2 years. Life satisfaction was relatively stable between years. Change that did occur was associated with marital status and depressed mood 2 years after injury.

CONCLUSIONS

Life satisfaction after TBI seems to be related to attaining healthy and productive lifestyles. Future research should investigate other factors that affect life satisfaction to increase prediction and appreciate all influences on subjective well being after TBI.

Role of agitation in prediction of outcomes after traumatic brain injury

OBJECTIVE

To determine the role of agitation in the prediction of traumatic brain injury rehabilitation outcomes.

DESIGN

A longitudinal study of 340 consecutive patients admitted to an acute traumatic brain injury rehabilitation unit was conducted. Outcomes under study included rehabilitation length of stay, discharge destination, functional independence at discharge (FIM instrument), productivity at 1-yr follow-up, and life satisfaction at 1-yr follow-up (Satisfaction with Life Scale).

RESULTS

Univariate analyses suggested that the presence of agitation in rehabilitation is predictive of a longer length of stay and decreased functional independence in the cognitive realm at discharge. In addition, individuals who exhibit agitation at any time during rehabilitation are less likely to be discharged to a private residence. However, multivariate analyses indicated that cognitive functioning at admission to rehabilitation (FIM cognitive) mediates the relationship between the presence of agitation and length of rehabilitation, as well as between agitation and FIM cognitive at discharge. Similar results were found when discharge residence was the dependent variable; however, agitation also contributed some unique variance to the prediction. Lower cognitive functioning at admission to rehabilitation was associated with the occurrence of agitation during rehabilitation, longer length of stay, lower cognitive functioning at discharge, and a decreased likelihood that an individual would be discharged to a private residence.

CONCLUSIONS

The results of the multivariate analyses support the contention that agitation and cognition are intimately related, with the long-term effects of the former being at least partially driven by the latter. These findings support the importance of systematically monitoring both agitation and cognition when applying interventions to reduce agitation.

A comparison of substance abuse and violence in the prediction of long-term rehabilitation outcomes after traumatic brain injury

OBJECTIVE

To determine the relative contributions of substance abuse history and violent etiology to the prediction of outcomes for individuals who sustained a traumatic brain injury (TBI) requiring inpatient rehabilitation.

DESIGN

Longitudinal study of outcomes 1 year postdischarge from rehabilitation.

SETTING

Specialized TBI acute rehabilitation unit.

PARTICIPANTS

Three hundred fifty-one individuals consecutively admitted for rehabilitation.

INTERVENTIONS

Gathered data from patients' medical records (including etiology of injury, initial Glasgow Coma Scale scores, and FIMtrade mark instrument scores at discharge), demographic details, and history of substance abuse; phone and mail survey data from individuals (Satisfaction with Life Scale [SWLS]; Community Integration Questionnaire [CIQ]).

MAIN OUTCOME MEASURES

CIQ and SWLS; relative contributions of injury etiology, demographic and injury-related dependent variables, and substance abuse history to predictive model.

RESULTS

Almost 80% of persons with injuries from violence-related causes had a history of substance abuse. Substance abuse was found to contribute to the prediction of life satisfacton and productivity, while violent etiology was not a significant contributor to predictive models.

CONCLUSION

Substance abuse history proved to be a strong predictor of long-term outcomes, while violent etiology of injury was less influential. The results of this study emphasize the need to include substance abuse history in all studies of outcomes after TBI, and to increase prevention efforts to limit the effects of such a history.

Defining sleep disturbance after brain injury

Sleep disorders are a relatively common occurrence after brain injury. Sleep disturbances often result in a poor daytime performance and a poor individual sense of well-being. Unfortunately, there has been minimal attention paid to this common and often disabling sequela of brain injury. This study attempts to define and to correlate the incidence and type of sleep disturbances that occur after brain injury. Consecutive admissions to a rehabilitation unit were used to create a longitudinal database designed to predict long-term outcomes for individuals who suffered a brain injury. Fifty percent of subjects had difficulty sleeping. Sixty-four percent described waking up too early, 25% described sleeping more than usual, and 45% described problems falling asleep. Eighty percent of subjects reporting sleep problems also reported problems with fatigue. Logistic regression analysis revealed the following: the more severe the brain injury the less likely the subject would be to have a sleep disturbance; subjects who had sleep disturbances were more likely to have problems with fatigue; females were more likely to have trouble with sleep. This study demonstrates the substantial prevalence of sleep disturbances after brain injury. It underscores the relationship between sleep disorders and perception of fatigue. It also underscores the need for clinicians to strive for interventional studies to look at the treatment of sleep and fatigue problems after brain injury.

Muscle atrophy is prevented in patients with acute spinal cord injury using functional electrical stimulation

Severe muscle atrophy occurs rapidly following traumatic spinal cord injury (SCI). Previous research shows that neuromuscular or 'functional' electrical stimulation (FES), particularly FES-cycle ergometry (FES-CE) can cause muscle hypertrophy in individuals with chronic SCI (> 1 year post-injury). However, the modest degree of hypertrophy in these already atrophied muscles has lessened earlier hopes that FES therapy would reduce secondary impairments of SCI. It is not known whether FES treatments are effective when used to prevent, rather than reverse, muscle atrophy in individuals with acute SCI. This study explored whether unloaded isometric FES contractions (FES-IC) or FES-CE decreased subsequent muscle atrophy in individual with acute SCI (< 3 months post-injury). Twenty-six subjects, 14-15 weeks post-traumatic SCI, were assigned to control, FES-IC, or FES-CE against progessively increasing resistance. Subjects were involved in the study for 3 or 6 months. Total body lean body mass (TB-LBM), lower limb lean body mass (LL-LBM), and gluteal lean body mass (G-LBM) were determined before the study, and at 3 and 6 months using dual energy X-ray absorptiometry (DEXA). Controls lost an average of 6.1%, 10.1%, 12.4%, after 3 months and 9.5%, 21.4%, 26.8% after 6 months in TB-LBM, LL-LBM and G-LBM respectively. Subjects in the FES-IC group consistently lost less lean body mass than controls, however, only 6 month G-LBM loss was significantly attenuated in this group relative to the controls. In the FES-CE group, LL-LBM and G-LBM loss were prevented at both 3 and 6 months, and TB-LBM loss was prevented at 6 months. In addition, FES-CE significantly increased G-LBM and LL-LBM after 6 months of training relative to pre-training levels. Within the control group, there was no significant relationship between LL-LBM loss (3 and 6 months) and the number of days between injury and baseline measurement. In summary, this study shows that FES-CE, but not FES-IC, training prevents muscle atrophy in acute SCI after 3 months of training, and causes significant hypertrophy after 6 months. The magnitude of differences in regionalized LBM between controls and FES-CE subject raises hopes that such treatment may indeed be beneficial in preventing secondary impairments of SCI if employed before extensive post-injury atrophy occurs.

Primary caregivers of persons with brain injury: life change 1 year after injury

The impact of a traumatic brain injury on the family of the injured person is just beginning to be explored. In the current study, 61 primary caregivers were contacted at 1 year following injury. They completed the Relative and Friend Support Index, Social Support Index, Trauma Complaints List and the Life Change Question. The majority of caregivers indicated at least mild negative life change following the brain injury. Greater social support was correlated with less life change and greater injury severity was correlated with negative life change. Neither of these relationships was found to be significant at the 0.05 level. A significant positive correlation was found between caregivers' perception of deficits and the degree of negative life change. Perceived deficits accounted for the greatest amount of variance in life change followed by relative and friend support when all variables were entered into a stepwise regression. Further analyses indicated that the most significant factor of the Trauma Complaints List in predicting life change may be problems with cognition, which accounted for a significant amount of the variance in life change. Implications for counselling and further research regarding caregivers of persons with brain injury are discussed.

Definition of agitation following traumatic brain injury: I. A survey of the Brain Injury Special Interest Group of the American Academy of Physical Medicine and Rehabilitation

OBJECTIVE

To determine national patterns of defining agitation after traumatic brain injury (TBI) by physiatrists with expressed interest in treating TBI survivors.

DESIGN

A random sample of 70% of the members of the Brain Injury Special Interest Group (SIG) of the American Academy of Physical Medicine and Rehabilitation (AAPM&R) were surveyed by telephone.

RESULTS

The 129 members who responded yielded an 82% response rate. Respondents rated 18 characteristics from established rating scales on a 5-point scale according to each characteristic's relation to its clinical definition of agitation. Physical aggression, explosive anger, increased psychomotor activity, impulsivity, verbal aggression, disorganized thinking, perceptual disturbances, and reduced ability to maintain or appropriately shift attention were rated by at least 50% of the sample as very important or essential to agitation. Delirium, as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM), has been proposed as a standard definition of agitation. The degree to which all characteristics from the 3rd revised edition of the DSM (DSM-IIIR), considered together, were perceived to relate to agitation predicted 24% of the degree to which the term "delirium" was perceived to relate to agitation (Canonical correlation r = .48, p = .0002). Physicians' ratings of individual delirium characteristics from the DSM-IIIR were examined to determine if a sufficient number were similarly ranked to fulfill the diagnostic criteria for delirium. A significant number of physicians rated diagnostic criteria for delirium in one direction, yet did not rank the term "delirium" accordingly (McNemar's p = .04).

CONCLUSIONS

There is considerable variation among physiatrists in their rating of characteristics that define agitation. Many define agitation during the acute recovery phase as posttraumatic amnesia plus an excess of behavior such as aggression, disinhibition, and/or emotional lability. Less support was given to defining agitation by the DSM-IIIR or DSM-IV diagnostic criteria for delirium. Delirium appears related to, but is not sufficient for, a diagnosis of agitation.

Measurement and treatment of agitation following traumatic brain injury: II. A survey of the Brain Injury Special Interest Group of the American Academy of Physical Medicine and Rehabilitation

OBJECTIVE

Determine national patterns of measuring and treating agitation after traumatic brain injury (TBI) by physiatrists with expressed interest in treating TBI survivors.

DESIGN

A 70% random sample of members of the Brain Injury Special Interest Group of the American Academy of Physical Medicine and Rehabilitation was surveyed by telephone.

MAIN OUTCOME MEASURE

The survey instrument was designed to determine the most common pharmacologic interventions for agitation and, where possible, match each drug with the target behavioral and cognitive characteristics for which it is prescribed. Data were also collected on the manner in which participants measured agitation and judged treatment efficacy.

RESULTS

One hundred twenty-nine of 157 responded, yielding an 82% response rate. The majority of respondents were not measuring agitation in a standard fashion. The five most frequently prescribed drugs by the expert stratum were carbamazepine, tricyclic antidepressants (TCAs), trazodone, amantadine, and beta-blockers. In comparison, the nonexperts most often reported prescribing carbamazepine, beta-blockers, haloperidol, TCAs, and benzodiazepines. Desyrel (p = .06) and amantadine (p = .001) were significantly more likely to be chosen by experts than by nonexperts. Experts chose haloperidol significantly less often than nonexperts (p = .01). Prescription of sedating drugs such as haloperidol or benzodiazepines was not found to be associated with the acuity of injury of TBI patients in the respondent's practice, practice setting, or years of practice since completing residency. Choice of haloperidol to treat agitation was not significantly associated with the degree to which explosive anger, verbal aggression, or physical aggression were considered important to the respondent's definition of agitation.

CONCLUSIONS

The majority of physiatrists surveyed did not formally measure agitation. Treatment strategies differ significantly between general physiatrists and those who specialize in the treatment of patients with TBI. The breadth of pharmacologic agents and strategies identified in this survey probably reflects the lack of research specific to the pathophysiology of the disorder of posttraumatic agitation.

The agitated brain injured patient. Part 2: Pathophysiology and treatment

The management of agitation after brain injury remains uncertain because of a lack of a consistent definition and a poor understanding of the underlying mechanism. Part 1 of this review focused on definitions, differential diagnosis, and assessment. Part 2 reviews potential mechanisms for posttraumatic agitation and common intervention strategies. The intent of this two-part series is to advocate for a consistent definition for posttraumatic agitation, to encourage the use of appropriate assessment and monitoring strategies, and to recommend that intervention decisions are based on at least a theoretical understanding of the relationship between specific target behaviors and probable brain-behavior relationships.

Systematic bias in outcome studies of persons with traumatic brain injury

OBJECTIVE

(1) Examine systematic biases created by subjects lost at 1-year follow-up in samples of persons with traumatic brain injury; (2) identify potential threats to generalization of outcomes data.

DESIGN

A consecutive sample of admissions to acute rehabilitation studied 1 year following discharge.

SETTING

An inpatient brain injury rehabilitation unit in a large, academic medical center.

SUBJECTS

Eighty-eight patients with primary diagnosis of traumatic brain injury.

MAIN OUTCOME MEASURES

Subjects were considered lost to follow-up when phone calls, mail, clinic visits, and assistance from family failed to allow contact 1 year after discharge from acute rehabilitation. Potential effects of the biased follow-up sample were examined for seven suboptimal outcomes.

RESULTS

A total of 38.6% of subjects were lost to follow-up. Subjects intoxicated at time of injury and those with history of substance abuse were more-likely to be lost. Among subjects followed, the likelihood of working or being in school 1 year after discharge was significantly less for those intoxicated at time of injury and those with a history of substance abuse.

CONCLUSIONS

Systematic bias in longitudinal studies may result from subjects with substance use problems being lost to follow-up. Population estimates for return to work or school will be overestimated if those lost who have substance use problems resemble those followed.

Bone mass and endocrine adaptations to training in spinal cord injured individuals

To investigate whether exercise training can produce increases in bone mass in spinal cord-injured (SCI) individuals with established disuse osteopenia, nine subjects (age 28.2 years, time since injury 6.0 years, level of injury C5-T7) were recruited for a 9-month training program using functional electrical stimulation cycle ergometry (FES-CE), which produces active muscle contractions in the paralyzed limb. After training, bone mineral density (BMD, by X-ray absorptiometry) increased by 0.047 +/- 0.010 g/cm2 at the lumbar spine; changes in BMD at the femoral neck, distal femur, and proximal tibia were not significant for the group as a whole. In a subset of subjects training at > or = 18 W for at least 3 months (n = 4), BMD increased by 0.095 +/- 0.026 g/cm2 (+18%) at the distal femur. By 6 months of training, a 78% increase in serum osteocalcin was observed, indicating an increase in bone turnover. Urinary calcium and hydroxyproline, indicators of resorptive activity, did not change over the same period. Serum PTH increased 75% over baseline values (from 2.98 +/- 0.15 to 5.22 +/- 0.62 pmol/L) after 6 months' training, with several individual values in hyperparathyroid range; PTH declined toward baseline values by 9 months. These data establish the feasibility of stimulating site-specific increases in bone mass in severely osteopenic bone with muscle contractions independent of weight-bearing for those subjects able to achieve a threshold power output of 18 W with FES-CE. Calcium supplementation from the outset of training in osteopenic individuals may be advisable to prevent training-induced increases in PTH.

The agitated brain injured patient. Part 1: Definitions, differential diagnosis, and assessment

This two-part review provides a critical analysis of the scientific and clinical literature on the agitated brain injured patient. Part 1 reviews nomenclature and classification issues, differential diagnosis, and assessment instruments designed for evaluation of the patient. Pathophysiology and treatment approaches will be discussed in Part 2 in a subsequent issue of the Archives. The review was unfortunately hampered by a lack of consistency in definitions, little scientific study of the neuroanatomic and neurochemical basis for the disorder, few outcome studies, and no randomized controlled treatment trials. Part 1 sets forth an interdisciplinary definition of agitation, establishes a differential diagnostic approach, and describes and critiques the assessment instruments available for clinical evaluation of the agitated patient. Part 2 will address treatment interventions including pharmacological, environmental, and behavioral approaches to this patient population.

Differential diagnosis of agitation following brain injury

Posttraumatic agitation is perhaps the most dramatic behavioral consequence of severe traumatic brain injury. The mechanism for this behavior remains to be determined. The development of effective management strategies has been hampered at least in part by the lack of a consensus definition for posttraumatic agitation. The diagnosis of posttraumatic agitation is a diagnosis of exclusion. Concurrent neurologic or medical decline during the recovery from an acute traumatic brain injury may precipitate delirium, which has many clinical features that overlap with posttraumatic agitation. Hence, the differential diagnosis of posttraumatic agitation includes all medical and neurologic etiologies for transient declines in consciousness and cognition.

Catecholamine response to exercise and training in individuals with spinal cord injury

It is unknown whether the catecholamine (CAT) response to acute exercise and prolonged training in humans with spinal cord injury (SCI) is similar to that of neurologically intact man. Plasma samples were collected from seven subjects with chronic SCI (level of injury C5-T7) at rest and during voluntary arm-crank ergometry (ACE) before and after 6 months of training with functional electrical stimulation cycle ergometry (FES-CE). Similar plasma collections were made during one FES-CE exercise training session after 6 months of training. Norepinephrine (NE) and epinephrine (EPI) were measured by HPLC. After FES-CE training, resting NE decreased 37% (950 +/- 150 vs 1510 +/- 350 pmol.l-1 pretraining); resting EPI decreased 80% (54 +/- 10 vs 163 +/- 32 pmol.l-1 pretraining) (P < 0.05 by paired t-tests). No significant changes were observed in group means after training for the CAT response to submaximal ACE; however, five of seven subjects exhibited greater increments in plasma NE with ACE after FES-CE training. Acute FES-CE exercise elicited a 55-844% increase in NE, and a 35-350% increase in EPI above resting values with power outputs eliciting heart rates of 90-146 bpm. These data provide evidence for a systemic CAT response in subjects with SCI during acute FES-CE and reduced resting CAT following 6 months of training with FES-CE.

Effect of stimulus parameters on characteristics of the F-response in normal subjects

The F-response is a valuable tool for evaluating the functional integrity of proximal nerve segments. Although many studies have focused on the various F-response characteristics observed (e.g., latency, amplitude, duration, persistence, etc.), few have examined the significance of stimulus parameters on the resultant F-response. In this study, we examined the F-responses obtained in 25 healthy subjects when using various stimulus parameters. The stimulus parameters used were: 1) 0.5 Hz, 25% supramaximal intensity at 0.05 ms duration; 2) 0.5 Hz, 25% supramaximal intensity at 0.1 ms duration; 3) 0.5 Hz, 25% supramaximal intensity at 0.2 ms duration; 4) 0.5 Hz, 50% supramaximal intensity at 0.1 ms duration; 5) 3.0 Hz, 25% supramaximal intensity at 0.1 ms duration. No significant differences in F-response latency, amplitude, duration or persistence were seen when duration or intensity of stimuli was altered. However, changing stimulus frequency resulted in a significant decrease in latency and a significant increase in persistence and amplitude. Care should be taken in controlling for stimulus frequency to enhance the reproducibility of F-response determinations.

Heterotopic ossification. The utility of osteocalcin in diagnosis and management

The status of 12 patients after severe traumatic brain injury was investigated to determine the clinical significance of serum osteocalcin levels during the active phase of neurogenic heterotopic ossification. The diagnosis of heterotopic ossification was confirmed on the basis of radiologic findings. The mean interval between the initial injury and diagnosis of heterotopic ossification was 29 weeks. At the time of diagnosis, serum osteocalcin and total alkaline phosphatase levels were determined along with 24-hour urinary calcium and hydroxyproline excretion. The mean serum osteocalcin level was normal at 4.3 ng/ml (normal range 1.6-6.6 ng/ml) in contrast to the elevated mean values for serum alkaline phosphatase (mean = 173 units/liter; normal range 0-105 units/liter) and urinary hydroxyproline concentration (mean = 39.6 mg/24 h; normal range 7-25 mg/24 hr). Only 17% of the subjects demonstrated an elevated serum osteocalcin level, whereas 58% of the patients had an elevated serum alkaline phosphatase level. Urinary calcium excretion and hydroxyproline excretion were elevated in 33% and 70% of subjects, respectively. These data did not reveal a significant correlation between serum osteocalcin and serum alkaline phosphatase, urinary calcium excretion or urinary hydroxyproline at the time of diagnosis or in serial measurements. Therefore, serum osteocalcin is not a valuable adjunct in confirming the diagnosis of neurogenic heterotopic ossification once the diagnosis has been suggested on the basis of clinical findings and it does not appear to play a role in assessing the maturation of heterotopic ossification.

Hyponatremia-associated cognitive impairment in traumatic brain injury

The case of a traumatic brain injury (TBI) patient with dramatic cognitive deterioration in the absence of medical aetiology other than simultaneous decline in serum sodium led to an investigation of the association between declines in sodium levels and cognitive status. In a population of 50 persons undergoing TBI rehabilitation, 12 (24%) had relative (3 mEq/L) decreases in serum sodium while five (10%) experienced absolute hyponatremia (136 mEq/L). Correlation with cognitive status was significant when the absolute hyponatremia group was compared with those whose sodium levels remained above 136 mEq/L. A case-matched study of the relative hyponatremia group yielded no significant association between sodium-level decreases and cognitive status. These data support previous conclusions indicating wide variation in individual responses to changes in serum sodium. The threshold for significant effects of hyponatremia may be higher in patients with TBI than in populations studied previously.

Academic productivity in physical medicine and rehabilitation

Academic productivity of faculty members in physical medicine and rehabilitation (PM&R) was evaluated retrospectively by using the numbers of scientific publications as a measurement instrument. This study was completed by examining ten medical peer-reviewed journals that regularly included original articles in the specialty area of PM&R during the years 1988 through 1990. The number of articles was weighted according to the specific journal's impact on the Science Citation Index. Academic productivity of physiatric departments showed wide variation. Ten units published at least 20 articles during the 3-yr period. Eight departments achieved a ratio of at least one article per faculty member based on reports from the Association of American Medical Colleges. Further study will be needed to assess the factors underlying these wide variations in departments' productivity.

Agitation, cognition and attention during post-traumatic amnesia

During the early phases of recovery from traumatic head injury, the level of functional cognition and the presence of agitation in patients appear to co-vary. However, it has been observed that there appears to be some temporal disassociation in the recovery of cognition and agitation. The purpose of this study was to investigate the degree to which attention accounts for the co-variation previously observed. Over a 1-year period, 130 patient-weeks of independent monitoring of cognition, agitation and attention were obtained from 20 head-injured patients in the acute phase of recovery. Weekly scores for measures of cognition, agitation and attention were each found to share approximately 50% of the variance when paired with one of the other two. When attention was extracted, only 7% of the variation in cognition was accounted for by agitation, and 40% of the variance could not be accounted for by either agitation or attention. These results support previous findings that cognition and agitation co-vary with most of the co-variance due to the effect of attention on each. Concomitantly, these results allow that significant portions of the variance in cognition and agitation may be temporally dissociated during the acute phases of recovery from traumatic head injury.

Fever of unknown origin following traumatic brain injury

Fever is a common complication of a traumatic brain injury, occurring during both the acute-care phase and the rehabilitation phase of recovery. The aetiology of fever in this population may remain obscure because of the presence of cognitive confusion associated with post-traumatic amnesia interfering with history taking and the difficult physical examination. We present a case where recovery from a traumatic brain injury was complicated by a fever of unknown origin that proved to be secondary to lateral sinus thrombophlebitis. This case emphasises the importance of a thorough knowledge of the differential diagnosis for fever that is unique to the traumatic brain injury population.

First lumbrical latency and amplitude. Control values and findings in carpal tunnel syndrome

It has been suggested that the nerve fibers to the first and second lumbrical muscles are relatively spared in patients with carpal tunnel syndrome compared with the fibers to the abductor pollicis brevis. Latencies and amplitudes of the first lumbrical and the abductor pollicis brevis (APB) muscles were compared with both wrist stimulation and midpalmar stimulation. The lumbrical latency at 12 cm and the APB at 8 cm were found to be similar at less than 4.3 ms. Amplitudes to the lumbrical were 0.6-8 mV compared with 4-13.6 mV for the APB. Three patients who had an abnormal sensory study, yet normal motor values to the APB, were found to have abnormal lumbrical latencies. This is an additional technique that could be useful for individuals suspected of carpal tunnel syndrome who have normal latencies and amplitudes to the APB.

Relationship of new-onset systemic hypertension and normal pressure hydrocephalus

Communicating normal pressure hydrocephalus (NPH) is an important remote complication of traumatic brain injury (TBI). The diagnosis of this hydrocephalus depends largely on clinical signs and symptoms, including cognitive deterioration, gait changes and incontinence. However, many of these signs are also seen during post-traumatic amnesia, making early recognition of this syndrome difficult. A case study of one man post-TBI, who presented with new-onset hypertension as a sign of NPH, prompted a retrospective chart review of all patients admitted over a 2-year period with a diagnosis of NPH. Ninety per cent of patients had one or more of the classic triad of NPH and 25% of patients had symptoms suggestive of raised intracranial pressure (unexplained nausea, headache and visual disturbance). Mean systolic and diastolic blood pressures among the 20 subjects for six consecutive days pre-operatively compared with those for days 8-14 and 15-21 post-operatively showed no significant differences; a subgroup of five patients (25%), however, demonstrated a significant change in blood pressure temporally related to shunting. We suggest that demonstration of new-onset systemic hypertension may also be a clinical sign suggestive of NPH useful in the evaluation of the TBI patient.

The ataxic subgroup: a discrete outcome after traumatic brain injury

We have observed five individuals who appear to represent a unique subgroup of patients with traumatic brain injury (TBI). Because of the prominence of severe ataxia, this group has been labelled the 'ataxic subgroup'. These individuals are distinguished by both clinical course and outcome, including severe ataxia, prolonged coma and prolonged post-traumatic amnesia (PTA). They distinguish themselves from other severely impaired TBI patients in that they spend a relatively longer length of time prior to the establishment of volition, but progress rapidly through the period of confusion. We hypothesized that this group is unique in that they have suffered Grade III diffuse axonal injury (DAI) with no or minimal complications due to other primary or secondary brain damage. In order to investigate these hypotheses, a retrospective file review of a selected group of 72 patients was undertaken to determine the specificity and sensitivity of two diagnostic criteria. The existence of severe Grade III DAI without other primary or secondary brain damage was presumed if severe ataxia was present in conjunction with normal CT scans. Results of this review indicated that 33% of the population demonstrated severe ataxia, although only 11% also had normal CT scans. These dual criteria were neither adequately sensitive nor specific to define the five patients who comprised the 'ataxic subgroup'. When rate of clearing the confused period of PTA was added to the diagnostic criteria, specificity improved. Although this attempt to define this subgroup empirically was not entirely successful, further attempts to delineate this group are important in that prognosis for clearing PTA is good despite early indicators of poor outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

F response characteristics in type I diabetes mellitus

Ulnar and tibial F response parameters were characterized in 17 healthy controls and 26 subjects with type I diabetes mellitus meeting or exceeding criteria for mild diabetic peripheral neuropathy. The presence of mild diabetic peripheral neuropathy was determined by utilizing conventional nerve conduction studies, the neuropathy symptoms score and a neurologic examination. Ulnar and tibial nerve F response latency, amplitude, duration, chronodispersion and persistence were then compared between populations. The relationship between tibial F response persistence and minimal F response latency was assessed in both populations. In addition, the relationship between tibial F response persistence and tibial nerve conduction velocity and tibial nerve compound action potential characteristics (e.g., latency, amplitude and duration) was assessed in the diabetic population. The results indicate that ulnar F response latency and chronodispersion failed to differentiate the subject and control populations; however, significantly decreased ulnar F response amplitude and duration were noted in the diabetic population. In the tibial nerve, the F response persistence was significantly decreased in the diabetic population but persistence did not correlate with compound muscle action potential latency, amplitude, duration or nerve conduction velocity. Finally, the tibial F response latency, amplitude, duration and chronodispersion failed to differentiate the control and diabetic populations.

Prospective cognitive assessment of stroke patients before inpatient rehabilitation. The relationship of the Neurobehavioral Cognitive Status Examination to functional improvement

Prospective studies establish cognitive status as an important determinant of post-stroke rehabilitation success. The Neurobehavioral Cognitive Status Examination (NCSE) briefly assesses cognition in the ability areas of language, constructions, memory, calculation and reasoning. The NCSE, as well as the commonly used Mini-Mental State Examination and Albert's Test, were administered to 38 stroke patients before inpatient rehabilitation to determine the extent to which they predict rehabilitation outcome. Rehabilitation outcome was measured as the difference between initial and discharge Barthel Index score. The NCSE was shown to be a more sensitive indicator of impairment than the Mini-Mental State Examination and Albert's Test, especially in subsections of orientation and memory (X2 = 8.690, df = 1, P less than 0.005; X2 = 13.348, df = 1, P less than 0.001, respectively). Stepwise multiple regression revealed that attention, calculations and judgement were in association the best predictors of improvement in the Barthel Index scores. Therefore, the NCSE provides both a rapid and sensitive measure of cognitive function and it appears to predict functional status change as a result of inpatient stroke rehabilitation.

Abnormal cortisol dynamics after traumatic brain injury. Lack of utility in predicting agitation or therapeutic response to tricyclic antidepressants

A period of significant agitation affects up to 30% of patients after traumatic brain injury. The severity and persistence of this agitation may be such as to require pharmacologic methods as part of the treatment plan. To define which subgroup of patients develop severe agitation warranting intervention and to utilize the information to predict therapeutic responsiveness to tricyclic antidepressants (TCA), we examined cortisol dynamics in 35 traumatically brain-injured (TBI) patients 2-10 months post-TBI. Fasting hypercortisolemia (cortisol greater than 20 micrograms/dl) and/or an absent diurnal variation (1600:0800 cortisol greater than 0.5) was noted in more than 70% of TBI subjects. These abnormalities in cortisol dynamics were not predictive of severe agitation (chi 2 = 0, df = 1, P = 0.99 for hypercortisolemia; chi 2 = 0.163, df = 1, P = 0.7 for absent diurnal variation) and did not differ significantly between TCA responders and nonresponders. The cortisol response to dexamethasone suppression was abnormal (postdexamethasone cortisol value at 0800 and 1600 greater than 5 micrograms/dl) in 34 of 35 subjects and was also not predictive of the presence of agitation. The 0800 cortisol was lower in TCA nonresponders in comparison with TCA responders (8.3 +/- 5 v 17.2 +/- 9). In summary, severe TBI warranting inpatient rehabilitation results in hypothalamic-pituitary-adrenal dysfunction. The extent of these abnormalities renders the assessment of cortisol secretion of limited value in making clinical judgments concerning the development of post-traumatic agitation or the management of that agitation by tricyclic therapy.

Orientation Group Monitoring System: an indicator for reversible impairments in cognition during posttraumatic amnesia

During posttraumatic amnesia (PTA), confusion, attention deficits, impaired memory, disorientation, and inability to process external stimuli often preclude accurate assessment of subtle neurologic changes. The Orientation Group Monitoring System (OGMS) has proven to be a simple, useful strategy for assessing cognitive status. Retrospective analysis of weekly aggregate OGMS scores indicated that a decline in performance of 0.23 or greater is clinically significant. Over a one-year period, 27 patients demonstrated significant decrements in OGMS performance, and in 93% of these instances, the decrease was attributable to a medical problem. Adverse effects of medication was the most common etiology of decreased performance (n = 13). Overwhelmingly, the decline in the OGMS score was the first indication of impaired cognition. This monitoring device is therefore useful as an indicator during PTA of declining cognitive function, warranting further medical evaluation.

Vocational evaluation of traumatic brain injury patients using the functional assessment inventory

Impaired work capacity is one of the most common residual impairments encountered after either a severe or moderate traumatic brain injury (TBI), yet no instrument is available for screening TBI victims regarding their readiness to participate in more comprehensive vocational planning and evaluation. In the study reported here, the Functional Assessment Inventory (FAI) was administered to 76 subjects who suffered a moderate or severe TBI and the results obtained were compared to the Rancho Los Amigos Hospital Levels of Cognitive Functioning, the Mini-Mental State and the Glasgow Outcome Scale for sensitivity in discerning vocational readiness. The results obtained indicated that the FAI composite score has the greatest discriminating power in screening the vocational readiness of this population, followed by the Glasgow Outcome Scale. In addition, the FAI cluster scores demonstrated reasonable discriminative ability, which may prove useful in directing ongoing remediation.

Agitation following traumatic head injury: equivocal evidence for a discrete stage of cognitive recovery

Agitation and confusion appear to be associated in the early period of recovery from traumatic head injury. Eighteen severely head-injured patients were assessed during acute rehabilitation for both the extent of agitation and level of cognitive functioning. Agitation was measured by the Agitated Behavior Scale developed by Corrigan. Simultaneous independent measurements of cognitive functioning were obtained from the Orientation Group Monitoring System and Mini-Mental State. Agitation was significantly correlated with both measures of cognitive functioning, indicating that as cognition improved, agitation diminished. Agitation was partitioned into high and low levels, and cognitive functioning was partitioned into low, middle, and high levels for each of the two measures of cognitive functioning. Chi-square analysis of the distribution of agitation and cognition indicated significant differentiation, with high agitation prevalent in low levels of cognition, and low agitation prevalent in high levels of cognition. Patients in the middle level of cognition were equally likely to demonstrate high and low agitation. Further descriptive analysis indicated that improvement from low levels of cognition preceded improved agitation, and improved agitation preceded clearing from posttraumatic amnesia. These results provide equivocal support for the long-held clinical observation that a period of pronounced confusion and agitation represents a discrete stage of recovery from traumatic head injury.

Electrophysiologic study of the anterior interosseous nerve

Nerve conduction studies of the anterior interosseous nerve were performed on 26 healthy subjects (6 women and 20 men, aged 24 to 63 years). The compound muscle action potential from the pronator quadratus muscle was obtained by using surface electrodes placed over the dorsal aspect of the distal forearm and median nerve stimulation at the elbow. The latency of the evoked potential was determined over distances that ranged from 17.5-28 cm from the elbow to the pronator quadratus muscle; this resulted in latencies of 3.5 ms (+/- 0.4) and 3.6 ms (+/- 0.4) for the left and right extremities, respectively, with a side-to-side difference of 0.1 ms (+/- 0.1). The amplitude of the potentials recorded was 3.1 mV (+/- 0.8); a difference in amplitude of 11.4% (+/- 7.7%) between extremities was seen. Although duration measurements were obtained, the frequent presence of biomodal peaks made interpretation difficult. This bimodal pattern was felt to represent either two heads of the pronator quadratus or another muscle innervated by the anterior interosseous nerve. The technique in the present study is easy to perform, allows better assessment of the compound muscle action potentials obtained and provides for side-to-side comparisons of latency and amplitude. This technique aids the electromyographer in evaluation of suspected cases of injury to the anterior interosseous nerve, particularly in unilateral cases.

Amitriptyline for post-traumatic agitation

Agitated behavior is exhibited in up to 30% of patients recovering from a traumatic brain injury. Past treatment protocols have included proactive behavioral management and major tranquilizers. We now report the use of amitriptyline for control of agitation. For a period of over 2 years, 43 male and 15 female patients with a "recent" severe brain injury were admitted for inpatient rehabilitation and subjected to traditional structured programming for treatment of post-traumatic amnesia (PTA). In 20 patients, 18 men and 2 women, where agitation persisted sufficiently to impede rehabilitation despite initiation of structure, amitriptyline was instituted. These patients were of a comparable age (29.4 years for the agitated group versus 25.6 years for the nonagitated group), but the agitated patients had a lower median Rancho Los Amigos Hospital Level of Cognitive Functioning in a comparison to nonagitated patients (V versus VI). All patients were monitored for cognitive performance by the Orientation Group Monitoring System, and a daily account of frequency, severity and type of agitation was recorded. Within 7 days of initiation of therapy, 12 of 17 patients within PTA had dramatic decrease in agitation (5/5 patients at Rancho IV; 4/8 at Rancho V; 3/4 at Rancho VI). Two of the three patients at Rancho VII had agitation that was unresponsive to amitriptyline. The amitriptyline-responsive patients were maintained on the drug through PTA, and the Orientation Group Monitoring System scale demonstrated no impedance in cognitive recovery. Thus, amitriptyline appears most useful as an adjunct for treatment of nondirected agitation; it also has a role in reducing the severity of the directed agitation that is seen during but not after PTA.