Utility of post-traumatic amnesia in predicting 1-year productivity following traumatic brain injury: comparison of the Russell and Mississippi PTA classification intervals.

BACKGROUND: Duration of post-traumatic amnesia (PTA) correlates with global outcomes and functional disability. Russell proposed the use of PTA duration intervals as an index for classification of traumatic brain injury (TBI) severity. Alternative duration-based schemata have been recently proposed as better predictors of outcome to the commonly cited Russell intervals. OBJECTIVE: Validate a TBI severity classification model (Mississippi intervals) of PTA duration anchored to late productivity outcome, and compare sensitivity against the Russell intervals. METHODS: Prospective observational data on TBI Model System participants (n=3846) with known or imputed PTA duration during acute hospitalisation. Productivity status at 1-year postinjury was used to compare predicted outcomes using the Mississippi and Russell classification intervals. Logistic regression model-generated curves were used to compare the performance of the classification intervals by assessing the area under the curve (AUC); the highest AUC represented the best-performing model. RESULTS: All severity variables evaluated were individually associated with return to productivity at 1 year (RTP1). Age was significantly associated with RTP1; however, younger patients had a different association than older patients. After adjustment for individually significant variables, the odds of RTP1 decrease by 14% with every additional week of PTA duration (95% CI 12% to 17%; p<0.0001). The AUC for the Russell intervals was significantly smaller than the Mississippi intervals. CONCLUSIONS: PTA duration is an important predictor of late productivity outcome after TBI. The Mississippi PTA interval classification model is a valid predictor of productivity at 1 year postinjury and provides a more sensitive categorisation of PTA values than the Russell intervals.

Emergence from minimally conscious state: insights from evaluation of posttraumatic confusion.

BACKGROUND: Guidelines for defining the minimally conscious state (MCS) specify behaviors that characterize emergence, including "reliable and consistent" functional communication (accurate yes/no responding). Guidelines were developed by consensus because of lack of empirical data. OBJECTIVE: To evaluate the utility of the operational threshold for emergence from posttraumatic MCS, by determining yes/no accuracy to questions of varied difficulty, including simple orientation questions, using all items from the Yes/No Subscale of the Mississippi Aphasia Screening Test. METHOD: Prospective observational study of a cohort of responsive patients recovering from traumatic brain injury in an acute inpatient brain injury rehabilitation program. RESULTS: Of the 629 observations from 144 participants, name recognition was the easiest yes/no question, with nonconfused individuals responding with 100% accuracy, whereas only 75% to 78% of confused participants on initial evaluation answered this question correctly. Generalized Estimating Equations analysis revealed that confused participants were more likely to respond inaccurately to all yes/no questions. Nonconfused participants had a reduction in odds of inaccuracy ranging from 45.6% to 99.7% (p = 0.001 to 0.02) depending on the type of yes/no question. CONCLUSIONS: Accuracy for simple orientation yes/no questions remains challenging for responsive patients in early recovery from traumatic brain injury. Although name recognition questions are relatively easier than other types of yes/no questions, including situational orientation questions, confused patients still may answer these incorrectly. Results suggest the operational threshold for yes/no response accuracy as a diagnostic criterion for emergence from the minimally conscious state should be revisited, with particular consideration of the type of yes/no questions and the requisite accuracy threshold for responses.

Botulinum neurotoxin versus tizanidine in upper limb spasticity: a placebo-controlled study.

BACKGROUND: While spasticity is commonly treated with oral agents or botulinum neurotoxin (BoNT) injection, these treatments have not been systematically compared. METHODS: This study performed a randomised, double-blind, placebo-controlled trial to compare injection of BoNT-Type A into spastic upper limb muscles versus oral tizanidine (TZD), or placebo, in 60 subjects with upper-limb spasticity due to stroke or traumatic brain injury (TBI). Wrist flexors were systematically injected, while other upper limb muscles were injected as per investigator judgement. Participants were randomised into three groups: (1) intramuscular BoNT plus oral placebo; (2) oral TZD plus intramuscular placebo; (3) intramuscular placebo plus oral placebo. The primary outcome was the difference in change in wrist flexor modified Ashworth score (MAS) between groups. Other outcome measures included MAS at elbow and finger joints, Disability Assessment Scale (DAS) and adverse events (AE). RESULTS: BoNT produced greater tone reduction than TZD or placebo in finger and wrist flexors at week 3 (p<0.001 vs TZD; p<0.02 vs placebo) and 6 (p = 0.001 vs TZD; p = 0.08 vs placebo), and greater improvement in the cosmesis domain of the DAS at week 6 (p<0.01). TZD was not superior to placebo in tone reduction at either time point (p>or=0.09). The incidence of AE related to study treatment was higher with TZD than in the BoNT (p<0.01) or placebo groups (p = 0.001). CONCLUSIONS: BoNT is safer and more effective than TZD in reducing tone and disfigurement in upper-extremity spasticity, and may be considered as first-line therapy for this disorder.

Serial yes/no reliability after traumatic brain injury: implications regarding the operational criteria for emergence from the minimally conscious state.

BACKGROUND: Published guidelines for defining the "minimally conscious state" (MCS) included behaviours that characterise emergence, specifically "reliable and consistent" functional interactive communication (accurate yes/no responding) and functional use of objects. Guidelines were developed by consensus because of the lack of empirical data to guide definitions. Criticism emerged that individuals with severely impaired cognition would have difficulty achieving the requisite threshold of accuracy and consistency proposed to demonstrate emergence from MCS. OBJECTIVE: To determine the utility of the operational threshold for emergence from post-traumatic MCS, by evaluating a measure of yes/no accuracy (Cognitive Test for Delirium, auditory processing subtest (CTD-AP).) METHODS: Prospective, consecutive cohort of responsive patients recovering from traumatic brain injury (TBI), including a subset meeting criteria for MCS at neurorehabilitation admission who improved and were able to undergo the study protocol. Participants were evaluated at least weekly, and given the CTD-AP to assess yes/no responding. RESULTS: Of the 1434 observations from 336 participants, 767 observations yielded inaccurate yes/no responses. 75 participants (22%) never attained consistently accurate yes/no responses at any time during their hospitalisation. Generalised estimating equations analysis revealed that confused participants were more likely to respond inaccurately to yes/no questions. Further, the subset of individuals who were in MCS on rehabilitation admission and improved, were also more likely to respond inaccurately to yes/no questions. CONCLUSIONS: Consistent yes/no accuracy is uncommon among responsive patients in early recovery from TBI. These results suggest that the operational threshold for yes/no response accuracy as a diagnostic criterion for emergence from MCS should be revisited.

Comparison of indices of traumatic brain injury severity: Glasgow Coma Scale, length of coma and post-traumatic amnesia.

BACKGROUND: Classification of traumatic brain injury (TBI) severity guides management and contributes to determination of prognosis. Common indicators of TBI severity include Glasgow Coma Scale (GCS) scores, length of coma (LOC) and duration of post-traumatic amnesia (PTA). OBJECTIVE: To compare GCS, LOC and PTA by examining distributions and intercorrelations and develop multivariable linear regression models for estimating LOC and PTA duration. METHODS: Prospective study of 519 of 614 consecutive patients with TBI. Indices of TBI severity studied were GCS, LOC, PTA and PTA-LOC (the interval from return of command-following to return of orientation). Candidate predictor variables for estimation of LOC, PTA and PTA-LOC intervals were age, years of education, year of injury (before 1997 vs 1997 or later), GCS, LOC (for PTA and PTA-LOC), pupillary responsiveness, type of injury, CT pathology and intracranial operations. RESULTS: Although there was a severity/response relationship between GCS and LOC, PTA and PTA-LOC intervals, there was overlap in these intervals between GCS severity categories. Age, year of injury, GCS, pupillary responsiveness and CT pathology were predictive of LOC. Age, years of education, year of injury, GCS, LOC, pupillary responsiveness and intracranial operations were predictive of PTA duration. Age, years of education, year of injury, GCS, LOC and pupillary responsiveness were predictive of PTA-LOC. GCS and LOC effects were influenced by age. CONCLUSIONS: Predictors for estimating LOC, PTA and PTA-LOC intervals were determined and simple equations were developed. These equations will be helpful to clinicians, researchers and those counselling family members of patients with TBI.

Neurophysiological basis and clinical applications of the H-reflex as an adjunct for evaluating response to intrathecal baclofen for spasticity.

Implanted programmable pumps that infuse intrathecal baclofen (ITB) markedly enhance the ability of clinicians to manage severe spasticity in appropriately selected patients. Studies addressing the efficacy of this treatment modality have primarily used clinical outcome measures of impairment, particularly reduction in stiffness as measured by the Ashworth scale. Several recent studies, however, highlight comparalively higher sensitivity of neurophysiologic techniques, especially the H-reflex, as an objective index of spinal cord response to ITB administration. We review the conceptual, physiological, and methodological hases for use of the H-reflex as an adjunct to clinical evaluation among patients receiving ITB infusion, including published reports and selected case studies that address the potential advantages and limitations of such techniques when applied to dose titration and system "troubleshooting" scenarios, We also address the implications of such findings in the context of reported complications such as "tolerance" to ITB administration and catheter "microfracture". The accumulated knowledge suggests that H-reflex is a sensitive method for documenting altered spinal cord responsiveness in the presence of ITB delivery. We therefore recommend using H-reflex as an adjunct to clinical evaluation when judging the overall effectiveness of ITB administration.

Brief assessment of severe language impairments: initial validation of the Mississippi aphasia screening test.

PRIMARY OBJECTIVE: To validate the Mississippi Aphasia Screening Test (MAST) which includes nine sub-scales measuring expressive and receptive language abilities. RESEARCH DESIGN: Evaluation of inpatients admitted to neurology, neurosurgery or rehabilitation units at two local hospitals and who were within 60 days of onset of a unilateral ischemic or haemorrhagic stroke (left hemisphere (LH; n=38); right hemisphere (RH; n=20)). Additional participants were recruited from the community to comprise a non-patient control sample (NP; n=36). METHODS: Data collection included administration of the MAST and chart review. RESULTS: The LH group showed more impairment than the RH and NP groups on summary scores. The LH group performed worse than the NP group on all sub-scales. The object recognition and verbal fluency sub-scales did not discriminate the stroke groups. CONCLUSION: Analyses suggest good criterion validity for the MAST in differentiating communication impairments among clinical and control samples.

Deep vein thrombosis: prevalence and risk factors in rehabilitation admissions with brain injury.

OBJECTIVE: To determine the prevalence and risk factors of deep vein thrombosis (DVT) among neurorehabilitation admissions with acquired brain injury (BI). METHODS: In this prospective, sequential case series, 709 consecutive initial neurorehabilitation patients with BI < 120 days-including traumatic brain injury (TBI; n = 360), intracranial hemorrhage (ICH; n = 213), primary brain tumor (n = 66), and hypoxia/other BI (n = 70)--were screened for evidence of DVT with lower extremity venous duplex ultrasonography (VDU). The admission screening protocol combined VDU and a commercial d-dimer (Dimertest [DDLx]) latex agglutination assay. DVT was considered present based upon VDU results only. RESULTS: DVT prevalence was 11.1%, and was higher with brain tumor (21.2%) and ICH (16%) than with TBI (6.7%) (chi2 test; p = 0.001). DVT risk factors identified by multivariable logistic regression analysis in the overall sample included older age (p = 0.002), type of BI (p = 0.04), DDLx (p = 0.0001), and greater postinjury duration (p = 0.0001), with a trend observed regarding lower Functional Independence Measure (FIM) locomotion (FIM-Loco) subscale score (p = 0.07). However, risk factors also varied with type of BI. Among patients with TBI, only DDLx (p = 0.001) and greater postinjury duration (p = 0.001) were associated with DVT. CONCLUSIONS: Admission venous duplex ultrasonography revealed occult proximal lower extremity deep vein thrombosis in 11% of neurorehabilitation patients with acquired brain injury. Deep vein thrombosis risk is multifactorial in this heterogenous patient population, with relative factor risk influenced by type of acquired brain injury. Semiquantitative d-dimer latex agglutination assay correlated significantly with presence of deep vein thrombosis.

Hypodipsic hypernatremia and diabetes insipidus following anterior communicating artery aneurysm clipping: diagnostic and therapeutic challenges in the amnestic rehabilitation patient.

Hypodipsic hypernatremia (HH) represents a pathological increase in serum sodium due to a lack of thirst and defect in hypothalamic osmoreceptors. While 15% of patients with HH have a vascular aetiology, few cases have been described. Moreover, the presence of such abnormalities in the amnestic patient can have particularly threatening implications, as HH tends to recur unless the patient complies with a regimen of water intake. This study reports the case of a 46-year-old male admitted for rehabilitation of functional deficits following subarachnoid haemorrhage (SAH), with clipping of an anterior communicating artery (ACoA) aneurysm. Clinical examination was remarkable for profound short-term memory loss and inability to retain new information. Blood chemistry on admission showed a serum sodium level of 160 mEq/L, increasing to 167 mEq/L the following day. The patient denied thirst, and showed no clinical signs of dehydration. Neuroendocrine evaluation revealed diabetes insipidus (DI) and HH. Treatment initially included DDAVP and intravenous hydration, later supplemented with chlorpropramide. Stabilization of serum sodium and osmolality did not ensue until the treatment regimen included hydrochlorothiazide and supervision of enforced fluid intake. Endocrine abnormalities may be encountered among patients with vascular lesions adjacent to the hypothalamus. Rehabilitation interventions include establishing a structured medication regimen with fluid administration in the amnestic patient with hypothalamic dysfunction.

Botulinum neurotoxin intramuscular chemodenervation. Role in the management of spastic hypertonia and related motor disorders.

There is a range of interventions available in the management of spastic hypertonia among patients with central nervous system injury. Many of these treatment options can be used concurrently with great effectiveness. Although manifestations of spastic hypertonia vary from patient to patient, they usually are not limited to one site. Nevertheless, problematic spastic muscle overactivity may be localized to one or more specific extremities, and these may be referred to as examples of focal dysfunctional spasticity. Botulinum neurotoxin (BTX) intramuscular chemodenervation procedures are an important therapeutic technique in focal spasticity management. Magnitude and duration of response varies with successful selection and localization of targeted muscles, spasticity severity, BTX dosage, and chosen functional goals. In focal dysfunctional spasticity and related motor disorders, BTX injections have demonstrated efficacy and safety when performed by clinicians familiar with the agent, regional anatomy, the specific condition, and patient being treated.

Conceptual dilemmas in evaluating individuals with severely impaired consciousness.

States of severely impaired consciousness (SIC) are characterized by cognitive and motor limitations. This case report describes a 45-year-old female with impaired consciousness who began to 'walk'. She initially presented to the hospital unresponsive and was subsequently diagnosed with metabolic encephalopathy due to severe hypoglycaemia. Traditional indices of consciousness indicated a low level of responsiveness; however, during physical therapy, she displayed reciprocal walking movements when lifted to a standing position by two therapists. Despite her ability to walk increased distances during and after neurorehabilitation, she was unable to consistently demonstrate responses indicative of higher levels of consciousness. This case illustrates the challenge of rating patients with limited behavioural repertoire using established measures of impaired consciousness.

Antiepileptic drugs.

Antiepileptics are a very important class of medications, and the number of these drugs available for clinical use has increased dramatically in the last decade. The pharmacology and indications for use in a variety of physiatric patient groups are comprehensively and systematically reviewed.

Incidence and sequelae of symptomatic venous thromboembolic disease among patients with traumatic brain injury.

Venous thromboembolism (VTE) is a potentially life-threatening complication among patients with traumatic brain injury (TBI). However, few reports describe the incidence of this important disease. We reviewed the incidence of symptomatic VTE among 124 consecutive admissions with TBI to a free-standing rehabilitation hospital over an 18-month period. Four patients manifested evidence of VTE within 2 months of injury: two with leg swelling, one with an oedematous arm, and one with respiratory distress. None of the patients with suspected VTE received prophylactic anticoagulant therapy. Diagnosis of VTE was confirmed with venograph in two of the four patients. Although VTE is frequently asymptomatic, the incidence of symptomatic VTE (1.6%) among this series of rehabilitation inpatients with TBI still appears surprisingly low. These results have implications regarding the utility of non-invasive diagnostic screening of asymptomatic VTE and routine anticoagulant prophylaxis of high-risk patients with TBI.

A clinical overview of treatment decisions in the management of spasticity.

Spasticity from an upper motor neuron syndrome may cause a variety of symptoms that interfere with function. Decisions regarding spasticity treatment are influenced by the chronicity, severity, and distribution of the spasticity; the locus of injury; the presence and severity of co-morbidities; the availability of support; and the goals of treatment. Not all spasticity can or even should be treated; tone reduction is indicated only if spasticity interferes with some level of function, positioning, care, or comfort. Treatment goals should be well outlined before treatment begins. Botulinum toxin may be used to treat focal spasticity as part of an overall treatment plan.

Botulinum toxin in severe upper extremity spasticity among patients with traumatic brain injury: an open-labeled trial.

We studied the effect of botulinum toxin A (BTXA) among patients with traumatic brain injury (TBI) and severe spasticity unresponsive to conservative management. Twenty-one consecutive adult patients with severe spasticity involving the wrist and finger flexor musculature were treated with BTXA injection (20 to 40 units per muscle) under EMG guidance. After injection, patients received passive range of motion (ROM) exercise, with modalities and casting as clinically indicated. Outcome measures, including wrist ROM and the modified Ashworth Scale (MAS), were assessed 2 to 4 weeks after injection. Among the respective acute and chronic groups, mean ROM improved 42.9 (p = 0.001) and 36.2 degrees (p < 0.001). Mean MAS rating improved 1.5 (p = 0.01) and 1.47 (p = 0.002) points. There were no significant adverse effects. BTXA, in conjunction with conventional modalities, significantly improves spasticity and ROM in the distal upper extremity musculature of patients with TBI.

Akathisia resulting from traumatic brain injury.

Restlessness and agitation are commonly reported early sequelae of traumatic brain injury (TBI). Severe restlessness (akathisia) is also observed in psychiatric patients as a result of the use of dopamine receptor blocking agents. A recent case study described akathisia in a patient with bilateral orbitofrontal lesions following TBI. We report a case of unusually marked motor restlessness (akathisia) following TBI in a 17-year-old woman. When admitted for rehabilitation she was alert but agitated, severely restless, and mute. She constantly paced her room and the hospital unit, repeatedly retracing the same route. MRI scan revealed large, well-delineated bifrontal contusions. During baseline evaluation prior to anticipated psychopharmacological intervention her restlessness began to resolve rapidly. She became verbal and oriented within expected limits without medication. This case lends support to the observation that akathisia is related to lesions of the prefrontal cortex.

Potential role of serum prolactin measurement in the diagnosis of late posttraumatic seizures. A case report.

Posttraumatic seizures are an important medical complication after traumatic brain injury. However, the diverse clinical presentation of posttraumatic seizures, combined with the cognitive and behavior deficits frequently seen in this patient population, can make the diagnosis of posttraumatic seizures particularly challenging. Electroencephalography and imaging studies are often abnormal and nonspecific. It has been reported that serum prolactin levels frequently rise after epileptic seizures. This case report describes the use of prolactin measurement to confirm two suspected posttraumatic seizure episodes in a 42-yr-old male with severe traumatic brain injury. Each episode lasted less than 1 min and involved conspicuously altered postural tone and respiratory pattern, followed by a change in verbal and motor responsiveness. No rhythmic extremity movements were observed. Diagnostic evaluation included electroencephalography and imaging studies, which demonstrated nonspecific abnormalities. Serum prolactin levels obtained within 20 to 40 min were markedly elevated and two to three times greater than the baseline level. The use of prolactin levels in the diagnosis of posttraumatic seizures is reviewed, accompanied by discussion of pertinent aspects of normal and abnormal states of prolactin secretion and regulation.

Subacute methylphenidate treatment for moderate to moderately severe traumatic brain injury: a preliminary double-blind placebo-controlled study.

OBJECTIVE: To determine the effect of subacute administration of methylphenidate on recovery from moderate to moderately severe closed head injury. DESIGN: Double-blind placebo-controlled with random assignment. Patients were enrolled when their Galveston Orientation and Amnesia Test score was at least 65. Drug/placebo treatment began the day following baseline cognitive assessment and continued for 30 consecutive days. Follow-up evaluations were conducted at 30 and 90 days after baseline, after discontinuation of drug/placebo. SETTING: A level I trauma center. PATIENTS: Twenty-three patients ranging in age from 16 to 64 years. Head injury severity ranged from moderately severe (Glasgow Coma Score [GCS] < or = 8, no intracranial pressure monitor) to "complicated mild" (GCS from 13 to 15 with positive computed tomography brain scan). Thirty-day follow-up was based on 12 patients, whereas 90-day evaluation was based on 9 patients, with complicated mild head injuries excluded from the analyses. INTERVENTIONS: Methylphenidate administered twice daily at a dose of .30 mg/kg; placebo administered according to the same schedule in identical pill form. MAIN OUTCOME MEASURES: The Disability Rating Scale (DRS) and tests of attention, memory, and vigilance. RESULTS: The methylphenidate group was significantly better at 30 days on the DRS (p < .02), and on tests of attention (p < .03) and motor performance (p, .05). No significant differences were noted between groups at 90 days. CONCLUSIONS: Subacute administration of methylphenidate after moderately severe head injury appeared to enhance the rate but not the ultimate level of recovery as measured by the DRS and tests of vigilance. Problems with possible selection bias and small sample size limit generalization of results.

Postoperative transcutaneous oxygen measurement in the prediction of delayed wound healing and prosthetic fitting among amputees during rehabilitation. A pilot study.

Postoperative assessment of amputation wound healing remains largely subjective in nature, being based on the physician's clinical judgement. These considerations significantly impact on the rehabilitation course, as premature prosthetic fitting may result in wound breakdown. Alternatively, delayed healing may result in prolonged hospital length of stay. Few attempts have been made to correlate objective parameters of limb perfusion with amputation wound healing or prosthetic fitting outcome during the rehabilitation phase of treatment. A pilot study was conducted, in which the transcutaneous oxygen monitor, a noninvasive device measuring transcutaneous partial pressure of oxygen (tcpO2), was applied to the stumps of 11 consecutive above-or below-knee amputees admitted for rehabilitation after amputation. All patients were tested within 1 wk of admission and 45 days of amputation. The treatment team was blinded as to the test results. A direct correlation was observed between wound healing outcome and tcpO2 results (Fisher's exact test [FET], P = 0.03), and no patient with a tcpO2 of < or 15 mm Hg healed during their rehabilitation stay (FET, P = 0.006). TcpO2 of < or = 15 mm Hg was significantly correlated with prolonged length of stay (Point Biserial Correlation Coefficient [rpbi], = -0.835; P = 0.01), delayed prosthetic fitting (rpbi = 0.742; p = 0.01), and poorer wound healing at admission (rpbi = 0.932; P = 0.001). Postoperative tcpO2 measurement may have use in objectively identifying patients at greater risk of delayed wound healing and prosthetic fitting, although further study is warranted.