Ross Zafonte

The minimally conscious state: Definition and diagnostic criteria

ObjectiveTo establish consensus recommendations among health care specialties for defining and establishing diagnostic criteria for the minimally conscious state (MCS). BackgroundThere is a subgroup of patients with severe alteration in consciousness who do not meet diagnostic criteria for coma or the vegetative state (VS). These patients demonstrate inconsistent but discernible evidence of consciousness. It is important to distinguish patients in MCS from those in coma and VS because preliminary findings suggest that there are meaningful differences in outcome. MethodsAn evidence-based literature review of disorders of consciousness was completed to define MCS, develop diagnostic criteria for entry into MCS, and identify markers for emergence to higher levels of cognitive function. ResultsThere were insufficient data to establish evidence-based guidelines for diagnosis, prognosis, and management of MCS. Therefore, a consensus-based case definition with behaviorally referenced diagnostic criteria was formulated to facilitate future empirical investigation. ConclusionsMCS is characterized by inconsistent but clearly discernible behavioral evidence of consciousness and can be distinguished from coma and VS by documenting the presence of specific behavioral features not found in either of these conditions. Patients may evolve to MCS from coma or VS after acute brain injury. MCS may also result from degenerative or congenital nervous system disorders. This condition is often transient but may also exist as a permanent outcome. Defining MCS should promote further research on its epidemiology, neuropathology, natural history, and management.

Summary of evidence-based guideline update: Evaluation and management of concussion in sports Report of the Guideline Development Subcommittee of the American Academy of Neurology

Objective: To update the 1997 American Academy of Neurology (AAN) practice parameter regarding sports concussion, focusing on 4 questions: 1) What factors increase/decrease concussion risk? 2) What diagnostic tools identify those with concussion and those at increased risk for severe/prolonged early impairments, neurologic catastrophe, or chronic neurobehavioral impairment? 3) What clinical factors identify those at increased risk for severe/prolonged early postconcussion impairments, neurologic catastrophe, recurrent concussions, or chronic neurobehavioral impairment? 4) What interventions enhance recovery, reduce recurrent concussion risk, or diminish long-term sequelae? The complete guideline on which this summary is based is available as an online data supplement to this article. Methods: We systematically reviewed the literature from 1955 to June 2012 for pertinent evidence. We assessed evidence for quality and synthesized into conclusions using a modified Grading of Recommendations Assessment, Development and Evaluation process. We used a modified Delphi process to develop recommendations. Results: Specific risk factors can increase or decrease concussion risk. Diagnostic tools to help identify individuals with concussion include graded symptom checklists, the Standardized Assessment of Concussion, neuropsychological assessments, and the Balance Error Scoring System. Ongoing clinical symptoms, concussion history, and younger age identify those at risk for postconcussion impairments. Risk factors for recurrent concussion include history of multiple concussions, particularly within 10 days after initial concussion. Risk factors for chronic neurobehavioral impairment include concussion exposure and APOE ε4 genotype. Data are insufficient to show that any intervention enhances recovery or diminishes long-term sequelae postconcussion. Practice recommendations are presented for preparticipation counseling, management of suspected concussion, and management of diagnosed concussion.

Etiology and incidence of rehospitalization after traumatic brain injury: A multicenter analysis

OBJECTIVE To investigate incidence and etiology of rehospitalizations at 1, 2, and 3 years after traumatic brain injury. DESIGN Descriptive statistics were computed in a prospective study of etiology and incidence of rehospitalization at years 1, 2, and 3 postinjury. Analysis of variance (ANOVA) and chi2 were used to identify factors relating to rehospitalization; factors included length of stay, admission and discharge functional status, payer source, medical complications, injury severity, and demographics. SETTING Four medical centers in the federally sponsored Traumatic Brain Injury Model Systems. In each setting, the continuum of care includes emergency medical services, intensive and acute medical care, inpatient rehabilitation, and a spectrum of community rehabilitation services. PARTICIPANTS Six hundred sixty-five rehabilitation patients admitted to acute care within 24 hours of traumatic brain injury between 1989 and 1996. MAIN OUTCOME MEASURES Annual incidence and etiology of rehospitalization. RESULTS The annual incidence of rehospitalization ranged from 20% to 22.5%. Approximately half the rehospitalizations were for elective reasons. The most common reason for rehospitalization was for orthopedic or reconstructive surgery, followed by infectious disorders and general health maintenance. After the first year, the incidence of readmissions for seizures and psychiatric difficulties increased substantially. ANOVA and chi2 analyses were performed on data from the first year postinjury. No statistically significant associations were noted between incidence and etiology of rehospitalization and: demographics; injury severity; payer source for rehabilitation; concurrent injuries; acute care and rehabilitation length of stays; discharge Functional Assessment Measure; and discharge residence (p > .05). CONCLUSIONS There is a relatively stable but high rate of rehospitalization for at least 3 years after injury. The costs of rehospitalization should be considered when evaluating the long-term consequences of injury.

Assessment Scales for Disorders of Consciousness: Evidence-Based Recommendations for Clinical Practice and Research

OBJECTIVES To conduct a systematic review of behavioral assessment scales for disorders of consciousness (DOC); provide evidence-based recommendations for clinical use based on their content validity, reliability, diagnostic validity, and ability to predict functional outcomes; and provide research recommendations on DOC scale development and validation. DATA SOURCES Articles published through March 31, 2009, using MEDLINE, CINAHL, Psychology and Behavioral Sciences Collection, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Biomedical Reference Collection, and PsycINFO. Thirteen primary terms that defined DOC were paired with 30 secondary terms that defined aspects of measurement. Scale names, abbreviations, and authors were also used as search terms. Task force members identified additional articles by using personal knowledge and examination of references in reviewed articles. STUDY SELECTION Primary criteria included the following: (1) provided reliability, diagnostic validity, and/or prognostic validity data; (2) examined a cohort, case control, or case series sample of persons with DOC who were age older than or equal to 18 years; and (3) assessed in an acute care or rehabilitation setting. Articles were excluded if peer review was not conducted, original data were not reported, or an English language article was not available. The initial search yielded 580 articles. After paired rater review of study abstracts, guideline development was based on 37 articles representing 13 DOC scales. DATA EXTRACTION Rater pairs classified studies addressing diagnostic and prognostic validity by using the American Academy of Neurology 4-tier level of evidence scheme, and reliability by using a task force-developed 3-tier evidence scheme. An independent quality review of ratings was conducted, and corrections were made. DATA SYNTHESIS The Coma Recovery Scale-Revised (CRS-R), Sensory Stimulation Assessment Measure (SSAM), Wessex Head Injury Matrix (WHIM), Western Neuro Sensory Stimulation Profile (WNSSP), Sensory Modality Assessment Technique (SMART), Disorders of Consciousness Scale (DOCS), and Coma/Near-Coma Scale (CNC) have acceptable standardized administration and scoring procedures. The CRS-R has excellent content validity and is the only scale to address all Aspen Workgroup criteria. The SMART, SSAM, WHIM, and WNSSP demonstrate good content validity, containing items that could distinguish persons who are in a vegetative state, are in a minimally conscious state (MCS), or have emerged from MCS. The Full Outline of UnResponsiveness Score (FOUR), WNSSP, CRS-R, Comprehensive Levels of Consciousness Scale (CLOCS), and Innsbruck Coma Scale (INNS) showed substantial evidence of internal consistency. The FOUR and the CRS-R showed substantial evidence of good interrater reliability. Evidence of diagnostic validity and prognostic validity in brain injury survivor samples had very high levels of potential bias because of methodologic issues such as lack of rater masking. CONCLUSIONS The CRS-R may be used to assess DOC with minor reservations, and the SMART, WNSSP, SSAM, WHIM, and DOCS may be used to assess DOC with moderate reservations. The CNC may be used to assess DOC with major reservations. The FOUR, INNS, Glasgow-Liege Coma Scale, Swedish Reaction Level Scale-1985, Loewenstein Communication Scale, and CLOCS are not recommended at this time for bedside behavioral assessment of DOC because of a lack of content validity, lack of standardization, and/or unproven reliability.

Traumatic Brain Injury Rehabilitation: State of the Science

Gordon WA, Zafonte R, Cicerone K, Cantor J, Brown M, Lombard L, Goldsmith R, Chandna T: Traumatic brain injury rehabilitation: State of the science. Am J Phys Med Rehabil 2006;85:343–382.

White Matter Integrity in the Brains of Professional Soccer Players Without a Symptomatic Concussion

into effect in 2006. Further labeling changes to specify whether a food product contains any quantity of TFAs would further increase transparency of a food’s TFA content. While we agree with Mr Katarey and Ms Francis that it is possible for a product labeled zero trans fat to have close to 0.5 g of trans fat per serving, we are unaware of any published data on the distribution of TFA content for foods labeled zero trans fat but still containing some partially hydrogenated oil that are necessary to estimate the proportion of these foods with close to 0.5 g per serving. We agree with Drs Backholer and Peeters that there are no known health benefits of industrially produced TFAs. We also agree that we cannot be sure that further food labeling changes would eliminate exposure to partially hydrogenated oil for all individuals. While we are not aware of any current data to indicate that persons of lower income have higher dietary intakes of TFAs or that less expensive brands of the same food product have higher TFA content than the more expensive brands, we agree these are important areas of research. A recent FDA study provided evidence of differences in the TFA content of different brands of the same food. For example, different brands of frozen pizza contained from 0 to 5 g of TFAs per serving. Therefore, elimination of partially hydrogenated oils from packaged foods would eliminate these differences and would help persons who may only have access to specific brands and those who are not aware of the different content levels of TFAs.

Insomnia in a post-acute brain injury sample

Objective : The purpose was to establish the frequency of insomnia within the post-acute TBI population and compare it with insomnia rates among other rehabilitation outpatients. Design : A prospective study was undertaken of 50 consecutive post-acute TBI admissions and a comparison group of 50 rehabilitation outpatients evenly divided between spinal cord injury (SCI) and musculoskeletal (MSK) cases. Setting : Subjects were recruited at various outpatient clinics of a major rehabilitation hospital. Patients : Among the TBI subjects, the predominant cause of injury was motor vehicle accident; both mild and severe injuries were well represented in the sample; and, on average, patients were almost 4 months post-injury. The comparison and TBI groups did not differ significantly with respect to education or marital status. However, the MSK group was older and a higher proportion of the SCI group was female. Measures : The Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and sleep diaries were administered to the TBI group. Only the PSQI and BDI were completed by the comparison group. Results : Thirty per cent of the patients were found to suffer from insomnia. Sleep initiation was a problem almost twice as often as sleep duration. An additional 12% did not meet the DSM-IV criteria for insomnia but, nevertheless, experienced a degradation of sleep quality, as measured by the PSQI. Conversely, only slightly more than half (58%) of the TBI sample reported sleep to be relatively normal and satisfactory. Insomnia was also commonly reported by the patients in the rehabilitation comparison groups. They generated significantly higher mean PSQI Global Scores relative to the TBI group and the frequency of poor sleep quality was elevated significantly above the TBI rate. Relative to the TBI cases, twice as many comparison group patients were classified by the PSQI as insomniacs. Conclusion : Poor sleep quality and insomnia were definitely problems for the TBI group, although the magnitude of these problems was much greater for the rehabilitation comparison group. Degraded and disordered sleep may represent widespread challenges within the rehabilitation population in general.

Safety and feasibility of craniectomy with duraplasty as the initial surgical intervention for severe traumatic brain injury.

BACKGROUND Decompressive craniectomy has historically served as a salvage procedure to control intracranial pressure after severe traumatic brain injury. We assessed the safety and feasibility of performing craniectomy as the initial surgical intervention. METHODS Of 29 consecutive patients undergoing emergent decompression for severe traumatic brain injury with horizontal midline shift greater than explained by a removable hematoma, 17 had traditional craniotomy with or without brain resection and 12 underwent craniectomy. RESULTS The craniectomy group had lower Glasgow Coma Scale scores at surgery (median, 4 vs. 7; p = 0.04) and more severe radiographic injuries (using specific measures). Mortality, Glasgow Outcome Scale scores, Functional Independence Measures, and length of stay in both the acute care setting and the rehabilitation phase were similar between the surgical groups. CONCLUSION Despite more severe injury severity, patients undergoing initial craniectomy had outcomes similar to those undergoing traditional surgery. A randomized evaluation of the effect of early craniectomy on outcome is warranted.

Relationships between cerebrospinal fluid markers of excitotoxicity, ischemia, and oxidative damage after severe TBI: The impact of gender, age, and hypothermia

Excitotoxicity and ischemia can result in oxidative stress after TBI. Female sex hormones are hypothesized to be neuroprotective after TBI by affecting multiple mechanisms of secondary injury, including oxidative damage, excitotoxicity and ischemia. Ca2+ mediated oxidative stress increases with age, and hypothermia is known to attenuate secondary injury. The purpose of this study was to determine if the relationship between cerebral spinal fluid (CSF) markers of excitotoxicity, ischemia, and oxidative damage are gender and age specific and the role of hypothermia in affecting these relationships. F2-isoprostane, glutamate, and lactate/pyruvate, were assessed in CSF from adults (n = 68) with severe TBI (Glasgow coma scale [GCS] score </= 8) using ventricular CSF samples (n = 207) collected on days 1, 2, and 3 post-injury. F2-isoprostane/glutamate and F2-isoprostane/lactate/pyruvate ratios were determined for patients at each time point. Six-month Glasgow Outcome Scores (GOS) were also obtained. Repeated measures multivariate analysis showed a significant gender effect (p < 0.002) and gender*time interaction (p = 0.012) on F2-isoprostane/glutamate ratios. A significant gender effect (p = 0.050) and gender*time interaction (p = 0.049) was also seen with F2-isoprostane/lactate/pyruvate. Hypothermia (p = 0.001) and age (p = 0.026) significantly increased F2-isoprostane/glutamate ratios. Females had a significant inverse relationship between day 1 F2-isoprostane/glutamate ratios and GOS scores (r =- 0.43; p = 0.05) as well as day 1 F2-isoprostane/lactate/pyruvate ratio (r =- 0.46; p = 0.04) and GOS scores. These results indicate that females have smaller oxidative damage loads than males for a given excitotoxic or ischemic insult and female gonadal hormones may play a role in mediating this neuroprotective effect. These results also suggest that susceptibility to glutamate mediated oxidative damage increases with age and that hypothermia differentially attenuates CSF glutamate versus F2-isoprostane production. Gender and age differences in TBI pathophysiology should be considered when conducting clinical trials in TBI.

Relationship between Glasgow coma scale and functional outcome.

The Glasgow Coma Scale (GCS) is routinely used in the acute care setting after traumatic brain injury (TBI) to guide decisions in triage, based on its ability to predict morbidity and mortality. Although the GCS has been previously demonstrated to predict mortality, efficacy in prediction of functional outcome has not been established. The purpose of this study was to assess the value of the acute GCS in predicting functional outcome in survivors of TBI. This study used the Multicenter National Institute on Disability and Rehabilitation Research TBI Model Systems database of 501 patients who had received acute medical care and inpatient rehabilitation within a coordinated neurotrauma program for treatment of TBI. Initial and lowest 24 hr GCS scores were correlated with the following outcome measures: the Disability Rating Scale (DRS), Rancho Los Amigos Levels of Cognitive Functioning Scale (LCFS), and cognitive and motor components of the Functional Independence Measure (FIM(SM)-COG and FIM(SM)-M). Outcome data were collected at admission to and discharge from the inpatient TBI rehabilitation unit. Correlation analysis revealed only modest, but statistically significant, relationships between initial and lowest GCS scores and outcome variables. Initial and lowest GCS score comparison with outcome demonstrated the following correlation coefficients: admission DRS, -0.25 and -0.28; discharge DRS, -0.24 and -0.24; admission LCFS, 0.31 and 0.33; discharge LCFS, 0.27 and 0.25; admission FIM-COG, 0.36 and 0.37; discharge FIM-COG, 0.23 and 0.23; admission FIM-M, 0.31 and 0.31; discharge FIM-M, 0.25 and 0.21. The GCS as a single variable may have limited value as a predictor of functional outcome.