The minimally conscious state: definition and diagnostic criteria.

OBJECTIVE: To establish consensus recommendations among health care specialties for defining and establishing diagnostic criteria for the minimally conscious state (MCS). BACKGROUND: There 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. METHODS: An 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. RESULTS: There 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. CONCLUSIONS: MCS 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.

Promoting ethical and objective practice in the medicolegal arena of disability evaluation.

As providers of medical information and testimony, clinicians have ultimate responsibility for ethical conduct as it relates to this information. The authors offer the following recommendations for enhancing ethical relationships between expert clinicians and the courts. 1. Avoid or resist attorney efforts at enticement into joining the attorney-client team. Such compromises of scientific boundaries and ethical principles exist on a continuum ranging from standard attorney-client advocacy at the beginning of the expert consultation phase (e.g., promotional information at the forefront of retaining an expert, with either provision of selective or incomplete records or less than enthusiastic efforts to produce all records) and extending to completion of evaluation, when requests for changes in reports and documentation might be made. 2. Respect role boundaries and do not mix conflicting roles. Remember that the treating doctor possesses a bond with the patient but does not as a rule obtain complete preinjury and postinjury information in the context of assessing causality and apportionment. In contrast, the expert witness must conduct a thorough and multifaceted case analysis sans the physician-patient relationship in order to facilitate objectivity and allow optimum diagnostic formulations. Finally, the trial consultant's function in this adversarial process is to assist with critically scrutinizing and attacking positions of experts for the opposing side. These roles all represent inherently different interests, and mixing them can only reduce objectivity. 3. Insist on adequate time for thorough record review, evaluation, and report generation. Also insist on sufficient time and preparation for deposition and court appearances. 4. Work at building a reputation for general objectivity, reliance on multiple data sources, reaching opinions only after reviewing complete information from both sides, and completing the evaluation. 5. Spend a good amount of time actually treating the patient population being examined or being offered testimony about. This treatment should be current and should be of a similar frequency to treating practitioner specialists. Be able to discuss relevant research and scientific methodology issues competently and without notes. 6. Arrive at opinions only after reviewing all of the evidence from both sides of the adversarial fence, employing multiple data sources, completing the evaluation, and interpreting data within the full context of comprehensive historical, behavioral observation, and contextual information. Being otherwise favorable to retaining attorney interests suggests endorsement of "opinion prostitute," "scientific perjurer," or "hired gun" status. The only way a practitioner can reduce the likelihood of facing an "opinion prostitute" on the opposing side in future cases is to insist on establishing and maintaining a reputation for scientific objectivity. 7. Balance cases from plaintiff and defense attorneys. Predilection for one side or the other suggests bias and sets up predisposition to nonobjectivity. For example, a preponderance of plaintiff work suggests an overdiagnosis or uncritical sympathy bias, whereas a ratio that favors hiring by the defense suggests an underdiagnosis or skepticism bias. Perhaps Brodsky's suggested cut-off ratio of .8 for favorability findings would represent an initial cutoff for defense versus plaintiff ratio. That is, experts should do at least 20% work for the opposite side of the current case being represented. Further, it might be a reasonable expectation that data on these ratios be collected as an important method for ensuring objective opinions. 8. Ensure against excessive favorability to the side of the retaining attorney or firm. Objectivity demands that scientific opinions not be influenced by the position of the legal advocate. Importantly, Brodsky recommends using a ratio of .8 as a cut-off for detecting excessive bias. That is, practitioners should possess prerequisite objectivity to disagree with the referring attorney at least 20% of the time. We suggest that a more useful cut-off would be .75, where experts are expected to generate findings that do not support the referring attorney's position at least 25% of the time. 9. Never arrive at opinions that are inconsistent with plaintiff records, examination data, test data, behavioral presentation, and so forth, especially when such opinions are favorable to the side of the retaining attorney firm. Instead, use the following recommendations. (ABSTRACT TRUNCATED)

Does pain confound interpretation of neuropsychological test results?

There is increasing evidence that pain and related problems (e.g., affective distress, sleep disturbance, medication use) can interfere with cognitive performance and confound the interpretation of neuropsychological test results. This may be of particular concern in cases of the persistent post-concussive syndrome where headache is the primary problem. Such effects can be pronounced, obscuring the effects associated with mild or even much more significant brain injury. However, it remains unclear what specific chronic or acute pain experiences, in what individuals, with or without which associated problems, will actually result in particular performance deficits. Whereas pain may disrupt brain function, this is likely to be temporary and not indicative of permanent impairment of neuropsychological function. Further study of this important topic is warranted.

Chronic pain and neuropsychological functioning.

This review article examines the effect of chronic pain on neuropsychological functioning. Primary attention is given to studies that include patient groups without a history of traumatic brain injury (TBI) or neurologic disorders. Numerous studies were identified that demonstrate neuropsychological impairment in patients with chronic pain, particularly on measures assessing attentional capacity, processing speed, and psychomotor speed. Despite suggestive findings, further studies are needed to clarify the variables that mediate the impact of pain on neuropsychological functioning and the unique role of various symptoms often associated with chronic pain.

Posttraumatic headache: caveats and controversies.

Posttraumatic headache (PTHA) although quite common, is still poorly understood in many ways. This article will provide opinions, insights, and analysis of some of the ongoing controversies and issues in PTHA assessment and treatment. Topics germane to nomenclature problems, classification criteria, paradoxes regarding headache incidence relative to injury severity, lack of identified medical specialty for referral of patients with PTHA, medicolegal issues, PTHA perpetuating factors, impairment and disability assessment, and research needs are addressed. Recommendations for addressing some of the concerns brought up in this commentary will be focused on in the article's concluding comments. These caveats and controversies will hopefully serve to familiarize readers with some of the inherent difficulties in PTHA management and treatment.

Medical management of posttraumatic headaches: pharmacological and physical treatment.

Posttraumatic headache can be a very difficult syndrome to manage, especially if chronic. As with most other types of headache, medications are the primary treatment modality, although there is very limited evidence-based data to support any given approach. A number of physical interventions also are available to be used in conjunction with medication, particularly for headaches with a musculoskeletal component. This article will review the general principles of pharmacological treatment for headache and the physical approach to treatment of headaches and head and facial pain. The major categories of medications commonly used for treatment of many varieties of headache will be discussed. In addition, the problems encountered in diagnosing and treating chronic daily headache and analgesic rebound headache are addressed. The approach to treatment of such syndromes as myofascial pain, cervico-zygapophyseal joint pain, neuritic pain, and craniocervical somatic pain are outlined.

Posttraumatic headache: neuropsychological and psychological effects and treatment implications.

Posttraumatic headache (PTHA) is a frequent occurrence following trauma to the head, brain, and/or neck. Estimates of persistence for 6 months are as high as 44%. Review of available studies examining the effect of headache on neuropsychological test findings reveals that chronic headache pain, and chronic pain generally, exerts a significant and negative effect that poses a challenge to differential diagnostic efforts in the evaluation of mild brain injury. Given that PTHA is the most common postconcussive symptom and most frequent type of posttraumatic pain associated with mild traumatic brain injury (TBI), it follows that resolution of the postconcussion syndrome, and successful posttraumatic adaptation, may frequently rely on success in coping with PTHA symptomatology. Viewing PTHA from a biopsychosocial perspective, a general outline is offered for improving both assessment and treatment of PTHA. In addition, the most promising psychology-based treatment interventions are reviewed.

Posttraumatic tension pneumocephalus.

This case presentation will review tension pneumocephalus as a rare etiology of delayed posttraumatic headache (PTHA). It demonstrates that clinicians must be aware of even the uncommon causes of PTHA if appropriate diagnostic assessment and treatment are to be rendered. The case involves a 26-year-old right-handed white male who was 4 years post severe traumatic brain injury with facial fractures and an initial Glasgow Coma Scale score of 5. The patient's main postinjury functional impairments were cognitive-behavioral dysfunction, dysmetria, left hemiparesis, and posttraumatic epilepsy. Approximately 3 years post injury, the patient started to have complaints of right unilateral frontal headache. This complaint was addressed conservatively by several treating physicians. Due to the progressive nature of the patient's complaints, a second opinion was obtained with the author. On assessment, the patient complained of unilateral right headache and described the pain as making him feel as if his head was going to "bust open." A computed tomography (CT) scan showed findings consistent with a tension pneumocephalus. The patient was referred to neurosurgery, at which time the tension pneumocephalus was evacuated and a dural leak, felt to be responsible for the condition, patched. The patient's headache complaints resolved postoperatively. Clinicians should be aware of uncommon conditions that may be present in patients presenting with late PTHA, particularly conditions such as tension pneumocephalus which may have a significant clinical morbidity.

Response bias in plaintiffs' histories.

This study investigated response bias in self-reported history of factors relevant to the assessment of traumatic brain injury, toxic brain injury and related emotional distress. Response bias refers to systematic error in self-report data. A total of 446 subjects (comprising 131 litigating and 315 non-litigating adults from five locations in the United States) completed a symptom questionnaire. Data were obtained from university faculty and students, from patients in clinics specializing in physiatry neurology, and family medicine, and from plaintiffs undergoing forensic neuropsychological evaluations. Comparisons were made for litigant and non litigant ratings of their past and current cognitive and emotional functioning, including life in general, ability to concentrate, memory, depression, anxiety, alcohol, drugs, ability to work or attend school, irritability, headaches, confusion, self-esteem, and fatigue. Although there is no basis for hypothesizing plaintiffs to be healthier than the general population, plaintiffs rated their pre-injury functioning superior to non-plaintiffs. These findings suggest that response biases need to be taken into account by forensic examiners when relying on litigants' self-reports of pre-injury status.

Prognostic indicators in medical rehabilitation of traumatic brain injury: a commentary and review.

The National Information System (NIS) project is developing consensus opinion regarding a proposed structural framework for the prognostic data to be collected as part of this proposed multicenter research effort on severe traumatic brain injury (TBI). This article provide a brief history of the process, examines challenges facing rehabilitation research in this particular area, discusses reasons for identifying prognostic data within the research context of the NIS project, and describes methodologies for use of mathematical models in predicting outcome from TBI. The literature regarding prognostic parameters in severe TBI is briefly reviewed, utilizing three broad parameter categorizations: preinjury, injury, and postinjury. The implications of this research and directions for further study within the NIS project are discussed.

Nomenclature: evolving trends.

In the past few years, there has been a burgeoning of interest in reassessing the appropriateness and applicability of historically well entrenched nomenclature germane to persons in low level neurological states following brain injury. Surprisingly, the effort to develop a cross-disciplinary uniform set of clinical definitions for low level states has only been a very recent endeavor within the neuroscience community. The intent of this review is to provide clinicians with a better understanding of some of the history and ongoing issues pertinent to appropriate diagnostic labeling and the ultimate rationale of a uniform terminology for this special population of neurologic patients.

Male pituitary-gonadal dysfunction following severe traumatic brain injury.

A prospective study was conducted to evaluate pituitary-gonadal function and correlated parameters in 21 adult males with severe traumatic brain injury during acute inpatient rehabilitation. Serum concentrations of testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured within 1 week after the patient was transferred to the rehabilitation unit. Fourteen of 21 patients (67%) had abnormally low testosterone levels. One of 21 patients had a subnormal FSH level and one had a supranormal level. Three of 21 patients had subnormal LH levels and two had supranormal levels. There was no correlation between the severity of brain injury and the levels of testosterone, FSH or LH. The presence of increased intracranial pressure, hypoxia, skull fracture or abnormal CT findings had no significant influence on the levels of testosterone, FSH or LH. The high incidence of hypotestosteronaemia in survivors of severe traumatic brain injury is seemingly more related to accompanying physiological stressors rather than structural or neurochemical disruption of the hypothalamic-pituitary-gonadal axis. Early identification is important relative to the potential neuromedical and rehabilitative consequences of prolonged hypotestosteronaemia in this patient population.