Screening and Identification of TBI

If you are a brain injury professional who cannot read an article without knowing what the Glasgow Coma Scale (GCS) scores are for the sample studied, then this issue of the Journal of Head Trauma Rehabilitation may be a source of some consternation. The articles presented here all address methodologies employed to screen for traumatic brain injury (TBI) in various populations. Whether the purpose for identifying cases is to determine prevalence, focus additional services, or compare those with and without TBI, unfortunately, the existence, let alone availability, of a GCS score is a luxury that none of these authors enjoyed. Instead the reader will find that new, and previously untested, methodologies were employed as part of scientific approaches that may seem quite foreign. Why is this? The research literature on TBI is dominated by cohorts for which a diagnosis of TBI (or its absence) was determined at the time that medical attention was given. Whether samples are collected prospectively or retrospectively from a given point in the system of care (eg, emergency department admissions, patients treated in rehabilitation), the standard for description relies on indicators reflecting the extent of altered consciousness as observed by professionals who treated the acute injury (eg, first GCS in the emergency department, time to follow commands during acute hospitalization). Even studies from later in the process of treatment identify a sentinel occurrence of a TBI (eg, 6 months after severe TBI), and whenever possible report the altered consciousness observed at the time (eg, with 5 days of posttraumatic amnesia). Even the epidemiological data in our field are dominated by reports of incident cases, most commonly identified by the International Classification of Diseases, Ninth Revision (ICD-9) code given at the time of treatment. When the methodology shifts to identifying TBI in cohorts defined not by having been treated, but by some other criteria (eg, schoolchildren with behavioral problems, nursing home residents, prisoners, clients treated for substance abuse disorders, or soldiers returning from combat), then the ways of detecting and categorizing TBI to which we are so accustomed are no longer available. For many readers, the first reaction will be, “why not just collect information about past TBI’s from previous medical records.” This is a logical approach and, if it were only impractical, someone would have done it. What is impractical, of course, is to attempt to find all of a person’s prior treatments and then gain access to those medical records. Perhaps at some time in the future we will carry our medical records in a computer chip imbedded in our arm, but for now there is no way of determining a person’s prior treatments without asking him or her to identify them. Putting aside the issue of self-report for the moment, the ability to actually obtain a lifetime’s worth of medical records for injuries treated in physicians’ offices, emergency departments, or hospitals is a daunting task without adding those injuries attended to only by a school nurse, athletic trainer, or emergency medical technician in the field. But obtaining all these medical records is only what makes the task impractical. What makes it impossible to use medical records to study a past history of TBI is the significant proportion of these injuries that receive no medical attention at all. Articles in this issue report that 61% of head injuries among prisoners were untreated1; similarly, 30% of TBIs experienced by persons with comorbid substance use disorders did not receive medical attention.2 A recent study reported that 42% of persons responding to a Webbased survey had experienced TBI without any medical attention.3 In other projects we have found 25% of adolescents in treatment for substance use disorders report prior TBI with loss of consciousness for which they received no medical attention of any kind; and 41% of TBIs reported by prisoners received no medical care (J.D.C. and J.A.B., written communication, September 2007). Quite clearly, if not treated there will not be a medical record to obtain. The second thought that often comes to mind when faced with the dilemma of identifying past TBI is to conduct testing. However, there is no biomarker for TBI. Techniques like computed tomography (CT) scans, magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), positron emission tomography (PET) scanning, or neuropsychological assessment can be used to detect acute TBI of sufficient severity, or chronic TBI of greater severity, but none of these techniques are sensitive to all TBI, especially not all TBI that may have occurred over a person’s lifetime. The validity of our customary