Personal Injury Law

American College of Rehabilitation Medicine Releases Definition of Traumatic Brain Injury

By Bruce Stern

In 1993 the American Congress of Rehabilitation Medicine (ACRM) put together an interdisciplinary special interest group to develop a definition of mild traumatic brain injury. That definition can be found at the Journal of Head Trauma Rehabilitation, 1993; 8(3):86-87. Obviously, in the past 17 years, advances in neuro imaging, brain injury rehabilitation and science in general have led researchers to redefine that definition. This month, a "Working Group" of the International and Interagency Initiative Toward Common Data Elements for Research on Traumatic Brain Injury and Psychological Health published a position statement entitled Definition of Traumatic Brain Injury. Arch Phys Med Rehabil 2010; 91:1637-40. As stated in the abstract, "a clear, concise definition of traumatic brain injury is fundamental for reporting, comparison and interpretation of studies on traumatic brain injury. Changing epidemiologic patterns, and increasing recognition of significance of mild TBI, and a better understanding of the subtler neurocognitive neuroaffective deficits that may result from these injuries make this need even more critical."

The position paper discussed the criteria for considering or establishing a diagnosis of traumatic brain injury, particularly focusing on problems of how a diagnosis of TBI can be made when patients present late after injury and how mild TBI may be differentiated from non-TBI causes with similar symptoms.

The definition of traumatic brain injury utilized in this position statement defines "traumatic brain injury as an alteration in brain function, or other evidence of brain pathology, caused by an external force." Alteration is defined as any period of loss of or a decreased LOC, any loss of memory for events immediately before (retrograde amnesia) or after the injury (post traumatic amnesia); neurologic deficits or any alteration in mental state at the time of the injury (confusion, disorientation, slowed thinking, etc.).

While acknowledging that factors other than TBI may be responsible for alterations in mental state such as pain, post traumatic shock, medication or alcohol intoxication, these confounding factors should not preclude a diagnosis of traumatic brain injury. However, they note that a careful clinical review may be needed before assigning a given set of clinical findings as being caused by TBI.

The authors of the definition felt that a short and concise definition of traumatic brain injury was preferable to a more lengthy description. They indicated that there was a great deal of discussion regarding the criteria for defining an "alteration in brain function." The authors noted the clinicians generally preferred hard criteria while surveillance studies tended to use a broader definition so as not to miss potential new cases nor to limit the risk of under-reporting. Obviously, the presence of loss of consciousness, post traumatic amnesia or neurologic deficits constituted objective criteria when captured in a clinical research center. However, particularly for patients with mild TBI presenting for care, information on loss of consciousness, PTA or other alteration of consciousness is captured only by self-report. Verification is often difficult. The authors acknowledge that a careful clinical interview is considered essential to establishing a diagnosis of traumatic brain injury particularly in the absence of clinical or other witnesses. However, the group "felt strongly" that a diagnosis of TBI should be considered when these symptoms are reported even in the absence of more objective criteria.

The authors stated that "the criteria we present under alteration in brain function are compatible with the diagnostic criteria for mild TBI presented by the ACRM in 1993".

Full post as published by Traumatic Brain Injury Law Blog on December 01, 2010 (boomark / email).