By Jenifer Kienle, Esq.

Anyone who has investigated a major vehicle accident scene can likely recall the horrific images, sounds and destruction with vivid clarity.  Absent a personal involvement in the event, there is little risk of developing a recognized psychiatric anxiety based disorder.  However, survivors of these accidents may not only claim a brain injury from the accident, it is reasonable to anticipate the plaintiff will allege a psychiatric disorder such as Post Traumatic Stress Disorder ("PTSD.")  Lawyers experienced in defending PTSD claims appreciate that the burden of proving PTSD requires meeting the diagnostic criteria set forth in the Diagnostic and Statistical Manual of Mental Disorders (DSM) which is published by the American Psychiatric Association.  At a minimum, to be diagnosed with PTSD, plaintiffs have historically been required to experience both an "extreme traumatic stressor" and an "actual or threatened death or serious injury."  In fact, "severe automobile accidents" have been recognized by the American Psychiatric Association as the kind of traumatic event which could cause PTSD.

In California, however, there is a recent push by plaintiffs' attorneys and medical experts to suggest that certain "eggshell" plaintiffs may develop PTSD even though the triggering event was merely a minor "fender bender."  There is an appreciable trend by the plaintiffs' bar to partner with neuropsychologists and neuroradiologists willing to attribute PTSD and its resultant cognitive impairment to a minor car accident. The theory being proffered: even in the absence of a direct brain injury, if the plaintiff perceived the low speed event as traumatic, the extreme stress would release unregulated amounts of corticosteroids in the brain, causing appreciable and measurable damage to the hippocampus.  The hippocampus is a part of the forebrain, located in the medial temporal lobe. It belongs to the limbic system and plays major roles in long term memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain, and the structure is shaped like a banana.

In more and more cases, plaintiffs' experts are offering opinions based upon studies which purportedly demonstrate that patients with PTSD have a smaller than average, or under formed hippocampus.

Specifically, these neuropsychologists are relying on the basic science work of Bruce McEwen, M.D., whose research of animals resulted in the conclusion that extreme stress is associated with brain volume reductions (including hippocampal formation). Dr. McEwen, head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at The Rockefeller University, has done extensive research on the impact of stress on brain structure and neurochemistry. Dr. McEwen's research is being used in the personal injury setting by attorneys and doctors to suggest that in addition to the recognized forensic psychiatric assessment such as diagnostic interviews and testing, magnetic resonance imaging (MRI) studies of the plaintiff's brain may reveal atrophy or below average hippocampal formation.  In such a case, the plaintiff attorney and the expert are arguing the stress of the accident (not a head injury) damaged the plaintiff's cognitive function.  Such opinions are dangerous and invite the conclusion that plaintiffs whose MRIs demonstrate a smaller than average hippocampus, are presumed to suffer from accident related PTSD.  Such "objective" evidence may also lead a jury to ignore persuasive defense evidence such as pre-injury personality characteristics and diagnostic test results which suggest malingering.

Selling this disorder to a jury when the "traumatic event" was neither significant nor the cause of any physical injuries would seem improbable.  However, the science of stress requires little more than a forensic neuropsychological assessment interpreted by a credible doctor to suggest PTSD,  a neuroradiologist who will testify that detailed measurements reveal atrophy, and an unexpectedly collaborative defense IME doctor.  Even in the absence of a pre-accident MRI, the plaintiff argument will be that the cognitive impairment presented after the accident, thus the PTSD is the causative factor.

The Scenario: An inattentive truck driver sitting in stop and go traffic inadvertently taps the rear bumper of the motorist in front of him. The motorist emerges from the vehicle upset, but claims no physical injuries.  The motorist drives away, only to file a lawsuit claiming soft tissue injuries and "brain damage" arising out of Post-Traumatic Stress Syndrome.  During discovery it is revealed the plaintiff suffers post-accident memory loss and severe anxiety whenever operating a vehicle.

Predictable Defense Reaction: Plaintiff's PTSD claim is unsupported by evidence of a traumatic brain injury, as there were insufficient forces to produce the requisite axial shearing or head injury associated with such a condition.  To defend the claim, it has been enough to retain a neuropsychologist to interview the plaintiff, submit the plaintiff to standardized validation tests and look for evidence of either malingering, or pre-injury conditions or disorders which may explain the plaintiff's complaints.

The New Litigation Plan:  The new science of stress suggests that once a direct brain injury is ruled out, it is imperative to forecast whether the plaintiff represents an eggshell plaintiff with the presentation capable of selling PTSD.  An excruciatingly thorough probe into the plaintiff's personality characteristics pre-injury requires obtaining a lengthy medical history, deposing family members, co-workers and looking for traits such as neuroticism, previous depression, psychiatric treatment or prior trauma.  And, obtaining any pre-injury MRI studies of the brain will allow the defense neuropsychologist to evaluate any changes to the hippocampi. 

Also, when screening and engaging a neuropsychologist to provide a defense assessment, it is essential not only that the expert be familiar with Dr. McEwen's stress theories, but that defense counsel remain fluent in the data flowing from the symptom validity tests being employed to establish the presence or absence of malingering.  Understanding the results of these standardized tests means finding a method of communicating the results, which are often complicated, to a jury. 

Finally, choosing a defense expert also requires an understanding that treaters in the mental health field frequently become involved with a patient, and while exploring their personality, subconsciously begin to "like" the plaintiff.  So, in addition to selecting an expert familiar with the theory of how stress effects brain function, be alert to any defense expert who, after spending considerable time interviewing the plaintiff, reports his/her impression of the plaintiff in complimentary terms.  This may be a sign the expert's professional judgment (and ultimate diagnosis) is impeded by favorable feelings toward the plaintiff.  Avoid this trap with early, frequent and candid discussions with the expert so that his/her favorable impressions of the plaintiff can be managed.  Getting familiar with the new science of stress is the best approach to what is likely to become a popular element of  personal injury damage claims - even when the event giving rise to the lawsuit appears on its face to be less than traumatic.

Jenifer Kienle is a partner in the Costa Mesa office of Lewis, Brisbois Bisgaard & Smith LLP