Traumatic Brain Injury Litigation: New Ways to Navigate TBI Cases Using Expert Witnesses

Traumatic brain injury (TBI) cases can be challenging to litigate. However, new methods for assessing TBI and establishing its long-term impact, along with testimony from the right experts, can improve case outcomes.

Traumatic Brain Injury Litigation: New Ways to Navigate TBI Cases Using Expert Witnesses

BySeth Mills, J.D.


Updated on March 15, 2023

Traumatic Brain Injury Litigation: New Ways to Navigate TBI Cases Using Expert Witnesses

Over 2.5 million people in the United States suffer a traumatic brain injury (TBI) every year. TBI is a leading cause of death and disability among people ages 1 to 44. Common causes include falls, motor vehicle accidents, sports, and firearms. Medical understanding of TBI has evolved over the past two decades, and the rate of TBI has grown. Proving or challenging TBI in personal injury or disability litigation relies heavily on the use of experts.

What Is TBI?

A traumatic brain injury is defined as a bump, blow, or jolt to the head or a penetrating injury that disrupts the normal function of the brain. The most severe TBI will result in death, but even mild TBI (mTBI) may lead to long-term disability. At least 10 – 20% of those affected report symptoms a year after mTBI, including headaches, sensory sensitivities (light, noise), cognitive deficiencies, grogginess, and behavior changes.

How Is TBI Assessed?

People presenting with head injuries are assessed on the Glasgow coma scale (GCS). An unconscious patient who cannot open their eyes, speak, or move in response to cues receives a 3 on the GCS. A score of <9 is considered severe TBI, 9 – 12 is considered moderate, and 13 – 15 is a mild TBI (mTBI). Someone who can blink, speak, and move voluntarily may still have an mTBI.

This makes damages and disability related to mTBI more challenging to prove in litigation. The unconscious patient brought in after a fall will receive a TBI-related diagnosis such as concussion. A person who walks in and can answer questions following a mild sports injury may not. In one study, 56% of mTBI received no TBI-related diagnosis in the ER.

Traditional imaging tests for TBI include Computed Tomography (CT or CAT) scans and Magnetic Resonance Imaging (MRI). These tests are able to show fractures, hemorrhages, swelling, and certain kinds of tissue damage. They cannot detect more subtle damage to the long thin nerve fibers of the brain called axons. In TBI, these axons strain and tear. This axonal damage is a feature of mTBI that may not show up in traditional imaging.

Diffusion Tensor Imaging (DTI) uses a type of magnetic resonance to visualize these axons or white matter. This makes it a valuable tool in proving TBI. Although DTI is a newer technology than MRI, defense counsel should not challenge the credibility of DTI scans. They should question the specific conclusions drawn by the plaintiff’s DTI expert.

Since 2018, the FDA has permitted the use of a blood plasma test to determine the severity of TBI and determine the necessity of further imaging. This test must be conducted on the day of the injury.

Neurological or neuropsychological tests are a useful tool for establishing or challenging the long-term impacts of mTBI. These tests can include examination of the cranial nerve, motor and tendon reflexes, gait and balance tests, memory and attention tests, and mental health evaluations. However, even standardized neuropsychological testing has subjective components. Neuropsychologists are usually unable to read neuroradiology images, which can undermine their credibility on cognition.

What Experts Are Used in TBI Litigation?

Choosing experts to consult or testify is case-specific. Biomechanical engineers and traffic or accident reconstructionists may be used to demonstrate how the injury occurred. Medical experts may specialize in neuroradiology, neuropsychology, neurology, blood analysis, neuro-ophthalmology, optometry, or audiology, depending on the plaintiff’s particular symptoms. Functional capacity evaluators, life care planners, and vocational rehabilitation specialists can testify to the plaintiff’s loss of capacity and long-term care needs.

What Criteria Should Plaintiffs’ Attorneys Use When Choosing Experts?

Plaintiff attorneys want to paint a vivid picture of the plaintiff’s life before and after the TBI and should screen for experts who can tell a story with medical evidence. Plaintiffs experts should have excellent credentials, experience with the type of TBI in the case, and be able to communicate effectively without jargon.

For plaintiffs’ counsel, cost is also a factor. Attorneys should identify which type of experts are needed at different points in the case in order to choose experts strategically.

Consistency is critical as the defense will use any inconsistency in the plaintiff’s or expert’s testimony to discredit the witness. For this reason, it is not always advisable to depose the expert before a case. This consideration should be a part of the overall case strategy.

What Criteria Should Defense Attorneys Use When Choosing Experts?

Defense counsel must also be well-credentialed, with research experience or skill in clinical practice. The plaintiffs’ counsel may suggest bias if the expert’s primary source of income comes from consulting for defense counsel. Experts should also have a friendly and cooperative demeanor.

In their testimony, defense experts should focus on the plaintiff’s symptoms in the first 72 hours after the injury. The defense should ask questions about the plaintiff’s responses in the ER, drawing attention to instances in which the plaintiff was awake and answering questions coherently. They should also highlight any pre-injury symptoms exhibited by the plaintiff. For example, if the plaintiff reported headaches or photosensitivity prior to the accident.

Causation Standards for TBI

Preparing experts to show evidence supporting legal standards for causation can be challenging. First, work with the expert to marshal the objective medical evidence: the GCS, post-traumatic amnesia (PTA) assessment and other assessments, CT, MRI, or DTI images, and clinical notes describing the plaintiff’s behavior. Use this evidence to show causality by addressing each of the three factors described inEtherton v. Owner Ins. Co. The Etherton factors for establishing causation are plausibility, temporality, and lack of a more likely alternative explanation for the symptoms.

Demonstrating causation can be particularly challenging with repetitive head injuries, such as those suffered by athletes, as the cumulative damage may be more significant than what any single mTBI might cause.

Key Takeaways

Traumatic brain injury cases are challenging to litigate, and working with the right experts is critical. Effective screening, strategic utilization, and well-researched direct and cross-examination is necessary to achieve the best outcome in the case.

About the author

Seth Mills, J.D.

Seth Mills, J.D.

Seth Mills, J.D., a career counselor at New York Law School, has a substantial background in legal education and public interest initiatives. Currently serving as the Director of Public Interest & Pro Bono Initiatives and an Adjunct Professor for the Law Office Externship Seminar at New York Law School, Seth focuses on guiding law students in their professional development and legal externship experiences.

Prior to these roles, Seth was a Legal Content Writer for the Expert Institute, contributing to the development and curation of legal content. At, Seth held multiple positions, including Senior Program Attorney and Managing Blog Editor, where he was responsible for creating legal educational materials and managing legal publications.

Seth's legal career began as an Associate Attorney at Sterling Analytics Group, providing a foundation in practical legal work. Additionally, Seth volunteered as a Policy Advocate with the Police Reform Organizing Project (PROP), demonstrating a commitment to public interest law.

In terms of education, Seth earned a J.D. cum laude from New York Law School, where they were involved in NYLS OUTlaws and the Criminal Law Society. Seth also holds a Bachelor of Arts in Linguistics from Bard College at Simon's Rock. Their educational and professional experiences reflect a deep commitment to legal education, public interest law, and the mentoring of future legal professionals.

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