Neuropsychology Expert Witness is Qualified to Offer Opinions on Causation
Posted on February 28, 2025 by Expert Witness Profiler
On October 24, 2019, William Harrison Sims (Plaintiff) was driving his 2004 BMW 330Ci (the “Vehicle”) in Florida when another vehicle unexpectedly turned left in front of him, causing a minor accident. As a result of the collision, the Vehicle’s front driver-side airbag was signaled to deploy. However, the airbag inflator unexpectedly ruptured and shot metal shrapnel into Plaintiff’s face and body, leading to severe, permanent, and life-altering injuries.
Defendants, BMW of North America (“BMW NA”) and Bayerische Motoren Werke AG (“BMW AG”), procured and installed the airbag inflator during the process of designing, manufacturing, assembly, and producing the vehicle. Plaintiff filed a lawsuit against both Defendants, alleging strict liability and negligence for procuring and installing the defective airbag.
Plaintiff retained Gordon Horn, a highly credentialed neuropsychologist with considerable clinical experience.
Defendants contended that because Horn is neither a biomechanical engineer nor a biomechanical expert, he is not qualified to offer opinions about the causation of Plaintiff’s traumatic brain injury.
Neuropsychology Expert Witness
Gordon Horn, Ph.D. has been a clinical neuropsychologist since 1996. His education includes a PhD in clinical psychology, and internship and 2-year fellowship completion in neuropsychology and rehabilitation from Duke University, School of Medicine. He has extensive hospital experience beginning in 1989 with inpatient neurological rehabilitation.
Discussion by the Court
Defendants did not question Horn’s qualifications or expertise. Horn issued two expert reports.
First Report
In his first report, Horn documents copious medical records he reviewed as part of Plaintiff’s neuropsychological examination. The patient history
portion of Horn’s report is brief, as is the history obtained from Plaintiff’s
mother.
Next, Horn documents Plaintiff’s past medical, neurological, developmental, psychiatric, and surgical histories. Horn discusses results covering a range of neurological assessments and impairment ratings.
Horn summarized his clinical summary and impressions after subjecting Plaintiff to a comprehensive battery of tests and examinations. Horn’s findings outline the following neurocognitive impairments: Auditory and Visual Attention (mild impairment; moderate to severe with visual attention); Information Processing (processing mildly impaired, multitasking mildly impaired); Language (mildly impaired complex instruction following); Memory (verbal learning and memory for related words moderately impaired, contextual memory moderately impaired); Visual-perceptual (mild impairment overall, severe impairment with visual discrimination); and Executive functions (mild impairment with complex processing, judgment and reasoning). Horn diagnoses Plaintiff with Depression, Anxiety, and PTSD with pre-existing Attention Deficit Disorder and with exacerbation of cognitive and behavioral impulsivity.
Diagnostic impressions are diffuse traumatic brain injury; frontal lobe and executive function deficit; mild cognitive impairment of uncertain or unknown etiology; adjustment disorder with mixed anxiety and depressed mood; and attention-deficit hyperactivity disorder.
Second Report
Horn issued a second expert report following his re-examination of Plaintiff and after two additional days of testing. Defendants did not appear to take issue with Horn’s methodology or findings outlined in the updated report. Horn’s neurological findings and the deficits attributed to Plaintiff remain unchanged in the 2024 updated report. Defendants filed a motion to exclude “injury causation” testimony of Horn. They did not challenge his neuropsychological testing or the results of those tests.
Defendants’ Objection to Causation Testimony
As for defense counsel’s contention that a neuropsychologist is not qualified to offer opinions on causation, the Court observed that Horn reviewed medical records replete with evidence that Plaintiff was injured by shrapnel from his airbag. Horn noted in his conclusions that the results of the examination were consistent with his injuries noted from the medical notations. The battery of examinations conducted by Horn cause him to opine that Plaintiff’s “neurocognitive profile shows deficits consistent with frontal lobe injury associated with the trauma.”
Defendants also argued that Horn is not qualified to opine that a zygomatic fracture was caused by shrapnel from the admittedly defective inflator because he did not adequately support his opinion that zygomatic fractures result in a 5–10% probability of TBI.
According to the Court, Horn’s opinion that Plaintiff’s frontal lobe injury was caused by trauma is supported by the neurocognitive examination administered by Horn. Horn did not opine that the shrapnel caused the zygomatic fractures documented on the CT scan. Defendants appeared to connect that dot by themselves.
As for the Defendants’ perfunctory argument that Horn’s testimony is cumulative because the Plaintiff has retained a biomechanical engineer and a neurologist, the Court held that Horn is skilled in evaluating and measuring cognitive impairment and in quantifying the damage caused, unlike these experts. Simply put, Horn’s testimony is not cumulative. It forms part of the concentric circles of proof.
Held
The Court denied the Defendants’ motion to preclude injury causation testimony of Gordon Horn.
Key Takeaway:
A neuropsychologist skilled in assessing cognitive impairment secondary to trauma—that is, traumatic brain injury—is qualified to render an opinion that the brain injury was caused by trauma. Moreover, Plaintiff’s personal history—which doctors routinely consider as a part of their evaluation—is not the basis of Horn’s findings.
Rather, the medical records and extensive testing from which Horn identifies Plaintiff’s cognitive impairments and limitations support his opinion.
Please refer to the blogs previously published about this case:
Accident Reconstruction Expert Witness’ Testimony Admitted Despite His Failure to Calculate G-Force
Neurology Expert Witness’ Injury Causation Testimony Admitted
Case Details:
| Case Caption: | Sims V. Bmw Of North America LLC |
| Docket Number: | 6:22cv1685 |
| Court: | United States District Court, Florida Middle |
| Order Date: | February 27, 2025 |
