In the May 23, 2013 issue of Brain Injury, David E. Ross, et al. submitted a Letter to the Editor entitled “Brain MRI volumetry in a single patient with mild traumatic brain injury.” The report described the case of a 42 year old man who was in a motor vehicle accident in May 2008, leading to a mild traumatic brain injury and other injuries. His MRI brain data were analyzed with Neuro Quant (a FDA‑approved computer‑automated method for measuring MRI brain volume) and susceptibility‑weighted imaging (SWI) to assess for signs of old bleeding. A volumetric cross‑sectional (one point in time) analysis showed no brain atrophy, consistent with initial CT and MRI scans of the brain. Volumetric longitudinal (2 points in time) analysis show progressive atrophy in several brain regions. Dr. Ross reports that the case demonstrated that in a single patient the principle discovered in multiple previous group studies, namely that longitudinal design is more powerful than the cross‑sectional design for finding atrophy in patients with traumatic brain injury.
The United States District Court for the Northern District of Illinois-Eastern Division denied defendants’ Rule 702 Daubert motion to strike the testimony of David Gibson, president of Vocational Economics, Inc. The case is Rossi v. Groft, Case No.10 C 50240 (U.S.D.C. ND April 16, 2013).
This case arose out of an incident in which plaintiff, a bank loan officer, sustained serious injuries. Prior to the accident, plaintiff had never made more than $10,000 per year. Plaintiff was 27 years old and had completed two semesters of college at the time of the incident. Plaintiff testified at his deposition that he had not applied for any jobs since the accident because the income he could earn with his limitations would be equivalent to paying child care, and he was looking to re-enter a physical rehabilitation program. At the time of the incident, plaintiff was in the process of applying for a position at the Cook County Sheriff’s Office as a deputy sheriff.
Plaintiff retained expert vocational economist David Gibson to opine as to plaintiff’s loss of earning capacity due to his injuries. Mr. Gibson opined that plaintiff had a loss in lifetime earning capacity in the range of $957,000.
To reach that conclusion, Mr. Gibson compared plaintiff’s pre-injury earning capacity and work life expectancy with his post injury earning capacity and work life expectancy using data from the U.S. Census Bureau’s American Community Survey. Mr. Gibson used a “proxy” upon which he based both his pre and post injury earning opinions.
Defendants moved to bar Mr. Gibson from testifying under Fed. R. Evid. 702. Defendants did not challenge Mr. Gibson’s credentials. The Court found it noteworthy that Mr. Gibson and his colleagues at Vocational Economics had been permitted by Court to testify as experts using work life expectancy tables to determine diminished earning capacity. See Goesel v. Boley Intl. (H.K) Ltd., No. 09 C 4595 2012 WL 5306284 @ *1-2 (N.D. Ill. October 26, 2012); and Thakore v. Universal Mach. Co. of Pottstown, Inc., 670 F. Supp. 2nd 705, 729‑31 (N.D. Ill. 2009). Rather, defendants argued that Mr. Gibson’s use of average age earning progression of the median male with Rossi’s educational level “utilizes certain generalities clearly contradictory to the facts proffered in this case.” Specifically, defendants complained that Mr. Gibson had failed to consider plaintiff’s earning history, his slim prospects of employment with the Cook County Sheriff’s Office, and plaintiff’s home life. Defendants further urged the Court to bar Mr. Gibson asserting that Gibson’s use of “median person” to assess plaintiff’s earning capacity because plaintiff’s income before the accident was substantially below what Mr. Gibson’s chart showed what would be expected of the median person.
The court reviewed Mr. Gibson’s report which laid out why he believed that the median person he hypothesized was a reasonable proxy for plaintiff. In his report, Mr. Gibson explained, “younger workers rarely have earnings that reasonably represent an average life time earning capacity.”
Defendants also attacked Mr. Gibson’s consideration of plaintiff’s application to the sheriff’s office, and provided the court with an affidavit from the deputy director of the Cook County Sheriff’s Office Merit Board showing that plaintiff may not have been hired by the sheriff’s office because of plaintiff’s prior arrest and history of drug use. Mr. Gibson testified, however, that he did premise his analysis on whether plaintiff would have been hired by the sheriff’s office finding that plaintiff’s application supported Mr. Gibson’s belief that plaintiff would have been actively employed or actively seeking employment similar in nature.
The court found that Mr. Gibson’s opinions were based on sufficient facts and data to be admissible provided that plaintiff presented evidence that his earning capacity has been impaired by the injury. Accordingly, defendants’ motion to strike Mr. Gibson’s report and bar his testimony was denied.
Neuro law attorneys are very familiar with the meta-analytic review of neurological studies that was authored by Binder, Rohling and Larrabee (Binder 1997). It is a study that is often cited by defense attorneys to support the myth that recovery after mild traumatic brain injury (mTBI) occurs within the first three months, with any subsequent changes in performance being of limited statistical and clinical significance. Binder, et al. found only a small overall effect size and concluded that the size of the overall effect was unimpressive and suggestive of clinical non-significance. That study was later updated by Frencham, Fox and Maybery (Frencham 2005). These meta-analyses are sometimes cited as evidence that mTBI has no lasting effect on neuropsychological status.
In 2009, Pertab JL, James KM and Bigler ED (Pertab 2009) conducted a study designed to clarify opposing conclusions in the mTBI literature by re-analyzing meta-analytic data sets. The study was conducted as there had not been, “A critical review of meta-analytic techniques in mTBI to help clarify discrepancies and conclusions that are drawn from the literature” (Pertab 2009). “Since Binder (1997), there had been a large volume of research published in the literature showing that a sub-set of those who sustained mTBI have long-term significant problems.” (Pertab 2009). Pertab “revisited the data combined in the meta-analysis of Binder and Frencham, specifically addressing four areas: (1) mechanism of injury, (2) diagnostic criteria employed, (3) type of neuropsychological assessment tool employed, and (4) whether symptomatic or non-symptomatic mTBI subjects were assessed separately.” Pertab concluded, after re-analyzing the data, “By using different mTBI characteristics as inclusion/exclusion criteria to re-examine the existing meta-analyses, the current results indicated significant statistical heterogeneity (a) the effect sizes of neuropsychological measures employed in the post-acute phase and marked qualitative heterogeneity in (b) the criteria used to define mTBI and mTBI severity, and (c) the populations and mechanisms of injury from which the mTBI samples were selected.”
As indicated in the introduction, we are not disputing the overall conclusions in mTBI meta-analyses where it appears that the majority of individuals who sustain an mTBI suffer no significant neuropsychological residue after three months. In fact, the largest effect size in this re-characterization was moderate, with most being small to trivial. It is well known and widely understood that group inferential statistics can obscure important individual differences.
As indicated in the introduction, the Binder, et al. and Frencham, et al. studies have been cited to support the non-effect of any lasting sequelae of mTBI as a general principal for the outcome of all mTBI’s. From the total group standpoint, that likely remains a true statement, but not one that necessarily applies to an individual within that sample.
If small sub-samples of clinically symptomatic mTBI patients do exist within a broader sample of non-symptomatic subjects where the mechanism of injury differs between studies or the methods of assessment differ, etc., the averaging process of meta-analysis is likely to obscure, rather than highlight, clinically relevant features of any minority sample within an mTBI group that may have residual symptoms and/or deficits.
Following the publication of Pertab (2009), Binder, Rohling and Larrabee updated their meta-analysis to include studies through 2002, observing similar results to Binder, et al. (1997). Rohling, et al. (2011) have now critiqued the methods used by Pertab (2009) and performed even more meta-analytic comparisons on the original twenty-five studies, again concluding that there were no lasting cognitive effects of mTBI.
Now, Bigler (2013) and his colleagues have again reviewed Binder (1997), Frencham (2005) and Rohling (2011). In their new paper, Bigler responds to the Rohling (2011) critique, reaffirming the original findings of Pertab (2009), and providing additional details concerning the flaws in prior meta-analytic mTBI studies and the effects on neuropsychological studies. “Reaffirmed Limitations of Meta-Analytic Methods in the Study of mTBI: A Response to Rohling, et al.”, Bigler ED, Farrer TJ, Pertab JL, Kelly JM, Petrie JA and Hedges DW, The Clinical Neuropsychologists (2013).
Bigler (2013) again acknowledges that:
The majority of mTBI patients over time enjoy a full functional return to their pre-injury baseline and their recovery follows a quick and rather benign course. However, some mTBI patients do experience persisting neuro cognitive and neural behavioral deficits and symptoms, even after controlling for such factors as depression and potential response bias.
Bigler (2013) responds further:
While such a statement may apply to the majority of mTBI participants who experience a positive outcome, this perspective does not match contemporary animal-model neuropathological investigations and human neuroimaging and neuropathological studies of mTBI which do indicate that permanent changes may occur after mTBI.
A major point of Pertab (2009) was that meta-analytic technique as applied to group data will not detect embedded impaired performance by the few, because it becomes averaged and therefore hidden within the overall group mean.
The Rohling (2011) critique strongly disagrees with the idea that embedded effects may go undetected in a meta-analysis and in fact cite literature demonstrating, … in some cases, low-powered individual studies of various medical topics have failed to show differences, while meta-analytic studies of the same topics have revealed significant results.
Bigler (2013) also addresses some important issues in the field of mTBI. Discussing the sensitivity or lack of sensitivity of neuropsychological measures to persistent effects of mTBI, Bigler (2013) notes, “Regardless of the type of neurologic and/or psychiatric disorder, neuropsychological assessment faces its biggest challenge in detecting subtle impairment,” citing B. Johnson, et al. (2011).“An fMRI investigation showing persistent deficits in the brain’s default network in athletes with mTBI, explicitly state that: ‘Neuropsychological testing and conventional neuroimaging techniques are not sufficiently sensitive to detect’ neurological changes.”
On this point, Bigler (2013) includes:
All of this suggests that traditional neuropsychological techniques, including those used in the twenty-five source studies for meta-analyses discussed herein have inherent sensitivity problems after the acute recovery time period; issues of sensitivity not discussed by Rohling, et al. in offering their conclusions. If the traditional neuropsychological measure is insensitive after the acute time frame, what should be used? The answer is likely to be found in the integration of functional neuroimaging with cognitive processing speed tasks that measure performance in milliseconds, a more direct representation of brain processing speed.
Bigler (2013) also criticizes Rohling’s failure to separate mTBI from complicated mTBI cases. Bigler (2013) finds:
Rohling and co-authors state that their conclusions were not necessarily applied to those with complicated mTBI. Is that conclusion not being made because in mild-complicated TBI there is objective indication (i.e., a bio-marker?) of neuro injury (see Green, Koshimori and Turner, 2010) and that mild-complicated TBI participants have been shown and even classified by some as having sustained a moderate TBI? As already stated, the distinction of whether mild-complicated TBI was present or not was not uniformly addressed whatsoever in the twenty-five source studies. In regards to technology, CT imaging – which was the basis for mild-complicated TBI classification for essentially all studies prior to the early 1990’s – is the least sensitive of the imaging technologies for detecting hemorrhage which is a typical marker for the mild-complicated TBI distinction. … Because current-day technology did not exist during any of the twenty-five source studies used to perform the meta-analyses, the issue of objective indications of neuro injury simply cannot be addressed, including the mild-complicated issue.
Rohling, et al.’s conclusions assume that neuropsychological measures represent the best approach for detecting impairment. However, as shown above, neuropsychological methods may simply be ineffective (i.e., lack of proper sensitivity) in detecting the subtleties of any type of residual impairment following mTBI from the sub-acute to chronic phase.
With regard to their initial evaluation of the twenty five source studies, Bigler (2013) write:
Given everything discussed to this point, the real mistake of Pertab et al. (2009) was that even after they demonstrated the various assumption violations and listed all of the limits of the Binder et al. (1997) and Frencham et al. (2005) meta-analyses, they went ahead and used some of the same studies in their metaanalysis. In fact Pertab et al. should have stopped and offered no additional analyses of the 25 mTBI articles because of the study quality issues and assumption violations. The real message of Pertab et al. is that past mTBI studies are problematic for all the reasons discussed herein, and if meta-analysis is to be used to address the mTBI problem, the highest quality of research and clinical standards need to be used.
Bigler (2013) concludes:
In conclusion, we show methodological violations, all of which were originally identified in Pertab (2009) that limit Rohling (2011) critique where their findings merely perpetuate type-II statistical errors. As already stated, it is an untenable and non-supportable position that neuron-based symptoms and deficits do not persist in some individuals who experience mTBI. (Citations omitted). Current neuroimaging and neuropathological findings indicate that mTBI results in permanent structural and physiological injury to the brain in some individuals. As such, neuropsychology’s goal should be to refine its methods, including its interface across disciplines to detect those individuals who have experienced an mTBI and in whom brain dysfunction and its symptoms persist, not to continue arguing that permanent deficits do not occur from mTBI.*
* It should be noted that Larrabee (2013) published a rebuttal to Bigler (2013) in an article entitled “Meta-Analytic Methods and the Importance of Non-TBI Factors Related to Outcome in Mild Traumatic Brain Injury: Response to Bigler, et al. (2013), Larrabee GJ, Binder LM, Rohling ML and Ploetz DM, The Clinical Neuropsychologist (2013).
The February 2013 issue of Archives of Clinical Neuropsychology included an interesting article out of Cape Town, South Africa, wherein researchers from the University of Cape Town examined the extent to which, during the process of litigation, individuals with moderate-to-severe traumatic brain injury might malinger in their performance on neuropsychological assessment batteries. The study was designed to explore whether financial settlement influenced neuropsychological test performances and activities of daily living. Thirty-one individuals out of an original group of 235 potential participants were utilized in this study. These thirty-one litigants were tested and interviewed both during litigation in one year or more after their case had settled.
According to the article, “results showed that neuropsychological test scores did not change from assessment during forensic proceedings to assessment after settlement. Although some improvement was evidenced in activities of daily living, the gains were small and their clinical significance questionable.” The authors concluded by finding that there was “no evidence that individuals with moderate-to-severe TBI, despite clear potential for secondary gain, malingered or delivered sub-optimal effort during neuropsychological evaluation taken place in the contest of litigation.” The study can be found at Archives of Clinical Neuropsychology 28 (2013) 38-51.
For many years now I have written about insurance companies influencing medical and neuropsychological research. For medical literature to be introduced and used at trial, it is necessary for an expert to testify that the article is the type relied upon by experts in the field or that the article is authoritative, depending on the law in an individual state. Thus, our Rules of Evidence in very large measure place a great deal of trust in the reliability of medical journals.
It was thus distressing to read in the November 24th issue of the Washington Post a story by Peter Whoriskey entitled “As Drug Industries’ Influence over Research Grows, so does the Potential for Bias.”
The article focused on seventy-three articles on original studies of new drugs published over a one year period in a New England Journal of Medicine. Of those articles, sixty were funded by the pharmaceutical company, fifty were co-written by drug company employees and thirty-seven had a lead author, typical an academic, who had previously accepted outside compensation from the sponsoring drug company in the form of consultant pay, grants or speaker fees.” The article quoted Marsha Angell, who retired as editor and chief of NEJM in 2000 who stated “that the research can be bias and that it can be difficult for medical journals to unmask the problems.” “I used to think that if studies were subject to rigorous peer review it would then be enough to simply disclose authors commercial ties. But, I know longer belief that is enough. It is too hard for anyone – editors, peer reviewers, readers – to tell whether that bias has affected the work.”
For trial attorneys, it is important when confronting an adversary’s use of medical literature to try and mine down to determine who funded the research and the biases that the article and research might contain.
In Chiulli v. Newberry Fine Dining, Inc., Civil Action Number 10-10488-JLT (U.S.D.C. MA. October 17, 2012), the Federal District Court denied defendant’s motion in limine to preclude plaintiff’s neuroimaging expert Randall Benson, M.D. from testifying and to preclude testimony with regard to diffusion tensor imaging.
Diffusion tensor imaging (DTI) has been shown to prove the existence of brain damage which other techniques, such as MRIs, CT scans and x-rays were unable to detect. DTI has the ability to show microscopic damage to the pathways, which messages use when traveling inside the brain.
For the past 10 years, the National Football League and the US military have been using DTI technologies to detect brain injuries, most commonly, concussions.
Although this technology could be critical in the diagnosing and treatment of brain injuries, some defense attorneys are challenging its validity. Several states currently allow this technology to be used in the courtroom, such as New York, Florida, Louisiana, Indiana, Minnesota, New Mexico and Massachusetts. However, the defense bar is not conceding the admissibility of DTI without a fight.
The argument is that even if an accident caused someone’s brain to change at a microscopic level in an area associated with memory the change may have nothing to do with why the person has become more forgetful. Before DTI, practitioners were limited to presenting the results of neuropsychological tests as evidence of mild traumatic brain injury. Although these neuropsychological tests are useful in prosecuting a brain injury case, the use of DTI technologies could greatly aid in future cases and the treatment of patients throughout the country.
Readers of my blog will recall that I often write about the use of a total offset when calculating future lost income. Too often, plaintiffs’ attorneys hire economic analysts who, in projecting future economic losses, net you a negative discount rate. This has the effect of reducing the overall projection of future lost income.
I have been arguing for a long time, that these economic analysts are doing a disservice to injured victims.
According to a story published by Bloomberg in early September, the yield on the 30-year treasury bond sank to a new low of 3.27%, while the 10-year note fell to 1.9%. If the inflation rate stays anywhere close to its current modest 3.6% pace, long term investors will be guaranteed to lose money after factoring in inflation’s toll.
This gives greater support why a net negative discount rate should not and must not be used.
Earlier this week, 75 retired players brought suit against the National Football League claiming that the NFL has known for the past 90 years of the harmful effects associated with football-related concussions and concealed this information from players, coaches and trainers. The suit states that the players relied upon the NFL for safety guidelines and regulations, and did not know the long-term effects associated with concussions. Riddell, Inc., the official helmet brand of the NFL for over 20 years, is also named as a defendant in the suit.
The former players accuse the NFL of engaging in "a scheme of fraud and deceit" by having members of the NFL’s Brain Injury Committee "deny knowledge of a link between concussion and cognitive decline and claim that more time was needed to reach a definitive conclusion on the issue."
The suit notes that in 1994, the NFL studied concussion research through the NFL’s Committee on Mild Traumatic Brain Injury and in 2004 published findings showed "no evidence of worsening injury or chronic cumulative effects" from multiple concussions. The committee also found that "many NFL players can be safely allowed to return to play" on the day of a concussion, if they are without symptoms and cleared by a doctor.
However, "it was not until June 2010 that the NFL acknowledged that concussions can lead to dementia, memory loss, CTE (chronic traumatic encephalopathy) and related symptoms by publishing (a) warning to every player and team," says the suit.