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Recent ‘Frye’ ‘Gatekeeping’ Rulings

November 22, 2019 in  News

Last month’s column, “Recent Expert Reliability Rulings,” NYLJ (Oct. 15, 2019), focused on a number of federal “gatekeeping” decisions under Daubert and Federal Evidence Rule 702. In this column, the focus shifts from the federal reliability test to the Frye and Parker (7 N.Y.3d 434 (2006)) expert reliability tests applied in the New York state courts. A July 30 trial court decision seems to teach valuable lessons for lawyers as it wrestles on how to decide an exquisite battle of expert opinions by well-qualified neurologists. Litigators may well take sides on this interesting one.


Guillain-Barré Syndrome (GBS) is a neurological disorder in which the body’s immune system attacks part of the peripheral nervous system. The onset can be quite sudden and unexpected. The disorder can develop over a few days or may take up to several weeks. By the third week, 90 percent of all patients are at the weakest point in their illness. GBS afflicts about one person in 100,000. Men and women can be affected equally.

It’s not clear why some people get GBS. What is known is that the body’s immune system begins to attack the body itself and starts to destroy the myelin sheath that surrounds the axons of many nerve cells, and sometimes the axons themselves. When this occurs, the nerves cannot send signals efficiently, the muscles lose ability to respond to commands of the brain, and the brain receives fewer sensory signals from the rest of the body. The symptoms may increase in severity until the disorder is considered a medical emergency during which: muscles cannot be used; the patient becomes nearly paralyzed; it may become difficult to breathe; blood pressure and heart rate are affected. Although symptoms can be life-threatening, partial recovery is possible from even the most severe cases. However, weakness may still be present. See Columbia University Department of Neurology, “Guillain-Barré Syndrome”; see also Johns Hopkins Medicine, “Guillain-Barré Syndrome.”

GBS is called a “syndrome” rather than a disease because it is not clear that a specific disease-causing agent is involved. A syndrome is a medical condition marked by a collection of symptoms (what the patient feels) and signs (what a doctor can observe or measure). Occasionally, it might be difficult to diagnose GBS in its earliest stages. GBS can occur after a viral infection, surgery, trauma or a reaction to an immunization. Despite these time-related, associative events, it is not known why GBS strikes some people. Currently, there is no known cure. The goal of treatment is to prevent breathing problems, relieve symptoms, suppress the immune system and/or reduce inflammation. Various therapies are used. Ibid.

Why is the foregoing pertinent to a Law Journal article? Because the GBS, for all its known symptoms and treatment therapies, is a phenomenon that is shrouded within some mysteries and beclouded by medical causation issues. Thus, when associative injuries occur in and around or because of allegedly tortious conduct, followed by GBS symptoms, the patient or family affected may sue the defendant for causing the GBS in addition to a lesser injury.

Increased Exposure?

For example, let’s say a person in a minor car accident sustains modest to moderate bruises or other trauma to muscles, ligaments, spine or brain. The original “insult” to the victim’s body may amount to a low-exposure injury or one that is not seriously disabling. Following several weeks, however, the putative plaintiff now develops GBS with near paralysis and residual post-treatment consequences. The mysterious GBS now explodes the “low exposure” nature of any lawsuit into a high-exposure case of major magnitude. Liability-wise, do the plaintiff and tort-defendant go from a mere bumps-and-bruises case to a severe neurological syndrome that makes the plaintiff’s immune system go haywire?

Or, let’s say a person has a slip-and-fall accident or trips on an obstacle located on defendant’s premises. The mishap causes cuts, bruises and soreness. Yet, in some three weeks, the victim is now in a hospital struggling to breathe, suffering pain and paralysis, getting a spinal tap, electrodiagnostic tests, removal of plasma (the liquid part of the blood), and undergoing other invasive therapies. Has defendant gone from a low-value lawsuit exposure to a shocking one? But, if yes, should that happen when science doesn’t really know the cause of GBS? How will plaintiff prove that a slip-and-fall with minor injuries caused a catastrophic GBS onset? Can the defendant in such a case urge that there is legally insufficient causation proof?

A scenario akin to the foregoing actually occurred in Supreme Court, Tompkins County, before Justice Joseph A. McBride, who issued a pivotal Decision and Order in the case on July 30. As yet unreported, the case is Murray v. Cayuga Medical Center at Ithaca, No. 2015-0855 (Sup. Ct. Tompkins Co. July 20, 2019) (Justice McBride). The tempest between the parties involved a judicial gatekeeping challenge to plaintiff expert testimony under the Frye “general acceptance” test. A battle between well-qualified neurological specialists ensued about GBS-causation.

Murray, an emergency room physician at the defendant hospital, fell at a drainage inlet outside the emergency room entrance and suffered a quadriceps muscle tear. He was prescribed to undergo physical therapy. Three weeks later, at his first therapy session, he had symptoms of numbness, muscle spasms and pain. The symptoms increased over the next month and additional symptoms appeared including increased, unexplained falls. He was admitted for a hospital stay and eventually diagnosed with GBS. Six months later, Dr. Murray and his wife sued for recovery under the theory of premises liability.

After years of discovery and preparation for trial, plaintiffs provided expert disclosure opining that Murray’s GBS diagnosis was caused by the muscle tear from the fall. Defendant hospital filed a motion in limine to preclude plaintiffs’ expert opinions on the ground they were not founded on theories generally accepted in the relevant scientific community. Plaintiffs opposed the motion stating that, while the result may be novel, the methodology that led to the theory is based on established scientific theory generally accepted in the relevant scientific community.

Experts’ Battle

The motion papers established the battle lines. Thus, plaintiffs’ expert alleged that Murray’s leg injury resulted in a traumatically induced variant of GBS. The hospital experts, on the other hand, alleged there is no scientific basis for the theory that a muscle tear could cause GBS, which is most often causally linked to bacterial infections. To resolve this conflict, Justice McBride conducted a Frye Hearing where he heard relevant testimony and accepted relevant exhibits as evidence.

Plaintiff’s expert, Dr. Steven Herskovitz, a professor of neurology at the Montefiore Medical Center, co-authored a book on neuropathy with a chapter specifically devoted to GBS. He reviewed plaintiffs’ medical records and reviewed several retrospective and prospective case studies on the subject. He explained that plaintiff suffered from the “acute inflammatory demyelinating polyneuropathy (AIDP) version of GBS which is premised in molecular mimicry.” Thus, a trigger (e.g., an infection) mistakes the patient’s molecules as invaders and inadvertently causes them to attack their own cells — “most akin to an autoimmune disease of the peripheral nerves. This response occurs in individuals that are both genetically predisposed and that have experienced an environmental trigger.” Murray, Slip Op. at p. 3.

Infections are known triggers for this molecular mimicry. But there was no evidence in plaintiff’s medical records of an infection. 50 years of case study research, said Dr. Herskovitz, led the scientific community to believe that surgical trauma can be a trigger when there is an antigen release that takes the form of the molecular mimicry in the AIDP form of GBS. The expert then explained that “it then follows” that regardless if it is surgical “cut” trauma or non-surgical “tear” trauma, the tissue trauma causes the immune system to release cells to clean up the debris, prompting the genetically predisposed patient’s immune system to attack the newly exposed nerve fibers. The expert opined with “a reasonable degree of medical certainty” that muscle tear trauma, much like surgical trauma, can trigger GBS and, “more likely than not,” plaintiff’s GBS was triggered by the quadriceps muscle tear. Murray, Slip Op. at p. 4.

The defendant hospital presented Dr. Scelsa, a professor of neurology at Mount Sinai, who gave a differing opinion as to the cause of Murray’s GBS. The expert explained there must be an antecedent event that triggers GBS. The most common is infections, followed “very rarely” by surgical trauma. He disagreed with the quality of the sources on which Herskovitz based his opinion. There was only a “tiny increased risk” of GBS after surgical trauma. He further explained that surgical trauma is not the same as non-surgical trauma in that “a cut and a tear are very different.”

In surgery the “premeditated stress” alters the immune system and that is the reason for the causal link in those cases. But “there are no large epidemiological studies for the non-surgical trauma to verify a direct correlation.” The defense neurologist stated that the scientific community “does not recognize post traumatic GBS.” Though admitting non-surgical trauma “could be possible”, a causal link conclusion with any degree of certainty is not justified because there is no scientific data to conclude it is a trigger of GBS. Murray, Slip Op, pp. 4 -5.

‘Frye’ Analysis

What should a court do with this kind of a stand-off? Justice McBride reviewed the Frye “general acceptance” test as explained in several Appellate Division decisions. He then cited the 2006 Parker decision by the Court of Appeals calling for a determination of the theory’s reliability where “the [science] from which the deduction is made must be sufficiently established to have general acceptance in the particular field in which it belongs.” These guidelines led the court to conclude that Dr. Herskovitz’ opinion “will be allowed at trial.” Three reasons for that expert’s opinion were deemed persuasive in favor of admissibility.

First, there was the “temporal relationship” between the injury and the GBS in the biological time frame. Second, there was “a lack of a presence of other triggers in the time frame.” And, finally, the expert prescribed a “sound biological explanation that trauma causes the autoimmune response antigen release theory.” The court found that there was a “reliable and logical foundation” following “scientific extrapolation” from a generally accepted principle as testified by Dr. Herskovitz. “General acceptance,” said the court, does not mean that a majority of scientists come to the same conclusion. Rather, the proper inquiry is whether the opinion is “properly founded on generally accepted methodology, rather than whether the causal theory is generally accepted in the relevant scientific community.”

Said the court: The expert explained that it is well-founded and generally accepted that the AIDP form of GBS is caused by the antigen release theory demonstrated by molecular memory usually found in infection. Then the expert explained that surgical trauma has shown the same autoimmune response markers. It then “follows logically” that non-surgical tear trauma, will trigger the same autoimmune response as the surgical trauma patient, even absent infections. Thus, concluded the court, the expert “established a foundation” for receipt of the evidence at trial. Murray, Slip Op at p. 5.

There’s little question that the foregoing determination is on the permissive side of Frye analysis. The expert basically said GBS is triggered by infections. The same autoimmune response sometimes occurs in surgical traumas. Therefore, it’s “logical” to conclude that non-surgical tear trauma also can cause GBS. And, thus, plaintiff’s GBS was caused by the trauma linked to the fall. The defense expert said there’s no scientifically valid studies permitting that conclusory leap. Should the case go to a jury trial, the jury will be left to gauge what science supports and what it doesn’t.

Other approaches to Frye analysis are less permissive and look to “general acceptance” as a search for a kind of scientific consensus. For contrast, readers can study New York County Supreme Court Justice Mark Dwyer’s copious recent opinion in People v. Thompson, 2019 N.Y. Misc. LEXIS 5162 (Sup. Ct. N.Y. Co. Sept. 25, 2019). The question there was whether a form of DNA evidence called “Forensic Statistical Tool” (FST) used by the Office of the Chief Medical Examiner was reliable enough under Frye to permit its use by the prosecution. In 2015, after a Frye hearing, Justice Dwyer ruled that the FST analysis should be excluded under Frye. That conclusion was upheld in 2017.

Since then, Justice Dwyer has followed developments on FST. Among the several reasons he issued his new opinion is that his views “may in the future influence other trial judges considering how to decide Frye issues about forensic science that are unrelated to the FST.” People v. Thompson, LEXIS at *4. Thus, Justice Dwyer’s Frye analysis will not only be informative to other trial judges, but also to litigators fighting gatekeeping battles. We don’t have space here to discuss the decision but readers will note an approach to Frye that differs from that of the Murray decision discussed above.

One reason for our focus here on the Murray decision is to inform lawyers pursuing gatekeeping challenges that Frye motions and hearings deserve dedicated, strategic planning, preparation and highly qualified, articulate experts. The variance in judicial approaches to implementing the Frye test is itself a challenge for litigators. There’s quite some homework to be done.