And with more survivors, Madras said in an email message, “there conceivably will be more cases of brain damage, especially in the very oxygen-sensitive hippocampus, the ‘epicenter’ of initial learning and memory.”
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After encountering more patients following that first one in 2012, Barash contacted the Massachusetts Department of Public Health in 2015, which put out a request to emergency-room physicians, neurologists, and radiologists statewide for information that might identify additional cases. By the end of 2016, a total of 14 people who matched the pattern had been identified. Then, in May of 2017, the DPH made what they called “an unusual amnestic syndrome” with “acute, bilateral hippocampal” damage a reportable disease syndrome—a status that requires any doctor who sees such a case to forward patients’ medical records for review.
As of today, however, DeMaria believes there is no such mechanism in place in other states, and that’s one of the barriers to getting a handle on the prevalence of the amnestic syndrome. Marc Haut, the neuropsychologist who examined the man from Virginia in 2015, and one of the authors on the new Annals paper, had no way of knowing about the investigation in Massachusetts and initially chalked up the damage to cocaine use. At the time, he saw no reason to consider opioids, in part because of the information the patient shared with him. “Patient reports about substance use [are] not always accurate for a couple of reasons, one being the patients themselves,” he says. “And the other being that patients often don’t know what they’re buying and using.”
So it was not until he received an email from Barash that Haut, the chair of the behavioral medicine and psychiatry department at West Virginia University, reconsidered whether opioids could have played a role. To date, only eight of the 16 patients reported in the cluster had cocaine in their system, making opioids a more consistent link than any other drug. Barash, who is also an author on the Annals paper, wonders if fentanyl—considered to be 50 times more potent than heroin—is a key component, in part because the timing and location of the appearance of these amnestic cases parallels the rise of fentanyl overdoses in two of the hardest hit regions in the country. Teasing this out is complicated with the ever-changing landscape of drugs that people are taking, often in combination. “Cocaine overdose deaths are escalating,” said Madras, “along with evidence of combined use of fentanyl, heroin, and cocaine in some deaths.”
And despite the fact that fentanyl abuse has become so common, routine toxicology screens don’t test for the presence of the drug. It was only because Haut had been tipped off that he requested the advanced toxicology screen for the 2017 patient, which found evidence that he had taken fentanyl in addition to cocaine. His MRI scan also revealed the signature hippocampal damage: “bright, big, and intense,” according to Haut.