CDC Report: Unusual Amnesia Cases May Be Caused By Opioid Use

By Victoria Kim 02/06/17

Massachusetts health officials have identified a total of 14 cases so far.

Woman scratching her head.

When a cluster of unusual amnesia cases emerged in Massachusetts over the last few years, doctors were confounded—the majority of the patients who developed sudden-onset amnesia had a history of opioid use disorder. After a little more digging, more of the same type of cases were discovered in the Bay State.

Now, the cases have been reported in the latest (Jan. 27) issue of the Morbidity and Mortality Weekly Report by the Centers for Disease Control and Prevention (CDC). Will more cases emerge?

The potential link between amnesia and opioid use was first reported by Dr. Jed Barash, a neurologist at Lahey Hospital & Medical Center in Burlington, Massachusetts. Barash presented four cases to the Massachusetts Department of Public Health in 2015; three of the patients with amnesia tested positive for opioids (heroin or prescription painkillers) while the fourth patient had a history of heroin use.

An MRI scan revealed that there was little to no blood flowing to the left and right hippocampi of the brain, damaging the brain’s hippocampus neurons and impeding new memory formation.

After Barash reported the pattern, 10 more cases were discovered in Massachusetts. The total of 14 cases in the state occurred between 2012 and 2016; the patients were aged 19 to 52 years old. Of the 13 patients who reported a history of substance use disorder, 12 had a history of opioid abuse. 

Eight of the 14 patients tested positive for opioids at the time, while two tested positive for cocaine and two tested positive for benzodiazepines. 

Doctors believe the emerging pattern is unusual, given the “relatively young patient age and extensive substance use” among the patients, according to the CDC report.

Nine of the patients were unconscious at the time they received medical attention. According to STAT News, they had overdosed. Five of them required help breathing through endotracheal intubation.

The doctors considered the possibility that respiratory depression during a drug overdose may be the cause of the patients’ amnesia—as less oxygen is able to reach the brain, potentially causing brain damage. 

An increasing number of medical professionals have reported hypoxic brain injury—the resulting damage of oxygen deprivation in the brain—in drug overdose survivors, according to a report by Canada’s Times Colonist in December.

However, some experts, like Alfred DeMaria Jr, an epidemiologist with the Massachusetts Department of Public Health who helped write the CDC report, suspect that there’s something more to the phenomenon—perhaps the effect of "new" synthetic drugs like fentanyl

“What we’re concerned about is maybe a contaminant or something else added to the drug might be triggering this,” DeMaria said. “Traditionally there’s no evidence that the drugs themselves can do this.”

“Considering 14 cases in four years, we’re worried we’re going to find more cases,” he added.

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Victoria is interested in anything that has to do with how mind-altering substances impact society. Find Victoria on LinkedIn or Tumblr