Public health officials on Thursday said they had detected a bizarre cluster of cases in which patients in Massachusetts developed amnesia over the past few years — a highly unusual syndrome that could be connected to opioid use.
The officials have identified only 14 cases so far. But officials said it's possible that clinicians have simply missed other cases.
The patients were all relatively young — they ranged in age from 19 to 52. Thirteen of the 14 patients identified had a substance use disorder, and the 14th patient tested positive for opioids and cocaine on a toxicology screen.
"What we're concerned about is maybe a contaminant or something else added to the drug might be triggering this," said Dr. Alfred DeMaria, the state epidemiologist at the Massachusetts Department of Public Health and an author of the new report
. "Traditionally there's no evidence that the drugs themselves can do this
The pattern emerged when Dr. Jed Barash, a neurologist at Lahey Hospital and Medical Center in Burlington, Mass., reported four of the amnesia cases to the state's public health department. The department then sent out an alert to specialists, including neurologists and emergency physicians, asking about similar cases, ultimately identifying 10 more from 2012 to 2016 at hospitals in eastern Massachusetts. (The patients included one person who lived in New Hampshire and one person who was visiting Massachusetts from Washington state.)
The patients experienced various memory problems affecting both long- and short-term memory. Some of them arrived at hospitals following overdoses, but in other cases, family members brought in patients who became confused or stopped being able to recognize their relatives or recall basic facts. Some of the patients also struggled with disorientation, attention, and executive function.
In addition to showing the clinical symptoms of amnesia, brain imaging showed a significant reduction in blood flow to the hippocampus, a part of the brain involved in memory, learning, and emotion.
There are only a few case reports in the medical literature of a similar combination of clinical and imaging results, which were a result of cocaine use
, or carbon monoxide poisoning
. There was only one case
of blood being cut off to the hippocampus as a result of heroin use, from France in 2013.