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, influenza, 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. 
 
 DeMaria said officials are concerned that increased exposure to synthetic opioids like fentanyl and synthetic marijuana could be playing a role in the recently identified cases. Twelve of the patients had a history of opioid use, and many patients either had a history of using other drugs — including cocaine and benzodiazepines — or tested positive for them. 
 
 “The best thing that could happen is, well, no one else has seen this,” he said. But “considering 14 cases in four years, we’re worried we’re going to find more cases.” 
 
 The new report appeared in the Morbidity and Mortality Weekly Report, which is published by the Centers for Disease Control and Prevention. 
 
 The researchers did not have follow-up data on all the patients, but one 19-year-old man recovered his short-term memory within five months, while one 33-year-old woman still had moderate short-term memory loss more than a year later. One 22-year-old man still had attention and processing problems almost two years later. 
 
 DeMaria said he and his colleagues had considered whether the memory loss might be a consequence of an overdose, which depresses breathing and means less oxygen gets to the brain. But he said that even though clinicians saw some wider damage on the brain imaging, the effect was so focused in the hippocampus that something beyond an overdose was probably occurring. 
 
 But other researchers not involved with the report said they guessed the amnesia could still have been caused by an overdose. 
 
 “I don’t really know if there’s any other plausible explanation,” said Dr. Gary Franklin, a research professor at the University of Washington and fellow of the American Academy of Neurology. 
 
 Still, Franklin called the report both shocking for detailing how some people were dealing with memory issues years later and, at the same time, not all that surprising. Researchers are uncovering new ways opioid use can harm someone, and this finding might just be the latest addition. 
 
 Franklin also said the report suggested that it was worth assessing people who recover or are revived from an overdose for damage to their brains. 
 
 “This would prompt me to want to study that,” he said. 
 
 By publishing the case reports, officials said they hoped that more clinicians will be on the lookout for cases. 
 
 “That’s why we want to bring this to people’s attention,” DeMaria said. “Maybe this isn’t an outbreak of a new syndrome, but we won’t know that until people start looking at this more widely and start looking for this earlier in the presentation.” 
 
 This article is reproduced with permission from STAT. It was first published on Jan. 26, 2017. Find the original story here. ||||| A neurologist in Massachusetts noticed the pattern about a year ago. He had seen four patients come in with amnesia—three who tested positive for opioids (heroin or prescription painkillers) and a fourth with a history of heroin use. Memory loss from drug use is not unusual, but when he peered inside their brains with a MRI scan, he saw something really strange. 
 
 All four patients had the same problem: Little or no blood was flowing to their hippocampi, two slivers of tissue deep in brain, one on the left and one right, involved in memory. And the effect was symmetrical. Whatever had damaged the brains of these patients seemed to specifically attack the hippocampus neurons. With their hippocampi impaired, the patients couldn’t form new memories. This is not how opioids are supposed to work. Could this be a rare undiscovered effect from existing opioids or a new effect of a novel synthetic drug? 
 
 The neurologist, Jed Barash, then at Lahey Hospital and Medical Center, wrote up the four cases and reported them to the Massachusetts Department of Public Health. This prompted doctors in the state to dig through their patient records for more cases of amnesia with a history of opioid use. 
 
 “It was when he peered inside their brains with a MRI scan that he saw something really strange.” 
 
 Eventually, they found 10 more, bringing the total to 14 in the last several years in Massachusetts. Doctors were only able to follow up with MRIs in three of the cases; one patient’s hippocampi recovered to normal, but the other two others continued to have shrunken hippocampi. The results were published this week in the CDC’s Morbidity and Mortality Weekly Report. “We wanted to put it to wider attention,” says Alfred DeMaria, Jr., an epidemiologist with the Massachusetts Department of Public Health. He hopes that more doctors will look out for the phenomenon, so they can get to the bottom of it. 
 
 The pattern of blood flow is confounding other brain experts, too. “I don’t think anybody really knows how the vasculature can lead to reduced blood flow in the hippocampus, rather specifically and bilaterally,” says Michael Bennett, a neuroscientist at Albert Einstein College of Medicine. That’s because blood vessels in the brain generally start in the center and radiate to the front and back. If the blood in the brain is somehow disrupted—by stimulants like meth that cause blood vessels to spasm or by an overdose where patients stop breathing—the front and back of the brain tend to bear the brunt of the damage. “Those areas are most affected because they’re the very end of the distribution of the arteries.” says Thomas Kosten, a psychiatrist at Baylor. 
 
 That’s why DeMaria fears the effect on the hippocampus may be specific to the opioid that those patients took. Synthetic opioids like fentanyl have fueled the opioid epidemic in the U.S. Perhaps a new synthetic drug can specifically affect the neurochemistry of neurons in the hippocampus. 
 
 Kosten hypothesizes it could also be the effect of opioids combined with another drug that is a stimulant. In several of the cases, the patients did report using cocaine, amphetamines, or benzodiazepines as well as opioids. 
 
 Whatever the explanation, doctors were only able to pick up this relatively rare amnesia cluster because so many patients are turning up with opioid overdoses. As the opioid crisis continues, scientists are going to learn a lot more about how opioids affect the brain. “There’s a lot we don’t know,” says Kosten, particularly about synthetic opioids like fentanyl. There’s a lot to know, and a lot to have to know, now that so many patients are turning up with a history of opioid use.
– Since 2012, doctors in Massachusetts have observed a most unusual kind of patient just 14 times—or, 14 times that we know about. It all started with Max Meehan, who was taken to the hospital after his behavior freaked out his family: his memory had suddenly vanished. "The kid was amnestic," neurologist Yuval Zabar says of the then-23-year-old, and what Zabar found when he reviewed an MRI scan of Meehan's brain essentially freaked him out: As BuzzFeed puts it, two bright white orbs where there should have been gray, each "perfectly localized" to both hippocampi, which plays a crucial role in the formation of memories. Zabar had never seen it before, but it wasn't a total anomaly: Doctors in the state have now identified 13 more people who experienced the same white orbs and memory issues, and one of their commonalities, with two exceptions, is opioid use. In Meehan's case, he shot up heroin and collapsed before waking to a seeming inability to form new memories, leaving him in a state that forced him to drop out of college and made it difficult to hold a job. Memory improvements came slowly over two years. "The only thing that seems to parallel" the condition—which has been named CHIAS, for complete hippocampal ischemic amnestic syndrome—"is fentanyl use," says another Massachusetts neurologist. Among the many varied theories: that there was a toxin in the drugs ingested, or that persistent fentanyl use results in severe respiratory issues that may deprive those parts of the brain of oxygen. For now, state public health officials are pushing the mystery forward by branding CHIAS a "reportable disease," meaning the state will have to be alerted to any new cases. Read the full piece.