A collection of rare amnesia cases in Massachusetts has doctors scratching their heads. In the last four years, 14 patients have been diagnosed with an unusual amnestic condition known as “striking anterograde amnesia” and health officials are still trying to determine a cause.
This particular type of rare amnesia prevents sufferers from creating new memories, and they often cannot remember recent events, such as something that happened just moments before. Now, health experts think there are likely more cases out there.
According to a report published by Dr. Jed Barash and Dr. Alfred DeMaria Jr., all the patients, ranging in age from 19 to 52, had recently consumed some type of drug or had a history of substance abuse. Of the 14 cases, 12 patients used opioids, like heroin or prescription painkillers on a consistent basis. These same patients also used other substances like cocaine and marijuana. While these drugs can negatively affect a person’s health, they have never been linked to this rare amnesia before now.
Nine of the patients diagnosed with the rare amnesia were unconscious when they arrived at the hospital and woke up with memory loss. In the other five cases, the individuals were experiencing severe memory loss and were brought to the emergency room by concerned family or friends. All the patients were admitted to the hospital between October 2012 and November 2015.
The patients suffering from this rare amnesia were given brain scans. The test results showed a similar pattern in all the patients. The screenings revealed the hippocampus, a region in the brain that rules memory and emotion, was not receiving an adequate supply of blood.
According to the report, sudden amnesia linked to reduced blood flow to the hippocampus is very rare. Previous cases were caused by exposure to a poisonous substance, like carbon monoxide, but were isolated incidents. DeMaria said the lack of oxygen or a stroke is not likely to have caused the damage to the hippocampus in these patients.
While anterograde amnesia has been reported in isolated cases in the past, there has never been this many cases in one area during a similar timeframe. The 14 cases are still being evaluated, and healthcare professionals are wondering if the current cluster of rare amnesia cases is part of “an emerging syndrome” connected to drug abuse or possibly something else.
“We couldn’t really address what was causing this,” said Dr. DeMaria, per a CNN report.
DeMaria speculates that it might not be the drugs themselves, but possibly something added. In recent years, synthetic drugs containing substances that either mimic or increase the effects of heroin and marijuana have flooded the market, so DeMaria thinks there is a connection.
While all the patients’ memory slowly improved, the 19-year-old patient had complete memory recovery after five months. However, he later started having seizures.
Another patient, a 22-year-old man, still did not have his complete memory back even after two years. A 41-year-old patient experienced severe short-term memory loss for eight weeks and later died from cardiac arrest.
A group of four rare amnesia cases was first noticed in Boston around November 2015 and a trend emerged. The patients were suffering from abrupt, inexplicable memory loss along with other neurological impairments. After a bulletin was sent out by the Massachusetts Department of Health asking doctors to be on the lookout for comparable cases, 10 other patients were discovered and reported to the agency.
More research is needed to completely comprehend what link, if any, the rare amnesia has to opioid abuse. Dr. DeMaria believes there are other cases out there and hopes doctors nationwide will learn to recognize the signs of anterograde amnesia, which is often mistaken for general intoxication.
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