Sudden Onset Amnesia Mysteriously Affects Boston-Area, Was it Drug Abuse?

Short-term memory loss in young people could be another consequence of the opioid abuse epidemic plaguing the United States.

The US Centers for Disease Control and Prevention (CDC) on January 26 published a report from health officials in Massachusetts on a mysterious cluster of patients who developed sudden amnesia involving acute and completely reduced blood flow to the brains’ hippocampi. There were 14 such cases from 2012 to 2016.

Jed A. Barash, MD, a neurologist, treated the first four patients at Lahey Hospital & Medical Center, Burlington, Massachusetts. and the remaining cases emerged following an email alert he sent to the Massachusetts Department of Public Health. All were in Eastern Massachusetts.

The patients all showed “striking anterograde amnesia,” meaning they had trouble creating new memories and couldn’t piece together events from their immediate past.

All 14 patients were fairly young (19 to 52 years), and according to the report in the CDC’s Morbidity and Mortality Weekly Report (MMWR), none had disorders that could explain their memory loss. Although the cause of amnesia was a mystery to health officials, investigation showed that 13 of the 14 patients had a history of substance abuse, the 14^th patient tested positive for opioids and cocaine, and 12 had past opioid use recorded in their medical history.

Nearly all patients’ medical histories specifically included use of opioids but also included use of benzodiazepines, marijuana, cocaine, amphetamines, LSD, MDMA, mushrooms, and PCP.

The report provided information of the long-term outcome for only four recent patients:

• The 19-year-old regained his memory five months later, but started experience seizures
• Two of the patients continued to experience cognitive problems for more than a year later
• One patient had persistent severe short-term memory problems even after eight weeks, but later died from cardiac arrest.

Based on the apparent temporospatial clustering, relatively young age, and extensive pattern of substance use, the researchers said they’ve stumbled onto a phenomenon worth investigating — despite the small number of reported cases.

While it’s easy to simply attribute the memory loss to overdose, researchers feel there’s something more at play given the impact on the hippocampi.

Since many cases occurred in a limited geographical area in a short period of time, the researchers believe this could be attributed to a new contaminant in the drugs. Conversely, it’s possible this isn’t a new syndrome, just a dormant one.

Regardless, the research team hopes this alert prompts doctors to start administering memory tests for patients who are admitted to the emergency room after overdosing.

The MMWR report is entitled Cluster of an Unusual Amnestic Syndrome — Massachusetts, 2012-2016.