Severe, Unusual Cases of Memory Loss Tied to Fentanyl Abuse

Fran Lowry

January 31, 2018

Survivors of a fentanyl overdose may have cheated death in the short term, but they may end up with long-term memory loss.

Researchers in West Virginia have identified another case of an unusual amnestic syndrome in a man who used fentanyl and cocaine.

The syndrome was documented in 14 patients from Massachusetts between 2012 and 2016.

"We want to make people aware that survivors of overdoses where fentanyl is involved may develop significant memory problems," Marc W. Haut, PhD, West Virginia University School of Medicine, Morgantown, told Medscape Medical News.

"There is a lot of talk about the folks who are not surviving a fentanyl overdose, but there are those who do survive for whatever reason. If you have someone with a chronic relapsing disease such as addiction, and then you add on cognitive and memory problems, managing them becomes even more difficult," Dr Haut said.

Dr Marc Haut

"We would like to find out how common this amnestic syndrome is, and if others are finding that it is specific to fentanyl plus stimulants," he said.

The case report was published online January 29 in the Annals of Internal Medicine.

Brain Imaging

The case involves a 30-year-old man with a history of heroin use who had recently been discharged from a residential addiction treatment program and had been abstinent from drugs for more than a month.

"The family recounted that he returned home late one night, and when they went into his room the next morning, he was difficult to arouse. As he became more alert, the family noticed that he kept on asking the same questions. Because of this, they brought him to the local hospital," Dr Haut said.

There, results of a serum toxicology screen were positive for cocaine, but results of a urine toxicology screen were negative for fentanyl.

"When you do urine drug screening, some things, like fentanyl and its by-products, don't show up unless you specifically test for them," Dr Haut noted.

A CT scan of his brain showed bilateral, symmetrical hypodensities in the hippocampi and basal ganglia.

Additionally, serum aspartate and alanine aminotransferase levels were slightly elevated.

Because the memory impairment persisted, the patient was transferred to the J. W. Ruby Memorial Hospital in Morgantown. There, an MRI of the brain found diffusion-weighted hyperintensities involving all of both hippocampi, as well as the fornices, mammillary bodies, and globus pallidus.

Urine testing, which was conducted approximately 80 hours after drug exposure, was negative for fentanyl but was positive for its metabolite norfentanyl.

No New Memories

The patient's amnesia was characterized as anterograde.

"This is not the type of amnesia that you see on a soap opera, where you can't remember anything about your past. In anterograde amnesia, you cannot lay down new memories going forward. Patients will repeat themselves. They cannot remember what they did yesterday, and they may not even remember what they did earlier in the day," Dr Haut said.

Whether or not the condition is permanent is difficult to say at present, he added.

"I'm a little hesitant to say that the condition is permanent. We were following this patient for a while, and his memory may have been improving slightly, but then we lost him to follow-up.

"It is very challenging to keep these patients in contact with us. If they still have family involved, it might be easier, but we're talking about people who have a significant history of drug use, and they may have no family around, so following them is a definite challenge," Dr Haut said.

He noted that this is the second case of a similar amnestic syndrome that had been seen here.

"The first was in September 2015, and to our knowledge, these two patients constitute the first cluster of this syndrome to be documented outside of Massachusetts. The fact that this syndrome has been identified in different areas of the country means that physicians in other states should be on the lookout for it when they evaluate patients with new-onset amnesia, especially if these patients have a history of substance abuse," he said.

"We recommend using diffusion-weighted MRI of the head, routine toxicology screening, and neurologic consultation, as well as toxicology tests that are specific for fentanyl, its metabolites, and its analogues."

Dr Haut has disclosed no relevant financial relationships.

Ann Int Med. Published online January 30, 2018. Abstract

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