Anterograde amnesia and bilateral hippocampus ischemia: is it caused by substance abuse?

Diffusion weighted MRI findings in patient with unusual amnestic syndrome — Massachusetts, 2012 [Source: MMWR]3.5 out of 5 stars
Cluster of an Unusual Amnestic Syndrome — Massachusetts, 2012-2016. Barash JA et al. MMWR Morb Mortal Wkly Rep 2017;66:76-79
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Late in 2015 a Boston neurologist reported a cluster of 4 cases of anterograde amnesia associated with MRI evidence of bilateral hippocampal ischemia. After a public health alert was issued an additional 10 cases were identified in the years 2012-2016, using the case definition of: “1) new onset amnesia in the absence of evidence to support a readily apparent cause, and 2) changes consistent with acute and complete ischemia of both hippocampi on MRI at initial assessment.”
Of the 14 identified patients, all had a history consistent with substance abuse or drug screening consistent with such abuse. In 13 of the patients, this history involved opioids. Additional neurological findings in these cases included deficits in attention orientation, and executive functioning. Some of these deficits resolved over time, but several patients had residual impairment at 1-year follow-up.
Authors note that previously reported causes of amnestic syndrome with bilateral complete hippocampal ischemia include cocaine, carbon monoxide, and influenza. They admit that hypoxia-induced hippocampal ischemia is a possibility. Others have speculated that changes in glutamate balance may be responsible.
The authors’ con...

Source: The Poison Review - January 27, 2017 Category: Toxicology Authors: Leon Gussow Tags: Medical amnestic syndrome e opioid overdose hippocampus ischemia opiat Source Type: news