Methamphetamine-induced encephalopathy in the absence of hyperammonemia

BMC Psychiatry. 2023 Apr 20;23(1):276. doi: 10.1186/s12888-023-04764-2.

Abstract

Background: Methamphetamine is an addictive drug with various effects on the neurotransmitters in the central nervous system. Methamphetamine-induced encephalopathy in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of methamphetamine-induced encephalopathy suggested that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. However, the literature is limited on methamphetamine-induced encephalopathy without hyperammonemia.

Case: This case presents a disoriented patient with methamphetamine use disorder in acute toxicity, unable to ambulate independently, and poorly responsive to verbal stimuli. The patient was found to have normal ammonia levels.

Discussion: This patient's presentation and laboratory findings, namely normal ammonia levels, suggest a different pathophysiological pathway for methamphetamine-induced encephalopathy. One potential pathway is through the direct action of methamphetamine on the central nervous system through acute disruption of neurotransmitter signaling and disruption of the blood-brain barrier.

Conclusion: Further research should be conducted into the prevalence and pathophysiology of methamphetamine-induced encephalopathy in the absence of hyperammonemia.

Key points: Methamphetamine-induced encephalopathy (MIE) in the absence of hyperammonemia presents a unique challenge in a clinical setting. Previously published cases of MIE suggest that methamphetamine-induced hepatotoxicity and subsequent hyperammonemia may be the cause of encephalopathy. Further research should be conducted into the prevalence and pathophysiology of MIE in the absence of hyperammonemia.

Keywords: Altered mental status; Encephalopathy; Hyperammonemia; Methamphetamine; Neurotoxicity.

MeSH terms

  • Ammonia / adverse effects
  • Ammonia / metabolism
  • Brain Diseases*
  • Chemical and Drug Induced Liver Injury*
  • Drug-Related Side Effects and Adverse Reactions*
  • Humans
  • Hyperammonemia* / chemically induced
  • Methamphetamine* / adverse effects

Substances

  • Methamphetamine
  • Ammonia