Nitrous Oxide Induced Posterior Cord Myelopathy: Beware of the Methyl Folate Trap

Mechanisms and recent advances in the diagnosis and treatment of nitrous oxide-induced peripheral neuropathy: a narrative review

Under standard conditions, nitrous oxide (N2O) manifests as a colorless, odorless gas with a mildly sweet taste. The compound finds applications in various fields, including its use as an aerosol propellants, an accelerant in motor racing, and an anesthetic in surgical procedures and dentistry. Unfortunately, the recreational misuse of N2O has become prevalent among young individuals due to its euphoric and hallucinogenic effects. Compounding this issue is the fact that nitrous oxide can be easily obtained from over-the-counter household items, facilitating its non-medical use. The global community has witnessed a surge in the recreational utilization of nitrous oxide gas in recent years. Despite the widespread non-medical abuse of N2O, there remains inadequate understanding of the potential adverse effects resulting from exposure to it. This paper provides an overview of management findings, laboratory and electrodiagnostic characteristics, as well as clinical presentations associated with neurological disorders induced by nitrous oxide usage.

Does nitrous oxide addiction exist? An evaluation of the evidence for the presence and prevalence of substance use disorder symptoms in recreational nitrous oxide users

BACKGROUND

Prevalence of nitrous oxide (N2 O) use appears to be increasing in numerous countries worldwide, and excessive use has been associated with physical and mental problems. Because there currently is no consensus whether N2 O has addictive potential, we aimed to evaluate the evidence for the presence and prevalence of DSM-5 substance use disorder (SUD) symptoms in N2 O users.

ANALYSIS

A literature search was conducted to assess the evidence for the presence of any of the 11 DSM-5 SUD symptoms in N2 O users and the prevalence experiencing those symptoms. A substantial part of the studied N2 O users use more than intended (i.e. 46% to 98%) and spend a substantial amount of time using N2 O. At least some of the studied N2 O users experience interpersonal problems (i.e. 13% to 80%) and use N2 O in risky situations, such as driving under the influence. Evidence for the other criteria is either insufficient or inconclusive.

CONCLUSIONS

The literature base for the presence and prevalence of DSM-5 substance use disorder (SUD) symptoms in nitrous oxide (N2 O) users is limited and largely consists of qualitative studies and case studies, but it provides consistent evidence for the presence of at least four SUD criteria in heavy N2 O users. N2 O could well be addictive and should be treated as a potentially addictive substance until systematic assessments can provide evidence-based guidance to users, healthcare professionals and legislators.

A rise in cases of nitrous oxide abuse: neurological complications and biological findings

BACKGROUND

The recent lockdown due to the COVID-19 pandemic has been linked to a higher incidence of psychiatric manifestations and substance abuse. The recreative use of nitrous oxide is more and more widespread and neurological complications are frequent.

METHODS

We report clinical characteristics and biological findings of five consecutive patients presenting to our tertiary care center between April 2020 and February 2021 with various neurological symptoms occurring after recent nitrous oxide abuse.

RESULTS

Our patients presented with subacute combined degeneration of the spinal cord (4/5 patients) or with acute inflammatory demyelinating polyneuropathy (1/5 patients). No patient had reduced vitamin B-12 titer, but all had elevated blood levels of homocysteine and methylmalonic acid. This reflects the functional deficit in vitamin B-12 that can be linked to nitrous oxide consumption. After vitamin B-12 supplementation, clinical signs regressed at least partially in all 5 patients.

CONCLUSION

We report an elevated incidence of neurological complications of nitrous oxide abuse occurring during the recent COVID-19 lockdown. Nitrous oxide abuse should be tracked down in patients presenting with compatible neurological symptoms and elevated homocysteinemia. Vitamin B-12 should be supplemented as soon as the diagnosis is made.