Brain and body disconnect: A retrospective case series of subacute combined degeneration of the spinal cord from chronic nitrous oxide use in Perth, Western Australia.
Jessamine Soderstrom, Jodie Grigg, Owen Mcwilliam, Daniel Fatovich
Drug and alcohol review September 1, 2024 DOI: 10.1111/dar.13858 via PubMed
Summary
Chronic nitrous oxide use inactivates vitamin B12, causing neurological and psychiatric damage. A case series from an Australian emergency department between 2019 and 2021 identified 22 patients, mostly young males (median age 22.4 years), who inhaled a median of 150 bulbs daily for 9 months. Common symptoms included ataxia, numbness, falls, urinary retention, and psychosis; 12 of 14 patients who underwent MRI had spinal cord degeneration. All received vitamin B12 injections, and many also oral methionine. Hospital stays lasted a median of 4 days, costing about $2,061 per day. The data prompted public health measures such as warning labels, purchase limits, and legal restrictions on sales intended for abuse.
Study at a glance
| Characteristics | Case series Case report Peer reviewed |
|---|---|
| Sample size | 22 |
| Population | Patients presenting to the emergency department at Royal Perth Hospital with chronic nitrous oxide-related symptoms |
| Keywords | Harm reduction Inhalant abuse Neurotoxicity Nitrous oxide Poisoning |
| Citations | 5 |
| Key finding | Chronic nitrous oxide use led to severe neurological sequelae in most patients, with substantial hospital costs, prompting public health interventions. |
Abstract
Chronic nitrous oxide (N2O) use causes inactivation of vitamin B12, resulting in neurological and psychiatric symptoms. This case series presents all N2O-related presentations to the emergency department at Royal Perth Hospital between June 2019 and June 2021, alongside the costs of these admissions. Twenty-two patients were identified; 68% (n = 15) were male. The median age was 22.4 years (interquartile range [IQR], 20-30). Median daily number of N2O bulbs inhaled was 150 (IQR, 64-300) with a median duration of use of 9 months (IQR, 3-12). Presentations included ataxia, paraesthesia and falls (n = 18), urinary retention (n = 3) and psychotic symptoms (n = 2). Fourteen patients had severe symptoms prompting a magnetic resonance imaging of brain and spine, confirming 12 cases of subacute combined degeneration of the spinal cord. All patients had IMI vitamin B12 therapy, while 14 had oral methionine therapy. The median length of admission was 4 days (IQR 1-23 days). The median cost of admission per day for patients where costs were accessible (n = 7) was $2061 (IQR, $1903-$2860). A case series of symptomatic chronic N2O use with severe neurological sequelae and significant costs associated per admission. Triangulation of emergency department and Ecstasy and Related Drugs Reporting System data helped prompt a swift public health response, including mandatory warning labels, limits to transaction amounts and legislative changes to the Medicines and Poisons Act to make it illegal for sale if there is a suspicion that it will be abused.