Abstract
BACKGROUND: Several causes lead to subacute combined degeneration (SACD) of the spinal cord, with nitrous oxide (N2O) inhalation rapidly emerging as the leading cause of functional Vitamin B12 deficiency [1]. CASE PRESENTATION: A 28-year-old man presented with numbness in the extremities and an unstable gait despite having a normal serum Vitamin B12 level. He also disclosed the recreational abuse of N2O. Magnetic Resonance Imaging (MRI) of the cervical spine revealed abnormal signals consistent with SACD. The patient's condition gradually improved after treatment with high dose Vitamin B12. Given the increasing number of N2O-induced SACD cases, the potential for drug abuse requires vigilance from clinicians. CONCLUSION: Healthcare providers are urged to inquire about a patient's history of N2O inhalation to prevent the missed diagnosis of SACD.