Subacute combined degeneration of the spinal cord caused by inhalation of nitrous oxide: two cases report

Abstract

Objective To summarize the clinical manifestations and image features of subacute combined degeneration of the spinal cord (SCD) caused by inhalation of nitrous oxide (laughing gas). Methods and Results SCD was happened in two patients who took in nitrous oxide for 5 and 19 months, with numbness and weakness of limbs as the first symptoms and the symptoms gradually got worse. The nerve conduction test showed that the nerve conduction velocity (NCV) was slow down and the amplitude was decreased. MRI showed "inverted V" in the posterior cord of cervical spinal cord on T₂ WI. After stopped taking nitrous oxide and treated with vitamin B, the symptoms gradually alleviated. Conclusions Inhalation of nitrous oxide can cause neurological damage, which can be manifested as SCD. Stopping the inhalation of nitrous oxide and using mecobalamin are the key of the treatment.

DOI:10.3969/j.issn.1672-6731.2019.09.016