Co-Occurring Subacute Combined Degeneration and Guillain-Barré Syndrome Resulting From Nitrous Oxide Abuse: A Case Report.

Growing in prevalence as a recreational drug of abuse across a broad scope of people, nitrous oxide (N2O) has proven to be a public health concern. Side effects of its abuse have a great degree of variation among people ranging from neurologic, psychiatric, and medical symptoms. We present a rare case of a 23-year-old female with a history of N2O abuse, who presented with symptoms of both subacute combined degeneration syndrome (SCD) and Guillain-Barré syndrome (GBS). She presented with three weeks history of progressive bilateral lower extremity weakness, burning and tingling sensation, difficulty walking, and falls. This patient underwent an extensive medical workup upon hospitalization. Notable findings of the magnetic resonance imaging (MRI) of her cervical spine showed an abnormal cervical cord signal intensity pattern typical for vitamin B12 deficiency and her lumbar puncture showed albuminocytological dissociation, which confirmed the diagnosis of GBS. For these conditions, this patient was successfully treated with weekly vitamin B12 injections and five treatments of plasmapheresis. Her condition was additionally complicated by worsening anxiety and depression, which were treated with gabapentin, escitalopram, trazodone, hydroxyzine, and melatonin. She demonstrated great clinical improvement with almost complete resolution of her symptoms at the time of her hospital discharge. This case highlights the easy accessibility, addiction potential, and adverse consequences related to N2O abuse.