2025 American Academy of Neurology Abstract Website

Objective:

To present two case reports highlighting nitrous oxide-induced vitamin B12 deficiency and myelopathy in individuals abusing whippets.

Background:

Whippet abuse has become prevalent among recreational drug users, leading to serious health complications. Nitrous oxide (N2O) inactivates vitamin B12, essential for neurological health. Myelopathy resulting from vitamin B12 deficiency can cause significant morbidity. This report illustrates the clinical manifestations and diagnostic challenges associated with this condition in whippet abusers.

Design/Methods:

We report two female patients, aged 22 and 35, with a history of regular whippet use over the past three years. Clinical evaluations included neurological examinations, serum vitamin B12 measurements, and MRI of the brain, cervical, and thoracic spines. Both patients were assessed for myelopathy symptoms, including motor weakness, rigidity, sensory changes, and gait abnormalities.

Results:

Case 1: A 35-year-old female presented with weakness, rigidity, and swelling in both legs. MRI of the cervical and thoracic spines showed no acute findings. Lab results revealed a low serum vitamin B12 level of 102 pg/mL, elevated homocysteine at 44 µmol/L, and high methylmalonic acid at 29,054 nmol/L. Serum vitamin D was low at 9.0 ng/mL.

Case 2: A 22-year-old female reported progressive stiffness and weakness in her legs, along with tingling and cramping in her hands. MRI of the brain revealed T2 hyperintensities in the right frontal lobe, and cervical/thoracic spine MRI showed diffuse T2 hyperintensities in the spinal cord. Her vitamin B12 level was 180 pg/mL.

Both patients improved with vitamin B12 supplementation, along with physical therapy and occupational therapy.

Conclusions:

These cases highlight the risk of nitrous oxide-induced myelopathy linked to vitamin B12 deficiency among whippet abusers. Early recognition and intervention are crucial to prevent irreversible neurological damage. Regular screening for vitamin B12 deficiency should be considered in this population. Further research is needed to understand the long-term implications of substance abuse.