Disclosures: Alexandra M. Ostromecki, DO: No financial relationships or conflicts of interest

Case Description: A 26-year-old female presented to an acute care hospital with numbness/tingling of bilateral lower extremities, impaired balance, and falls following inhaled N2O (whippets) use as a means of coping with anxiety. Pre-morbidly, the patient read about the side effects of such use, and prophylactically took vitamin B12 to prevent neurological impairment. She used 100 whippets daily for two months prior, alternating one week on and off. Her initial B12 was elevated at 1,182 pg/mL and folate was 21.51 (unremarkable). The patient was admitted to the hospital for further workup, high-dose vitamin B12 supplementation per neurology recommendations, and eventual inpatient rehabilitation. MRI C/T-spine showed abnormal signaling of the spinal cord dorsal column secondary to subacute combined degeneration. MRI brain showed nonspecific T2/FLAIR hyper-intensities in the periventricular and subcortical deep white matter of uncertain etiology and advanced for patient age.

Setting: Inpatient rehabilitation (IPR)

Patient: 26-year-old female

Assessment/Results: The patient’s rehabilitation course was complicated by neurogenic bowel and bladder, both of which improved and functioned upon discharge from IPR. Her CARES scores for ADLs improved from 3-4 on admission, to 6’s upon discharge. She was ambulating >350 feet with 4-wheeled walker, completed 12 steps, and was independent with toileting, dressing, and bathing.

Discussion: Nitrous oxide (N2O) is an inhaled anesthetic agent commonly used in dental and medical procedures, the automotive industry, and the food industry, and increasingly, for recreational use among young people. Its neurologic manifestations include subacute combined degeneration (SCD). This case involves a young female found to have SCD who showed improvement across all functional domains through intensive inpatient rehabilitation and intramuscular B12 supplementation.

Conclusion: This case demonstrates the significant neurological deficits that may present following recreational N2O use. High-dose vitamin B12 supplementation combined with intensive inpatient rehabilitation are effective treatment options to improve functional outcomes.

Level of Evidence: Level IV

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/subacute-combined-degeneration-induced-by-recreational-nitrous-oxide-whippet-use-a-case-report/