Letter re: Clinical Reasoning: A young woman with respiratory failure, hearing loss, and paraplegia.

Abstract

I read with interest the case presented by Ntranos et al.1 of acute-onset bilateral lesions in the globus pallidi, hearing loss (possible cochlear dysfunction), and upper thoracic anterior spinal cord lesion in a patient with an opioid/acetaminophen overdose and possible transient hypoxia. Did the authors consider the possibility of methylmalonic acidemia (MMA) as a potential underlying susceptibility factor? The lesions on the patient's MRI in the globus pallidi are characteristic of MMA. There are several possibilities, including an unrecognized minor mutation in the MMA pathway resulting in partial loss of function that was subclinical until the stress of the opioid overdose or an acquired form due to severe B12 deficiency. If the authors did not check, it may be worthwhile to perform a follow-up test on the patient's urine sample for MMA and blood for B12 level. Even if results are normal, I wonder whether the patient has an underlying energy metabolism disorder that clinically manifested with the acute stressor given the particular combination of the lesions.