Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disorder of the central nervous system. Although it is more commonly described in the pediatric population, it can infrequently affect adults. It can present with an array of neurological symptoms and is usually preceded by an infectious process. A causative pathogen is rarely isolated in adults and limited data with case reports has shown an association mostly with viral pathogens. To the best of our knowledge, this is the first report of an association of ADEM with Staphylococcus species in children and adults.

Case:

24-year-old woman with recent history of methicillin-sensitive Staphylococcus aureus bacteremia with tricuspid valve endocarditis, septic pulmonary emboli, and septic arthritis of left sacroiliac joint due to intravenous drug use undergoing treatment with parenteral antimicrobials for one month presented with a new-onset generalized tonic-clonic seizure, requiring intubation for airway protection. Her neurologic exam was remarkable for diffuse hyperreflexia. CT head without contrast revealed bilateral periventricular hypodensities and MRI brain with and without contrast revealed extensive, nonenhancing T2/FLAIR supratentorial white matter hyperintense lesions in periventricular and subcortical U fiber distribution with involvement of the corpus callosum without evidence of diffusion restriction. MRI cervical and thoracic spine were unremarkable. CSF cell count with differential, protein, and glucose were normal and extensive infectious workup was negative. CSF myelin basic protein was elevated at 3.9, but oligoclonal bands were absent. Patient was diagnosed with ADEM given the clinical history as well as MRI and CSF findings and was treated with methylprednisolone 1000 mg IV daily for 5 days with complete resolution of symptoms. Repeat MRI brain at one year was normal.

We conclude that Staphylococcal species should be considered as a cause of ADEM in adults.