Opsoclonus associated with salmonellosis in a 6-week-old infant

A 6-week-old male infant presented with 2 days of fever, emesis, and diarrhea, associated with episodic and chaotic rapid eye movements, determined to be opsoclonus. An electroencephalogram (EEG) obtained during the events was normal. He was treated empirically for meningitis, and an initial workup for neuroblastoma including urine homovanillic acid and vanillylmandelic acid levels, abdominal ultrasonography, and computed tomography (CT) of the chest, abdomen, and pelvis was negative. Stool and blood cultures were positive for Salmonella, and antibiotic regimen was adjusted appropriately. Over the next few days, his fever, emesis, and diarrhea subsided, and the opsoclonus resolved by hospital day 6. He was back to baseline by hospital day 9. Although there have been cases of parainfectious opsoclonus associated with Lyme disease, enterovirus, Streptococcus, and West Nile virus, this represents the first reported pediatric case of opsoclonus associated with salmonellosis. Only 2 such cases in adults have been reported in the literature.