Reversible dentate nucleus and corpus callosum lesions in acute Legionnaires’ Disease

Abstract

A 41-year-old man presented with a two-day history of fever, malaise and diarrhoea. He was disoriented to time and situation with mild dysarthria on neurologic examination. He was found to be hyponatremic (132 mmol/L) and a chest X-ray showed left lower lobe consolidation. He was started on broad-spectrum antibiotics including two doses of Metronidazole. MRI of the brain without contrast showed T2/FLAIR hyper intensities within bilateral DN and in the central aspect of the splenium of the corpus callosum (CC) (Figure 1). His urine Legionella Pneumophila serogroup-1 antigens came back positive and antibiotics were de-escalated to Levofloxacin for two weeks. On his five-week posthospitalization follow-up, he was noted to have persistent dysarthria for which he continued to work with speech therapy twice a week. Repeat MRI brain with and without contrast six weeks from his initial MRI scan showed a complete resolution of the previously noted abnormal signal hyperintensity within the dentate nuclei and the corpus callosum. He was subsequently seen in clinic ten weeks from discharge and was noted to be asymptomatic.