A 35-year-old woman with a remote history of HSV encephalitis presented as a stroke code, with rapidly evolving dysarthria over a few hours. On presentation, fever, delay in response time, dysarthria, left upper and lower facial weakness, "blurry vision" which corrected with covering up either either eye (likely a subtle binocular diplopia), impaired saccades, left upper motor neuron-type weakness, bilateral dysmetria and ataxia were noted. Basic labs were significant only for hyponatremia, and chest x-ray showed a left lower lobe infiltrate. CSF studies were unremarkable for infection and serum and CSF paraneoplastic antibody panels were negative. Legionella urinary antigen was positive. The patient did not develop pulmonary symptoms until day 3 of admission.
MRI brain with and without contrast, performed twice, including the FIESTA sequence for cranial nerves, was unremarkable. The patient had nearly recovered by the time of discharge following an 8 day course of targeted antibiotic treatment for Legionnaire's disease, with resolution of binocular diplopia, cognition and right sided weakness.