Objective:

To describe a unique case of stroke mimicry.

Background:

Non-vascular causes of acute neurological symptoms may clinically and radiographically mimic ischemic strokes. In the brainstem, such considerations are generally restricted to neoplastic, demyelinating, or infectious etiologies. HSV-2 may very rarely cause isolated mesencephalitis.

Design/Methods:

We describe a patient who presented with headache, arthralgias, and visual dysfunction who was initially diagnosed with giant cell arteritis (GCA) but was eventually found to have HSV-2 infection.

Results:

A 75-year-old man with past medical history notable for atrial fibrillation (on apixaban), hypertension, hyperlipidemia, and rheumatoid arthritis (on adalimumab) presented for evaluation of gait instability. Four weeks prior to presentation, he developed bitemporal headaches without visual symptoms and arthralgias. His rheumatologist checked an ESR (40) and ordered a temporal artery biopsy. He presented the day his apixaban was held prior to biopsy (1 week prior to this presentation) with right eye inferior visual field loss. Fundoscopy revealed disc edema felt consistent with anterior ischemic optic neuropathy. He was treated with pulse-dose steroids out of concern for GCA and underwent bilateral temporal artery biopsy before being discharged home on an oral steroid taper and resumed anticoagulation. CT, CTA, and MRI were reportedly normal and the biopsies were ultimately negative. He then presented this admission with gait instability and MRI exhibited a diffusion restricting lesion with T2-FLAIR hyperintensity without hemorrhage in the left cerebral peduncle. His visual symptoms progressed and he underwent right eye anterior chamber paracentesis with fluid resulting PCR positive for HSV-2. Subsequent CSF sampling also revealed lymphocytic pleocytosis and HSV-2 positivity. Despite maximal medical therapy, he lost vision in both eyes over a matter of weeks before developing Charles-Bonnet syndrome.

Conclusions:

HSV-2 encephalitis may cause mesencephalic, non-hemorrhagic, restricting lesions mimicking acute ischemic stroke. HSV may also cause a necrotizing retinitis, initially mimicking ischemic, even arteritic, optic neuropathy.