Ischemic Stroke as a Complication of Varicella Zoster Encephalitis

A 72-year-old man with varicella zoster virus (VZV) encephalitis complicated by an ischemic stroke in the right internal capsule, possibly due to secondary small-vessel vasculopathy, is described in this case report. The focus of this article is on the electroencephalogram (EEG) description of varicella zoster encephalitis and secondary vasculopathy because EEG descriptions are scarce in the literature and detailed descriptions are lacking. In this patient’s EEG, right temporal theta waves were found in combination with a mild slowing of the background rhythm to 7.5 to 8 Hz in the acute stage with an amplitude asymmetry (right temporal lobe amplitudes were significantly higher compared with the left side). The theta waves were thought to originate from the ischemic lacunar stroke, the slowing of the background rhythm from early encephalitis, and the amplitude asymmetry was presumed to be of physiologic origin. A follow-up EEG 6 days after initiation of treatment with acyclovir showed a normal symmetrical background rhythm of 8 to 8.5 Hz, wherein the theta waves were significantly reduced in abundance, and the amplitude asymmetry was unchanged. In conclusion, the EEG may localize focal abnormalities possibly due to cortical or lacunar ischemia, which could be explained by early small and/or large vessel vasculopathy in patients with suspected VZV encephalitis.