Woman Presents With Confusion After Shingles Infection

History of Present Illness

A 54-year-old woman is brought to the emergency department (ED) by family members because of the onset of confusion and excessive sleepiness. The patient has been taking acyclovir for 1 week for management of shingles affecting the V2 dermatome. She denies any fever or headache but has vomited once. In addition to acyclovir, the patient is taking acetaminophen and hydrocodone for pain.

Vital Signs and Physical Examination

The patient’s vital signs are normal. Physical examination is normal except for a crusted zosteriform rash on the right face and an overall lack of animation without lethargy. She is alert and oriented x 4 but slow to respond. Laboratory tests are normal and an initial computed tomography (CT) scan is normal. A brain magnetic resonance imaging (MRI) is performed (Figure).