Shingles is the common name for the disease produced by reactivation of the varicella-zoster virus--the same virus that produces chickenpox upon initial infection--within the nerve roots. In rare cases, according to University of Alabama Professor of Infectious Disease Richard J. Whitely in the 2008 edition of "Harrison's Principles of Internal Medicine," the virus strikes the brain, resulting in a complication called encephalitis. Encephalitis with shingles can occur at any time, even months or weeks after other symptoms seem to have resolved. Encephalitis symptoms usually persist for one to two weeks, even with treatment. Without treatment, encephalitis may be fatal.
Flu-Like Illness
According to the National Institute of Neurological Disorders and Stroke, encephalitis typically presents with symptoms similar to a mild case of the flu. Common complaints include fever, headache, non-specific body aches, increased sensitivity to light and poor appetite. Headache may be generalized, or it may seem to come from a specific area of the head, such as behind the temples. Fever is generally mild, according to Whitely, and may only come to light when the patient presents to the hospital or clinic for evaluation of other symptoms.
Mental Status Changes
Doctors use the term "mental status" to describe a person's level of cognition, alertness and emotional state. Patients with encephalitis, according to NINDS, often exhibit progressive mental confusion, irritability, disorientation and drowsiness. In some cases, say the authors of a 2009 report in the journal "Current Neurology and Neuroscience Reports," mental status changes develop slowly, appearing months or weeks after other symptoms of shingles, making them easy to miss. Plus, as the authors note, shingles frequently strikes older adults, so mental status changes may be mistakenly attributed to "old age" or missed altogether.
Focal Neurologic Deficits
Doctors use the term "focal neurologic deficits" refer to problems in the brain, spinal cord or nerves that result in loss of function in a specific location. Common focal neurologic deficits that accompany encephalitis, according to NINDS, include changes in speech or hearing, double vision or loss of vision, loss of sensation in a part of the body, muscle weakness and inability to move the muscles in a certain part of the body. However, focal neurologic deficits are usually a late sign of shingles encephalitis. A case series published in the 2010 edition of the journal "Infection" found that fewer than 15 percent of patents exhibited focal neurologic deficits at the time they sought treatment, although some developed them later.
References
- "Harrison's Principles of Internal Medicine, 23rd Edition;" A.S. Fauci et al.; 2008
- National Institute of Neurologic Disorders and Stroke: Meningitis and Encephalitis
- "Infection;" Herpes Zoster Meningoencephalitis; A. Douglas et al.; 2010
- "Current Neurology and Neuroscience Reports;" Neurologic Manifestations of Varicella Zoster Virus Infections; C. Amlie-Lefond and B. Jubelt; 2009
- National Institute of Neurological Disorders and Stroke: Meningitis and Encephalitis Information Page
