Varicella zoster virus (VZV) encephalitis can be due to either an immune reaction to primary infection or reactivation of latent infection in cranial nerve or dorsal root ganglia following childhood chickenpox 1.
Diagnosis
Diagnosis is often made with a combination of serum blood tests, cerebrospinal fluid samples and neuroimaging. CT and MRI brain may be normal, however, they are important in their ability to rule out other differential diagnoses ref.
Pathology
Manifestations following primary infection include:
Reactivation occurs mainly with age-related immunosuppression, but immunocompromised patients i.e. transplant recipients are also at greater risk ref. Manifestations of secondary reactivation include 1:
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neuritis/plexitis
Immunocompromised patients have a much wider range of manifestations and not surprisingly, these tend to be more serious. In addition to those listed above, they also include 1: