Slowly progressing varicella zoster brainstem encephalitis complicating Ramsay Hunt syndrome in an immunocompetent patient: case report and review of the literature.

A 56-year-old immunocompetent male developed brainstem encephalitis complicating Ramsay Hunt syndrome. The disease had a slowly progressing course of months after the triggering infection, much longer than previously reported. Furthermore, magnetic resonance imaging, physical-chemical, and cell count analyses on cerebrospinal fluid were normal, whereas polymerase chain reaction for varicella zoster virus DNA was positive. The simultaneous negativity of both imaging and basic CSF exams is very rare, although possible event which confirms the irreplaceable role of viral screening on CSF. A systematic review of similar reports with highlights on the unusual aspects of our case is also presented.