An immunocompetent adult developed cytomegalovirus (CMV) meningoencephalitis with paroxysmal neurologic symptoms of a self-limited nature and with a favourable outcome. Consistent with known cases in the clinical literature, two clinical forms of CMV meningoencephalitis will be identified: a monophasic form and a paroxysmal form. The clinical, diagnostic and therapeutic aspects of the two types will be analysed, and a pathogenetic hypothesis for the paroxysmal type will be proposed. Copyright 2000 S. Karger AG, Basel