Hypoglossal nerve palsy in infectious mononucleosis.

Involvement of the central nervous system is a rare complication of infectious mononucleosis. Isolated cranial nerve palsy is the least reported neurologic complication. We report a second case of hypoglossal nerve palsy associated with infectious mononucleosis, and review 20 other reported cases of cranial nerve palsies. Any cranial nerve may be involved. The onset of the palsy usually follows the diagnosis and clinical presentation of infectious mononucleosis. The prognosis for a complete recovery is excellent, although recovery may be protracted. The use of steroids does not appear to be etiologic, nor beneficial or deleterious in treatment.