Nervous system involvement in infectious mononucleosis. The heralding and-or major manifestation.

Fifteen patients with infectious mononucleosis (IM) had neurological signs and symptoms as the major and/or heralding features of the illness. In six, the only detectable clinical manifestations were neurological. The incidence of objective neurological involvement among 144 patients hospitalized with IM was 5.5%. Infectious mononucleosis should be one of the etiological considerations in children and young adults presenting with short histories and showing neurological deficits reflecting involvement of almost any part of the nervous system. Pharyngitis, adenopathy, splenomegaly, etc, need not be present.