Mononucleosis: A Possible Cause of Idiopathic Hypersomnia.

Idiopathic hypersomnia (IH) is a rare central hypersomnia of unknown physiopathology. In this study, we determine if the presence of infectious mononucleosis evaluated by serological markers of Epstein Barr virus infection plays a role in this hypersomnia. Ten patients with a suspicion of IH underwent to clinical assessment, 24 h polysomnography, and serologic testing for mononucleosis including Viral Capside Antigen (VCA) IgG, the VCA IgM, and the EBV nuclear antigen (EBNA). None of the patients reported neurological inflammatory disease and viral infection prior the onset of the disease. Compared to the laboratory serological reference values, all patients had high levels of VCA IgG and EBNA with lower level of VCA IgM, overall indicating past infection. This study shows that prior infectious mononucleosis may predispose some subjects to idiopathic hypersomnia suggesting the role of inflammatory and immunological processes in this sleep disorder.