Bilateral Facial Palsy Complicating Infectious Mononucleosis in Infancy

This report presents the second case of infectious mononucleosis (IM) complicated fry facial palsy in Japan. The patient was an eight months old male infant. Diagnosis was defined as the Epstein-Barr virus (EBV) infection by analysis of EBV titer. Four days before admission the patient began to cough and became febrile. The next day he developed right facial palsy and on the third day left facial palsy. Cervical lymphadenopathy was noted, and the liver and the spleen were moderately enlarged. Neurological examination was negative except for bilateral facial palsy. The white blood cell count was 36,900; 57.5% lymphocytes, 16% atypical lymphocytes, and 5% monocytes. CSF revealed raised cell count ; 124/3 per μ I. Paul-Bunnel test was 1 : 128. Serum EBVCA-IgG titer rised from less than 1 5 to 1 I 80 in two weeks. From the eighth day steroid hormone preparations was administered to the patient for six days. Ten days after admission left facial palsy began to improve, and completely recovered six weeks later. About three months after the onset right facial palsy was completely recovered. Eighteen cases of facial palsy complicating IM have been reported in the literature. Ten of were bilateral. Most cases occurred in adolescence or in young adults, but in Japan two cases including the present case occurred in infancy. Neurological complications in IM including bilateral facial palsy sometimes appear as the sole manifestation of the illness. In infancy, moreover, EBV infection is often mild or atypical, so it is difficult to make the diagnosis. As one of the etiologies of facial palsy EBV should always be remembered.