[Bilateral facial nerve palsy associated with Epstein-Barr virus infection in a 3-year-old boy].

Bilateral facial nerve palsy is a rare and sometimes difficult diagnosis. We describe a case of bilateral simultaneous facial nerve palsy associated with Epstein-Barr virus (EBV) infection in a 3-year-old boy. Several symptoms led to the diagnosis of EBV infection: the clinical situation (fever, stomachache, and throat infection), white blood cell count (5300/mm3 with 70% lymphocyte count), seroconversion with EBV-specific antibodies, lymphocytic meningitis, and a positive blood EBV polymerase chain reaction (9.3×103 copies of EBV-DNA). An MRI brain scan showed bilateral gadolinium enhancement of the facial nerve. A treatment plan with IV antibiotics (ceftriaxone) and corticosteroids was implemented. Antibiotics were stopped after the diagnosis of Lyme disease was ruled out. The patient's facial weakness improved within a few weeks. Bilateral facial nerve palsy is rare and, unlike unilateral facial palsy, it is idiopathic in only 20% of cases. Therefore, it requires further investigation and examination to search for the underlying etiology. Lyme disease is the first infectious disease that should be considered in children, especially in endemic areas. An antibiotic treatment effective against Borrelia burgdorferi should be set up until the diagnosis is negated or confirmed. Further examination should include a blood test (such as immunologic testing, and serologic testing for viruses and bacterium with neurological tropism), a cerebrospinal fluid test, and an MRI brain scan to exclude any serious or curable underlying etiology. Facial bilateral nerve palsy associated with EBV is rarely described in children. Neurological complications have been reported in 7% of all EBV infections. The facial nerve is the most frequently affected of all cranial nerves. Facial palsy described in EBV infections is bilateral in 35% of all cases. The physiopathology is currently unknown. Prognosis is good most of the time.