Congenital Unilateral Facial Nerve Hypoplasia and Parotid gland Agenesis (P2.105)

OBJECTIVE: To recognize facial nerve hypoplasia as a distinct cause of facial asymmetry and to look for associated craniofacial maldevelopement. BACKGROUND: The incidence of congenital facial paralysis has been estimated to be between 0.8 and 1.8 per 1000 births. These cases are due to developmental anomalies that occur during embryogenesis. They may present as isolated unilateral or bilateral facial paralysis or as part of syndrome of other congenital abnormalities, such as congenital unilateral lower lip paralysis or Mobius syndrome. Unilateral isolated facial nerve agenesis is rare. Its is important to consider this condition in children presenting with unusually exaggerated facial asymmetry as some cases may be associated with dysfunction of eighth cranial nerve. CASE DESCRIPTION: 5-month-old infant, born at full term by normal vaginal delivery presented with facial asymmetry noted at birth. Mom denied any problem with eye closure on left side and he slept with both eyes closed. No history suggestive early handedness or hearing concerns. Neurological examination was significant for obvious facial asymmetry with pulling of the left angle of the mouth upwards when he is crying or smiling. Rest of the neurological examination is non-focal. MRI did show marked attenuation of the left facial nerve in the cisternal portion and in left internal auditory canal, suggestive of developmental hypoplasia of left facial nerve. Left parotid gland is not visualized, likely developmentally absent. Hearing screen was normal. On follow up, 4 months later, child was well ahead with developmental milestones with no concerns for hearing ability and facial asymmetry was persistent. CONCLUSIONS: It may be prudent to have neuroimaging done in children with exaggerated facial asymmetry. If facial nerve developmental anomaly is detected, hearing ability has to be established. Early detection of the condition helps in parental counseling and early institution of measures to address co morbidities Disclosure: Dr. Sannagowdara has nothing to disclose. Dr. Harmelink has nothing to disclose. Dr. Inglese has nothing to disclose. Dr. Maheshwari has nothing to disclose.