A neonate with facial asymmetry

Description

A 3-day-old male neonate was presented with facial asymmetry and difficulty in breastfeeding since birth. He was born by assisted vaginal delivery to a primigravida mother with a history of difficult labour. On examination, there was facial asymmetry with a deviation of the angle of mouth towards the right side. The baby was not able to close the left-side eyelid, and the mouth was not moving down the same way on both sides. There was almost no movement on the left side of the face (figure 1). The rest of the systemic examination was unremarkable. A diagnosis of complete congenital lower motor neuron-type left facial nerve paralysis was made. Brainstem evoked response audiometry (BERA) and MRI brain was normal. He was kept under follow-up after prescribing artificial tears and lubricants along with eye patches during sleep. On the last follow-up at 2 months of age, the facial palsy has totally resolved.

Figure 1.

Facial asymmetry with deviation of the angle of mouth towards the right side. Inability to close the left-side eyelids, and the mouth not moving down the same way on both sides. There is almost no movement on the left side of the face.

Congenital facial palsy (CFP) is present at birth or shortly thereafter.¹ The incidence is around 2.1/1000 live-births.¹ Causes include perinatal trauma, intrauterine posture, intrapartum compression and congenital aplasia of the nucleus (most commonly bilateral).¹ The majority (78–90%) are associated with birth trauma. Cardiofacial, Moebius, Poland's and Goldenhar's syndromes encompass CFP as part of their symptoms.² An important differential diagnosis is congenital ‘facial asymmetry during cry’ due to a congenital absence or weakness of depressor anguli oris muscle (cardiofacial syndrome), so when the child is crying the corner of the mouth does not lower leading to facial asymmetry.¹ In congenital or syndromic causes, the facial palsy is not reversible.²

Learning points.

• In a new born with congenital facial paralysis, early establishment of aetiology is very important to distinguish between traumatic and developmental causes, as this will determine the course of disease process and treatment plan.

• A careful history and full-body examination may reveal the causes of the paralysis but additional investigations may be necessary (electromyography (EMG), nerve conduction studies, CT and MRI).

• Most often children are born with facial nerve paralysis (typically affecting one side only) that has no identifiable cause and treatment is difficult since a complete and accurate assessment of the patient cannot realistically take place before the child has reached a cooperative age.