Facial nerve palsy due to birth trauma: About 2 cases and review of the literature

Introduction

Peripheral facial paralysis (FP) caused by forceps use is a relatively frequent pathology; its incidence is estimated to be approximately 2 to 8,8 per 1000 births by forceps delivery.¹ The first case was studied by Landouzy in 1839 in his thesis, where he presented several cases of neurological complications resulting from forceps deliveries.² If the paralysis is present from birth (Congenital FP), it can be developmental or traumatic. Traumatic FP has a good outcome and leaves fewer chances of sequelae. Developmental FP is often an element of a syndrome (Mobius syndrome, hemifacial microsomia, or hypoplasia of the depressor anguli or is muscle).³

We report two cases of facial paralysis in the neonatology department of the regional hospital of Sidi Bouzid. These patients had received corticosteroid and hygienic treatments and showed complete recovery from the first week.

In presenting our clinical cases, we aimed to discuss the clinical characteristics and prognosis of congenital facial nerve palsy secondary to obstetric forceps.

Case 1

A male infant was born at 39 weeks of gestation to a 23-year-old primigravida mother using forceps due to bradycardia of the fetal heartbeat. The pregnancy, antenatal course, and family medical history were unremarkable. birth weight was 3130 g, Head Circumference was 34 cm, and Apgar scores were 6 (1 min), 7 (5 min), and 8(10 min). Facial paralysis was noted immediately after birth. Physical examination revealed contusion of the left zygomatic region, a 1 × 2 hematoma in the left temporal region, and left facial paralysis with asymmetric spontaneous facial expression. In fact, the right eye was closed, but the left eye was open and motionless during the different facial movements produced by the child’s cries. It is classified as grade 4 according to the House-Brackman classification, with no apparent associated facial or ear malformations ( Figure 1). Physical examination was completed by ophthalmic evaluation, which revealed the absence of an ocular abnormality. The newborn received corticosteroid at a dose of 1 mg/kg in his first hours of life and for 7 days, lubricating eye drops were applied to avoid exposure keratopathy. He was followed up closely and displayed a favorable response to treatment from the 3rd day, with total recovery in the first week.

Figure 1. Case 1: Male newborn with grade 4 facial paralysis.

Case 2

A male infant was born using forceps at 39 weeks of gestation to a 27-year-old, gravida2, para2 mother. Pregnancy and antenatal course were unremarkable, and no significant family history was noted. The birth weight was 3200 g, Head Circumference was 32 cm, and Apgar scores were 4 (1 min), 5 (5 min), and (10 minutes). Left facial palsy was observed immediately after birth. In this case, the use of forceps caused further damage, which was respiratory distress that required the use of artificial ventilation. After stabilization of his breathing state, our clinical examination showed a 1 × 2 cm ecchymosis of the left inframastoid area, a 4 cm hematoma of the left frontal region, a palpebral edema of the right eye and a 0.5 cm superficial eyebrow wound. Facial palsy was classified as grade 4 according to the House-Brackman classification more pronounced during crying ( Figure 2). There was no other cranial nerve palsy or associated major malformations, and ophthalmic evaluation was exempt from ocular abnormalities. On the 1st day of life, corticosteroids were administered at a dose of 1 mg/kg. Reevaluation at five-days age showed bilateral full and symmetric facial movements.

Figure 2. Case 2: Male newborn with grade 4 facial paralysis.

Discussion

Congenital facial palsy is a paralysis noticed from birth and is divided into two main groups: traumatic and developmental.¹ It is facial asymmetry is increased to mimic and especially crying. Asymmetry was more marked in the lower quadrant, with a deviation of the mouth from the healthy side. This is often inconspicuous in the upper quadrant. Palpebral occlusions were also possible. It has been reported that FP can make breastfeeding more difficult.³

Developmental FP is often an element of a syndrome such as the Mobius, Oculo-Auriculo Vertebral Spectrum (OAVS), Asymmetric crying Fancies, CHARGE, or Branchio-oto-renal (BOR) syndrome.^3–5

Traumatic congenital FP is the most common cause of congenital facial paralysis with a prevalence of 0,03% by Falco et al and 0, 03% by Al Tawil et al.^1,6 Falco et al found in their series that 91% of the cases were associated with forceps delivery. In contrast only 24, 1% of all deliveries in the study by Altawil involved the use of forceps. This study identified other factors, in addition to forceps, that increased the risk of traumatic facial palsy: primiparous, male sex, birth weight, maternal obesity, and maternal diabetes, but the results were not significant.⁶

In addition to forceps, traumatic injury of the facial nerve is caused by prolonged pressure of the maternal sacral promontory on the stylomastoid foramen or by compression of the nerve in the fallopian canal during delivery.^7–9

With regard to forceps delivery, Landouzy assumed that symptoms appear immediately after birth secondary to the compression of the seventh cranial nerve.² It shows a dysfunction of the hemiface, and the asymmetry is more pronounced in the lower quadrant with a deviation from the mouth to the healthy side; however, the tongue and tear duct were not injured. Clinical features are generally associated with ecchymotic lesions of the face, hemotympanum, and fractures of the temporal bone.

All symptoms worsened during the crisis period. The degree of paralysis of the facial nerve is generally close to moderate, with an intermediate degree of severity of 3–4 on the House–Brachman scale.⁷

It should be noted that the mastoid tip does not exist in newborns. The stylomastoid foramen is found just under the skin, making the facial nerve more vulnerable to forceps trauma.

In the literature, facial nerve trauma in newborns generally does not require further examination; however, a complete clinical evaluation, including otoscopy for hemotyman, is necessary. However, Smith recommended an adequate evaluation, because there are cases in his studies that do not totally recover.¹⁰ He organized his results into four groups of children according to the electrical excitability of the facial nerve, which required observation until recovery. Moreover, radiological exploration may be needed for fractures of the temporal bone and EMG if there is electrical silence or if the nerve shows signs of an increased threshold of excitability of the facial nerve. Acoustic reflex and Schirmer’s test are of limited use in newborns.¹⁰ Also Bergman recommended the use of radiological and electrophysiological examinations to differentiate between traumatic and developmental causes.⁸

Surgical exploration of the facial nerve in neonates has limited indications, as detailed by Bergman: First, complete unilateral facial palsy at birth. Second, a hemotympanum with a moved fracture of the petrous bone.⁸ Third, there was no total motor activity in all muscles innervated by the facial nerve in 3 to 5 days on electrophysiological examination. Finally, there was no recovery of facial activity on clinical and electrophysiological evaluations on the 5th day of life.

Our two patients had rapid and complete recovery after a few days of corticosteroid treatment. The majority of authors in the literature do not suggest a specific treatment for the disease due to its spontaneous and rapid healing process. Only a healthy lifestyle is required, as suggested by Kirschen Baumth, that is, to keep the baby on his unharmed side when he sleeps and to avoid putting any tightness on the child’s head or neck.¹⁰

The generally favorable evolution of facial paralysis has been well established. In the series studied by Falco, 89% of the children with adequate follow-up recover completely.¹ In the Duval series, a 100% recovery of well-monitored patients has been documented.⁷ Altawil et al. found in their series that only one in 27 patients continued to have facial paralysis at the age of 12 years.¹⁰

Conclusion

Facial nerve palsy caused by forceps use has a great potential for recovery in the first months of life. In our two cases, paralysis was classified as severe with an average grade of 4 on the House Brachman scale, with good evolution and total recovery under corticosteroids.

Consent for publication

Written Informed Consent was obtained from the patient’s legally authorized representative for publication of this case report.

Ethical approval and consent to participate

Our institution does not require ethical approval for reporting individual cases or case series.

Written Informed Consent was obtained from the patient’s legally authorized representative for the publication of this case report.