Facial Nerve Paralysis in Children

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Original Editor

Top Contributors - Carina Therese Magtibay, Habibu Salisu Badamasi, Chelsea Mclene, Rishika Babburu and Mila Andreew  

Original Editor - User Name
Top Contributors - Carina Therese Magtibay, Habibu Salisu Badamasi, Chelsea Mclene, Rishika Babburu and Mila Andreew

Introduction

Facial Palsy is one of the most common cranial nerve dysfunctions in children and is a frequent presentation in pediatric emergency facilities. Spontaneous recovery is noted in the majority of the cases and prognosis correlates with age and severity of paralysis. Although less common in children than in adults, facial paralysis can have a huge impact on a child's life as well as the family especially if left untreated.

Clinically Relevant Anatomy

For an in-depth discussion on the facial nerve anatomy, please head to the Facial Nerve page.

The facial nerve, which is the seventh cranial nerve (CNVII), is responsible for facial muscle movement, lacrimation and salivation. Many parts of the head and neck region are innervated by its parasympathetic (secretomotor), motor, and sensory nerve fibers.

The course of the facial nerve is divided into two parts:

• intracranial segment
• extracranial segment

The facial nerve divides at the end of the parotid gland into five terminal branches:

• temporal - innervates the frontalis and orbicularis oculi muscles and the muscles along with the upper part of the face
• zygomatic - innervates the middle part of the face
• buccal - innervates the cheek muscles
• mandibular - innervates muscles of the lower part of the face
• cervical - innervates the muscles below the chin and platysma muscle

Mechanism of Injury / Pathological Process

Idiopathic

The cause of about 60-80% of facial palsy in children remains unknown. Commonly known as Bell's Palsy, studies hypothesize that inflammation damaging the nerve may have resulted from viruses such as Herpes Simplex 1, although there are no conclusive studies yet to prove its causative role in facial nerve dysfunction.

Congenital

The following can cause congenital facial paralysis:

1. Delivery traumas:
   • Primiparity
   • Birth weight > 3500 g
   • Forceps
   • Cesarean section
   • Prematurity
2. Syndromic malformative:
   • Möbius syndrome
   • Goldenhar syndrome
   • Syringobulbia
   • Arnold-Chiari syndrome
3. Genetic
   • Hereditary myopathies
   • 3q21-22 and 10q21.3-22.1 mutations

Acquired

Acquired causes include:

1. Infectious
   • Ramsay Hunt syndrome
   • Epstein-Barr virus
   • Haemophilus influenzae
   • Tubercolosis
   • Lyme disease
   • Cytomegalovirus
   • Adenovirus
   • Rubella
   • Mumps
   • Mycoplasma pneumoniae
   • Human immunodeficiency virus
   • Acute otitis media
   • Chronic otitis media/cholesteatoma
2. Inflammatory
   • Henoch-Schönlein porpora
   • Kawasaki syndrome
3. Neoplastic
   • Schwannomas of the VII c.n.
   • Hemangiomas
   • Rhabdomyosarcoma
   • Temporal bone histiocytosis
   • Leukemia
   • Parotid gland tumors
4. Traumatic
   • Temporal bone fractures
   • Iatrogenic

Clinical Presentation

Facial palsy can have motor, sensory, and visceral affectations. Signs and symptoms to look out for:

• Facial asymmetry -facial creases and nasolabial fold disappear, dropping mouth, eyelid widening and lagophthalmos
• Inability to whistle, puff cheeks, frown, close the eyelid
• Bell's Sign
• Hyperacusis (due to stapedius muscle paralysis)
• Paresthesias or pain of the ear (pinna or of the concha)
• Lacrimal and salivary production can be reduced (visceral deficit)
• Corneal irritation(secondary to lagophthalmos)
• Metallic taste in the mouth (due to the taste alteration of the anterior 2/3 of the tongue)

For newborns and infants:

• Unilateral facial paralysis can be suspected when there's asymmetry of the face when crying
• With severe paralysis, newborns or infants may not be able to close their eye on the affected side, leading to uneven facial appearance and can potentially interfere with breastfeeding.

Diagnostic Procedures

A thorough medical history review and physical exam are vital for the proper diagnosis of facial paralysis. The history of onset and progression, associated symptoms, and comorbidities should be identified and investigated. Relevant examinations include:

• Facial nerve evaluation
• ENT exam to assess the external auditory canal, eardrum, mastoid region
• Audiological assessment
• Blood pressure and blood count
• Serologic testing (immunoglobulin G and M) for children living in Lyme-endemic territories during the spring and autumn months
• Imaging such as computed tomography (CT) or magnetic resonance imaging (MRI)- for suspected chronic otitis media, acute mastoiditis, trauma, or neoplasm.
• Electroneuronography (ENoG)
• Lumbar puncture- done only if central nervous system infection such as meningitis and Guillain-Barré syndrome is suspected

Outcome Measures

The severity of facial paralysis can be assessed using House–Brackmann Scale. It is a grading system that assesses facial muscle functions, including the closing of eyes, elevating brows, frowning, smiling, and puckering lips.

Management / Interventions

• Drug Therapy- As Bell's palsy typically resolves on its own in pediatric population, the goal of drug therapy is to reduce the likelihood of incomplete resolution and minimize the risk of complications such as synkinesis, autonomic dysfunctions (e.g., crocodile tears), and facial spasms.
• Eye Care- Facial palsy can cause incomplete closure of the affected eyelid, which increases the risk of irritation and corneal ulceration due to inadequate eye protection and decreased tear production. Eye-protective measures such as artificial tears, ophthalmic lubricating ointment during sleep, an eyelid patch at night, and sun protection are recommended.
• Physiotherapy - Although there is little evidence available, various rehabilitative techniques such as physiotherapy, biofeedback therapy, relaxation exercises with massage therapy, and coordination and facial expression exercises may be effective in reducing muscle stiffness and improving facial movements.

Differential Diagnosis

• Lyme Disease
• Meningitis
• Chronic otitis media
• Acute mastoiditis
• Guillain-Barré syndrome

Causes

There are several causes of facial nerve paralysis in children. its can be cause by congenital or acquired.

Congenital

This may be due to traumas during birth, as well as hereditary or malformative disorders.

• Delivery trauma: Mother's first child, birth weight larger than 3500 g, use of forceps, cesarean birth, and prematurity are the main known risk factors for traumatic facial paralysis.
• syndromic malformation: can be one of the following:

1. Möbius syndrome: It is reported to be due to hypoplasia of the motor nuclei of the cranial nerves within the brainstem, probably due to a hypoxic-ischemic encephalopathy.
2. Goldenhar syndrome : Also known as hemifacial microsomia, with a spectrum of congenital malformations involving the structures derived from the first and second branchial arch), can also present a congenital facial paralysis.
3. Congenital pseudobulbar palsy (Syringobulbia) : is a condition that clinically manifests with facial paralysis, dysphagia and speech difficulties.
4. Arnold-Chiari syndrome: Congenital facial paralysis is usually associated to other cranial nerves paralysis (especially the VI one) due to malformations of the posterior fossa that allow herniation of brain structures through the foramen magnum.

• Hereditary myopathies: such as myotonic dystrophy and myasthenia, are among the genetic causes of facial nerve paralysis. Two loci (chromosome 3q21-22 and 10q21.3-22.1) have also been found to be responsible for isolated hereditary types of facial paralysis.

Acquired

Facial paralysis can frequently be due to viral infections.

Herpes Varicella-Zoster may be responsible, even in children, of Ramsay Hunt syndrome (zoster oticus); in this case, facial palsy can be associated to the presence of vesicular lesions of the external auditory canal and/or of the auricular concha. The incidence of this syndrome under 10 years of age is reported to be 2.7/100000.

Not frequently, a bilateral facial nerve palsy may be the onset of a Epstein-Barr virus, Haemophilus influenza, tuberculosis or Borrelia burgdorferi infection.

Lyme disease has become the most common cause of acute facial paralysis in children in those areas where Borrelia Burgdorferi infection is endemic. Other agents that may cause facial nerve palsy in children are cytomegalovirus, adenovirus, rubella, mumps, Mycoplasma pneumoniae and HIV.