is a common problem that involves the
Paralysis of any structures innervated by the
Facial Nerve .
The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis.
The most common is
Bell's Palsy , an
Idiopathic disease that may only be diagnosed by exclusion.
A thorough
Medical History and
Physical Examination are the first steps in making a diagnosis.
Culture Representation of Facial Paralysis. 300 A.D.
Larco Museum Collection Lima ,
Peru .]]
During the , a distinction must first be made between paralysis and
Paresis (incomplete paralysis).
Not surprisingly, paralysis is far more serious and requires immediate treatment.
It must also be determined whether the
Forehead is involved in the motor defect or not.
This is usually accomplished by assessing how well a patient can raise her
Eyebrow s.
The question is an important one because it helps determine if the lesion is in the
Upper Motor Neuron component of the facial nerve, or in its
Lower Motor Neuron component.
Laboratory investigations include an
Audiogram ,
Nerve Conduction Studies (ENoG),
Computed Tomography (CT) or
Magnetic Resonance (MR) imaging.
Bell's Palsy is the most common cause of acute facial nerve paralysis (>80%). Previously considered
Idiopathic , it has been recently linked to
Herpes Zoster of the facial nerve (rarely
Lyme Disease ).
Bell's palsy is an exclusion diagnosis. Some factors that tend to rule out Bell's palsy include:
# Recurrent paralysis
# Slowly progressive paralysis (The onset of Bell's palsy is very sudden)
# Twitching
# Associated symptoms (either
Cochlea r or neurologic)
Bell's palsy is believed in the most recent studies to be due to herpes virus. Other proposed etiologies include vascular problems in the inner ear. Treatment include
Steroids and antivirals.
Physical Trauma , especially
Fracture s of the
Temporal Bone , may also cause acute facial nerve paralysis.
Understandably, the likelihood of facial paralysis after trauma depends on the location of the trauma.
Most commonly, facial paralysis follows temporal bone fractures, though the likelihood depends on the type of fracture.
''Transverse fractures'' in the horizontal plane present the highest likelihood of facial paralysis (40-50%).
Patients may also present with
Hemotympanum (blood behind the tympanic membrane), sensory
Deaf ness, and
Vertigo – the latter two symptoms due to damage to
Vestibulocochlear Nerve (
Cranial Nerve VIII) and the inner ear.
''Longitudinal fracture'' in the vertical plane present a lower likelihood of paralysis (20%).
Patients may present with
Hematorrhea (
Blood coming out of the
External Auditory Meatus ),
Tympanic Membrane tear, fracture of
External Auditory Canal , and
Conductive Hearing Loss .
Traumatic injuries can be assessed by
Computed Tomography (CT) and nerve conduction studies (ENoG).
In patients with mild injury, management is the same as with Bell's palsy – protect the
Eye s and wait.
In patients with severe injury, progress is followed with nerve conduction studies.
If nerve conduction studies show a large (>90%) change in nerve conduction, the nerve should be decompressed.
The facial paralysis can follow immediately the trauma due to direct damage to the facial nerve, in such cases a surgical treatment may be attempted. In other cases the facial paralysis can occur a long time after the trauma due to oedema and inflammation. In those cases steroids can be a good help.
A
Tumour compressing the facial nerve anywhere along its complex pathway can result in facial paralysis.
Common culprits are
Facial Neuroma s, congenital
Cholesteatoma s,
Hemangioma s,
Acoustic Neuroma s,
Parotid Gland Neoplasm s, or
Metastases of other tumours.
Patients with facial nerve paralysis resulting from tumours usually present with a progressive, twitching paralysis, other neurological signs, or a recurrent Bell's palsy-type presentation.
The latter should always be suspicious, as Bell's palsy should not recur.
A chronically discharging ear must be treated as a cholesteatoma until proven otherwise; hence, there must be immediate
Surgical exploration.
Computed tomography (CT) or magnetic resonance (MR) imaging should be used to identify the location of the tumour, and it should be managed accordingly.
Herpes Zoster Oticus is essentially a
Herpes Zoster Infection that affects
Cranial Nerve s VII (
Facial Nerve ) and VIII (
Vestibulocochlear Nerve ).
Patients present with facial paralysis, ear pain,
Vesicle s,
Sensorineural Hearing Loss , and
Vertigo .
Management includes
Antiviral s and oral
Steroid s.
''
Otitis Media '' is an infection in the middle ear, which can spread to the facial nerve and inflame it, causing compression of the nerve in its canal.
Antibiotic s are used to control the ''otitis media'', and other options include a wide
Myringotomy (an incision in the
Tympanic Membrane ) or decompression if the patient does not improve
Chronic ''otitis media'' usually presents in an ear with chronic discharge (
Otorrhea ), or hearing loss, with or without ear pain (
Otalgia ).
Once suspected, there should be immediate surgical exploration to determine if a cholesteatoma has formed and must be removed.
