What are the Tests Required Before Facial Nerve Decompression?
- Blood tests: These tests help to determine if a virus such as herpes zoster oticus or other infections may be the cause of facial nerve weakness as in Bell’s palsy
- MRI scan: This imaging technique uses radio waves and a magnetic field to create computerized, three-dimensional images of the facial nerve
- Electroneurography (ENoG): This test helps to evaluate the functions and quantify the extent of damage of the peripheral nerves
- Electromyogram: This test is used to measure the electrical impulses transmitted along nerves and muscle tissue
- Stapedius reflex test: It is a type of hearing test used to assess damage to the facial nerve
- Muscle biopsy: This is useful in patients with longstanding paralysis and in cases with congenital facial paralysis
How is Facial Nerve Decompression Performed?
Facial nerve decompression surgery is performed using the transmastoid approach, middle fossa (transtemporal) approach or the translabyrinthine approach. The technique is decided prior to surgery depending on the location, extent of facial nerve damage and whether hearing is impaired or not.
What Happens During the Facial Nerve Decompression?
During the facial nerve decompression surgery the pressure or compression on the facial nerve is removed using following either one of the three approaches as appropriate. Firstly, general anesthesia is administered to the patient.
Transmastoid facial nerve decompression: The facial nerve is exposed between the stylomastoid foramen and lateral semicircular canals. The sheath of the facial nerve is opened at the injury site and also for some distance away from site of injury. After repair work the wound is closed in layers and dressing is applied over the affected ear.
Middle fossa facial nerve decompression: A six by eight centimeter trap door incision is made above the ear. This technique exposes the whole length of the internal auditory canal and labyrinthine segment. This enables the surgeon to see the entire course of the facial nerve. This procedure also keeps hearing intact.
Translabyrinthine facial nerve decompression: A three centimeter skin incision is made behind the post auricular crease extending to the apex of the mastoid. This procedure decompresses the entire intra temporal course of the facial nerve from the stylomastoid foramen to the internal auditory canal. This procedure is performed when there is complete loss of hearing.
What Happens After Facial Nerve Decompression?
- Approximately eight to ten days after the facial nerve decompression surgery the sutures are removed.
- Patients can resume their normal activities within a fortnight following the surgery.
- However, periodic follow-ups are necessary to prevent any complications and to make sure that the recovery is on track.
- Complete recovery after facial nerve decompression surgery depends on extent of nerve damage and some patients are left with some degree of permanent facial weakness.
