Indications for facial nerve decompression
Bell’s Palsy, traumatic facial nerve palsy, skull fractures, chronic suppurative otitis media, parotid tumours and tumours of the facial nerve.
It is a distinctive type of nerve that is responsible for facial expression. It starts from the pons which is a part of the brain. It passes very close to the ear and runs through the Parotid gland to enter the face. It divides into further branches which spread across all the facial muscles.
The facial nerve is the longest nerve that travels in the bony canal with a complicated course. This rigid bony canal does not give space for expansion, making the nerve more susceptible to injury.
There are some conditions in which functions of the facial nerve get compromised. Compression is due to swelling of the nerve and vascular congestion. One of the most common disorders of the facial nerve is facial paresis. Facial paresis happens when the nerve either gets compressed or severed. This leads to facial weakness, drooping mouth, drooling of saliva, incomplete eye closure, facial asymmetry, etc.
Investigation
The doctor will determine if a decompression surgery is required by an electroneurography test. This diagnostic test measures the muscle response to nerve stimulation. It allows doctors to assess whether the nerve can regenerate and eventually return motor function to the facial muscles.
If there is an improvement in nerve activity, the doctor waits a few days for further improvement. If the nerve activity continues to improve, there is no need for surgical intervention. The patient should recover over 3 to 6 months.
However, when there is either no nerve activity or, there has been no improvement, decompression surgery would be advised to help the nerve recover.
The procedure
Decompression surgery is where doctors enlarge the space through which the facial nerve passes. It comprises opening the bony canal and nerve sheath to release pressure and reduce compression on nerve fibres. It is a complicated procedure that involves removing the bone that is causing the compression of the nerve. Decompression surgery is challenging because the nerve follows a complex meandering path from the brainstem to the face going through the temporal bone and around the inner ear structures. Hence, intricacy and accuracy are essential. The goal of decompression surgery is to improve blood circulation. It minimises damage to distal nerve fibres.
For best results, surgery should preferably be performed within a few days and a maximum of two weeks from the onset of symptoms. Doctors would then be able to relieve pressure on the nerve, possibly preventing permanent nerve damage. It would also accelerate the patient’s recovery.
Post-Operative Management
After the surgery, the nerve could take a long time to recover. However, people can resume most of their routine activities about two weeks after the surgery. Sutures are removed ten days after surgery.
Regular follow-up visits are vital to assess the progress and recovery of the patient.
Certain precautions must be taken until the facial muscles regain their motor functions. Eye protection is crucial until proper eyelid closure is possible. Frequent use of lubricating eye drops prevents the eye from drying out. Therapy is also advised that focuses on facial nerve rehabilitation. It helps to regain control over the facial muscles more naturally.