Well, hope what I found below will be able to shed some light on the confusion.
Facial nerve paralysis, or facial nerve palsy refers to the paralysis of the facial muscles. This disorder can have numerous causes. These includes
Trauma: such as birth trauma, skull base fractures, facial injuries, middle ear injuries, or surgical trauma.
Nervous system disease: including Opercular syndrome, Millard-Gubler syndrome.
Infection: of the ear or face, or Herpes Zoster of the facial nerve (Ramsey-Hunt syndrome).
Metabolic: diabetes mellitus or pregnancy.
Tumors: acoustic neuroma, schwannoma, cholesteatoma, parotid tumors, glomus tumors.
Toxins: alcoholism or carbon monoxide poisoning.
If no apparent cause can be found in a patient with facial nerve paralysis, then it is said to be idiopathic and the patient is diagnosed as having Bell's palsy (a diagnosis of exclusion). In other words, Bell's palsy is an idiopathic facial paralysis.
As the name suggests, there is no known etiology behind Bell's palsy as yet. Some schools of thought suggest that Bell's palsy is caused by a viral infection of the facial nerve with the most likely virus being the herpes simplex virus.
Bell's palsy is usually a self-limiting, non-life threatening condition that spontaneously remits within six weeks. The incidence is 15-40 new cases per 100,000 people per year in the US. It is one of the most common neurological disorders affecting the cranial nerves. There is no predominant age or racial predilection; however it is 3.3 times more common during pregnancy and slightly more common in menstruating females. In general, the incidence increases with advancing age.
The typical symptoms of Bell's palsy include:
Unilateral acute paralysis of facial muscles. The paralysis involves all muscles, including the forehead.
About half the time, there is numbness or pain in the ear, face, neck or tongue.
There is a preceding viral illness in 60% of patients.
There is a family history of Bell's palsy in 10% of patients.
Less than 1% of patients have bilateral problems.
There may be a change in hearing sensitivity (often increased sensitivity).
The proposed mechanism of injury of the facial nerve in Bell's palsy is:
Primary viral infection (herpes) sometime in the past.
The virus lives in the nerve (trigeminal ganglion) from months to years.
The virus becomes reactivated at a later date.
The virus reproduces and travels along the nerve.
The virus infects the cells surrounding the nerve (Schwann cells) resulting in inflammation.
There immune system responds to the damaged Schwann cells which and causes inflammation of the nerve and subsequent weakness or paralysis of the face.
The course of the paralysis and the recovery will depend upon the degree and amount of damage to the nerve.
Facial nerve palsy or Bell's palsy? You tell me! =)
Source: http://www.medicinenet.com/facial_nerve_problems/page3.htm
No comments:
Post a Comment