Neurological disorder, facial palsy is due to a "functional alteration of the facial nerve (or VII cranial nerve), an alteration that may arise from unrecognizable causes (Bell's palsy), a head injury, an" infection, an episode of stroke or a tumor.
Facial paralysis presents with characteristic symptoms and signs; these symptoms and signs consist of: wide eye, lowering of the corner of the mouth, difficulty making facial expressions and smiling, wrinkle-free forehead, immobile eyebrow and flat nasolabial fold.
For the diagnosis of facial paralysis, a thorough physical examination, a scrupulous medical history and a neurological examination are essential; sometimes, blood tests and imaging are also needed.
The presence of a facial paralysis requires the use of therapy aimed at counteracting the triggering cause of the condition; only with such an approach, in fact, is it possible to hope for a recovery of facial expressions.
(i.e. between the Varolio bridge and the medulla oblongata) and, through its innumerable ramifications, it is distributed in various regions of the head, to innervate:
- The muscles responsible for facial expressions; these include elements such as, for example, the depressor of the corner of the mouth, the frontal muscle, the orbicularis muscle of the lips, the orbicularis muscle of the eye, the levator muscle of the upper lip, the procerus muscle, the corrugator muscle of the eyebrow and the buccinator muscle.
- The digastric muscle and the stylohyoid muscle; these muscles are involved in functioning such as speaking, swallowing food, chewing and breathing.
- The stapedius muscle of the middle ear; this muscle controls the movements of the stirrup, one of the three ossicles of the middle ear involved in the process of perception of sounds.
- The mucous glands of the nose, mouth and pharynx.
- The lacrimal glands.
- The submandibular and sublingual salivary glands.
- The front 2/3 of the tongue; here, the innervation is of the sensitive type and contributes to the gustatory sensitivity of the area in question.
What are the Causes of Facial Paralysis?
Several conditions can alter the functioning of the facial nerve, thus causing the phenomenon of facial paralysis.
Just to mention some of the most important causes, the functional alteration of the facial nerve and the consequent facial paralysis can be identified with Bell's palsy, they can be due to an "infection or a head injury, they can depend on a tumor, they can be the consequence of stroke etc.
Bell's palsy and facial palsy
Bell's palsy is the condition resulting from inflammation or compression of the facial nerve.
The exact cause of this disorder is not at all clear; experts, however, are inclined to think that there is a correlation with some viral infection of the 7th cranial nerve.
Numbers in hand, Bell's palsy is the main cause of facial paralysis; just think that, in the United States alone, it affects about 40,000 people every year.
Fortunately, Bell's palsy is a condition from which it is possible to fully recover (only rarely, it leaves unrecoverable marks).
When identified with Bell's palsy, facial palsy is also called idiopathic facial palsy, as it cannot be associated with any well-defined cause.
Infections and Facial Paralysis
Various infections can cause facial paralysis; these include:
- Lyme disease, caused by the bacterium Borrelia burgdorferi.
- Type II Ramsay Hunt syndrome, caused by a reactivation of the virus Herpes zoster hidden at the level of the geniculate ganglion of the facial nerve.
- Otitis media.
- AIDS, caused by HIV.
Did you know that ...
Where it is a common infection, Lyme disease is responsible for 25% of facial paralysis cases.
Head Trauma and Facial Paralysis
If localized at the level of the temporal bone, head injuries can cause more or less severe damage to the facial nerve and trigger the classic symptoms of facial paralysis.
Typically, the head injuries in question are the consequence of a fall; in the newborn, however, it is possible that they also arise from the use, during birth, of the suction cup or forceps.
Facial Tumors and Paralysis
Tumors that originate from a cell constituting the facial nerve or that arise in the vicinity of the facial nerve are responsible for facial paralysis; tumors with such characteristics, in fact, cause compression of the cranial nerve in question and, consequently, alter its function.
Examples of tumors related to facial paralysis are hemangioma or schwannoma of the facial nerve, acoustic neuroma and neoplasms of the parotid gland.
Stroke and Facial Paralysis
Stroke consists of an "interruption in the flow of blood to a specific part of the brain, followed by necrosis of the latter" due to a lack of oxygen and nutrients (which are carried by the blood).
A stroke episode can cause facial paralysis when it affects the arteries that supply the bulb-pontine junction of the brainstem, which is the site of the motor neurons of the facial nerve responsible for controlling the muscles of the face.
Other Causes of Facial Paralysis
Other potential causes of facial paralysis are:
- Diabetes mellitus;
- Sarcoidosis;
- Guillain-Barré syndrome;
- Moebius syndrome;
- The application of piercings on the eyebrow or tongue (rare, but possible).
- Eyes wide open;
- Lowering of a corner of the mouth;
- Difficulty making facial expressions and smiling
- Wrinkle-free forehead and immobile eyebrow;
- Flat nasolabial fold.
The aforementioned manifestations generally concern only one half of the face, specifically the half innervated by the compromised facial nerve (NB: remember that the facial nerve is an even and symmetrical nerve, therefore it is present in two copies and is distributed in a similar way to the right and left of the head).
It should also be noted that some patients complain of all the symptoms and signs listed above, while others only a part: the precise symptomatology essentially depends on the location of the alteration along the course of the facial nerve.
Other Symptoms of Facial Paralysis
Sometimes, facial paralysis also causes:
- Reduced lacrimation and consequent dry eye;
- Sialorrhea (excessive saliva production);
- Hyperacusis (hypersensitivity to sound) combined with ear pain;
- Difficulty eating and drinking
- Difficulty speaking
- Alteration of the sense of taste at the lingual level.
These symptoms and signs are explained by the fact that the facial nerve also controls the lacrimal glands, the submandibular and sublingual salivary glands, the stapedius muscle of the middle ear, two muscles - the digastric and the stylohyoid - important for phonation, swallowing of the food and chewing, and the gustatory sensitivity of the anterior 2/3 of the tongue.
Furthermore, it should be noted that:
- If it is due to type II Ramsay Hunt syndrome, facial paralysis involves the appearance of small blisters inside the ear;
- If it is due to a stroke, facial paralysis could be associated with disorders such as: confusion, impaired consciousness, dizziness, loss of coordination, vision problems and a sense of weakness affecting the limbs on one side of the body.
To know in detail the treatment of Bell's palsy, we recommend reading what is reported here.
In case of Bell's palsy, the use of lubricating eye drops and artificial tears is very important, because it protects the eye which, since it is always open, is not subject to proper lubrication and is continually exposed to harmful agents. health.
Treatment of Facial Paralysis due to a Tumor
When facial paralysis is the result of the presence of a tumor, the treatment involves the removal of the tumor mass, in order to decompress the facial nerve and restore normal functionality.
Treatment of Facial Paralysis due to a Stroke
Facial paralysis due to stroke basically requires therapy to restore normal blood flow to the brain (if the stroke is ischemic) and rehabilitation therapy.
Facial Paralysis Therapy due to an Infection
If facial paralysis has an infectious origin, it is essential to treat the infection responsible for the condition for healing.
