There are 12 cranial nerves in total. These nerves leave the base of the brain and travel through different parts of the face and head. The cranial nerves perform important functions, from providing sensation and controlling facial movements to initiating protective reflexes.
The cranial nerves are vulnerable to head injury because many of them run along the surface of the skull and are protected only by the muscles and tissues of the face. Penetrating, scraping, and cutting injuries can stretch, break, or cut the cranial nerve. Broken bones in the face and skull can also damage nerves. The consequences of a cranial nerve injury can be temporary or permanent, depending on the nature of the injury.
Functions of the cranial nerves
Because the cranial nerves control observable actions such as eye movement, chewing, and smiling, damage can be seen and felt when the function associated with the nerve changes. Here's what the 12 cranial nerves do and what can be lost if the nerve is damaged:
Smell : provides the sense of smell.
II Optics: transfers visual information from the eye to the brain
III Oculomotor: controls multiple movements of the eyes and eyelids; it also controls the size of the pupils depending on the light.
IV Trochlear : controls the movement of the eyes downward and inward toward the nose
V Tee: conveys the sensation of touching your face; also controls the chewing muscles
VI Abducens: controls the horizontal movement of the eyeball.
VII Facial: moves the muscles that create facial expressions; provides a taste sensation to the front two-thirds of the tongue.
VIII Auditory-vestibular: provides a sense of hearing and also transmits information about the position of the body in space to the brain.
IX Glossopharyngeal: controls the muscles of the throat, the salivary glands and provides taste information from the posterior third of the tongue; It detects changes in blood pressure and reports it to the brain so it can respond.
X Vagus: controls the heart, lungs, and abdominal organs.
XI Back accessory: controls the muscles of the throat and neck.
XII hypoglossal: move the tongue and allow to speak
These nerves are understood to control important functions of the head, face, and neck. Although the damage is sometimes noticeable immediately, the disability can manifest itself within hours or days. For example, if a growing blood clot presses on the cranial nerve and the nerve begins to die, this may appear after a while.
What does the damage look like?
One of the nerves most commonly damaged during a head injury is the olfactory nerve I. Damage to this nerve affects not only the sense of smell, but also the ability to taste food, as smell is an important component of the taste.
If the facial nerve , the seventh cranial nerve, is damaged, one side of the face will not be able to express emotions and taste can change . The damage to this nerve is alarming because it alters one of the most used forms of expression and also affects self-esteem.
The optic nerve , cranial nerve II, can be damaged by skull fractures. If it is cut, it results in irreversible blindness of the affected eye .
These are just some examples. After injury, each nerve exhibits unique symptoms.
If the cranial nerve is cut completely in two, it cannot be repaired. However, if it is stretched or bruised, but the nerve remains intact, it may heal. This takes time and can cause many unpleasant symptoms, such as tingling and pain. These symptoms are a good sign that the nerve is healing.
Steroids can be used to reduce inflammation around the cranial nerve. Surgery is sometimes required if blood called a hematoma compresses the nerve and causes paralysis or dysfunction.
Neurologists and neurosurgeons perform specialized scans and interventions to correct this type of nerve damage and should be consulted.