As it is well known, Multiple Sclerosis is a demyelinating disease and autoimmune disease. This might sound like a whole lot, but it’s actually related. MS is considered an autoimmune disease because the sufferer’s own immune system begins to attack the body. The myelin is attacked, and hence the demyelinating disease name for this condition.
Myelin is an insulating substance that covers axons and neurons. When the myelin is attacked, the electrical signals sent by the brain don’t reach their destination and the person begins to experience several symptoms, like fatigue, muscle weakness, sexual dysfunction, bowel problems, depression, etc. Naturally, not everybody experiences the same symptoms and at the same degree of intensity. However, since there is a lot of myelin in the brain, it’s only natural to find that some of the brain’s nerves are affected by multiple sclerosis.
There are 12 cranial nerves in the brain, the olfactory nerve (smell), the optic nerve (vision), the oculomotor nerve ( responsible for pupil constriction and eye movement), the trochlear nerve ( also responsible for eye movement), the trigeminal nerve ( somatosensory information from the face and head and the muscles for chewing), the abducens nerve ( again eye movement), the facial nerve (responsible for taste -anterior 2/3 of one’s tongue- and somatosensory information from one’s ears; it also controls the muscles used in facial expression), the vestibulocochlear nerve ( responsible for hearing and balance), the glossopharyngeal nerve ( taste – posterior 1/3 of one’s tongue – and somatosensory information from tonsil, tongue, pharynx; it also controls some of the muscles used in swallowing), the vague nerve ( responsible for the autonomic, sensory and motor functions of the viscera, meaning the heart rate, glands and digestion), the spinal accessory nerve ( which controls the muscles used in head movement) and the hypoglossal nerve ( controls one’s tongue muscles).
How can one test his or her cranial nerves?
The Olfactory Nerve should be tested by smelling various and distinctive smells.
The Optic Nerve should be tested by trying to read a “Snellen Chart” like the ones your ophthalmologist has in its office.
The Oculomotor Nerve, Trochlear Nerve, and Abducens Nerve control eye movement and pupil diameter, so you should have a partner who will show you a finger and you need to follow it – up, down, left and right.
The Trigeminal Nerve has motor and sensory functions. To test it close your jaws as you were biting down on a piece of gum. This tests the motor functions. For the sensory function, you should touch lightly your face with a piece of cotton or blunt object.
The Facial Nerve’s motor function can be tested when smiling or making funny faces. The sensory function ( responsible for taste) can be tested with a bit of sugar and salt on the tongue.
The Vestibulocochlear Nerve is responsible for balance and hearing. Only the hearing portion can be tested at home. With your eyes closed, determine the distance at which you can hear the ticking of a clock.
The Glossopharyngeal Nerve and Vagus Nerve can be tested by drinking water and observing the swallowing reflex.
The Spinal Accessory Nerve can be tested by putting your hands on the sides of your head, and applying light pressure, move it side to side.
The Hypoglossal Nerve should be tested by sticking your tongue out and moving it side to side.