American Medical Association Family Medical Guide - American Medical Association [442]
Trigeminal nerve
The trigeminal nerve, which supplies sensation to the scalp, face, eyes, nose, mouth, teeth, sinuses, tongue, and jaw muscles, divides into three main branches—the ophthalmic branch, the maxillary branch, and the mandibular branch. Damage or disease in one branch of the trigeminal nerve can cause pain and inflammation in the area of the face or head served by that nerve branch.
Symptoms
Trigeminal neuralgia produces severe, shooting pain on one side of the face, usually in the cheeks, lips, gums, or chin. The pain can be disabling and can last from a few seconds to a few minutes. The pain can occur without warning or, in some people, can be triggered by touching a sensitive area of the face. In some cases, the pain recurs every few minutes over a period of several days or weeks.
Diagnosis
Trigeminal neuralgia is diagnosed by the symptoms and a neurological examination. Your doctor may refer you to a neurologist (a doctor who specializes in treating disorders of the nervous system) for diagnostic tests and treatment.
Treatment
Doctors prescribe pain relievers to treat trigeminal neuralgia, usually along with anticonvulsant medications or antidepressants, to prevent irritated nerves from firing pain messages to the brain. In severe cases, doctors may recommend surgery to remove a blood vessel that is pressing on the nerve. Occasionally, doctors will destroy the damaged nerve. Because destruction of the nerve results in permanent numbness in the face, doctors usually recommend this type of surgery only in cases of extreme, recurring pain.
Myasthenia Gravis
Myasthenia gravis is a rare, chronic autoimmune disease in which the body’s immune system mistakenly produces antibodies that interfere with the transmission of nerve impulses to muscle tissues, preventing muscle contraction. The thymus gland, which is part of the immune system, has a significant role in this faulty immune response that doctors do not fully understand. Although myasthenia gravis can occur at any age, it usually affects women under 40, but can also occur later in life, when it is more likely to be associated with a tumor.
Symptoms
The main symptom of myasthenia gravis is muscle weakness. Weakness in the eye muscles can cause drooping eyelids and blurred vision. Because the muscles that control the mouth are also affected, some people may have difficulty speaking, chewing, or swallowing. Weakened muscles in the arms, hands, and fingers may make it difficult to perform simple manual tasks. Weakened leg muscles may make standing or walking difficult. Breathing problems can result from weakened respiratory muscles. The weakness increases with physical exertion and decreases with rest. The degree of weakness can vary throughout the day and from one day to the next.
Diagnosis
To diagnose myasthenia gravis, a doctor takes a detailed health history and performs a physical examination. He or she pays special attention to signs of problems with eye movement and muscle weakness. The doctor also may order a blood test to check the blood for antibodies (infection-fighting proteins), nerve conduction tests to determine if another condition is causing the symptoms, and an electromyogram to evaluate the electrical activity of muscles. A CT scan (see page 112) or an MRI (see page 113) may be used to look for a growth in the thymus gland. A lung function test (see page 647) can evaluate the severity of breathing problems resulting from muscle weakness.
Treatment
Myasthenia gravis has no cure, but treatment can relieve the symptoms and enable a person to lead an active, productive life. A doctor may prescribe a long-acting medication such as pyridostigmine to restore transmission of nerve impulses to the affected muscles and increase muscle strength. He or she also may prescribe corticosteroids or immune-suppressing