Lesson 1, Topic 1
In Progress

Structural Diseases and Disorders

April 11, 2024

Structural Diseases and Disorders

Learning Objective: Examine structural diseases and disorders that impact the nervous system, including the signs, symptoms, etiology, diagnostic procedures, and treatments.

Structural diseases and disorders of the nervous system include Bell’s palsy, Guillain-Barré syndrome, and trigeminal neuralgia. These diseases and disorders are discussed in this section.

Bell’s Palsy

Learning Objective: Describe Bell palsy, including the signs, symptoms, etiology, diagnostic procedures, and treatments.

Bell’s palsy is the most common cause of facial paralysis. The symptoms typically affect one side of the face and are at their worst about 48 hours after the onset. The exact cause is unknown. The facial nerve becomes swollen and inflamed. The risk of Bell’s palsy increases with pregnancy, diabetes, or an upper respiratory viral infection. The signs and symptoms include facial twitching, weakness, and paralysis; drooping of the eyelid or corner of the mouth; dry eyes or excessive tearing; drooling, dry mouth, and a diminished ability to taste (FIGURE 22.10).
The provider will do a medical history and a physical examination. No other tests are usually ordered. Usually, symptoms resolve within 2 weeks, but it may take 3 to 6 months to return to normal function. Some mild cases do not require treatment, whereas others may be treated with antiviral and corticosteroid medications. Protecting the eye from injury is important; thus eye drops for lubrication and a patch for protection may be used.

FIGURE 22.10  Bell’s palsy (right sided).

Guillain-Barré Syndrome

Learning Objective: Describe Guillain-Barré syndrome, including the signs, symptoms, etiology, diagnostic procedures, and treatments.

Guillain-Barré syndrome is a rare autoimmune disorder in which the immune system attacks the peripheral nervous system. The etiology is unknown, but the disorder may be triggered by surgery, an infection, or vaccination. Weakness and tingling start in the legs and spread through the body, making the person almost paralyzed. The disease is life-threatening, and the person may require a respirator to breathe. It may take several weeks before the symptoms improve, and recovery can take up to a few years.
After the physical examination, the provider may order electromyography, nerve conduction studies, and a lumbar puncture. This disorder is difficult to diagnose. Treatment is aimed at relieving the symptoms and supporting breathing if needed.

Trigeminal Neuralgia

Learning Objective: Describe trigeminal neuralgia, including the signs, symptoms, etiology, diagnostic procedures, and treatments.

Trigeminal neuralgia (TN) is also called tic douloureux. TN is a chronic pain condition that affects the trigeminal nerve (cranial nerve V).
A blood vessel or tumor pressing on the trigeminal nerve can cause trigeminal neuralgia. People with multiple sclerosis can also experience TN. This condition is more common in people over age 50 and in females than males. Pain is felt in the cheek, lips, gums, or chin on one side of the face. Pain can vary from sudden, severe, and stabbing to constant, aching, and burning. The pain can be widespread or just in a small area. Activities such as shaving, eating, and talking can trigger intense flashes of pain. The symptoms can stop for a period of time but will come back with greater intensity.
The provider will perform a physical examination and neurologic examination. An MRI may also be ordered. Treatment may include analgesics, anticonvulsants, and antidepressants. Surgical procedures may also be done. A rhizotomy is a surgical procedure that damages nerve fibers to block pain. This procedure may cause sensory loss and facial numbness. Trigeminal neuralgia is a debilitating disorder.

Other Structural Diseases and Disorders

Learning Objective: Describe other structural diseases and disorders.v

The following are additional structural diseases and disorders.

• Astrocytoma: A malignant tumor of nervous tissue composed of astrocytes. This type of tumor can spread widely throughout the brain, making it hard to surgically remove.
• Medulloblastoma: A fast-growing brain tumor composed of medulloblasts, seen in children and adolescents.
• Meningioma: A common malignant tumor that begins in the meninges. The risk increases with age, and this tumor is more common in females.
• Neuroblastoma: A rare malignant tumor of the sympathetic nervous system seen in young children.