Functional Diseases and Disorders of the Nervous System
Functional Diseases and Disorders of the Nervous System
Learning Objective: Examine functional diseases and disorders, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Functional diseases and disorders impact the function of the neurologic system. The most common functional diseases and disorders include headaches, migraines, seizures, and epilepsy.
Cluster Headaches
Learning Objective: Describe cluster headaches, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Cluster headaches occur in cyclical patterns or clusters. The person may awaken in the middle of the night with a headache on one side of the head.
The etiology is unknown, but there may be an increase in the release of histamine or serotonin that causes the pain. The signs and symptoms include a severe, sudden, one-sided headache with tearing of the eyes, droopy eyelids, and stuffy nose. The onset commonly occurs 2 to 3 hours after falling asleep.
The provider will do a physical examination and may order an MRI to rule out other conditions. Often medications such as sumatriptan (Imitrex), dihydroergotamine (DHE), and analgesics may be ordered. Breathing in 100% pure oxygen may also help to reduce the headaches. The cluster of headaches may last for weeks to months, and then a remission period follows.
Tension Headaches
Learning Objective: Describe tension headaches, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Tension headaches are the most common type of headaches. Tension headaches occur when the neck and scalp muscles become tense. Stress, depression, anxiety, and head injuries may be the most common causes. The person may experience a dull, aching headache and feelings of tightness and pressure in the forehead area to the back of the head.
After taking a history, the provider may order a CT scan or MRI. Usually, the patient manages the pain with home treatments, such as over-the-counter (OTC) analgesics. Muscle relaxants and antidepressants may also be used.The etiology is unknown, but there may be an increase in the release of histamine or serotonin that causes the pain. The signs and symptoms include a severe, sudden, one-sided headache with tearing of the eyes, droopy eyelids, and stuffy nose. The onset commonly occurs 2 to 3 hours after falling asleep.
The provider will do a physical examination and may order an MRI to rule out other conditions. Often medications such as sumatriptan (Imitrex), dihydroergotamine (DHE), and analgesics may be ordered. Breathing in 100% pure oxygen may also help to reduce the headaches. The cluster of headaches may last for weeks to months, and then a remission period follows.
Migraines
Learning Objective: Discuss migraines, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Migraines are recurring headaches that can affect children through adults. The causes of migraines may include stress, anxiety, hormone changes, strong smells, and bright lights. Many times, migraines progress through four stages:
• Prodrome (1 to 2 days before): May cause mood changes, food cravings, neck stiffness, increased thirst, and constipation.
• Aura (may occur before or during the migraine): May cause visual, sensory, motor, or verbal disturbances. Examples include hearing noises, difficulty speaking, vision loss, and jerking.
• Attack (may last up to 72 hours): May cause throbbing pain on one or both sides of the head; sensitivity to light, noise, and smells; nausea and vomiting, blurred vision, and lightheadedness.
• Postdrome (up to 24 hours after): May cause confusion, moodiness, dizziness, weakness, and sensitivity to noise and light.
The provider will do physical and neurologic examinations. Treatment consists of rest, fluids, and medications, such as sumatriptan (Imitrex), dihydroergotamine (DHE), and analgesics.
Seizure Disorders
Learning Objective: Describe seizure disorders, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
A seizure (or convulsion) is a sudden increase of electrical activity in one or more parts of the brain. The seizures are classified based on how the abnormal brain activity begins.
• Generalized onset seizure (was called generalized seizure): Affects both sides of the brain.
• Focal onset seizure (was called partial seizure): Affects one area of the brain.
• Unknown onset seizure: How it affects the brain is unknown.
Some seizures may start as a focal onset and then spread to both sides of the brain, like clonic and atonic seizures. There are many types of seizures, and the more common types are listed in TABLE 22.2.
Seizures can be caused by medications, high fevers, head injuries, diseases, and illegal drugs. The signs and symptoms of the different seizure classifications are listed in TABLE 22.2. Most seizures do not cause harm, but if they last longer than 5 minutes or the person has repeated seizures without waking up between them, it is a medical emergency.
The provider will do a neurologic exam and may order blood tests to check for conditions associated with seizures (e.g., infections). Additional tests may include neuropsychological tests, an electroencephalogram (EEG), CT, MRI, PET, and a single-photon emission computed tomography (SPECT) scan. Depending on the type of seizure, antiseizure medication may be used.
22.6
Critical Thinking Application
Nancy is attempting to remember the three classifications of seizures. What might be ways that she can remember them?
Table 22.2
Seizure Classification
| New Groups | New Classification(Older Name) | Description | Symptoms |
|---|---|---|---|
| Generalized onset | Tonic-clonic (Grand mal) | Loses consciousness. Tonic phase (rigid muscles) comes first, followed by clonic phase (jerking rapidly). May be incontinent of stool and urine. Lasts 1–3 minutes; sleepy and confused after seizure. | Motor: Sustained jerking (clonic), weak muscles (atonic), rigid muscles (tonic), brief twitching (myoclonus), and spasms Nonmotor: Staring spells, twitching |
| Focal to bilateral tonic-clonic (Secondarily generalized) | Starts in one area of the brain and spreads to involve both sides. Usually lasts 1–3 minutes. | ||
| Absent (Petit mal) | Lapse of awareness of the environment; more common in children. | ||
| Atypical absence | Will stare but may be able to respond; begin and end gradually. May fall. Can last 5–30 seconds. | ||
| Focal onset | Focal aware (Simple partial) | Awake and alert during seizure; lasts less than 2 minutes. | Motor: Clonic, atonic, tonic, myoclonus, spasms, automatic movements (e.g., lip smacking, clapping, chewing) |
| Focal impaired awareness (Complex partial) | Confused during seizure; lasts 1–2 minutes. Aura may occur. | Nonmotor: Changes in emotions, thinking, heart palpitations, goose bumps, lack of movement | |
| Atonic | Can begin as a focal seizure and then spread to both sides of the brain, becoming a generalized seizure). Lasts less than 15 seconds. | Loss of muscle tone, head or body may go limp; head may drop | |
| Unknown onset/unknown | When seizure began is not known, or seizure was not witnessed. | Motor: Tonic-clonic, spasms Nonmotor: No movements, stares |
From the Centers for Disease Control and Prevention (CDC), www.cdc.gov/epilepsy/communications/features/seizures.htm; and the Epilepsy Foundation, www.epilepsy.com/learn/types-seizures.
Epilepsy
Learning Objective: Describe epilepsy, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Epilepsy is a disorder that causes recurring seizures. A person must have at least two unprovoked seizures before epilepsy is diagnosed. The type of seizure is classified either as generalized or focal. Epilepsy can affect anyone at any age, ethnic background, or sex. Children can outgrow epilepsy.
There are several causes of epilepsy, including genetics, brain injury, abnormal development, and illness. Many times, the cause is not known. Signs and symptoms vary based on the type of seizure and can include confusion, staring, uncontrolled jerking, and loss of consciousness (see TABLE 22.2). Status epilepticus, an emergency condition, occurs when a seizure lasts longer than 10 minutes or if the person has three or more seizures without regaining consciousness between them.
The provider will do a neurologic examination and may order the tests listed in the Seizure Disorder section. Treatments include antiseizure medications, a ketogenic diet (eating foods high in fats and low in carbohydrates), vagus nerve stimulation, and deep brain stimulation (from a surgically implanted generator and electrodes). If medications fail to control the seizures, surgery can be done to remove the portion of the brain causing the seizures.
Other Functional Diseases and Disorders
Learning Objective: Describe other functional diseases and disorders.
Additional functional diseases and disorders include the following:
• Functional neurologic disorder (FND) (also called conversion disorder and functional movement disorder): A neurologic disorder that affects the transmission of signals from the nervous system and the body. The cause is unknown. Symptoms include motor dysfunction (e.g., limb weakness, paralysis, spasms, problems walking), dysphagia, sensory dysfunction (e.g., numbness, loss of vision), syncope, and seizures.
• Narcolepsy: A chronic neurologic disorder that affects the brain’s ability to control the sleep-wake cycle, thus causing extreme daytime sleepiness, cataplexy, hallucinations, and sleep paralysis. Narcolepsy can be genetic and also an autoimmune disease.
• Sciatica: Occurs when the sciatic nerve can become compressed by a herniated disk, spinal stenosis, or a bone spur on the vertebrae. This condition causes burning or stabbing pain that radiates along the path of the sciatic nerve. The person can have pain and numbness in the lower back, hip, buttock, and leg on one side of the body.
• Tourette syndrome (TS): A neurologic disorder that causes tics and can be seen as early as 3 years of age. Tics are repetitive, involuntary movements and vocalizations. Simple motor tics involve a small number of muscle groups and cause sudden, brief, repetitive movements, such as eye blinking, facial grimacing, shoulder shrugging, and head jerking. Complex motor tics involve several muscle groups and movements (e.g., grimacing, shrugging, and jerking). Simple vocal tics involve sounds made by moving air through the mouth or nose, causing barking, hissing, sniffing, grunting, or throat-clearing. Complex vocal tics may include repeating phrases, words, or sentences. People may repeat their own phrases, another person’s words, or obscene words. Tics can worsen with emotion (e.g., excitement and anxiety).