Parkinson’s disease is a progressive degenerative disease like amyotrophic lateral sclerosis (see page 333), though it has a much slower course. Researchers believe that a combination of factors—including environmental toxins, genetic predisposition, accelerated aging, or damage to cells from free radicals—may bring about the disease. The average age of onset is 60, but many younger adults have early symptoms. Men and women are affected equally by Parkinson’s disease.
In Parkinson’s disease, the neurons in the basal ganglia (clusters of paired nerve cells deep inside the brain) that control muscular activity become dam- aged or die. These nerve cells produce an important neurotransmitter (chemical messenger) called dopamine, which has an essential role in controlling muscle actions. Without sufﬁcient dopamine, the nerve impulses are disrupted, causing the primary symptoms of the disease: tremor (trembling) in the hands, feet, arms, legs, and head; stiffness and weakness; slow movement; and impaired bal- ance and coordination.
The early symptoms of Parkinson’s disease are subtle and appear gradually. The hands and feet may tremble slightly. Eventually the person’s speech may become slow and halting, and his or her handwriting will become very small. Some people may have a ﬂat facial expression and become stiff and unsteady. As the disease progresses, they may experience problems with memory and thought processes. The skin may become oily (especially on the forehead, nose, and
scalp) or very dry, or excessive sweating may occur. People with Parkinson’s dis- ease often have difﬁculty sleeping. Depression also is common.
A diagnosis of Parkinson’s disease is based on the symptoms. There is no cure for the disease, but medication can relieve the symptoms for most people in less severe stages of the disease. The most common medication is levodopa (also called L-dopa), which the body converts to dopamine. Not all symptoms respond well to levodopa, and those that do will return if the medication is stopped. Anti- cholinergic drugs such as benztropine may be prescribed to relieve tremor. Brain surgery to reduce tremor and rigidity may be performed on some people for whom medication has not been effective. Although the progression of Parkin- son’s disease cannot be slowed, treatment to relieve symptoms can help people continue to lead active lives.
Tourette’s syndrome is a rare inherited disorder characterized by involuntary movements and nasal and vocal sounds. Researchers believe that the abnormal- ity in the gene or genes responsible for the disease affects the way the brain con- trols neurotransmitters (chemical messengers such as serotonin and dopamine). Symptoms usually begin before age 18, and men are up to four times more likely to have the disease than women. In some cases the symptoms are not noticeable or do not continue into adulthood.
Early symptoms of the disease include facial tics such as eye blinking, nose twitching, or grimaces. (Note that most such tics are not due to Tourette’s syn- drome.) Over time the tics may become more noticeable and may include head jerking, neck stretching, foot stamping, and body twisting or bending. The per- son also may make strange noises, such as coughing, snifﬁng, grunting, yelping, barking, or shouting. More disturbing symptoms, such as involuntary shouting of obscenities, constantly echoing words of others, touching others excessively, or repeating actions obsessively, also may occur. In severe cases people with Tourette’s syndrome may harm themselves by biting their lips and cheeks and banging their heads against hard objects.
Tics periodically change in number, frequency, type, and location. They also may disappear for a time and then reappear. If a person tries to suppress a tic, tension will build until the tic occurs, often in a more dramatic manner. Tics tend to worsen in stressful situations and improve during periods of relaxation or when the person concentrates on another activity.
Tourette’s syndrome is diagnosed through monitoring of symptoms (the tics must be present for at least 1 year) and conﬁrmation of a family history of the disease. In some cases neurological tests may reveal another cause of the symptoms.
There is no cure for Tourette’s syndrome, although symptoms tend to decrease with age. The disorder does not affect the intellect. The person may not require
any treatment, but the doctor may prescribe medications to reduce speciﬁc symptoms that interfere with daily routine. Relaxation techniques (see page 119) and biofeedback (see page 118) can help prevent tics.
A headache is a very common type of pain. The pain of a headache may extend over the entire head, or it may be limited to a speciﬁc area. Headache pain may range from mild to severe. Unusual or sudden changes in posture or prolonged coughing, sneezing, or exposure to sunlight can lead to a headache. In some cases, however, a headache may be a symptom of a serious underlying condi- tion, such as a stroke or a brain tumor.
Call your doctor immediately if your headache is severe or persistent, if it occurs after a blow to the head, or if it is accompanied by any of the following:
• stiff neck
• pain in your eye or ear
• dizziness, confusion, or loss of consciousness
• weakness or paralysis
Tension headaches (also called muscle contraction headaches) are the most common type of headache. These headaches produce mild to moderate pain that feels as though pressure is being applied to the head or neck. The pain may be accompanied by muscle tenderness. Tension headaches can be brought on by head or neck injury, anxiety, stress, eyestrain, or poor posture. If the headaches occur almost every day, they are referred to as chronic daily headaches, and they may cause fatigue, depression, and difﬁculty sleeping.
A migraine is a severe, persistent headache accompanied by certain recogniz- able symptoms. Migraine headaches produce intense throbbing pain that occurs on one side of the head and may spread to the other side. Evidence suggests that susceptibility to migraines is inherited.
Symptoms may include nausea, vomiting, diarrhea, sensitivity to light and noise, fever, chills, aches, and sweating. Some people experience a speciﬁc warning sign called an aura, such as a visual disturbance, just before the onset of a migraine. Migraine attacks usually last for a few hours, but more severe episodes may last for a few days. Attacks can occur several times per week or once every few years. A migraine can be completely disabling; following an attack, the person is often exhausted, irritable, or unable to concentrate.
People who have migraines may be able to identify triggers (speciﬁc sub- stances, conditions, or circumstances that can bring on a headache), such as alcohol, monosodium glutamate (MSG; found in processed foods), tyramine
(found in aged cheese and red wine), or nitrates and nitrites (found in processed meat products). Other potential triggers include ﬂuorescent lights, glaring light (such as from computer screens), high altitudes, strong smells, and sudden changes in temperature or barometric pressure.
A cluster headache is a series of headaches that affects one side of the head. Cluster headaches come on suddenly and produce intense symptoms, which may include a runny nose; drooping eyelid; and an irritated, watery eye on the affected side. The pain often centers just behind the eye. Cluster headaches often occur early in the morning and can be as brief as 15 minutes or as long as 3 hours. With episodic cluster headaches, attacks occur daily or several times per day for many weeks or months and then disappear for an extended period (months or years). With chronic cluster headaches, attacks occur at least once per week.
Over-the-counter pain relievers such as aspirin, acetaminophen, and ibuprofen will relieve most headaches. Some antidepressants are useful for treating chronic pain and may help reduce the occurrence of most types of headaches. Muscle relaxants may reduce the pain of muscle contraction headaches. People with migraine headaches can take ergot alkaloids or serotonin agonists at the onset of symptoms to help reduce the severity and duration of their headaches. Migraines
Keeping a headache diary is a good way to help you identify the factors that trigger your headaches so that you can take steps to prevent future headaches. Whenever you have a headache, carefully mark down the following information:
• time headache began
• time headache ended
• intensity of pain (such as mild, moderate, or severe)
• type of pain (such as aching, throbbing, or stabbing)
• location of pain
• other symptoms (such as nausea, vomiting, or sensitivity to light)
• medication taken for headache (type and amount) and results
• self-treatment for headache (such as sleep, cold compresses, or relaxation techniques) and results
• activity you were engaged in (such as sleeping or exercising) when headache began
• your location when headache began (such as indoors or outdoors)
• potential allergens nearby when headache began (such as pollen, tobacco smoke, dust, or pets)
• other environmental factors (such as noises, odors, or weather)
• food or drink consumed before headache began
• your emotional state before headache began
(such as angry, stressed, or tired)
• medication you are taking for other reasons
(both prescription and over the counter)
Take your headache diary with you when you visit your doctor. The information it contains will reveal any patterns related to your headaches, which is helpful for determining the triggers of your headaches and recommending appropriate treatment.
often can be reduced or prevented in people who experience frequent episodes by daily use of medication. If you have frequent headaches you will beneﬁt from keeping a headache diary (see previous page) to track your headache triggers, symptoms, and sources of relief.
Other Neurological Disorders
This section describes several less common disorders of the central nervous system.
• Meningitis. Meningitis is inﬂammation of the meninges (the membranes that surround the brain and spinal cord), usually caused by a viral or bacterial infection. Symptoms often appear suddenly and include high fever, severe and persistent headache, sensitivity to light, stiff neck, nausea, and vomiting. In viral meningitis the symptoms are less severe. Symptoms of bacterial menin- gitis develop more rapidly and are followed by drowsiness and, in some cases, loss of consciousness. Viral meningitis usually clears up within a week or two and requires no treatment other than medication to relieve pain. Bacterial meningitis is a medical emergency and requires immediate treatment with large doses of antibiotics given intravenously. Contact your doctor immedi- ately if you have symptoms of meningitis.
• Encephalitis. Encephalitis is inﬂammation of the brain, usually caused by a viral infection. Symptoms include sudden fever, headache, vomiting, sensi- tivity to light, stiff neck and back, confusion, drowsiness, clumsiness, unsteady gait, and irritability. More serious symptoms include muscle weakness, changes in behavior, memory loss, impaired judgment, seizures, and loss of consciousness. Some types of encephalitis may be treated with drugs such as acyclovir. In most cases, however, treatment focuses on relieving symptoms, keeping the person comfortable, and allowing the body’s immune system to ﬁght the infection. The doctor may prescribe anticonvulsant medication to prevent seizures and corticosteroid drugs to reduce swelling in the brain. Some cases of encephalitis are short and relatively mild. Other cases can be severe, causing long-term disability or even death. Symptoms of encephalitis require immediate evaluation by a physician because early diagnosis and treatment may prevent serious, perhaps fatal, complications.
• Arteriovenous malformation. An arteriovenous malformation (AVM) is a con- genital (present from birth) disorder in which there is a tangled web of arter- ies and veins in the brain or spinal cord. Symptoms include bleeding (at the site of the malformed blood vessels), seizures, headaches, paralysis, loss of speech or vision, or other neurological symptoms. Once detected, the AVM can be removed surgically, closed off by injecting a special medicinal glue (in a procedure called embolization), or shrunk with radiation. If an AVM is untreated it can bleed into the brain or spinal cord, causing severe disability or death.
• Bell’s palsy. Bell’s palsy is a temporary paralysis of facial muscles due to inﬂammation of one of the facial nerves. Usually only one side of the face is affected. Symptoms include weakness, twitching, or paralysis (which may prevent the eye from closing completely), drooling, and impairment of taste. Other symptoms may include pain, watery eye, and hypersensitivity to sound. Bell’s palsy can occur in anyone at any age but is more common among preg- nant women and people who have diabetes or a viral infection such as the ﬂu, a cold, or cold sores. There is no speciﬁc treatment, and symptoms often clear up on their own in people who do not have other related illnesses. Sometimes facial weakness is caused by a more serious disease. If you have other symp- toms, or if the condition does not improve quickly, see your doctor.
If you have symptoms of a neurological disorder, your doctor will use one or more of the following diagnostic procedures to determine the cause of your symptoms. He or she may refer you to a neurologist (a physician who specializes in treating disorders of the brain and spinal cord) for further evaluation and treatment.
• Neurological examination. During a neurological examination, a physician performs a variety of physical tests to check the functioning of a person’s nervous system. He or she will test vision (by examining eye movement, pupil reaction, and other eye reﬂexes); reﬂexes (by tapping the knee with a rubber hammer, for example); hearing; sensation (by gently sticking the foot with a pin); movement (by asking the person to perform simple tasks); and balance and coordination (by asking the person, for example, to balance on one foot, touch the nose with the eyes closed, or walk heel-to-toe).
• Lumbar puncture. For a lumbar puncture (also called a spinal tap), a hollow needle is inserted into the spinal column in your lower back to obtain a sample of cerebrospinal ﬂuid, which circulates around the brain and spinal cord. The fluid is examined for signs of infection, cancer, bleeding, or inﬂammation. A lumbar puncture also is performed as part of myelography (see next page).
• Electroencephalography. This is a painless examination in which electrodes are placed on the scalp to record the electrical activity of the brain. Electroen- cephalography helps identify signs of a tumor, epilepsy, or other neurological disorders.
• Computed tomography (CT) scanning. CT scanning uses computer and low- dose X rays to produce detailed cross-sectional images of body tissues such as the brain and spinal cord. The images, which are clearer than conventional X-ray images, are displayed on a video monitor. During the procedure, you lie on a table inside a circular opening in the scanner. A contrast medium (a dye) may be injected before the scan to highlight blood vessels, organs, or any abnormalities. The procedure is painless.
• Magnetic resonance imaging (MRI). MRI uses a computer, a powerful mag- net, and radio waves to create detailed two- or three-dimensional images of body tissues. The images are displayed on a video monitor. MRI often pro- duces better images than CT scanning, especially when the tissue being exam- ined is located near bone. The procedure is painless and has no known side effects. During the procedure, you lie in a tunnel inside the magnet. Some people feel claustrophobic during an MRI. You are given a signal button to hold so that you can signal the technician to stop the procedure if you become anxious. If you think that you might feel claustrophobic during the MRI, ask the doctor for a tranquilizer before the procedure. Because the magnet makes loud knocking noises, you may be offered headphones to wear during the pro- cedure, to help block the noise. Also, because of the powerful magnetic ﬁeld that is created during the procedure, you cannot carry or wear any metal objects (such as jewelry or a watch) or electronic devices (such as a hearing aid or a pager). You cannot have an MRI if you have a pacemaker or any mag- netic metal (including plates, screws, or artiﬁcial joints) implanted in your body.
• Cerebral angiography. This diagnostic procedure is used to examine the arter- ies in the brain and the carotid arteries in the neck and to help diagnose prob- lems such as narrowed or blocked arteries, aneurysms (see page 323), and arteriovenous malformations (see page 341). In cerebral angiography, a catheter (a thin, ﬂexible tube) is inserted into the femoral artery, a large blood vessel in the groin area, and threaded up through the main blood vessels of the abdomen and chest and into the main arteries in the neck (carotid arteries). Contrast medium (a dye) is injected through the catheter into the arteries, and a series of rapid-sequence X rays (similar to a movie) is taken. The images are displayed on a video monitor. Cerebral angiography produces better images than carotid ultrasound (see below) and allows the doctor to look deeper inside the brain.
• Myelography. Before CT scanning and MRI (see above) became available, doctors relied on myelography to look inside the spinal canal. In this proce- dure, contrast medium is injected into the spinal canal after a lumbar punc- ture, and a series of X rays is taken. Because the procedure is lengthy and may be painful, myelography is generally used only when CT scanning or MRI cannot be performed or do not provide enough information.
• Carotid ultrasound. If you are at risk for stroke (see page 323) or have expe- rienced a transient ischemic attack (see page 323), you will likely undergo a carotid ultrasound. In this procedure, sound waves are used to produce images that help the doctor detect changes in the rate of blood ﬂow through the carotid arteries (the major arteries in the neck that supply blood to the brain). The images, which are displayed on a video monitor, reveal blockages or potential blockages in the carotid arteries.