CHAPTER 107

Headaches

Headaches are a very common medical problem and a common cause of disability among men and women. Headaches interfere with the ability to work and do daily tasks. Some people have frequent headaches. Other people hardly ever have them.

Causes

Although headaches can be painful and distressing, they are rarely due to a serious condition.

Primary Headache Disorders: Most headaches are not caused by another identifiable disorder. Such headaches are called primary headache disorders. They include

Tension-type

Migraine

Cluster headaches

Tension-type headaches are the most common type of headache.

Secondary Headache Disorders: Less commonly, headaches result from another disorder. Such headaches are called secondary headache disorders. Usually, disorders that cause headaches are not serious. These disorders often affect the eyes, nose, throat, sinuses, teeth, jaws, ears, or neck and are minor or temporary. For example, a dental infection, sinus infection (sinusitis), or a problem with the joint of the jaw (temporomandibular disorder) may cause a headache.

Rarely, headaches are caused by a serious disorder, including the following:

Brain infections, such as abscess, meningitis, and encephalitis

Other infections, such as tuberculosis, if they affect the brain

Brain tumors

Accumulation of blood in the tissues that cover the brain (subdural hematoma), often due to a head injury

Bleeding in the brain (intracerebral hemorrhage)

Bleeding in the tissues that cover the brain (sub-arachnoid hemorrhage), often due to rupture of a bulge in an artery (cerebral aneurysm) or of an abnormal connection between arteries and veins (arteriovenous malformation)

Intracranial hypertension

Very high blood pressure (rarely)

Breathing disorders, such as emphysema and sleep apnea

Giant cell (temporal) arteritis

Some of these disorders, such as brain tumors, hemorrhages, hematomas, and intracranial venous hypertension, increase pressure within the skull. In their early stages, many infections, including Lyme disease and Rocky Mountain spotted fever, can cause headaches, as can influenza if severe. These infections can be serious.

Headaches commonly result from withdrawal of caffeine, withdrawal of pain relievers (analgesics) after long-term use, and use of certain drugs that widen blood vessels (such as nitroglycerin).

Did You Know…

Headaches rarely result from a serious disorder.

If people have a sudden, excruciating (thunderclap) headache, they should seek medical attention right away.

Diagnosis

Usually, doctors can determine the type or cause of headaches on the basis of the person’s medical history, the characteristics of the headache, and the results of a physical examination. Doctors ask about the characteristics of the headache: frequency, duration, location, severity, and any symptoms that accompany it. Doctors also ask what triggers the headache, what makes it worse, and what relieves it.

The following characteristics may indicate that a serious disorder is the cause of headaches, and people who experience any of them should promptly seek medical attention.

Headaches that are increasing in frequency or severity

Daily headaches

A very sudden, severe headache (thunderclap headache)

Any change in the pattern or nature of headaches

Headaches that begin after age 50

Headaches accompanied by symptoms such as fever, a stiff neck, changes in sensation or vision, weakness, loss of coordination, fainting, or very high blood pressure

Headaches that cause seizures or confusion

For example, a severe headache with a fever and a stiff neck suggests meningitis—a life-threatening infection of the layers of tissues covering the brain and spinal cord (meninges). A headache that occurs very suddenly and that is more severe than any others the person has experienced may suggest a subarachnoid hemorrhage—bleeding within the meninges, which is often due to a ruptured aneurysm.

Testing: When doctors suspect a serious disorder, diagnostic tests are usually done. If a tumor, a hemorrhage, or increased pressure within the skull is suspected, computed tomography (CT) or magnetic resonance imaging (MRI) is done immediately.

If meningitis is suspected, a spinal tap (lumbar puncture—see art on page 635) is done immediately. A spinal tap may also be done if doctors suspect a subarachnoid hemorrhage or encephalitis. If doctors think that a mass (such as a tumor or abscess) may be present, CT or MRI is done before the spinal tap to determine whether a spinal tap can be done safely. A spinal tap decreases pressure below the brain. If a mass is present, the brain may shift downward and be pressed through one of the small natural openings in the tissues that separate the brain into compartments—a life-threatening disorder called herniation.

Occasionally, blood tests are done to check for a disorder such as Lyme disease. The erythrocyte sedimentation rate (ESR—the rate at which red blood cells settle to the bottom of a test tube containing a blood sample) may be determined to check for giant cell arteritis, which causes inflammation. A high ESR suggests inflammation.

Tension-Type Headaches

A tension-type headache is usually mild to moderate pain that feels like a band tightening around the head.

Pain in other parts of the head and neck may trigger these headaches.

Headaches may occur several or many days each month.

Doctors base the diagnosis on symptoms and results of a physical examination, but sometimes imaging tests are done to rule out other disorders.

Pain relievers and some drugs used to treat migraines may help, as may relaxation and stress management.

Many people occasionally have tension-type headaches. The cause is not well understood but may be related to a lower-than-normal threshold for pain. Stress may be involved. However, how stress is involved is not clearly understood, and it is not the only explanation for the symptoms. Other problems may contribute to or trigger the headaches. For example, sleep disturbances, a problem with the joint of the jaw (temporomandibular joint disorder), neck pain, or eyestrain may trigger a tension-type headache.

HOW HEADACHES DIFFER

TYPE OR CAUSE	CHARACTERISTICS*	DIAGNOSTIC TESTS
Primary (not due to another disorder)
Cluster	The pain is severe and piercing. It affects one side of the head and is focused around the eye. The pain lasts 30 minutes to about 1 hour. People with cluster headaches cannot lie down, frequently pace, and sometimes bang their heads. Headaches occur in clusters, separated by periods when no headaches occur. They are usually not worsened by light, sounds, or smells and are not accompanied by nausea and vomiting. On the same side as the pain, the nose runs, the eye tears, the eye lid droops, and the area below the eye may swell.	Tests are the same as those for tension-type headaches.
Migraine	The pain is moderate to severe. A pulsating or throbbing pain is felt on one side or sometimes on both sides of the head. The pain lasts several hours to days. Headaches may be worsened by physical activity, light, sounds, or smells and are accompanied by nausea, vomiting, and sensitivity to sounds, light, and odors. Attacks can occur for a long period of time, then disappear for weeks, months, or years. Often, people have a sensation that a migraine is beginning. This sensation (called a prodrome) may include mood changes, loss of appetite, and nausea. Attacks may be preceded by temporary disturbances in sensation, balance, muscle coordination, speech, or vision (such as seeing flashing lights and blind spots). These disturbances are called the aura.	Tests are the same as those for tension-type headaches.
Tension-type	The pain is usually mild to moderate. It feels like tightening of a band around the head and affects the whole head. The pain lasts 30 minutes to several days. It may be worse at the end of the day. Headaches are not worsened by physical activity, light, sounds, or smells and are not accompanied by nausea and vomiting.	CT or MRI of the head is occasionally done to rule out other disorders, particularly if the headaches have developed recently or if the symptom pattern has changed.
Secondary (due to another disorder)
Brain abscess	The pain is similar to that caused by a brain tumor. However, if an abscess ruptures, acute meningitis results, causing an intense headache and a stiff neck.	MRI or CT is done.
Brain tumor	Pain is mild to severe and may become progressively worse. It usually recurs more and more often and eventually becomes constant without relief. People often become clumsy, weak, or confused. They may vomit or have seizures.	MRI is done.
Encephalitis	Encephalitis (infection of the brain) can cause headaches. People may also have a fever. They may become very drowsy, clumsy, weak, or confused. They may vomit or have seizures. Coma can develop. Some people also have meningitis.	MRI or CT and a spinal tap are done.
Eye disorders (such as iritis, glaucoma, and papillitis)	The pain is moderate or severe and is often worse after using the eyes. It is felt at the front of the head or in or over the eyes. Vision is impaired.	An eye examination is done.
Giant cell (temporal) arteritis	A throbbing pain is felt on one side of the head at the temple. The scalp hurts when the hair is combed, and chewing hurts. The arteries in the temples may be enlarged. Aches and pains may occur, particularly in the shoulders, thighs, and hips. Vision may be lost.	The erythrocyte sedimentation rate (ESR) is determined, and a biopsy of the temporal artery is done.
High blood pressure (hypertension)	Extremely high blood pressure can cause headaches. The pain is throbbing, occurs in spasms, and is felt at the back or top of the head. Usually, high blood pressure does not cause headaches.	Blood pressure is measured, and blood tests and kidney function tests are done.
Intracerebral hemorrhage	The pain may be mild or severe and occurs on one or both sides. People may become very drowsy, clumsy, weak, or confused. They may vomit or have seizures. Coma can develop.	CT or MRI is done.
Meningitis	The pain is severe and constant and is felt over the whole head. It travels down the neck, making bending the neck to rest the chin on the chest difficult. People feel ill, have a fever, and vomit.	Blood tests and a spinal tap are done.
Sinus disorders	The pain is severe and may be dull or sharp. It is felt at the front of the head. It may begin suddenly and last only a short time, or it may begin gradually and be persistent. It is usually worse in the morning and less severe in the afternoon. Cold, damp weather and lying down make the pain worse. People have a runny nose, sometimes with pus or blood. They feel ill, may cough at night, and often have a fever.	CT of the sinuses or endoscopy of the nose may be done.
Subarachnoid hemorrhage	The pain is severe, constant, and widespread. It may reach its peak intensity within a few seconds. Occasionally, it is felt in and around one eye. The eyelid droops. People often describe the headache as the worst ever experienced. They may briefly lose consciousness. Some people are sleepy, confused, and hard to rouse. Others are restless. Later, the neck may become stiff, with a continuing headache and often with vomiting, dizziness, and low back pain.	MRI or CT is done. If the results are negative, a spinal tap is done.
Subdural hematoma	The pain is mild to severe and intermittent or constant. It can be felt in one spot or over the whole head and travels down the neck. People may feel sleepy or become confused or forgetful.	MRI or CT is done.
Other disorders if they affect the brain (such as cancer, cryptococcosis, sarcoidosis, syphilis, and tuberculosis)	The pain may be mild or severe and dull or sharp. It is felt over the whole head. People whose headache is caused by one of these disorders have a moderate fever and other symptoms of the disorder.	A spinal tap and MRI are done.
* One, some, or all of the characteristics listed may be present. CT = computed tomography; MRI = magnetic resonance imaging.

Symptoms

Tension-type headaches feel like tightening of a band around the head, making the whole head ache. These headaches may be episodic or chronic.

Episodic headaches occur fewer than 15 days a month. The pain is usually mild to moderate. It may last 30 minutes to several days. These headaches typically start several hours after waking and worsen as the day progresses. They rarely awaken people from sleep.

Chronic headaches occur more than 15 days a month. Severity tends to increase as more headaches occur. The pain may vary in intensity throughout the day but is almost always present.

Unlike migraine headaches, tension-type headaches are not accompanied by nausea and vomiting and are not made worse by physical activity, light, sounds, or smells.

Some mild migraines resemble tension-type headaches.

Diagnosis

The diagnosis is based on the person’s description of the headache and the results of a physical examination. Doctors ask the person about problems that may trigger the headaches.

No specific procedures can confirm the diagnosis. Sometimes computed tomography (CT) or magnetic resonance imaging (MRI) of the head is done to rule out other disorders that may be causing the headache, particularly if headaches have developed recently.

Treatment

For most mild to moderate tension-type headaches, almost any over-the-counter pain reliever (analgesic), such as aspirin, acetaminophen, or ibuprofen, can provide relief. Massaging the affected area may help relieve the pain. Most people with mild to moderate episodic headaches do not go to a health care practitioner.

Severe headaches may require stronger, prescription analgesics. Some contain opioids (narcotics), such as codeine or oxycodone (see page 642).

For some people, caffeine, an ingredient of some headache preparations, enhances the effect of analgesics. However, overuse of analgesics, caffeine (in headache preparations or caffeinated beverages), or opioids can lead to daily headaches. Such headaches, called medication overuse headaches, begin or worsen when these drugs are suddenly stopped.

If tension-type headaches are chronic, some drugs used to prevent migraine, particularly amitriptyline (a tricyclic antidepressant), can help.

Behavioral and psychologic interventions, such as relaxation and stress management techniques, may help.

Migraines

A migraine headache is a pulsating or throbbing pain that usually ranges from moderate to severe. It can affect one or both sides of the head. It is worsened by physical activity, light, sounds, or smells and is accompanied by nausea, vomiting, and sensitivity to sounds and light.

Migraines may be triggered by lack of sleep, changes in the weather, hunger, excessive stimulation of the senses, stress, or other factors.

Doctors base the diagnosis on typical symptoms.

There is no cure for migraines, but drugs to stop the progression of migraines, pain relievers (analgesics), and drugs to prevent migraines can help control them.

Although migraines can start at any age, they usually begin during puberty or young adulthood. In most people, migraines recur periodically (fewer than 15 days a month). After age 50, headaches usually become significantly less severe or resolve entirely. Migraines are 3 times more common among women. In the United States, about 18% of women and 6% of men have a migraine at some time each year.

Migraine may become chronic. That is, headaches occur more than 15 days a month. These headaches often develop in people who overuse drugs to treat migraines.

Migraines tend to run in families. More than half the people who have migraines have close relatives who also have them.

Causes

Migraines occur in people whose nervous system is more sensitive than that of other people. That is, nerve cells in the brain are easily stimulated, producing electrical activity. As electrical activity spreads over the brain, various functions, such as vision, sensation, balance, muscle coordination, and speech are temporarily disturbed. These disturbances cause the symptoms that occur before the headache (called the aura). The headache occurs when the 5th cranial (trigeminal) nerve is stimulated. This nerve sends impulses (including pain impulses) from the eyes, scalp, forehead, upper eyelids, mouth, and jaw to the brain. When stimulated, the nerve may release substances that cause painful inflammation in the blood vessels of the brain (cerebral blood vessels) and the layers of tissues that cover the brain (meninges). The inflammation accounts for the throbbing headache, nausea, vomiting, and sensitivity to light and sound.

A rare subtype of migraine called familial hemiplegic migraine is associated with genetic defects on chromosomes 1, 2, and 19. The role of genes in the more common forms of migraine is under study.

Estrogen, the main female hormone, appears to trigger migraines, possibly explaining why migraines are more common among women. During puberty (when estrogen levels increase), migraines become much more common among girls than among boys. Some women have migraines just before, during, or just after menstrual periods. As menopause approaches (when estrogen levels are fluctuating), migraines become particularly difficult to control. Oral contraceptives (which contain estrogen) and estrogen therapy may make migraines worse and may increase the risk of stroke in women who have migraines with an aura. Other triggers include the following:

Lack of sleep, including insomnia

Changes in the weather, particularly barometric pressure

Red wine

Certain foods

Hunger (as when meals are skipped)

Excessive stimulation of the senses (for example, by flashing lights or strong odors)

Stress

Head injuries, neck pain, or a problem with the joint of the jaw (temporomandibular joint disorder) sometimes trigger or worsen migraines.

Symptoms

In a migraine, pulsating or throbbing pain is usually felt on one side of the head, but it may occur on both sides. The pain may be moderate but is often severe and incapacitating. Physical activity, light, sounds, or smells may make the headache worse. This increased sensitivity makes many people retreat to a dark, quiet room and lie down until the headache subsides. The headache is often accompanied by nausea, sometimes with vomiting. Severe attacks can be incapacitating, disrupting family and work life.

People often have sensations warning them that an attack is about to begin. These sensations, called the prodrome, may include mood changes, loss of appetite, and nausea.

In about 25% of people, migraines are preceded by an aura. The aura involves temporary, reversible disturbances in vision, sensation, balance, muscle coordination, or speech. People may see jagged, shimmering, or flashing lights or develop a blind spot with flickering edges. Less commonly, people experience tingling sensations, loss of balance, weakness in an arm or a leg, or difficulty talking. The aura lasts minutes to an hour before and may continue after the headache begins. Some people experience an aura but have only a mild or no headache. These mild headaches are similar to tension-type headaches.

Migraine attacks may last for hours to a few days (typically 4 hours to 3 days). Usually, they subside during sleep. They may occur frequently for a long time, then disappear for many weeks, months, or even years.

Did You Know…

Only 1/4 of people have sensations that warn them that a migraine is about to begin.

Taking pain relievers too often can make migraines worse.

Diagnosis

Doctors diagnose migraines when symptoms are typical and results of a physical examination (which includes a neurologic examination) are normal.

No procedure can confirm the diagnosis. If headaches have developed recently or if the pattern of symptoms has changed, computed tomography (CT) or magnetic resonance imaging (MRI) of the head may be done to exclude other disorders. For example, an imaging test may be done to check for stroke in older people who have migraines with an aura, especially when the migraine is mild or does not occur.

Prevention

When treatment does not prevent people from having frequent or incapacitating migraines, taking drugs every day to prevent migraine attacks helps. Taking preventive drugs may help people who are taking other migraine drugs too often and who need to reduce their use.

Beta-blockers, such as propranolol, are often used. The anticonvulsants topiramate and divalproex and the tricyclic antidepressant amitriptyline are also effective. The choice of a preventive drug is based on the side effects of the drug and on other disorders present. For example, people who are overweight may be given topiramate, which can promote weight loss. People with depression or insomnia may be given amitriptyline (see table on page 868).

Treatment

Migraines cannot be cured, but they can be controlled.

Doctors encourage people to keep a headache diary. In it, people write down the number and timing of attacks, possible triggers, and their response to treatment. With this information, triggers may be identified and eliminated when possible, and doctors can better plan and adjust treatment. Behavioral interventions (such as relaxation, biofeedback, and stress management) are used to control migraine attacks, especially when stress is a trigger or when people are taking too many drugs to control the migraines.

DRUGS USED TO TREAT MIGRAINES

TYPE	EXAMPLES	SOME SIDE EFFECTS
Prevention
Anticonvulsants	Divalproex Topiramate	Hair loss, stomach upset, liver dysfunction, a tendency to bleed, tremors, and weight gain (see table on page 716) With topiramate, weight loss, confusion, and depression
Beta-blockers	Atenolol Metoprolol Nadolol Propranolol Timolol	Spasm of the airways (bronchospasm), fatigue, insomnia, worsening of heart failure, and sexual dysfunction With some beta-blockers, unfavorable effects on lipid (fat) levels (see table on page 340)
Calcium channel blockers	Verapamil	Dizziness, low blood pressure, and weakness With verapamil, constipation (see table on page 341)
Tricyclic antidepressants	Amitriptyline	Drowsiness, weight gain, increased heart rate, dry mouth, confusion, and constipation (see table on page 868)
Treatment of severe migraines
Antiemetic drugs	Metoclopramide Prochlorperazine	Low blood pressure, drowsiness, and muscle spasms
Ergot derivatives	Dihydroergotamine	Nausea, vomiting, minor muscle cramping, and, rarely, chest pain due to an inadequate blood supply to the heart muscle (angina)
Triptans (5-hydroxytryptamine [5-HT] agonists)	Almotriptan Eletriptan Naratriptan Rizatriptan Sumatriptan Zolmitriptan	Flushing, tingling, dizziness, drowsiness, nausea, a sense of pressure in the throat or chest, and, rarely, angina
Opioids	Codeine Meperidine Oxycodone	Slowing of breathing, constipation, retention of urine, drowsiness, and nausea (see table on page 643)
Treatment of mild to moderate migraines
Analgesic	Acetaminophen	Rebound headache if the dose is increased and, occasionally, skin rash
Nonsteroidal anti-inflammatory drugs (NSAIDs)	Aspirin Indomethacin Naproxen	Worsening of headache if the dose is increased and later suddenly decreased. With indomethacin, worsening of depression, seizures, and tremors with decreased mobility and muscle stiffness and, in older people, dizziness and confusion

Some drugs stop a migraine from progressing. Some are taken to control the pain. Others are taken to prevent migraines.

When migraines are or become severe, drugs that can stop the migraine from progressing are used. They are taken as soon as people sense a migraine is beginning. They include the following:

Triptans (5-hydroxytryptamine [5-HT], or serotonin, agonists) are usually used. Triptans specifically target the receptors that stimulate nerves supplying the meninges and cerebral blood vessels, where migraine symptoms originate. These drugs are most effective when taken as soon as the migraine begins. They may be taken by mouth, inhaled, or injected under the skin.

Dihydroergotamine is used to stop severe, persistent migraines.

Prochlorperazine, an antiemetic, may be used when people cannot tolerate triptans or dihydroergotamine.

Because triptans and dihydroergotamine cause blood vessels to narrow (constrict), they are not recommended for people who have angina, coronary artery disease, or uncontrolled high blood pressure. If older people or people with risk factors for coronary artery disease need to take these drugs, they must be monitored closely.

If migraines are usually accompanied by nausea, a drug to relieve nausea (antiemetic) may also be taken. Antiemetics alone may stop mild or moderate migraines from progressing.

For less severe migraines, analgesics with or without caffeine can be useful. They can be taken as needed during a migraine, with or instead of a triptan.

Overuse of analgesics, caffeine (in analgesic preparations or in caffeinated beverages), or triptans can lead to daily, more severe migraines. Such headaches, called medication overuse headaches, occur when these drugs are taken more than 2 to 3 days each week. Missing or reducing a dose or taking it late may trigger or worsen a migraine.

When other treatments are ineffective in people with severe migraines, opioids may be needed (see page 643). Opioids are a last resort.

Cluster Headaches

A cluster headache causes severe pain that is felt at the temple or around the eye on one side of the head and that lasts a relatively short time (usually 30 minutes to 1 hour). Headaches usually occur regularly during a 1- to 3-month period, followed by a headache-free period of months to years.

Excruciating pain occurs one side of the head, causing the nostril and the eye on that side to water.

People are often restless and pace.

Doctors base the diagnosis on symptoms.

Oxygen, given by a face mask, or drugs are needed to treat headaches.

Cluster headaches are relatively rare, affecting about 1 to 4 of 1,000 people. Cluster headaches affect mostly men. They typically begin between the ages of 20 and 40. Drinking alcohol may trigger attacks.

Symptoms

An attack almost always starts suddenly. It may begin with itching of or a watery discharge from one nostril. Excruciating pain on the same side of the head follows and spreads around the eye. The pain reaches peak intensity within minutes and usually lasts 30 minutes to 1 hour. The pain often awakens people from sleep. People with cluster headaches, unlike those with a migraine, cannot lie down, frequently pace, and sometimes bang their heads.

After the attack, the eyelid on the same side as the headache may droop, and the pupil often constricts. The area below the eye may swell, and the eye may water. The face may be flushed. Nausea may accompany the headaches.

Attacks may occur several times a day. They usually occur regularly during a 1- to 3-month period (cluster period), occasionally longer, followed by a headache-free period of several months or even years before they recur. They usually recur at the same time of day or night. Some people do not have a headache-free interval. They have chronic cluster headaches.

Diagnosis

Diagnosis is based on the person’s description of the headache and the accompanying symptoms. If the pattern of symptoms changes, magnetic resonance imaging (MRI) of the head may be done.

Treatment

Most people with cluster headaches need to take drugs to prevent recurrences. The following may be used to stop (abort) a cluster headache as it is beginning:

Oxygen given by face mask

A triptan or dihydroergotamine given by injection (see table on page 654)

Other drugs are given to prevent headaches:

Prednisone, a corticosteroid given by mouth

A local anesthetic plus a corticosteroid given by injection into the back of the head (a procedure called a nerve block)

Drugs used to prevent migraines (such as topiramate, valproate, and verapamil)

Lithium

Prednisone or the nerve block may be used first because they take effect more quickly. Then one of the other drugs is used for long-term prevention. Oxygen and injections of dihydroergotamine or a local anesthetic plus a corticosteroid must be given in the hospital. The other treatments can be taken at home.

Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (benign intracranial hypertension, pseudotumor cerebri) involves increased pressure within the skull (intracranial pressure), without any evidence of a cause.

People have daily headaches, sometimes with nausea, blurred or double vision, and noises within the skull.

Imaging of the head is done to rule out possible causes of increased pressure, and a spinal tap is done.

Without prompt treatment, vision can be lost.

Weight loss, diuretics to reduce fluids in the brain, and spinal taps done periodically to reduce the pressure can help, but surgery is sometimes needed.

Idiopathic intracranial hypertension occurs in only about 1 of 100,000 people, usually in women during their reproductive years. However, among young overweight women, it is 20 times more common. As more and more people are becoming overweight, the disorder is becoming more common.

Pressure in the skull may be high in some cases because the large veins (venous sinuses) that carry blood from the brain are blocked. These changes cause blood to back up in the veins, including those that carry blood from the skull. The increased pressure does not result from tumors, infections, or blockages that prevent the fluid that surrounds the brain (cerebrospinal fluid) from draining as it normally does.

In most people, the development of idiopathic intracranial hypertension cannot be traced to any particular event. In children, this disorder sometimes develops after corticosteroids are stopped or after a child has taken large amounts of vitamin A or the antibiotic tetracycline.

Symptoms

Idiopathic intracranial hypertension usually begins with a daily or almost daily headache. At first, the headache may be mild, but it varies in intensity and may become severe. The headache may be accompanied by nausea, double or blurred vision, and pulsating noises within the skull (tinnitus). A few people do not have any symptoms.

Increased pressure within the skull may cause the optic nerve to swell near the eyeball—a condition called papilledema. Doctors can observe the swelling by looking at the back of the eye through an ophthalmoscope.

The first sign of vision problems is loss of the peripheral (side) vision. As a result, people may bump into objects for no apparent reason. Late in the disorder, vision becomes blurred. About 5% of people lose their vision, partially or completely, in one or both eyes. Once vision is lost, it may never return, even if the pressure around the brain is relieved. In some people, the disorder becomes chronic and progressively worse, increasing the risk of blindness. However, close monitoring of such people can prevent loss of vision.

The disorder recurs in about 10% of people.

Diagnosis

Doctors suspect this disorder based on symptoms and results of a physical examination. Sometimes doctors suspect it when they detect papilledema during a routine examination with an ophthalmoscope.

Then an imaging test, usually magnetic resonance imaging (MRI), is done to check for other possible causes of increased pressure within the skull. One type of MRI (called magnetic resonance venography) can provide images of the veins that carry blood from the brain. It enables doctors to determine whether these veins are narrowed. If results are normal, a spinal tap (lumbar puncture) is done to measure the pressure of the cerebrospinal fluid and to analyze the fluid. In idiopathic intracranial hypertension, the pressure of the fluid is usually increased, and the content is usually normal.

Treatment

Idiopathic intracranial hypertension often disappears without treatment within 6 months. Nonetheless, overweight people should lose weight because doing so reduces pressure within the skull. The disorder may resolve when as little as 10% or 20% of body weight is lost. However, weight reduction programs are often unsuccessful.

Drugs known to trigger the disorder, such as tetracycline, should be stopped.

Aspirin, acetaminophen, or drugs used to treat migraines may relieve the headache. Doctors may prescribe acetazolamide to help reduce the pressure. This drug is a diuretic, which helps the kidneys eliminate water in urine and thus decrease the amount of fluid in the body, including the brain.

The usefulness of doing spinal taps daily or weekly to remove cerebrospinal fluid is debated. If this treatment is used, people are closely monitored to determine whether pressure is decreasing.

People are closely monitored by an ophthalmologist so that vision problems can be recognized as soon as possible.

If vision deteriorates despite these measures, surgery to reduce pressure within the skull may be needed and may be able to save vision. In one procedure (called optic nerve sheath fenestration), slits are cut in the covering of the optic nerve behind the eyeball. These slits allow cerebrospinal fluid to escape into the tissues around the eye, where the fluid passes into veins. Alternatively, a permanent drain (shunt) can be surgically placed so that excess cerebrospinal fluid can be removed. The shunt is a piece of plastic tubing placed in the spaces within the brain or in the space just below the spinal cord in the lower back. The tubing is run under the skin, usually to the abdomen, where excess fluid can drain.

If magnetic resonance venography detects a blockage in a vein, a tube made of wire mesh (stent) may be inserted through an incision into a vein in the neck and placed in the blocked vein to hold it open.

If people are obese and other measures are ineffective, surgery to help with weight reduction (bariatric surgery, such as a gastric bypass—see page 956) may be done. If successful, it may cure the disorder.

Low-Pressure Headache

Low-pressure headaches result when cerebrospinal fluid is removed during a spinal tap (lumbar puncture) or leaks out because of a cyst or tear. Loss of this fluid, which flows around the brain, reduces pressure around the brain.

A headache commonly occurs after a spinal tap, usually hours to a day or two afterward. The procedure removes some cerebrospinal fluid. Cerebrospinal fluid flows through a channel between layers of tissue (meninges) that cover the brain and spinal cord and fills spaces within the brain. Removal of some cerebrospinal fluid reduces pressure around the brain, causing headaches, which can be severe. Young, small people are most likely to be affected.

Sometimes cerebrospinal fluid leaks because a cyst in the meninges bursts or the meninges are torn (as can occur when the head or face is injured). Rarely, a cyst may burst when people cough or sneeze.

Low-pressure headaches are intense. They occur when people sit or stand and may be relieved by lying flat. People usually also have a stiff, painful neck and may vomit.

Diagnosis

Doctors base the diagnosis on the symptoms and the situation. If people have had a spinal tap, the diagnosis is usually obvious, and testing is rarely needed. If not, imaging tests, such as magnetic resonance imaging (MRI), may be done.

Treatment

Doctors advise people who have had a spinal tap to lie flat. They are given fluids (by mouth or, if very dehydrated, intravenously), mild analgesics, and caffeine. An elastic binder may be wrapped around their abdomen. It can help increase pressure of the fluid around the brain. If the headache persists after a day of such treatment, a small amount of the person’s blood can be injected in the space between the spine and the meninges in the lower back. This procedure is called an epidural blood patch. The blood plugs the hole made by the spinal tap.

A blood patch may also be effective for a leak. Surgery for a leak is rarely required.