Headache

There are more than 200 types of headaches. Some are harmless and some are life-threatening. The description of the headache and findings on neurological examination, determine whether additional tests are needed and what treatment is best. Headaches are broadly classified as "primary" or "secondary". Primary headaches are benign, recurrent headaches not caused by underlying disease or structural problems. For example, migraine is a type of primary headache. While primary headaches may cause significant daily pain and disability, they are not dangerous from a physiological point of view. Secondary headaches are caused by an underlying disease, like an infection, head injury, vascular disorders, brain bleed, stomach irritation, or brain tumor. Secondary headaches can be dangerous. Certain "red flags" or warning signs indicate a secondary headache may be dangerous. Primary Ninety percent of all headaches are primary headaches. Primary headaches usually first start when people are between 20 and 40 years old. The most common types of primary headaches are migraines and tension-type headaches. Tension-type headaches usually present with non-pulsing "bandlike" pressure on both sides of the head, not accompanied by other symptoms. Such kind of headaches may be further classified into-episodic and chronic tension type headaches Other very rare types of primary headaches include: More serious causes of secondary headaches include the following: The treatment of the gastrointestinal disorders may lead to a remission or improvement of headaches. == Pathophysiology ==

The brain itself is not sensitive to pain, because it lacks pain receptors. However, several areas of the head and neck do have pain receptors and can thus sense pain. These include the extracranial arteries, middle meningeal artery, large veins, venous sinuses, cranial and spinal nerves, head and neck muscles, the meninges, falx cerebri, parts of the brainstem, eyes, ears, teeth, and lining of the mouth. Pial arteries, rather than pial veins are responsible for pain production. The pain receptors may be stimulated by head trauma or tumours and cause headaches. Blood vessel spasms, dilated blood vessels, inflammation or infection of meninges and muscular tension can also stimulate pain receptors. Primary headaches are more difficult to understand than secondary headaches. The exact mechanisms which cause migraines, tension headaches and cluster headaches are not known. Migraines are currently thought to be caused by dysfunction of the nerves in the brain. Previously, migraines were thought to be caused by a primary problem with the blood vessels in the brain. This vascular theory, which was developed in the 20th century by Wolff, suggested that the aura in migraines is caused by constriction of intracranial vessels (vessels inside the brain), and the headache itself is caused by rebound dilation of extracranial vessels (vessels just outside the brain). Dilation of these extracranial blood vessels activates the pain receptors in the surrounding nerves, causing a headache. The vascular theory is no longer accepted. Studies have shown migraine head pain is not accompanied by extracranial vasodilation, but rather only has some mild intracranial vasodilation. Currently, most specialists think migraines are due to a primary problem with the nerves in the brain. followed by a period of depressed activity. Some people think headaches are caused by the activation of sensory nerves which release peptides or serotonin, causing inflammation in arteries, dura and meninges and also cause some vasodilation. Triptans, medications that treat migraines, block serotonin receptors and constrict blood vessels. People who are more susceptible to experiencing migraines without headaches are those who have a family history of migraines, women, and women who are experiencing hormonal changes or are taking birth control pills or are prescribed hormone replacement therapy. Tension headaches are thought to be caused by the activation of peripheral nerves in the head and neck muscles. Cluster headaches involve overactivation of the trigeminal nerve and hypothalamus in the brain, but the exact cause is unknown. == Diagnosis ==

Most headaches can be diagnosed by the clinical history alone. The first step to diagnosing a headache is to determine if the headache is old or new. Headaches that are possibly dangerous require further lab tests and imaging to diagnose. • age younger than 30 years • features typical of primary headache • history of similar headache • no abnormal findings on neurologic exam • no concerning change in normal headache pattern • no high-risk comorbid conditions (for example, HIV) • no new concerning history or physical examination findings A number of characteristics make it more likely that the headache is due to potentially dangerous secondary causes which may be life-threatening or cause long-term damage. These "red flag" symptoms mean that a headache warrants further investigation with neuroimaging and lab tests. • Systemic symptoms (fever or weight loss) • Systemic disease (HIV infection, malignancy) • Neurologic symptoms or signs • Onset sudden (thunderclap headache) • Onset after age 40 years • Previous headache history (first, worst, or different headache) Other red flag symptoms include: Old headaches Old headaches are usually primary headaches and are not dangerous. They are most often caused by migraines or tension headaches. Migraines are often unilateral, pulsing headaches accompanied by nausea or vomiting. There may be an aura (visual symptoms, numbness or tingling) 30–60 minutes before the headache, warning the person of a headache. Migraines may also not have auras. Cluster headaches are relatively rare (1 in 1000 people) and are more common in men than women. They present with sudden onset explosive pain around one eye and are accompanied by autonomic symptoms (tearing, runny nose and red eye). Cephalalgiaphobia is fear of headaches or getting a headache. New headaches New headaches are more likely to be dangerous secondary headaches. They can, however, simply be the first presentation of a chronic headache syndrome, like migraine or a tension headache. One recommended diagnostic approach is as follows. If any urgent red flags are present such as visual impairment, new seizures, new weakness, or new confusion, further workup with imaging and possibly a lumbar puncture should be done (see red flags section for more details). If the headache is sudden onset (thunderclap headache), a computed tomography scan (CT scan) to look for a brain bleed (subarachnoid hemorrhage) should be done. If the CT scan does not show a bleed, a lumbar puncture should be done to look for blood in the cerebrospinal fluid (CSF), as the CT scan can be falsely negative and subarachnoid hemorrhages can be fatal. If there are signs of infection such as fever, rash, or stiff neck, a lumbar puncture to look for meningitis should be considered. In an older person, if there is jaw claudication and scalp tenderness, a temporal artery biopsy should be performed to look for temporal arteritis, immediate treatment should be started, if results of the biopsy are positive. Neuroimaging Old headaches The US Headache Consortium has guidelines for neuroimaging of non-acute headaches. Most old, chronic headaches do not require neuroimaging. If a person has the characteristic symptoms of a migraine, neuroimaging is not needed as it is very unlikely the person has an intracranial abnormality. If the person has neurological findings, such as weakness, on exam, neuroimaging may be considered. New headaches All people who present with red flags indicating a dangerous secondary headache should receive neuroimaging. Lumbar puncture A lumbar puncture is a procedure in which cerebral spinal fluid is removed from the spine with a needle. A lumbar puncture is necessary to look for infection or blood in the spinal fluid. A lumbar puncture can also evaluate the pressure in the spinal column, which can be useful for people with idiopathic intracranial hypertension (usually young, obese women who have increased intracranial pressure), or other causes of increased intracranial pressure. In most cases, a CT scan should be done first. The third edition of the International Headache Classification was published in 2013 in a beta version ahead of the final version. This classification is accepted by the WHO. Other classification systems exist. One of the first published attempts was in 1951. The US National Institutes of Health developed a classification system in 1962. ICHD-2 The International Classification of Headache Disorders (ICHD) is an in-depth hierarchical classification of headaches published by the International Headache Society. It contains explicit (operational) diagnostic criteria for headache disorders. The first version of the classification, ICHD-1, was published in 1988. The current revision, ICHD-2, was published in 2004. The classification uses numeric codes. The top, one-digit diagnostic level includes 14 headache groups. The first four of these are classified as primary headaches, groups 5-12 as secondary headaches, cranial neuralgia, central and primary facial pain and other headaches for the last two groups. The ICHD-2 classification defines migraines, tension-types headaches, cluster headache and other trigeminal autonomic headache as the main types of primary headaches. Secondary headaches are classified based on their cause and not on their symptoms. == Management ==

Primary headache syndromes have many different possible treatments. In those with chronic headaches the long term use of opioids appears to result in greater harm than benefit. Secondary headaches (caused by another disease) Treatment of secondary headaches involves treating their underlying cause. For example, a person with meningitis will require antibiotics, and a person with a brain tumor may require surgery, chemotherapy or brain radiation. The possible origins of a headache have been studied and classified. Migraines Migraines can be somewhat improved by lifestyle changes, but most people require medicines to control their symptoms. Possible therapies include beta blockers, antidepressants, anticonvulsants and NSAIDs. Sphenopalatine ganglion block (SPG block, also known nasal ganglion block or pterygopalatine ganglion blocks) can abort and prevent migraines, tension headaches and cluster headaches. It was originally described by American ENT surgeon Greenfield Sluder in 1908. Both blocks and neurostimulation have been studied as treatment for headaches. Several complementary and alternative strategies can help with migraines. The American Academy of Neurology guidelines for migraine treatment in 2000 stated relaxation training, electromyographic feedback and cognitive behavioral therapy may be considered for migraine treatment, along with medications. Tension-type headaches Tension-type headaches can usually be managed with NSAIDs (such as ibuprofen and aspirin) or acetaminophen. Amitriptyline is a medication which treats depression and also independently treats pain. It works by blocking the reuptake of serotonin and norepinephrine, and also reduces muscle tenderness by a separate mechanism. Overall, they show that acupuncture is probably not helpful for tension-type headaches. Cluster headaches Abortive therapy for cluster headaches includes subcutaneous sumatriptan (injected under the skin) and triptan nasal sprays. High flow oxygen therapy also helps with relief. How it may work is still being looked into. == Epidemiology ==

Literature reviews find that approximately 64–77% of adults have had a headache at some point in their lives. However, the prevalence of headache varies widely depending on how the survey was conducted, with studies finding lifetime prevalence of as low as 8% to as high as 96%. Most of these headaches are not dangerous. Only approximately 1–5% of people who seek emergency treatment for headaches have a serious underlying cause. More than 90% of headaches are primary headaches. Most of these primary headaches are tension headaches. Most people with tension headaches have "episodic" tension headaches that come and go. Only 3.3% of adults have chronic tension headaches, with headaches for more than 15 days in a month. Approximately 12–18% of people in the world have migraines. More women than men experience migraines. In Europe and North America, 5–9% of men experience migraines, while 12–25% of women experience migraines. Cluster headaches are relatively uncommon. They affect only 1–3 per thousand people in the world. Cluster headaches affect approximately three times as many men as women. == History ==

depicting a headache The first recorded classification system was published by Aretaeus of Cappadocia, a medical scholar of Greco-Roman antiquity. He made a distinction between three different types of headache: i) cephalalgia, by which he indicates a sudden onset, temporary headache; ii) cephalea, referring to a chronic type of headache; and iii) heterocrania, a paroxysmal headache on one side of the head. Another classification system that resembles the modern ones was published by Thomas Willis, in De Cephalalgia in 1672. In 1787 Christian Baur generally divided headaches into idiopathic (primary headaches) and symptomatic (secondary ones), and defined 84 categories. == Children ==

In general, children experience the same types of headaches as adults do, but their symptoms may be slightly different. The diagnostic approach to headaches in children is similar to that of adults. However, young children may not be able to verbalize pain well. If a young child is fussy, they may have a headache. Approximately 1% of emergency department visits for children are for headache. Most of these headaches are not dangerous. The most common type of headache seen in pediatric emergency rooms is headache caused by a cold (28.5%). Other headaches diagnosed in the emergency department include post-traumatic headache (20%), headache related to a problem with a ventriculoperitoneal shunt (a device put into the brain to remove excess CSF and reduce pressure in the brain) (11.5%) and migraine (8.5%). The most common serious headaches found in children include brain bleeds (subdural hematoma, epidural hematoma), brain abscesses, meningitis and ventriculoperitoneal shunt malfunction. Only 4–6.9% of kids with a headache have a serious cause. If a child with a recurrent headache has a normal physical exam, neuroimaging is not recommended. Guidelines state children with abnormal neurologic exams, confusion, seizures and recent onset of worst headache of life, change in headache type or anything suggesting neurologic problems should receive neuroimaging. Some measures can help prevent headaches in children. Drinking plenty of water throughout the day, avoiding caffeine, getting enough and regular sleep, eating balanced meals at the proper times, and reducing stress and excess of activities may prevent headaches. Treatments for children are similar to those for adults, however certain medications such as narcotics should not be given to children. In another study of people with chronic daily headache, 75% did not have chronic daily headaches two years later, and 88% did not have chronic daily headaches eight years later. Cardiac Cephalgia in Heart Attack Cardiac cephalgia is a rare type of headache occurring during myocardial infarction, characterized by sudden, severe head pain that typically develops during or immediately following a heart attack. The pain is usually located in the occipital or frontal regions and can be accompanied by other cardiac symptoms like chest pain, shortness of breath, or radiating arm pain. This specific headache type is considered a potential warning sign of cardiac distress and requires immediate medical attention to prevent potentially life-threatening complications. ==See also==