stretchingstimulusto Dr. Alamzeb Associate Professort HOD physiology Department SMCh swat
Headache (Cephalgia)• Is a condition of pain in the head; neck or upper back pain may also be interpreted as a headache.• Headaches are a type of pain referred to the surface of the head from deep head structures.• Some headaches result from pain stimuli arising inside the cranium, but others result from pain arising outside the cranium, such as from the nasal sinuses.• It ranks amongst the most common local pain complaints.• majority of headaches are benign and self- limiting.
Common causes are• Tension,• Migraine,• Eye strain,• Dehydration• and sinusitis.• Much rarer are headaches due to life-threatening conditions such as• Meningitis,• Encephalitis,• Cerebral aneurysms,• and brain tumors.• When the headache occurs in conjunction with a head injury the cause is usually quite evident.
Pain-Sensitive Areas in Cranial Vault.• The brain tissues themselves are almost totally insensitive to pain. Even cutting or electrically stimulating• Tugging on the venous sinuses around the brain, or stretching the dura at the base of the brain can cause intense pain that is recognized as headache.• Also any type of traumatizing, crushing, or stretching stimulus to the blood vessels of the meninges can cause headache.• Especially sensitive structure is the middle meningeal artery,
Areas of Referred Headache• Stimulation of pain receptors in the cerebral vault above the tentorium, including the upper surface of the tentorium itself, initiates pain impulses in the fifth nerve and, causes referred headache to the front half of the head in the surface areas supplied by this• pain impulses from beneath the tentorium enter the central nervous system through the glossopharyngeal, vagal, and second cervical nerves, which also supply the scalp above, behind, and slightly below the ear.• Subtentorial pain stimuli cause "occipital headache" referred to the posterior part of the head
• Types• There are five types of headache:• vascular,• Myogenic (muscle tension),• Cervicogenic,• Traction,• Inflammatory.• Muscular/myogenic headaches appear to involve the tightening or tensing of facial and neck muscles; they may radiate to the forehead.• Tension headache is the most common form of myogenic headache.
• Vascular 1. The most common type of vascular headache is migraine. 2. After migraine, the most common type of vascular headache is the "toxic" headache produced by fever. 3. headaches resulting from high blood pressure (rare).
Cervicogenic headaches • Originate from disorders of the neck, including the anatomical structures innervated by the cervical roots C1–C3. • Cervical headache is often precipitated by neck movement and/or sustained awkward head positioning.
• Specific types of headaches include:• Tension headache• Migraine• "Brain freeze" (also known as: ice cream headache)• Thunderclap headache• Toxic headache• Coital cephalalgia (also known as: sex headache)• Sinus headache• Rebound headache (also called medication overuse headache, abbreviated MOH)• Red Wine Headache• Like other types of pain, headaches can serve as warning signals of more serious disorders. This is particularly true for headaches caused by inflammation, including those related to meningitis
What is a migraine headache?• A migraine headache is a severe pain felt on one, and sometimes, both sides of the head. The pain is mostly in the front around the temples or behind one eye or ear. Besides pain, there is nausea and vomiting, and be very sensitive to light and sound.• Migraine can occur any time of the day, though it often starts in the morning. The pain can last a few hours or up to one or two days.• Causes of migraine headaches, are not known but some things are more common in people who have them.• ages of 15 and 55.• family history of migraine.• They are more common in women.
causes migraine?• One cause of migraine is the blood flow theory.• Blood vessels either narrow or expand.• Narrowing can constrict blood flow, causing problems with sight or dizziness.• When the blood vessels expand, they press on nerves nearby, which causes pain.• Another theory focuses on chemical changes in the brain. When chemicals in the brain that send messages from one cell to another, including the messages to blood vessels to get narrow or expand, are interrupted, migraines can occur.• Most migraines are not caused by a single factor or event.• Many women with migraine tend to have attacks brought on by:• lack of food or sleep• bright light or loud noise• hormone changes during the menstrual cycle• stress and anxiety• weather changes• chocolate, alcohol, or nicotine
Classic Migraine• With a classic migraine, a person has these visual symptoms (also called an “aura”) 10 to 30 minutes before an attack:• sees flashing lights or zigzag lines• has blind spots or loses vision for a short time• The aura can include seeing or hearing strange things. It can even disturb the senses of smell, taste, or touch. Women have this form of migraine less often than men.• Common migraine. With a common migraine, a person does not have an aura, but does have the other migraine symptoms, such as nausea and vomiting
Menstrual cycle & migraine• More than half of women with migraine have more headaches around or during their menstrual cycle. This is often called “menstrual migraine.• Just before the cycle begins, levels of the female hormones, estrogen and progesterone, sharply go down. This drop in hormones may trigger a migraine, because estrogen controls chemicals in the brain that affect a woman’s pain sensation.
Headache of Meningitis.• Most severe headaches of all is that resulting from meningitis, which causes inflammation of all the meninges, including the sensitive areas of the dura and the sensitive areas around the venous sinuses. Such intense damage can cause extreme headache pain referred over the entire head.
Headache Caused by Low CerebrospinalFluid Pressure.• Removing as little as 20 milliliters of fluid from the spinal canal, causes intense intracranial headache.
Alcoholic Headache.• As many people have experienced, a headache usually follows an alcoholic binge. It is most likely that alcohol, because it is toxic to tissues, directly irritates the meninges and causes the intracranial pain.
Headache Caused by Constipation.• Constipation causes headache in many people. result from absorbed toxic products
Extracranial Types of Headache• Headache Resulting from Muscle Spasm. Emotional tension often causes many of the muscles of the head, spastic, and is one of the common causes of headache.
Headache Caused by Eye Disorders.• Difficulty in focusing ones eyes clearly may cause excessive contraction of the eye ciliary muscles in an attempt to gain clear vision. cause retro-orbital headache.• when the eyes are exposed to excessive irradiation by light rays, especially ultraviolet light. Looking at the sun or the arc of an arc- welder for even a few seconds may result in headache that lasts from 24 to 48 hours.
Sinus headache• There are several paired paranasal sinuses, including the frontal, ethmoid, maxillary and sphenoid sinuses.
• Maxillary sinusitis• cause pain or pressure in the maxillary (cheek) area (e.g., toothache, headache)
• Frontal sinusitis - can cause pain or pressure in the frontal sinus cavity (located behind/above eyes), headache
Ethmoid sinusitis• can cause pain or pressure pain between and/or behind eyes, headache
Sphenoid sinusitis• - can cause pain or pressure behind the eyes, but often refers to the vertex of the head.
Tension headaches• Renamed tension-type headaches by the International Headache Society in 1988, are the most common type of primary headaches.• The pain can radiate from the neck, back, eyes, or other muscle groups in the body.• Tension-type headaches account for nearly 90% of all headaches.• Approximately 3% of population suffers from chronic-tension type headache.
Frequency and duration• Tension-type headaches can be episodic or chronic.• Episodic tension-type headaches are defined as tension-type headaches occurring less than 15 days a month, whereas chronic tension headaches occur 15 days or more a month for at least 6 months.• Tension-type headaches can last from minutes to days or even months, though a typical tension headache lasts 4-6 hours.
Cause and pathophysiology• The exact cause of tension-type headaches is still unknown.• It is suggested that abnormalities in the peripheral and central nervous systems may be involved in the pathophysiology of TTH.• It has long been believed that they are caused by muscle tension around the head and neck and the restriction of blood flow to those areas as a result, the cause of which is in often the presence of an unresolved subconscious emotional conflict and anxiety.• One of the theories says that the main cause for tension type headaches is teeth clenching which causes a chronic contraction of the temporalis muscle.
Pain and possible symptoms• Tension-type headache pain is often described as a constant pressure,• The pain is frequently bilateral which means it is present on both sides of the head at once. Tension-type headache pain is typically mild to moderate, but may be severe. In contrast to migrain the pain does not increase during exercise.
• Another theory is that the pain may be caused by a malfunctioning pain filter which is located in the brain stem.• The view is that the brain misinterprets information, for example from the temporal muscle or other muscles, and interprets this signal as pain.• One of the main molecules which is probably involved is serotonin.• Evidence for this theory comes from the fact that chronic tension-type headaches may be successfully treated with certain antidepressants such as amitriptyline.
Toxic headache• A toxic headache is the least common type of vascular headache that usually comes from a fever from acute illnesses such as measles, mumps, pneumonia and tonsillitis.• Common hazards in our environment also cause toxic headaches with exposure.• These include chemicals, fumes, pollution, allergens and other health hazards.• A chemical factor from the outside or inside of body can result in a toxic headache.