Print
Email
SaveMedia Gallery
 |
When Is a Headache a Migraine?
|
 |
What Are the Different Types of Headaches?
|
play video
Causes
PHYSICAL A person feels headache pain when specialized nerve endings known as nociceptors are stimulated by pressure on or injury to any of the pain-sensitive structures of the head. Most nociceptors in humans are located in the skin or in the walls of blood vessels and internal organs; the bones of the skull and the brain itself do not contain nociceptors.
The specific parts of the head that are sensitive to pain include:
- the skin that covers the skull and cervical spine
- the 5th, 9th, and 10th cranial nerves and the nerves that supply the upper part of the neck the venous sinuses inside the head
- the large arteries at the base of the brain
- the large arteries that supply the dura mater, which is the outermost of the three meninges (membranes) that cover the brain and spinal cord
- the portion of the dura mater at the base of the skull
Tension headaches typically result from tightening of the muscles of the face, neck, and scalp as a result of emotional stress; physical postures that cause the head and neck muscles to tense (e.g., holding a phone against the ear with one's shoulder); depression or anxiety; temporomandibular joint dysfunction (TMJ); or degenerative arthritis of the neck. The tense muscles put pressure on the walls of the blood vessels that supply the neck and head,
The pathophysiology of migraine headaches has been debated among doctors since the 1940s. Some researchers think that migraines are the end result of a magnesium deficiency in the brain or of hypersensitivity to a neuro-transmitter known as dopamine. Another theory holds that certain nerve cells in the brain cortex become unusually excitable and depolarize (lose their electrical potential) spontaneously, releasing potassium and glutamate, an amino acid. These substances then depolarize nearby nerve cells, resulting in a chain reaction known as cortical-spreading depression (CSD). CSD then leads to changes in the amount of blood flowing through the blood vessels and stimulation of their nociceptors, resulting in severe headache. More recently, the discovery of specific genes associated with migraine indicates that genetic mutations are responsible for the abnormal excitability of the nerve cells in the brains of patients with migraine.
Little is known about the causes of cluster headaches or changes in the central nervous system that produce them.
PSYCHOLOGICAL Chronic headaches are often associated with anxiety, depression, or a specific group of mental disorders known as somatoform disorders. These disorders include hypochondriasis and pain disorder; they are characterized by physical symptoms (frequently headache) that suggest that the patient has a general medical condition, but there is no diagnosable disease or disorder that fully accounts for the patient's symptoms. The relationship between psychological and physical factors in headaches is complex in that headaches may be either the cause or result of emotional disturbances, or both. Some patients find that chronic headaches disappear completely after a stressful family- or job-related situation has been resolved.
Warning symptoms
Most headaches are not associated with serious or life-threatening illnesses. Patients should, however, immediately call their primary physician if they have any of the following symptoms:
- three or more headaches per week
- need for a pain reliever every day or almost every day
- need for greater than recommended doses of over-thecounter medications (OTCs)
- stiff neck or fever accompanying the headache
- shortness of breath, hearing problems, blurry vision, or severe sore throat
- dizziness, weakness, slurred speech, mental confusion, or drowsiness headache following a head injury that is not relieved by OTCs
- headache triggered by exercise, coughing, sexual activity, or bending over
- persistent or violent vomiting
- change in the character of the headaches—for example, persistent severe headaches in a person who has previously had only mild headaches of brief duration
- recurrent headaches in a child
- recurrent severe headaches, beginning after age 50
 |
Author Info: Rebecca J. Frey PhD, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Neurological Disorders, 2005 |
Related Learning Centers |
 |
 |
 |
Advertise | Terms of Use | Privacy Policy