– Pain or aching of the head associated with various intracranial or extracranial factors; headaches may be categorized as tension, vascular (cluster, migraine), or traction inflammatory.
Causes and Incidence
Although tension headaches are the most common type, their precise etiology is not well defined. However, most are related to muscle tension, minor trauma, increased stress or anxiety, food and environmental allergens, infection or lesions of the oral or nasal cavity, ear infections, or eye strain. Traction inflammatory headaches are either intracranial or cranial. Intracranial headaches may be caused by increased intracranial pressure stemming from an underlying process such as a brain tumor, abscess, or hematoma; meningitis; syphilis; tuberculosis; cancer; or subarachnoid hemorrhage. Cranial changes in the skull caused by neoplasms, temporal arteritis, or involvement of the sensory nerves of the scalp with a disease such as herpes zoster also can cause headaches. Vascular disturbances caused by exposure to toxic substances (e.g., alcohol, lead, arsenic, and carbon monoxide) are causes of headache. Some vascular headaches, such as migraines and cluster headaches, are idiopathic.
Each year approximately 30 million Americans seek medical treatment for recurrent headache. Tension headaches are most common and occur in adults across age and gender lines. Migraines affect about 5% of the general U.S. population, and women in their early childbearing years are the most susceptible, particularly just before or during menstrual periods. Cluster headaches are most common in men in their 30s and 40s.
Headache pain occurs when afferent pain fibers on the cranial nerves (V, VII, IX, or X) carry sensory stimuli to central nervous system tissue. The location and diffusion of the pain are dictated by the cause, the extent of tissue affected, and the cranial nerve or nerves involved. Pain can be highly localized and specific or diffuse and generalized. Involvement of the deep brain structure often causes referred pain.
Bilateral, dull, nonpulsatile ache, typically bifrontal or nuchal-occipital; transient or chronic
Paroxysmal, throbbing, unilateral pain that lasts hours to days; cyclic pattern; possible nausea and vomiting; aversion to light and noise; may be preceded by an aura (shimmering visual manifestation) or prodromal behavioral alterations ranging from depression to euphoria or triggering food cravings
Deep, agonizing, nonthrobbing pain often beginning during sleep and involving an eye, temple, cheek, and forehead on one side; lasts from 30 minutes to 3 hours, with several headaches occurring each day for several weeks; tearing and redness of affected eye
Deep, dull, steady ache that is worse in the morning and aggravated by coughing or straining
Soreness of one or both temples that becomes a chronic, burning, well-localized pain; the affected scalp artery is prominent, tender, incompressible, and pulseless
Complications are usually associated with an underlying disease process rather than the headache itself. However, headaches associated with temporal arteritis, if left untreated, may cause blindness.
Diagnostic Tests Diagnosis centers on classification of the head pain and identifying the potential cause. A neurologic history and a physical examination, with identification of precipitating or underlying disease, are paramount. Computed tomography and magnetic resonance imaging are useful in detecting intracranial lesions. Cerebral angiography may help detect vascular abnormality.
Migraine: analgesics, ergot preparations, sumatriptan for acute attacks; betablockers, serotonin agonists for prophylaxis in chronic retractable syndromes.
Cluster: prophylaxis with drugs such as valproic acid, verapamil, or lithium carbonate is more effective than administration of drugs during acute attacks.
Treatment of any identified underlying disease; application of cold or heat compresses; elimination of food or environmental allergens; counseling, stress management, biofeedback.