Health Questions and Answers

Headache

What are the three key principles in evaluating headache?

  • The brain is anesthetic. This means that most causes of head pain do not arise from the brain itself but rather from surrounding structures, such as blood vessels or periosteum. Since most headaches are not caused by brain disease, most are benign.
  • The more severe the headache, the more benign the disease. The exception to this rule is intracranial hemorrhage, but, in general, most severe headaches are due to self-limited causes.
  • Eye problems and sinus disease seldom cause headaches. Patients tend to blame their headaches on eye strain or sinusitis, but, in fact, these are rare causes.

List the common types of headache.

  • Common migraine (without aura)
  • Classic migraine (with aura)
  • Tension headaches

What are the less common types of headaches?
Other less common or rare types of headaches include cluster headaches and headaches from brain tumor, meningeal irritation, and temporal arteritis.

Which serious diseases capable of causing permanent neurologic dysfunction can present as headaches?
Most processes causing headache are benign, but some are serious. Examples include:

  • Primary brain tumor
  • Metastatic brain tumor
  • Abscess
  • Subdural hematoma
  • Intracerebral hemorrhage
  • Subarachnoid hemorrhage
  • Meningitis
  • Temporal artery disease
  • Hypertension
  • Hydrocephalus
  • Glaucoma

What clinical features are seen with increased intracranial pressure (ICP)?
Because the brain is completely surrounded by the hard bony skull, any increase in ICP can impair brain function. The most sensitive indicator of increased ICP is an altered mental status, and it is usually the first symptom to change as the pressure rises. With increased pressure, the brain can herniate downward through the foramen magnum, compressing and destroying the brain stem. Herniation can be recognized by the development of brain-stem signs as the top of the brain stem (midbrain) becomes impaired. In addition to altered mental status, these signs include dilatation of one or both pupils (“blown pupil”), hyperventilation, and focal neurologic signs such as hemiparesis. Herniation can progress to coma and death.

What basic principle underlies all techniques of lowering ICP?
Lowering ICP requires reduction of the intracranial contents to make room for the mass lesion and increased pressure. The intracranial contents consist essentially of the brain, CSF filling the ventricles, and blood within the blood vessels.

List four specific techniques for lowering ICP.

  • Lowering blood pressure lowers the ICP and can be accomplished with a diuretic such as furosemide.
  • Incubation and hyperventilation cause vasospasm that reduces the blood volume intracranially.
  • Steroids can reduce swelling secondary to vasogenic edema. They may take hours or days to work and have little value acutely.
  • Shunting can be used in emergency situations to remove CSF and to lower ICP.

How does intracranial hemorrhage present?
Intracranial hemorrhage causes the abrupt onset of an extremely severe headache. Patients report that it is “the worst headache in my life.” Approximately half of these patients die at the time of the bleed. The remainder usually present to an emergency department with an altered mental status but may not have significant focal neurologic findings.

What causes intracranial hemorrhage?
The bleeding may result from the rupture of a vessel outside the brain (subarachnoid hemorrhage) or inside the brain (intracerebral hematoma). Subarachnoid hemorrhage is usually due to the rupture of a small intracranial aneurysm, called a berry aneurysm, often located on the anterior communicating artery, middle cerebral artery, or their branches.

What is temporal arteritis?
Temporal arteritis is a giant cell arteritis, which is a systemic illness with generalized symptoms such as fevers, myalgias, arthralgias (polymyalgia rheumatica), anemia, and elevated liver function tests. The headache is a mild-to-moderate diffuse pain, not necessarily confined to the temples or frontal region of the head. The disease should be suspected in elderly people, over age 55, who develop new headaches.

How is temporal arteritis diagnosed?
The erythrocyte sedimentation rate (ESR) is usually very elevated, >100 mm/min, and is a good screening test. The confirmatory test is a temporal artery biopsy showing granulomatous arteries.

How is temporal arteritis treated?
High-dose steroids for a period of 1-2 years are often required, sometimes in doses of 60 mg/day of prednisone equivalent or more. Approximately 15% of patients, if left untreated, develop significant visual loss.

What are migraine headaches?
Migraine headaches are paroxysmal, intermittent headaches occurring on an average of once a month and lasting from 4-12 hours or more. Migraines typically begin in the teenage years, sometimes even in childhood, and diminish in both frequency and intensity of attacks in later adulthood. About half of all patients with migraine have a family history of the problem.

What are the common symptoms of migraines?

  • About one third of patients have hemicranial pain, but in two thirds of patients the headache is diffuse over the entire head.
  • Some patients have a preceding aura for 20-40 minutes before the headache. This often consists of visual changes, such as flashing lights.
  • Gastrointestinal disturbances are very common, including nausea, vomiting, and anorexia. If the patient can eat during the headache, it is probably not migraine!
  • Photophobia and phonophobia.
  • Mood changes.
  • Visual or sensory loss.

What causes migraine headaches?
The cause is not entirely understood. Probably low serotonin levels in the brain trigger certain brainstem neurons to fire, which alters cerebral function and blood flow. The nausea, neurologic deficits, and head pain result from low brain serotonin levels, aggravated by concomitant vascular changes.

What is the best treatment for a migraine headache?
For symptomatic relief from mild to moderate migraines, simple analgesics or NSAIDs such as aspirin or naproxen may be sufficient. For more severe attacks, triptans are the drugs of choice. Sumatriptan, a 5-hydroxytryptamine receptor agonist, was the first triptan to be used, but multiple other triptans are now available in various routes of administration. Patients should be warned of the flushing, sweating, and chest tightness that can occur as side effects.

When is prophylactic therapy indicated for migraine headaches?
For patients having frequent headaches (2-3/month or more) or for the occasional patient whose headache is complicated by persistent neurologic deficits, prophylactic treatment may be indicated.

Which drugs may be used for prophylaxis of migraine headaches?

  • Amitriptyline, a tricyclic compound. Doses of 100 mg/day or more may be necessary. Many other tricyclics are not effective.
  • Propranolol, a beta-adrenergic blocking agent. Again, doses of 100 mg/day or more may be needed. Most other beta-adrenergic blockers are not effective.
  • Calcium channel blockers. Both nifedipine and verapamil are useful.
  • Anticonvulsants, especially valproic acid, are sometimes effective.

Describe the clinical features of tension headaches.
Tension headaches are diffuse headaches, often described as a band around the head, usually bifrontal but sometimes occipital. Unlike migraine, these headaches are usually not paroxysmal but are constant and chronic. Like migraine, they are more common in women and generally begin early in life. About half of the patients have a family history. Usually, there are no associated neurologic symptoms (such as visual changes) or nausea and vomiting.

What causes tension headaches?
The cause is not known. There is no convincing evidence that they are due to psychological factors or emotional stress, nor do sound data show that they are related to muscle contraction. Some of them may be transformed migraines.

How should tension headaches be treated?
Amitriptyline, up to 75-150 mg/day, works independently of its antidepressant effects. NSAIDs are useful for common headaches but are seldom successful in chronic persistent tension headache. Muscle relaxants are not effective.

References
WEB SITES
www.neuroguide.com
www.aan.com (American Academy of Neurology)
www.medmatrix.org
www.internets.com/mednets/sneurolo.htm
www.medwebplus.com/subject/Neurology.html

BIBLIOGRAPHY

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