Saturday, April 16, 2011

Headache

Headache is of three types:

1. Cluster Headache
2. Tension type headache
3. Migraine headache

Characteristics of Cluster Headache:
1. Males are more often attacked by this than females.
2. It usually occurs during sleep.
3. It is unilateral and its location is behind and around eyes.
4. It is excruciating, sharp and steady.
5. Its duration is from 10 minutes to 3 hours.
6. It can cause unilateral sweating, facial flushing, nasal congestion and lacrimation.

Characteristics of Tension Type headache:
1. It is more often in females than in males.
2. It occurs usually under stress.
3. It is bilateral in band around head.
4. It is dull and persistant.
5. It occurs in episodes from 30 minutes to 7 days and.
6. It can cause mild intolerance to light and noise.

Tension type headaches respond very well to over the counter analgesics.

Characteristics of Migraine:
1. It occurs in females more often than males.
2. It is variable and can start any time.
3. It is unilateral.
4. The pain caused by this is pulsating and throbbing.
5. It can last, in episodes, from 2 to 72 hours.
6. It can cause visual auras, sensitivity to light and sound, pale facial appearance, nausea and vomiting.

Types of Migraine headache:
Note: Migraine and cluster headaches are the types of “Vascular headaches”, whereas Tension headache is the most common form of “Myogenic / Muscular headache”.


Biologic basis of Migraine Headache:
Hypoperfusion occurs in Migraine with aura. Migranious aura is due to abnormally high release of serotonin from platelets.

Firstly: There is a spreading depression of neuronal activity.
Secondly: Reduced blood flow in the most posterior part of the cerebral hemisphere.
Thirdly: This hypoperfusion spreads on the surface of the cortex.

These hypoperfused regions show an abnormal response to changes in arterial pCO2 (this is alteration of function) and there is an increase in the amplitude of temporal artery pulsations.

Hypoperfused state remains during aura and headache phase and after that hyperperfused state comes.

No hypoperfusion occurs in Migraine without aura.

Pain in migraine headaches is considered to be due to extra cranial and intracranial arterial dilation that results in release of neuro-active molecules such as substance P.

In woman, whose headache is related to menstrual cycle, migraine is due to
1. Falling levels of estrogen.
2. Elevated levels of prostaglandin E1.

Phases in Migraine headache:
There are three phases:
1. Asymptomatic phase: No symptoms or pathologic features are found between the previous attack and until next attack.
2. Prodromal Phase: It starts with visual disturbances. In this phase there is vasoconstriction of arteries and release of serotonin.
3. Headache Phase: Here pain starts along with nausea and vomiting. Here, cerebral vasodilation occurs and due to release of serotonin, there is a large amount of serotonin.

Treatment of Migraine:

Prophylaxis of Migraine headache:
When there is recurrence of migraine headache two or more times in a month. Drugs on prophylactic bases can be taken such as β-blockers (propranolol, nadolol) can be taken. Some ergot alkaloids like Methysergide are also effective.

Acute migraine headache:
When the first symptoms of migraine headache started, following medicines are effective to prevent the near future headache:
1. Sumatriptan
2. Ergotamine
3. Dihydroergotamine
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