Vishal Sharma

Overview

Migraine and Statistics History Classification and symptoms Etiology and Pathophysiology Treatment

Migraine and statistics

Migraine is a neurovascular disease caused by neurogenic inflammation and characterized by severe, recurring headaches

It usually characterized by the severe pain on one side of the head as compare to the pain in rest of the head.

It occurs more often in Women than in men.

History

History goes back to 9000 years. First mode of treatment: trepanation

Medical intervention in which a hole is drilled or scraped into the human skull, exposing the dura mater in order to treat health problems related to intracranial diseases.

History cont.

In 2nd century AD, Pergamum a Greek physician used a term hemicrania. The brain and stomach were connected “Migraine” evolved from this term

However, this idea was replaced by blood flow in 17th century

In 80s, Dr. Harold G. Wolff said that dilation of blood vessels is the main cause of migraine.

Classification of Migraine headache.1) Migraine without Aura or common migraineDoes not give any warning signs before the onset

of headache.It occurs in about 70 to 80% of migraine patients2) Migraine with AuraGive some warning signs “ called aura” before

the actual headache begins. Approximate, 20 to 30% migraine sufferers experience aura.

The most common aura is visual and may include both positive and negative (visual field defects) features.

Negative scotoma. Loss of local awareness of local structure

Positive Scotoma. Additional structures One side loss of perception.

Zigzag structure

Classification of Migraine headache cont.3) Retinal migraine It involves attacks of monocular scotoma

or even blindness of one eye for less than an hour and associated with headache.

4) Childhood periodic syndromes that involve cyclical vomiting (occasional intense periods of vomiting), abdominal migraine (abdominal pain, usually accompanied by nausea), and benign paroxysmal vertigo of childhood (occasional attacks of vertigo).

They may be precursors or associated with migraine.

Classification of Migraine headache cont. 5) Complications of migraine

describe migraine headaches and/or auras that are unusually long or unusually frequent, or associated with a seizure or brain lesion.

Etiology and Pathophysiology The precise etiology and

pathophysiology of migraine is unknown.

However, neuronal dysfunction theory is most acknowledged theory.

Activity in trigeminovascular system.

Abnormal Neuronal activity

Instability in release of neuropeptides e.g., Substance P, neurokinin A, calcitonin gene-related polypeptide, serotonin

Promote vasodilation and plasma protein extravasations.

Initiate inflammatory response, sensitizes surrounding tissues and produce headache

Activates trigeminovascular system, which in turn, stimulate pain stimulating neurons in brain stem and upper spinal cord

Activates nociceptive trigeminovascular system and causes prolong pain

Cerebral cortex, thalamus or hypothalamus in response to stress, emotion.

‡

Abnormal Neuronal activity

Releases vasoactive neuropeptides e.g., Substance P, neurokinin A, calcitonin gene-related polypeptide, serotonin

Promote vasodilation and plasma protein extravasations.

Initiate inflammatory response, sensitizes surrounding tissues and produce prolong headache

Activates trigeminovascular system, which in turn, stimulate pain stimulating neurons in brain stem and upper spinal cord

Activates nociceptive trigeminovascular system and causes prolong pain

Cerebral cortex, thalamus or hypothalamus in response to stress, emotion.

‡

Boss

Serotonin Neurotransmittor Serotonin ( 5- hydroxytryptamine) is

thought to be an important mediator of migraine.

Unstable serotonergic neurotransmission , so has lower threshold for migraine.

There are 7 classes of 5-HT receptors Out of 7, 2 involve in migraine pain.

Serotonin cont.

It is basic as amines and Ammonia Changes Ph of blood Serotonin causesVasodilation Serotonin causesVasoconstrictionDuring migraine the level of serotonin is

low in blood. (Low Ph)Drug target

5- HT1 Presynaptic receptor

5- HT2 Postsynaptic receptor

Serotonin binds to 5-HT1 and 5-HT2

How bad could migraine be… It could distrub the normal life

activities. Could lead to brain damage Recently, a woman in London had a

migraine Lost her accent

Treatment

Identification and elimination of factors.

For example, Tobacco smoke, loud noise, stress, caffeine, emotions, contrasty light etc.

If they don’t work then move on to medicines

1)Prophylactic therapy2)Abortive therapy

Prophylactic therapy

Used in case of frequent migraines Used when abortive therapy has

failed Medicines have to taken everyday to

be effective On the other hand, abortive

medicine are taken during actual migraine pain.

Medicines used in this therapy 1) Medicines that block beta-

adrenergic. For example, Propranolol, nadodol,

timolol, atenolol, and metoprolol.Reduce the frequency of attacks by

50% in 60 to 80% patients.Side effects- fatugue, sleep

disturbance, depression, hypotension etc

Cont.

2) Tricyclic antidepressantsFor example, amitryptiline, nortryptiline,

doxepin, imipramine etcIndependent of antidepressant activity.Antagonist of 5-HT2, thus stabelize

serotonin neurotransmission 3) Methysergide:-Semisynthetic ergot alkaloid and is 5-HT2

antagonist. Gives best result when taken with mealsSide effects- gastrointestinal intolerence, insomnia,

and muscle cramps.

Prophylactic therapy cont. Calcium channel Blockers- Verapmil Takes up to 8 weeks to show any

good effect Side effects- Hypotension,

constipation etc

Abortive therapy

1) simple analgesics:- For mild and infrequent migraine- Aspirin

and acetaminophenAspirin+acetaminophen+barbiturate

butabital = To induce sleepaspirin+acetaminophen+narcotics =

FiorinalAspirin+ acetaminophen+caffiene =

EsgicDrawback- Continuous use fails to provide

pain relief.

Abortive Therapy cont.

2) NSAIDs:- Inhibit prostaglandin synthesis. So may prevent inflammation in

trigeminovascular system and alleviate migraine pain

They are effective for reducing the frequency, severity, and duration of migraine attacks. e,g. Aspirin, Ibuprofen, Naproxen etc.

Corticosteroids mediate glucose metabolism and inflammation

Arachidonic Acid (AA)

Plasma Membranephospholipids

Phospholipase A2

Prostaglandins,leukotrienes

Cyclooxygenase(COX)

AspirinAnnexin

Inflammation,Asthma

Non-steroidalAnti-inflammatory

Steroidal (corticosteroid)Anti-inflammatory

Abortive therapy cont.

3) Ergot familyErgotamine- It is secondary metabolite obtained from

ergot fungusDihydroergotamine- available in inject able

form.

The structure shares some similarit with neurotransmittor serotonin.

Acts as agonist, bind to 5-HT1,

More effective when given during early migraine attacks

Abortive therapy

5) Triptan Family 5-HT1 receptor agonists Examples-

Sumatriptan – Imitrex

Zolmitriptan – Zomig

Rizatriptan – Maxalt

Eletriptan – Relpax

Naratriptan - Amerge

ElitriptanSumatriptan

Rizatriptan Zolmitriptan

Side Effects

nausea, vomiting, dizziness, fatigue, and vertigo.

Not good for hypertensive patients at all.

Ergot and Triptan comparison The rates of ergotamine and

sumatriptan overuse were 14.2% and 3.5%, respectively

Drug-induced headache could be found more frequently in cases of ergotamine overuse then drugs of triptan family.

Miscellaneous agent

Midrin = Isometheptane+ dichlorophenazene+ acetaminophen

Used in patients who do not respond to ergot and triptan

Less effective then ergot and triptan family’s drugs

Most frequent side effects are nausea, dizziness, insomnia, and vomiting.

References

"Etymology of migraine". Online Etymological Dictionary. http://www.etymonline.com/index.php?term=migraine. Retrieved 27 May 2009

http://en.wikipedia.org/wiki/Migraine

Headache Classification Subcommittee of the International Headache Society (2004). "The International Classification of Headache Disorders: 2nd edition". Cephalalgia 24 Suppl 1: 9–160. doi:10.1111/j.1468-2982.2004.00653.x. PMID 14979299. 

Questions

Name the major neurotransmitter that mediate the migraine pain.

Name major medicines that act as 5-HT1 agonist and 5-HT antagonist.

How does NSAIDs work?