Pathophysiology ,Diagnosis and Treatment
of MIGRAINE
(Dr boyapati venupriya)
Migraine
is defined as pulsating throbbing headache which increases in intensity on
physical activity. It occurs typically on one side of the head accompanies with
vision changes, sensitivity to light, and nausea.
Types
of Migraine
:
There
are two types of migraine headache:
1) Migraine with aura
2) Migraine without aura
1)
Migraine with aura: It is simply a physiological warning that occurs in
individuals (patient) vision or other senses alerting the onset of a migraine.
It can occur during or after migraine pain begins. Around 15% to 20% of those
with migraines experience auras.
Patients
who experience visual auras can see zig- zagging lines, lights look like stars
or dots or even have a blind spot before a migraine starts. Besides visual
auras, other senses are affected. Hearing auras can be experienced as ringing
in ears before a migraine. Patients who experience smell auras will notice
strange odors and taste, touch or simply sensing a “funny feeling” have also
been reported as symptoms of migraine with aura. Whatever the type of aura
symptoms will last less than one hour.
2)Migraine
without aura:
Around 85% of those with migraines experience migraine without aura. Patients
experience all of the other features of a migraine attack, including intense
pain on one/ other sides of the head, nausea, vomiting, and light/ sound
sensitivity. Other signs include anxiety depression/ fatigue. it can last up to
72 hours before the headache pain. Other warning signs include feeling
thirsty/sleepy/craving sweets.
In
general, it consists of three phases which include the prodrome phase, headache
phase, and postdrome phase. Prodrome (pre headache) phase experience several
hours/ even days before accompanied by food cravings, mood changes, muscle
stiffness. During the headache phase, there will be quite debilitating pain in
the entire body. In some patients between the prodrome phase and headache
phase, they experience the aura phase. The postdrome phase goes with feeling
hungover or tired.
Triggers for migraine:
Most
of the patients reported that migraine headache starts whenever they got
triggered by some factors. The most common trigger factors are emotional
stress, sleep disturbance, and dietary factors. Some studies found that lack of
sleep and stress are the factors associated with migraine with aura.
Environmental factors play a crucial role in patients having migraines without
aura.
Pathophysiology:
Migraines
are regularly called as a threshold disorder connected with dysfunctional
nociceptive processing. Several genetic, hormonal, and neurochemical factors
work together and result in dysregulation of cortical and brainstem
excitability.
A
theory called cortical spreading depression is assumed to be related to
migraine. CSD is depicted by a wave of significant cortical activation shadowed
by sustained inhibition of activity. This excitability leads to cortical
activation via neuronal and glial activation, which in the sequence is related
to nociceptive activation and vascular changes comprising enhanced blood-brain
barrier permeability. The
vasodilation and neurogenic inflammation further increase activation of the
sensory trigeminal fibres, continue the release of vasoactive peptides
including CGRP, and modulate the transmission of pain impulses to the brain.
The cortical activation extends to the brain stem via trigeminal pathways
broaden boosting central sensitization. The central sensitization increases
pain perception(migraine).
The
added activity in the descending pain modulating neural networks sensitize an
individual to be more susceptible to physiological and environmental elements
that play a part in migraine attacks.
Diagnosis
To
diagnose migraine a prior patient’s history must be collected to identify the
possible triggers. Avoidance of triggers may result in better control of the
disorder.
International
classification of headache disorders gave criteria to diagnose migraine.
A. At least 5 attacks 1
fulfilling criteria B-D
B. Headache attacks lasting 4-72
hours (untreated/ unsuccessfully treated)
C. Headache has at least 2 of
the following 4 characteristics
1.unilateral location
2.pulsating quality
3.moderate/ severe pain
intensity
4.aggravation by / causing
avoidance of routine physical activity
D. during headache at least one of the following
1.nausea and/ vomiting
2.photophobia and phonophobia
E. not better accounted for by another ICHD-3 diagnosis
To
rule out other co-morbidities orthopedic tests, cranial nerve examination,
complete blood count, urinalysis and cranial magnetic resonance imaging will be
recommended.
Treatment
Till
now there are no standard treatments available. To treat a migraine patient's
choice of medication based on individual bias and it is important to find out
the underlying cause before selecting the drugs. Studies revealed that there
are two approach considerations in treating migraine headaches.
· Acute therapy or abortive
therapy
· Preventive therapy or
prophylactic therapy
Acute
therapy
Migraine
medications act by changing the way cell function. Acute therapy reverse / at
least stops the progression of a headache that has started.it is prescribed
when the migraine starts. Medications include analgesics and triptans.
Acute
medication for the treatment of migraine attacks: Limit intake to <10/15 days/ month.
· Nausea / vomiting:
Metoclopramide 10mg oral
Domperidone
10mg oral
· Acute: Acetyl salicylic acid
1000mg
Ibuprofen
200mg/400mg/600mg
Metamizole
1000mg
Diclofenac
potassium 50mg/ 100mg
· Combination analgesics: 2
tablets ASA 250mg/265mg+ Paracetamol/ Acetaminophen 200mg/ 265mg+ Caffeine
50mg/65mg
If
the patient is contraindicated for NSAIDs:
Paracetamol
/ acetaminophen 1000mg oral / metamizole 1000mg oral
For
moderate and severe migraine attacks and lack of response to analgesics:
Triptan
therapy:
Fast
onset of action: Sumatriptan 6mg sc
Eletriptan 20mg/40mg/80mg oral
Rizatriptan 5mg/ 10mg oral
Zolmitriptan 5mg nasal spray
Moderately
fast onset and longer-lasting effect:
Sumatriptan 50mg/ 100mg oral
Zolmitriptan 2.5mg / 5mg oral
Almotriptan 12.5 mg oral
Slow
onset with the long-lasting duration of action:
Naratriptan 2.5 mg oral
Frovatrpitan 2.5 mg oral
If
monotherapy is insufficient: Triptan + NSAIDS (naproxen 1000mg)
For
recurrence of headache:
Re
administration of a triptan after at least 2 hours.
Initial
combination therapy: Triptan+ long-lasting NSAID (naproxen)
Emergency
medication for migraine attacks:
Metoclopramide 10mg IV
Lysine acetyl salicylate 1000mg IV
Sumatriptan 6mg sc
Preventive
therapy:
Preventive
therapy will be prescribed in the absence of a headache to reduce the frequency
and severity of the migraine attack, make acute attacks more responsive to
abortive therapy. Also, improve the patient’s quality of life.
Medications
include beta-blockers, anti-depressants, calcium channel antagonists, antiepileptics.
Beta-blockers:
Atenolol:
50-200mg
Metoprolol:
100-200mg
Nadolol:
20-160mg
Propranolol:
40-240mg
Timolol:
20-60mg
Anti-depressants:
Amitriptyline:
10-200mg
Doxepin:
10-200mg
Nortriptyline:
10-150mg
Calcium
channel antagonists:
Verapamil:
120-480mg
Flunarizine:
5-10mg
Anti-epileptics:
Carbamazepine:
600-1200mg
Gabapentin:
600-3600mg
Topiramate:
50-200mg
Valproate:
500-2000mg
By Dr Boyapati Venupriya
