Migraine Clinical Guideline
Migraine is a common condition characterized by enhanced sensitivity of the nervous system and activation of the trigeminal-vascular system . Individuals prone to migraine have a genetic migrainous threshold that renders them susceptible to an acute migraine attack depending upon the balance between excitation and inhibition of the nervous system .
Diagnosis A migraine is a severe headache , usually unilateral but occasionally bilateral , that may be accompanied by nausea , vomiting , and visual disturbances . Findings suggest that the best criteria differentiating migraine from other headache types are the presence of nausea and / or vomiting in combination with two of the following three symptoms : photophobia , phonophobia , and osmophobia — all of which may be made worse with movement or activity . ( National Headache Foundation , 1996 [ NA ])
Testing Neuroimaging is subject to physician judgment with consideration of the following :
• Patients with an unexplained finding on neurologic examination
• Patients with atypical headache features or headaches that do not fulfill the definition of migraine or other headache disorder
• Patients with a first-time sudden severe headache to rule out subarachnoid hemorrhage
• A head CT without contrast is sufficient to rule out subarachnoid hemorrhage . An MRI with contrast is indicated when posterior fossa lesions or a cerebrospinal fluid leak are suspected .
Prevention Prophylactic treatment is indicated if the headaches are frequent ( 2 or more per month ), long lasting ( 3 days of disability or more per month ), or significantly interferes with daily routine despite acute treatment .
• For menstrual migraines , preventive medication is started one to two days prior to the expected onset of a headache and continued for the expected duration of the headache .
• Antihypertensives : blood pressure treatment appears to reduce the overall prevalence of headache .
• Beta-blockers : may take several weeks to be effective and should NOT be used as initial therapy for migraine prophylaxis in patients over age 60 and in smokers . They are contraindicated in patients with uncontrolled asthma , decompensated heart failure , heart block , severe bradycardia and severe hepatic impairment . Use caution with patients with depression , impotence , or hypotension .
• Calcium channel blockers : tolerance may develop . Verapamil is the first choice for therapy .
• ACE inhibitors / ARBs
• Tricyclic antidepressants and venlafacine : established role in headache prophylaxis . Severe anticholinergic effects and weight gain can be limiting .
• Anticonvulsants : valproate and topiramate are approved by the US FDA for migraine prophylaxis . Avoid use in females of childbearing age .
Evaluation Clinical Manifestations :
• Commonly begins early in the morning .
• Nocturnal migraines can occur as well . If a patient has a recent onset of nocturnal headaches , brain tumor , and glaucoma should be excluded .
• 60 to 70 percent of patients have lateralized headache ; bifrontal or global occurs in 30 percent .
• Pain has a gradual onset , following a crescendo pattern with gradual resolution .
• Headache is dull , deep , and steady when mild to moderate ; headache becomes throbbing when severe .
Premonitory symptoms : Such symptoms precede a migraine attack by several hours up to two days . Symptoms include : fatigue , concentration difficulty , neck stiffness , sensitivity to light or sound , nausea , blurred vision , scintillation , scotoma , yawning , or pallor .
Migraine aura : An aura occurs before the onset of a migraine and presents as a progressive neurologic deficit or disturbance . The headache begins simultaneously or just after the end of the aura phase . Most auras resolve in less than one hour , but motor auras may persist longer .
Types of auras :
• Visual disturbances
• Sensory symptoms
• Motor weakness
• Speech disturbances
Autonomic and sinus symptoms :
• Tearing
• Nasal congestion
• Changes in pupil size • Rhinorrhea
• Changes in color and temperature
A migraine can occur with or without an aura . Oral contraceptives are absolutely contraindicated in women with migraines with aura . Oral contraceptives are relatively contraindicated in women less than 35 in migraine without aura .
Treatment The main goal of acute migraine treatment is to abort an attack once it begins . Therapeutic success is higher at the onset of an acute attack than when the migraine is well-established .
• Have the patient keep a diary of migraines . This will help the patient identify triggers that precipitate a migraine .
• Try non-steroidal anti-inflammatory ( NSAID ) drugs first . If the patient is unresponsive to those , triptans or dihydroergotamine are indicated .
• Use a non-oral medication for patients with significant early nausea or vomiting .
• Use prophylactic medications for patients with frequent headaches to prevent medication overuse .
• Anti-emetics may be helpful .
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