Prevalence
► Familial
► Young, healthy women; F>M: 3:1
17 – 18.2% of adult females
6 – 6.5% adult males
► 2-3rd decade onset… can occur sooner
► Peaks ages 22-55.
► ½ migraine sufferers not diagnosed.
► 94% pt’s seen in primary care settings for HA have migraines
► Common misdiagnoses for migraine:
Sinus HA
Stress HA
► Referral to ENT for sinus disease and facial pain.
► Migraineurs more likely to have motion sickness.
► Half of Meniere’s patients claim to have migrainous symptoms.
► BPPV
► $13 billion/year in lost productivity
► 1/3 participants in American Migraine Study II missed work in prior 3 months
Migraine Definition
► IHS Diagnostic criteria: migraine w/o aura
HA lasting for 4-72 hrs
HA w/2+ of following:
► Unilateral
► Pulsating
► Mod/severe intensity.
► Aggravated by routine physical activity.
During HA at least 1 of following
► N/V
► Photophobia
► Phonophobia
► IHS criteria: Migraine/aura (3 out of 4)
One or more fully reversible aura symptoms indicates focal cerebral cortical or brainstem dysfunction.
At least one aura symptom develops gradually over more than 4 minutes.
No aura symptom lasts more than one hour.
HA follows aura w/free interval of less than one hour and may begin before or w/aura.
Migraine Subtypes
► Basilar type migraine
Dysarthria, vertigo, diplopia, tinnitus, decreased hearing, ataxia, bilateral paresthesias, altered consciousness.
Simultaneous bilateral visual symptoms.
No muscular weakness.
► Retinal or ocular migraine
Repeated monocular scotomata or blindness < 1 hr
Associated with or followed by a HA
► Menstrual migraine
► Hemiplegic migraine
Unilateral motor and sensory symptoms that may persist after the headache.
Complete recover
► Familial hemiplegic migraine
Migrainous vertigo
► Vertigo – sole or prevailing symptom.
► Benign paroxysmal vertigo of childhood.
► Prevalence 7-9% of pts in referral dizzy and migraine clinics.
► Not recognized by the IHS
► Diagnosis (proposed criteria)
Recurrent episodic vestibular symptoms of at least moderate severity.
One of the following:
► Current of previous history of IHS migraine.
► Migrainous symptoms during two or more attacks of vertigo.
► Migraine-precipitants before vertigo in more than 50% of attacks.
Response to migraine medications in more than 50% of attacks
Migraine mechanism
► Neurovascular theory.
Abnormal brainstem responses.
Trigemino-vascular system.
► Calcitonin gene related peptide
► Neurokinin A
► Substance P
► Extracranial arterial vasodilation.
Temporal
Pulsing pain.
► Extracranial neurogenic inflammation.
► Decreased inhibition of central pain transmission.
Endogenous opioids.
► Important role in migraine pathogenesis.
► Mechanism of action in migraines not well established.
► Main target of pharmacotherapy.
Aura Mechanism
► Cortical spreading depression
Self propagating wave of neuronal and glial depolarization across the cortex
► Activates trigeminal afferents
Causes inflammation of pain sensitive meninges that generates HA through central/peripheral reflexes.
► Alters blood-brain barrier.
Associated with a low flow state in the dural sinuses.
► Auras
Vision – most common neurologic symptom
Paresthesia of lips, lower face and fingers… 2nd most common
Typical aura
► Flickering uncolored zigzag line in center and then periphery
► Motor – hand and arm on one side
► Auras (visual, sensory, aphasia) – 1 hr
► Prodrome
Lasts hours to days…
Clinical manifestations
► Clinical manifestations
Lateralized in severe attacks – 60-70%
Bifrontal/global HA – 30%
Gradual onset with crescendo pattern.
Limits activity due to its intensity.
Worsened by rapid head motion, sneezing, straining, constant motion or exertion.
Focal facial pain, cutaneous allodynia, GI dysfunction, facial flushing, lacrimation, rhinorrhea, nasal congestion and vertigo…
Precipitating factors
Treatment
► Abortive
Stepped
Stratified
Staged
► Preventive
Abortive Therapy
► Reduces headache recurrence.
► Alleviation of symptoms.
► Analgesics
Tylenol, opioids…
► Antiphlogistics
NSAIDs
► Vasoconstrictors
Caffeine
Sympathomimetics
Serotoninergics
► Selective - triptans
► Nonselective – ergots
► Metoclopramide
Abortive care strategies
► Stepped
Start with lower level drugs, then switch to more specific drugs if symptoms persist or worsen.
► Analgesics – Tylenol, NSAIDs…
► Vasoconstrictors – sympathomimetics…
► Opioids (try to avoid) - Butorphanol
► Triptans – sumatriptan (oral, SQ, nasal), naratriptan, rizatripatan, zomatriptan.
Limited by patient compliance.
► Stratified
Adjusts treatment according to symptom intensity.
► Mild – analgesics, NSAIDs
► Moderate – analgesic plus caffeine/sympathomimetic
► Severe – opioids, triptans, ergots…
Severe sx treatment limited due to concomitant GI sx’s.
► Staged
Bases treatment on intensity and time of attacks.
HA diary reviewed with patient.
Medication plan and backup plans.
Preventive therapy
► Consider if pt has more than 3-4 episodes/month.
► Reduces frequency by 40 – 60%.
► Breakthrough headaches easier to abort.
► Beta blockers
► Amitriptyline
► Calcium channel blockers
► Lifestyle modification.
► Biofeedback.
Botox
51% migraineurs treated had complete prophylaxis for 4.1 months.
38% had prophylaxis for 2.7 months.
Randomized trial showed significant improvement in headache frequency with multiple treatments.
Conclusions
► Migraine is common but unrecognized.
► Keep migraine and its variants in the differential diagnosis.
No comments:
Post a Comment