Flashcards in Lec 65 Migraines Deck (37)
Can symptoms differentiate between primary and secondary headache?
symptoms alone cannot differentiate!
What are IHS criteria for migraine without aura?
- at least 5 attacks
- attacks last 4-72 hrs
- headache with 2 of: unilateral, pulsating, moderate/severe, avoidance of physical activity
- during headache N/V and/or photophobia
- not attributed to another disorder
What are criteria for migraine with aura?
- headache same as non-aura PLUS
- aura has no motor weakness and consists of: fuly reversible visual OR sensory symptoms OR dysphasic speech
- homonymous visual symptoms OR unilateral sensory symptoms OR develops over 5 minutes
When does aura occur?
can be before, during, or without headache
are migraines unilateral or bilateral? how long does it last?
lasts 4-72 hours
What is episodic vs chronic migraine?
episodic = less than 15 days per month
chronic = more than 15 days per month
What percent of migraine pts have auras?
- most common = visual
What is CSD?
cortical spreading depression = wave of neuronal depolarization followed by suppression neuronal activity with corresponding blood flow change moved across cortex at 3mm/min
linked to migraine course/clinical feat
What is prevalence of migraine?
43% of women, 18% of men likely associated with estrogen
-- pre-puberty = equal between sexes
What causes migraine? triggers?
migraine is hereditary polygenic
migraine has many triggers = exertion, dietary, sleep disturbances, head trauma, hormones, meidcation
What diseases have co-morbidity with migraine?
mitral valve prolapse, stroke, epilepsy, sever psychiatric
What is association vascular changes and migraine?
vascular changes occur but they are not primary cause
migraine aura associated with vasoconstriction, headache with vasodilation
researches debating the relationship
What type of blood flow before/during headache?
- aura/migraine begin during hypo-perfusion phase
- then get hyper-perfusion as headache continues
- hyper-perfusion may outlast headache apin
How can you provoke CSD?
chemical, electrical, mechanical stimuli
What is role of CSD in migraine?
plays an important role in genesis of migraine attack [but not exclusive to migraine]
Can you feel sensation of brain parenchyma?
NO! but you can feel it from dura mater/vessels, blood vessels, and CNs
What innervates intracranial contents about the tentorium cerebelli?
What innervates intracranial contents below the tentorium cerebelli?
CN2, 3, 7, 9, 10
What are 2 common misdiagnosis of pts who have migraine
tension headache: pt with neck pain = due to referred pain by CN V
sinus headache = pt with tearing, rhinorrhea, nasal congestion cause by trigeminal-ANS reflex
What is the trigeminocervical complex?
- runs from the medulla down into C3 where blends gradually into cervical dorsal horns
receives fibers from upper cervical roots and sends them to thalamus and collateral to ANS nuclei in brainstem and hypothalamus
- thalamic neurons project to S1 and limbic
- TNS also synaptically connects to parasympathetic superior salivatory nucleus [SSN] in pons
What innervates meningeal vessels?
parasympathetic superior salivatory nucleus [SSN] in pons via greater superficial petrosal
What is important about TNC as a convergence of different sensory info?
- pain from face and head referrred to neck
- pain from neck referred to face V1 distribution
When is ipsilateral greater occipital nerve [at C2] tender? importance for treatment?
during migraine OR cluster headache
- give occipital nerve block at C2 to terminate acute headache
What happens to midbrain during migraine attack?
- periaqueductal gray in midbrain is activated
What are premonitory symptoms?
- symptoms that occur hours to day before a migraine attack [irritability, food cravings, fatigue, excess yawning, etc]
- suggest hypothalamic involvement
What is the cortical spreading depression [CSD] theory of migraines?
- wave of neuronal depolarization moves 3 mm/min through cortex accompained by transiet hyperemia then oligemia and suppression of neuronal activity
- Ca waves propagate through glia affecting vascular activity
- as wave of depolarization moves, release inflammatory factors [NO, H, K, arachadonic acid] --> activates meningeal nociceptors + trigeminal neurons release stuff --> pain, inflammation
What is the trigeminovascular reflex?
occurs with CSD
trigeminal neurons that supply dural vessels release CGRP [calcitonin gene-releated peptide], substance P and neurokinin A] --> vessel dilation and inflamation --> "peripheral sensitization" of trigeminal neuron --> carries pain centrally
What is the trigeminoparasympathetic reflex?
through polysnaptic connects with SSN, parasympathetic fibers innervating dural vessels release ACh, NO, VIP [vasoactive intestinal polypeptide] --> miosis, ptosis, red eye, lacrimation, rhinorrhea
What happens if you treat during early stage of attack when there is only peripheral sensitization?
migraine can be fully termianted