Headaches and Migraines Flashcards
What is the difference between a primary and secondary headache?
Primary = absence of physical signs Secondary = presence of physical signs (headache due to an underlying condition)
Describe normal/tension-type heaches.
Will disappear soon after noxious stimulus has ceased (can last 30 mintues to several days)
Pain is band-like, bilateral (tightness, pressure, dull ache)
Treated with general painkillers, can also use prophylactics
Describe cluster headaches - how long do they last, treatment etc.
Very extreme and painful type of headache
More likely to occur in men
Can last 6-8 weeks, with each attack lasting 20 minutes to 3 hours
For acute attacks, treat with 100% oxygen for ~20 minutes
Use verapamil
Migraines are the result of central neuronal hyperexcitability. What are the causes of this hyperexcitability?
Abnormality of calcium channels - mutant voltage gated P/Q type calcium channels - this influence presynaptic NT release
Could also be due to genetic abnormalities - these might reduce the threshold of response to triggering factors
What % of migraine attacks are accompanied by an aura?
20-30%
How long does each stage of a migraine attack last?
- 12-48 hours
- <1 hour
- 4-72 hours
- 2-12 hours
- 2-24 hours
What is the 1st stage of a migraine attack, what are the signs?
Premonitory Signs: - food cravings - yawning - neck pain - heightened perception - fluid retention
What is the 2nd stage of a migraine attack, what are the signs?
Aura
Signs:
- visual (99%) and/or sensory and/or speech/language symptoms
- duration of each symptom is approx. 20-30 minutes
What is cortical spreading depression (CSD)?
a transient and local suppression of spontaneous electrical activity in the cortex which moves slowly across the brain resulting in an aura
(rate of spread is ~3 mm/min)
What is the 3rd stage of a migraine attack, what are the signs?
Headache Signs: - anorexia - N+V - malaise - lethargy - sensitive to light/sound - heightened sense of smell - difficulty focusing/concentrating
Explain what the trigeminovascular pathway is in relation to migraines/pain.
- Blood vessels vasodilate (induced by neuropeptides)
- This causes further release of inflammatory peptides
- Neuropeptides activate the nerve pathways - nerves send pain signals to the trigeminal ganglion
- Peripheral sensitisation mediates throbbing pain
- Trigeminal nerve transmits pain impulses to the SpV (spinal trigeminal nucleus caudalis) in the brainstem
- SpV relays these impulses to the thalamus
- Information passes from the thalamus to the cortex
- Cortex then decodes information into our experiences of pain
What is CGRP and how is it related to migraines?
CGRP = calcitonin gene-related peptide
It is a 37 amino acid neuropeptide and a potent vasodilator
CGRP increases during spontaneous migraine attacks
CGRP decreases after effective symptomatic treatment with triptans
CGRP infusions TRIGGER migraines
Migraine drugs include CGRP receptor antagonists
What is the 4th stage of a migraine attack, what are the signs?
Resolution
Signs:
- vomiting
- deep sleep
What is the 5th stage of a migraine attack, what are the effects on the body after a migraine attack?
Recovery After migraine: - limited food tolerance - tiredness - feel hungover - diuresis
What preventative medications are there for migraines and how do they work?
- 5-HT1D receptors = trigeminal inhibition
- CGRP monoclonalantibodies = prevent vasodilation
(includes erenumab, fremanezumab, eptinezumab, galcanezumab)
