Serotonin Agonists - Migraine Pathophysiology Flashcards
The development of migraine headaches depends on the activation of what afferent fibers?
Nociceptive sensory fibers of the ophthalmic division of the trigeminal nerve which innervate the meningeal blood vessels
What is cortical spreading depression (CSD)
Before the headache occurs, a region of neural activation followed by inactivation travels across the cortex.
What is the initiating event of the migraine according to the trigeminovascular theory of migraine?
Cortical spreading depression (CSD). This theory of migraine is said to be a neurogenic theory
What is hypothesized to initiate sterile inflammation?
The activation of the afferent terminals of the othalmic branch of the trigeminal nerve. Collateral axons of activated neurons in the trigeminal ganglion (TCG) release pro-inflammatory peptides in the meninges and their vessels leading to a local inflammatory reaction called sterile inflammation
What is one of the most powerful endogenous vessel dilating substances yet identified?
Calcitonin gene -related peptide (CGRP)
When the Antidromic pulse arrives at the trigeminal nerve terminal in the Dura, which vasodilating neuropeptides are released?
- Neurokinin-A (NK-A)
- calcitonin gene -related peptide (CGRP)
- substance P (SP)
- nitric oxide (NO)
The vasodilation mediated by the neuropeptides and nitric oxide promotes release of what into the perivascular space?
- Albumin
- bradykinin
- histamine (mediated by substance P)
- prostaglandins
- serotonin from platelets
all of these substances participate in the sterile inflammatory process
Are trigeminal nerve endings sensory or afferent?
Both. Sensory because they are able to generate new Orthodromic signals, and afferent because they convey impulses toward the trigeminal nucleus.
What is another term for the supra-salivary pathway?
The parasympathetic reflex
Which drugs produce potent vasoconstriction of anastomoses (direct vascular connections between arteries and veins without intervening capillaries)?
Ergot alkaloids and triptans
What are all the things happening in a migraine?
- Vasodilation
- sterile inflammation
- cholinergic reflex
- anastomoses
In cortical spreading depression, after the blood brain barrier becomes leaky which compounds do you release?
- Potassium
- arachidonic acid
- protons
- nitric oxide
The perception of pain is mediated by what?
Higher order projections from the TGN
What do the mast cells release?
- Histamine
- bradykinin
- substance P
- serotonin
Do migraines start out in the Pia matter or the Dura matter?
Pia
