What are migraines?
An episodic neurologic disorder characterized by headaches lasting 4–72 hours
Diagnostic criteria for migraines (pain features)
Must have ≥2: unilateral head pain; throbbing pain; worsens with activity; moderate to severe pain
Diagnostic criteria for migraines (associated symptoms)
Must have ≥1: nausea/vomiting; photophobia (light sensitivity); phonophobia (sound sensitivity)
What is photophobia?
Sensitivity to light; patients prefer dark rooms and may wear sunglasses
What is phonophobia?
Sensitivity to sound; normal sounds feel loud and irritating
Migraine classifications
With aura; without aura (most common); chronic migraines
Definition of chronic migraines
≥15 days/month for ≥3 months
How do chronic migraines typically develop?
Start as episodic and increase in frequency over time
Primary risk factor for migraines
Family history
Hormonal influence on migraines
Associated with estrogen and progesterone
Who is more susceptible to migraines and why?
Females due to hormonal involvement
When are migraines more frequent hormonally?
Before and during menstruation
When do migraines often decrease?
During pregnancy and menopause
Proposed hormonal trigger mechanism
Cyclical withdrawal of estrogen/progesterone during menstrual cycle
Other contributing factors for migraines
Genetic and environmental factors
Common migraine triggers
Fatigue;
sleep disturbances (too little or too much sleep)
missed meals;
overexertion;
weather changes
stress; hormonal changes
alcohol (especially red wine)
bright lights
strong smells
Example of environmental trigger example
Strong smells (e.g.
Is migraine pathophysiology well understood?
No
Key pathophysiologic associations
Changes in brain metabolism and blood flow
Proposed migraine mechanism
Neurotransmitter changes and altered blood vessel tone
Neuronal activity in migraines
Increased depolarization → hyperactivity
Effect of excitatory neurotransmitters
Activate vascular system → vasodilation → migraine
Four phases of a migraine
Premonitory; Aura; Headache; Recovery
Premonitory phase timing
Hours to days before headache
