21. Headaches and migraines Flashcards
What is the difference between a primary and a secondary headache?
Primary headache - diagnosis is based on the absence of physical signs - due to itself
Secondary headache - diagnosis based on the presence of physical signs - the headache occurs as a result of something else e.g. sinusitis
What are the different types of primary headaches?
Tension-type headache
Migraine
Cluster headache
What are tension type headaches?
Most common type of headache - essentially the normal headache
These disappear soon after the noxious or potentially noxious stimulus has ceased
Generally don’t need painkillers for these but if you do use them then the headache will generally disappear within about 20 minutes
What are the signs and symptoms of tension headaches?
Band-like, bilateral Tightness/Pressure/Dull ache Radiates to the neck and the shoulders Mild to moderate pain Not aggravated by movement Can last from 30 minutes to several days
What is the treatment for a tension-type headache?
Treatment generally involves stopping the cause of the headache i.e. the noxious stimulus or by taking a painkiller
What is a cluster headache?
Aka. Suicide headache
This is a severe type of headache resulting in excruciating pain
Occurs multiple times a day lasting for 6-8 weeks
Often occurs a couple of hours after they go to sleep
Can last from 30 minutes to three hours
This is a unilateral headache - the pain and symptoms are all one-sided e.g. one eye waters and goes red, one nose will run etc
What is the treatment for a cluster headache?
The most effective symptomatic treatment is the delivery of 100% oxygen for 12-15L per minute
Can give vasoconstrictors but these must be adminsitered non-orally
What is a migraine?
A throbbing headache that may be accompanied by a feeling of nausea, vomiting or sensitivity to light and sound
Can often occur only on one side of the head
These are episodic headaches and are essentially a condition of healthy people
In simple terms, explain the cause and onset of a migraine
Environmental triggers can act on an excitable brain and result in a headache
If the triggers reach the threshold for a migraine, there is a change in the chemistry of the brain and this stimulates a migraine
This change in the chemistry can now not be altered and the migraine will occur even if you receive the stimuli
What are the genetics of migraines?
Inheritable - inheritance of an ‘excitable brain’ - can be excited by environmental stimuli to a greater extent - are more likely to reach the threshold for a migraine
Have heightened senses to e.g. smell, lights, sounds, touch
What is a migraine aura?
Auras are present in 20-30% of migraine sufferers
Theses are visual/sensory/speech/language symptoms which occur and resolve before the onset of the headache
The aura is generally around 20-30 minutes and lasts no longer than one hour
A visual aura will be present even if the patient closes their eyes - this is because it originates from the visual cortex at the back of the brain rather than actually from the eyes
What is the pathophysiology behind a migraine aura?
Believed to be due to cortical spreading depression (CSD)
This occurs once the migraine threshold has been met by the environmental stimuli
This is a wave of electrophysical hyperactivity followed by a transient and local suppression of the electrical activity in the cortex and this moves slowly across the brain
CSD occurs within the visual cortex and is believed to trigger the visual aspect of the aura
Give the pathophysiology of a migraine
The chemical changes that occur due to the environmental stimuli i.e. the cortical spreading depression results in swollen meningeal arteries
These release inflammatory neuropeptides and this is known as neurogenic inflammation
This causes an activation of nerves which results in the transmission of pain signals to the trigeminal ganglion - this causes peripheral sensitisation and results in the throbbing pain that is the headache
Action potentials/pain signals are then transmitted to the trigeminal nucleus caudalis in the brainstem and this area is responsible for prolonging and continuing the migraine attack i.e. why it will not disappear during treatment (the symptoms will just be masked)
The pain impulses are then relayed to the thalamus and then to the cerebral cortex where it is decoded as pain
What is the role of central sensitisation in a migraine and how does this occur?
Central sensitisation occurs due to the neuronal hyperexcitability in the trigeminal nucleus caudalis
This occurs within 60 minutes of the onset of pain and can last up to 10 hours - results in allodynia causing a prolongation of the attack
How is a migraine resolved?
Some people, especially children, find that it resolves from vomiting
Others require a deep sleep
