NEURO 18: Headache Pathophysiology

Primary Headache (4)

1. Migraine

2. Tension-type

3. Cluster

4. Paroxysmal

Migraine episodic WITHOUT aura

1) How long do they last

2) Symptom description

• Unilateral vs bilateral

• Symptom

• Intensity

3) Additional requirements (4)

4) HOW MANY REQUIRED FOR DIAGNOSIS

1) 4-72 hours

2)

• Unilateral

• Pulsating, throbbing

• Moderate-severe intensity

3) Nausea/Vomiting + BOTH photophobia & phonophobia

4) 5 or more

Migraine episodic WITH aura

1) How many required for diagnosis

2 or more

Migraine phases: PRODROMAL

1) Timeline

2) Symptoms

1) 12-36 hours BEFORE aura/headache

2)

• Yawning

• Excitation

• Depression

• Impaired concentration

• Lethargy

• Craving OR distaste for foods

Migraine Phases: Aura

1) Duration timeline

2) Symptoms

1) 5-60 minutes

2)

• Visual = scintillations or vision loss

• Sensory = numbness, feelings of pins & needles

• Speech/language = Aphagia, dysarthria

• Motor = Weakness on 1 side of body or face

• Brainstem = Vertigo, tinnitus, diplopia, ataxia, hypacucis, decreased LOC

Migraine Phases: Headache

1) Duration timeline

2) Symptoms

3) More often unilateral or bilateral

1) 4-72 hours

2)

• Pulsating, nausea, vomiting, photophobia, photophobia, tinnitus

3) Unilateral

Migraine Phases: Post-drome

1) Duration timeline

2) Symptoms

1) 24-48 hours AFTER headache

2)

• Fatigue

• Depression

• Severe exhaustion

• Difficulty concentrating

• Cognitive difficulties

• Feeling unusually fresh

Trigeminovascular system in order (7)

1. Intracranial arteries

2. Dura Mater

3. Trigeminal Nerve (CN 5)

4. Trigeminal Ganglion

5. Vasoactive Peptides

6. Brainstem Structures

7. Cerebral Cortex + Thalamus

Intracranial Arteries

1) ___ and ___ arteries

2) Innervated by what

3) Sites of what

1) Meningeal + Cerebral

2) Trigeminal sensory fibres

3) Neurogenic inflammation and vasodilation

What is the Dura Mater

Outermost layer of meninges — innervated by trigeminal sensory fibres

Trigeminal Nerve (CN5)

Sensory fibers from:

• Opthalmic

• Maxillary

• Mandibular

Trigeminal ganglion

Cell bodies of sensory neurons innervating intracranial blood vessels

Vasoactive Neuropeptide Roles:

1) CGRP (Calcitonin Gene-Related Peptide)

2) Substance P

3) VIP (Vasoactive Intestinal Peptide)

1) Pain transmission, vasodilation, inflammation response

2) Pain transmission, inflammation response

3) Vasodilation, inflammation response

Brainstem structures: TNS (Trigeminal Nucleus Caudalis)

Relay center in the medulla where sensory inputs from the trigeminal nerve are processed; connects to higher brain centres involved in pain perception

Cerebral Cortex + Thalamus

Higher brain centers involved in pain perception as relayed from the TNS

Neurovascular Theory

1) What does it focus on

2) Flowchart

1) Neural + vascular components; explains changes that occurs across the trigeminovascular system

2)

1. Intracranial arteries vasodilate

2. Trigeminal nerve activation (5HT1B/D receptors)

3. Vasoactive peptides

4. Pain

Central Sensitization Theory

1) What does it focus on

2) Flowchart

1) Focus on change in the CNS that leads to heightened pain sensitivity to normal or lower stimuli

• Explains the pain intensity + chronicity of migraines

2)

Cortical Spreading Depression

Wave of overexcited then "tired" brain cells that spreads across the brain, triggering aura and migraine pain.

1) What can alter serotonin (5HT)

2) what can affect migraine threshold

1. Abnormalities in Na and Ca channels / Na + K pumps

2. Increased excitatory amino acids (glutamate) or K+

TENSION TYPE HEADACHES:

Episodic:

1) How many episodes, how many days/month, for how long

2) Unilateral vs bilateral

3) Intensity (mild→severe)

4) Symptom

5) Aggrevated by routine physical activity?

6) Nausea/vomiting present?

7) Phonophobia or photophobia present?

Chronic

8) How many episodes for how long

1. 10 or more episodes less than 15 days a month for at least 3 months

2. Bilateral

3. Mild-moderate

4. Non-pulsating, dull, aching, tight pressure

5. No

6. Non present

7. Only one can be present (or non, BUT NOT BOTH)

8. 10 or more episodes for 15 or more days a month for at least 3 months

Medication Overuse Headache

1) Headache occurring on ___ / ___ in a patient with pre-existing headache disorder

Regular use for > 3 months of 1 or more drugs:

2) Ergot derivatives, opioids, triptans, combination analgesics

3) Non-opioid analgesics (NSAID/acetaminophen)

4) WHAT ARE THE SYMPTOMS

1) 15 or more days / month

2) 10 or more days / month

3) 15 or more days / month

4) Symptoms similar to tension-type headache

Cluster Headache

1) How many attacks required

2) Intensity of pan (mild→ severe)

3) Unilateral vs bilateral

4) Common symptoms associated with it

5) Where is the pain typically located

6) Frequency of attacks

1) 5 or more attacks

2) Severe or very severe

3) Unilateral

4)

• Nasal congestion/rhinorrhea

• Eyelid oedema

• Forehead and facial sweating

• Miosis or ptosis

• Sense of restlessness or agitation

5) Near the eyes

6 Once every other day —> 8 attacks / day