Headache
Origin of Headache Pain
pain-sensitive structures in the head: sinuses and veins; arteries of the dura and base of the brain; dura itself near large vessels; nerves (CN V, VII, X, IX, C1, C2); structures outside the skull (skin, fascia, muscles, mucosa)
not pain-sensitive: brain, arachnoid, pia
Ominous Signs
first or worst: sudden, severe headache in someone with no history could mean hemorrhage, ischemia, hydrocephalus, mass lesion (get CT, lumbar puncture to look for blood, angiogram if positive)
new onset in midlife or older (with no previous history of headache)
- possible meningitis, brain abscess in HIV or cancer patient
change in character or pattern in a person with a history
headache associated with abnormal neurologic exam
unilateral headache: controversial; may indicate AVM or aneurysm
Warning Signs: most headaches are benign, but certain signs point to more serious pathology
- sudden onset
: subarachnoid hemorrhage, bleed into mass or AVM, pituitary apoplexy
- occipital headache on cough
: could indicate Arnold-Chiari malformation (protrusion of the cerebellum through the foramen magnum along with meninges) or posterior fossa lesion
- early morning nausea/vomiting
: possible increase in intracranial pressure; intracranial pressure is normally 9-12 torr with little fluctuation; two things happen when it is increased:
- (1) the baseline pressure increases
- (2) plateau waves are generated: these are transient periods during which pressure is further increased; they happen about every 90 minutes and last ~ 30 mins; symptomatic periods occur during the plateau phase; cause is unknown, but plateaus may be due to vasodilation
- sudden headache with nausea/vomitting and loss of consciousness due to positional change
: possible colloid cyst of the third ventricle causing acute hydrocephalus
- headache with upright posture
– 2 possibilities:
- (1) low pressure headache (common after lumbar puncture)
- (2) basal skull defect (associated with trauma)
- headache with stiff neck and pain with eye movement
: indicates meningitis, encephalitis, Lyme disease, systemic infection
- ‘sentinal’ headache
: precedes an aneurysmal rupture (controversial)
- subacute dementia, fluctuating facial signs
: subdural hematoma
Types of Headaches
(1) Migraine: two types Þ without aura (termed common – 99%); with aura (termed classic – 1%)
- epidemiolgy: 4-15% of population; more common in females; age of onset peaks at middle age
- possible familial or genetic link (although the tendency to see a doctor for headache might be the inherited quality)
- Symptoms
: headache of variable intensity (usually unilateral and throbing); anorexia, nausea/vomitting, photo/phonophobia
- aura
: may or may not be present; precedes headache by 30 mins; 85% of auras have a visual component, other sensory auras could include paresthesias, numbness, aphasia, unilateral weakness; it is also possible to get the aura without the headache
- Diagnosis
:
- (1) headache preceded by some neurologic symptom, visual or sensory
- (2) no evidence of any organic disease
- Potential Triggers
: hormones – migraines
ß with pregnancy and menopause, oral contraceptives increase or decrease; chronobiologic challenge (too much or too little sleep), drugs (MSG), emotional stress, food (red wine and chocolate often implicated)
Pathogenesis
: trigger Þ vasoconstriction Þ aura Þ vasodilation Þ headache
- evidence exists for association between vascular events and headache, but causal relationship unestablished
nerurogenic (from Harrison’s) Activation of cells in the trigeminal nucleus caudalis in the medulla (a pain processing center for the head and face region) results in the release of vasoactive neuropeptides, including substance P and calcitonin gene-related peptide, at vascular terminations of the trigeminal nerve; these peptide neurotransmitters induce a sterile inflammation that activates trigeminal nociceptive afferents originating on the vessel wall
serotonin (5HT) also has a probable role: elevated in migraines, presence in gut could account for nausea/vomitting
- 5HT-1 receptors seem to be the most important for headache
- triptans (sumatriptan, rizatriptan, etc): 5HT-1 inhibitors; effective for both pain and migraine-related symptoms
(2) Tension-type: bilateral, pressing/tightening sensation (non-pulsating); more common in women
- often described as a band tightening around the head; not associated with nausea/vomitting or photo/phonophobia
- often associated with depression
(3) Cluster: severe, unilateral, orbital or supraorbital, brief (15 – 18 mins, usu < 1 hr); more common in men
- relapsing/remitting: regular headaches for a period of time, then none for months or years
- patients will move around, pace, hit head into wall, etc., unlike migraine where patients just want to lie in the dark
- also associated with autonomic abnormalities: Horner’s, facial sweating, red eye, rhinorrhea