About 21% of the adult population develops headache in any 2-week period.

CAUSES OF HEADACHE (Hyperlinks provide more detail).

1. Vascular (Migraine, Cluster,   arteritis, vascular malformations)
2. Musculoskeletal
   1. tension,
   2. cervical
   3. Chiari malformation
   4. TMJ
3. Sinus (about 10% of all HA, very often misdiagnosed)
4. Post-trauma
5. Infectious (osteomyelitis, dental, encephalitis or meningitis)
6. Neoplastic (i.e. brain tumor)
7. Neuralgias
8. Psychogenic

MISCELLANEOUS MINOR CAUSES OF HEADACHES

• Dental including TMJ (usually stress related, common), micro-abscess.
• Iatrogenic headache (due to vasodilator medications such as NTG, isordil, procardia: common).
• Hypertensive (25% increase in BP or > 180/130, bilateral, constant, moderately common)
• Ocular -provoked by near viewing or new glasses, glaucoma, rare (Gil Gouvea R et al, 2002)
• Increased intracranial pressure (similar to hypertensive in symptoms/signs, very rare, worsening course)
• Decreased intracranial pressure
• Temporal arteritis (very rare). Unilateral, tender temporal artery, jaw claudication, Polymyalgia. High sed rate. Trial of steroids if sed-rate is high.
• Aneurysmal (similar to migraine, rare - 28,000/year compared to 50 million migraines/year)
• Chiari Malformation - type I (CM-I). Headache is common (about 50%). Characteristic headaches are brief, occipital or nuchal, triggered by cough, straining, postural straining. Caused by transient  tonsillar herniation.  There are also long-lasting headaches in CM-I of unclear etiology.

Headaches can also be sorted by their timing:

• Chronic daily headache
  • Chronic migraine
  • chronic tension headache
  • hemicrania continue
  • medication overuse headache
• Thunderclap headache
  • Subarachnoid hemorrhage
  • Sentinal headache
  • hypertensive crisis
  • pituitary apoplexy
  • spontaneous CSF leak
  • thrombosis or expansion of unruptured aneurysm
  • "primary" thunderclap headache
  • exertional headache
  • cough headache
  • sexual headache

HEADACHE: HISTORY

• Quality: throbbing, constant, shooting, shock, bizarre
• Location: hemicranial, front, back, top, sides
• Timing (may need a headache diary)
  • Determine how long it takes for headache to reach maximum intensity
  • Duration and periodicity
• Associations (foods like MSG or alcohol, menses, stress, sleep)
• Social history (especially, litigation)
• Past medical history (head-trauma, medications)
  • Fever and weight loss suggest abnormality -- 80% of AIDs patients presenting with new headache have incracranial mass
• Review of systems (such as previous cancer, etc).
• Family history (Migraine, Aneurysm)
• Previous studies

Examination is usually normal unless having a headache.

• Blood Pressure (important!)
• Vision and Fundi (anisometropia, papilloedema, hypertensive change)
• Ears/Sinuses
• TMJ: crepitus/clicking, put fingers in ears and pull forward while jaw is opening.
• Myofascial pain: pain on lateral movement of jaw.
• Neck: Spurling's maneuver, check for spasm of neck muscles, try traction
• Temporal Arteries (tenderness, indurated, relieve headache)
• Carotid Compression (relieve or increase headache, avoid in vasculopaths)
• Neurological screening examination: Reflexes, Babinski, coordination

LABORATORY TESTS FOR HEADACHE

• ESR if temporal arteritis suspected
• Sinus X-rays, endoscopy or CT if sinusitis suspected
• MRI - if central signs, or increase intensity, or from Mexico (cystacercosis risk)
• Cervical Spine - cervical headache
• LP - if meningitis suspected
• MRA if vascular lesion suspected

Tests usually not helpful

• EEG

Guidelines for scans.

• MRI single most useful test.
• CT acceptable if index of suspicion is low.
• PET no indication.

• Cooper B, Lucente FE (ed). Management of facial, head and neck pain. Saunders, 1989.
• Dalessio DJ (Ed). Wolff's headache and other head pain. Oxford Univ Press, 1967.
• Diamond S, Dalessio DJ. The practicing physicians approach to headache, 3rd edition, Williams and Wilkins, 1982.
• Gil-gouvea R. and others. Headache 2002:42:256-262
• Sapir JR, Silberstein SD, Gordon CD, Hamel RL. Handbook of Headache Management, Williams and Wilkens, Baltimore, 1993.
• Schiffman E, Haley D, Baker C, Lindgreen B. Diagnostic criteria for screening headache patients for temporalmandibular disorders. Headache 1995:35:121-134.
• Schreiber CP and others. Prevalence of migraine in patients with a history of self-reported or physician diagnosed "Sinus" headache. Arch Int Med. 2004: 164: 1769-1772
• Silberstein SD. Intractable headache: inpatient and outpatient treatment strategies, Neurology 42: 1992, supplement 2.
• Tollison and Kunkel, Ed. Headache Diagnosis and Treatment. Williams and Wilkins, 1993.

(C) Timothy C. Hain, MD