Pinpointing the type of headache
An accurate diagnosis requires a thorough headache history and a HEENT and neurological examination. The history should include questions about the characteristics of the headache, including the location, intensity, frequency, timing, associated symptoms, previous headache diagnoses, and triggers, and address comorbidities, medication use, caffeine intake, and family history.8 In the absence of red flags—age >50 years, history of headache or systemic illness, sudden onset, or papilledema, among other findings that may indicate more serious conditions (TABLE 2)7—advanced imaging and further work-up are not needed.
TABLE 2
Beyond headache: Red flags warrant additional testing7
| Red flag | Condition(s) to rule out |
|---|---|
| Age of onset >50 y | Giant cell arteritis, mass lesion, stroke |
| No prior history of headache OR change in characteristic from prior headaches | Cancer, aneurysm, stroke, cerebral sinus thrombosis, infection |
| “Thunderclap” headache | Ruptured aneurysm |
| Signs or symptoms of systemic illness (eg, fever, chills, weight loss) | Meningitis, encephalitis, cancer |
| History of systemic illness, such as cancer, autoimmune disease, or HIV | Brain metastasis, mass lesion, autoimmune meningitis, thrombosis |
| Headache brought on by change in head position or Valsalva maneuver | Spontaneous CSF leak or Chiari malformation |
| Occipital location of headache (in children) | Brain tumor |
| Neurological symptoms | Mass lesion, encephalitis |
| Papilledema | Idiopathic intracranial hypertension, cerebral sinus thrombosis |
| CSF, cerebrospinal fluid; HIV, human immunodeficiency virus. | |
Migraine or tension headache?
Chronic migraine. To be classified as CM, the headache must have occurred ≥15 days a month for 3 months or more and have features of migraine, such as unilateral location, pulsating quality, and moderate to severe intensity. Migraines are aggravated by physical activity and associated with nausea and/or vomiting, photophobia, and phonophobia, and may or may not be preceded by aura. Common triggers include stress, menstruation, alcohol, skipped meals, dehydration, and chocolate. Migraines typically respond to ergots and triptans.4,5
Partial treatment. Patients with CM often take medication early in the course of a headache. This sometimes results in a partially treated migraine that develops into a headache with tension-type features, such as a bilateral location, a pressing quality, and mild-to-moderate intensity, as well as a possible transformation to MOH. This is most likely to occur in patients who have migraines without an aura.
To avoid partial treatment, medications for acute migraine should be taken within 30 minutes of an attack, in a dose that’s sufficient to relieve the pain within 2 hours, with no need for a second dose—a protocol known as “one and done.” Efficacy of a triptan can be improved by adding a nonsteroidal anti-inflammatory drug (NSAID).10
A definitive diagnosis of CM is only possible in the absence of medication overuse.4,5 A patient who is overusing abortive headache medication and whose headache meets the criteria for CM should be given a diagnosis of probable CM instead.
Chronic tension-type headache. In addition to traits common to tension headaches, CTTH may be associated with mild nausea, photophobia, or phonophobia (but typically only one such feature at a time). There may also be tenderness to palpation of the pericranial muscles. Unlike migraine, CTTH is not affected by physical activity.
Here, too, overuse of headache medication is often a factor and should be stopped, if possible, before a definitive diagnosis of CTTH can be made.
Headache with overlapping features. It is possible for a patient to have chronic headache with features of both migraine and tension headache. Advise patients whose headaches have varying characteristics to keep a headache journal to determine which features are more prominent. Patients with smart phones can download a free app, such as iHeadache or My Headache Log Pro, to be used for this purpose.11,12
When to suspect medication overuse headache
MOH is sometimes referred to as a rebound headache or drug-induced headache. Headaches associated with medication overuse have variable intensity. Patients with MOH often awaken from sleep with a headache, and neck pain is highly prevalent.10
Quantifying overuse. According to ICHD-II, overuse is defined as using a single abortive headache medication ≥10 times a month or using 2 or more such drugs ≥15 times a month.5
Triptans have the potential to cause MOH more quickly and in lower doses compared with other acute headache medications. However, analgesics—especially combination products such as butalbital/acetaminophen/caffeine (Fioricet)—are most frequently associated with the development of MOH.13,14 NSAIDs have less potential to cause MOH and are sometimes given as bridge therapy for patients who are discontinuing their acute headache medication.