The adult patient with headache

Exclude secondary causes

The physician should first exclude secondary headache in the patient who presents with a headache. A coexisting pathology causing the headache accounts for approximately 10% of all causes of headache.(10) A careful history and focused neurologic examination (Fig. 1) is usually adequate to exclude secondary headache. The SNOOP4 mnemonic (Table I) may be used to elicit red flags that are mostly secondary causes of headache. These would necessitate referral to either the emergency department or a specialist, depending on the sense of urgency and index of suspicion.

Fig. 1

Flowchart shows the stepwise diagnosis and management of headaches.

Table I

The SNOOP4 mnemonic for excluding red flags (secondary causes of headache).

Exclude local causes

Local causes of headache should be considered, including toothache, sinus, eye, ear or neck disorders; attention should be paid to the neuralgias, such as trigeminal neuralgia in the patient with hemifacial pain. If these are present, the patient should be treated and/or referred accordingly.

Categorise the primary headache disorder

Having ensured the absence of red flags and local causes, consider a primary headache disorder as the likely diagnosis. The type of primary headache can be categorised based on phenotype. This may be determined by attack frequency, duration, concomitant symptoms and whether cranial autonomic symptoms are present (Table II). The third edition of the International Classification of Headache Disorders (ICHD-3) can be a helpful reference (Table III).(11)

Table II

Primary headache disorders.

Table III

ICHD-3 diagnostic criteria for tension-type headaches, migraines and cluster headaches.

Broadly speaking, the frequency of headache attacks may be described as episodic (< 5 days/month), chronic (≥ 15 days/month) or daily. In addition, the different types of headaches vary in duration. TTH may last from 30 minutes to seven days, a migraine headache usually lasts 4–72 hours, and a cluster headache typically lasts 15–180 minutes.

The character of the headache aids in further differentiation. TTH is usually bilateral, has a pressing quality, is not typically aggravated by physical activity, and is mild to moderate in intensity. It predominantly affects females. On the other hand, migraine is typically unilateral, pulsatile or throbbing. It is sensitive to movement, may be associated with photophobia, nausea and vomiting, and is of moderate to severe intensity. Up to one-third of migraines may be associated with a visual or sensory aura. Most patients have a positive family history. Cluster headache, also known as ‘suicide headache’, is strictly unilateral and usually occurs around the eye. It is associated with prominent cranial autonomic symptoms such as hyperlacrimation, conjunctival injection, rhinorrhoea, nasal congestion, ptosis and changes in pupillary size. Circadian rhythmicity is the hallmark of a cluster headache: typically, periods of relatively short-lived (clusters of 15–180 minutes) but intensely painful attacks occur between periods of remission. Males are predominantly affected.

ID Migraine is a three-item (disabling headache, photophobia and/or vomiting) tool that may be used to screen for migraine. The presence of two out of three items positively predicts migraine by 93% (Box 1).(12) Similarly, the presence of four out of five criteria in the POUND mnemonic (Box 2) gives a likelihood ratio of 24 for possible migraine.(13) Both POUND and ID Migraine are user-friendly screening tools that encompass the major criteria in the ICHD-3 diagnostic criteria for migraine (Table III).

Box 1

ID Migraine (1 point for each symptom).

Box 2

POUND mnemonic (1 point for each symptom).

Management of primary headache

The majority of patients with primary headache may be safely managed in the outpatient setting. In managing primary headache, look for predisposing, precipitating and/or perpetuating factors in the patient’s history. Inadequate hydration, irregular meals, irregular sleep, excessive alcohol, excessive caffeine and/or lack of exercise may all act as predisposing factors. Precipitating and perpetuating factors include stress, adjustment reactions, anxiety and depressive episodes.(14) Specific factors such as sensory stimuli, menses, medications (e.g. oral contraceptives, vasodilators), and foods (e.g. wine, cheese, salty food) may precipitate and trigger migraine. Prior rapport and familiarity with a patient’s pattern of health and illness, borne of a long-term doctor-patient relationship, may allow the primary care physician to readily recognise any underlying psychosocial issues that may present as a change in this pattern.(15) The headache diary is useful for the patient with chronic severe headache. Trigger avoidance, reassurance and patient education are important for successful management. All modifiable factors should be addressed, and medications prescribed as required. Patients who fail to respond to treatment need a review to revisit the diagnosis and/or to address any medication non-adherence or overuse.

Treatment of tension-type headache

For episodic TTH, simple analgesics such as paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) generally suffice (Table IV). The use of opioids such as codeine should be carefully considered in view of possible adverse effects such as dependency and medication overuse headache.

Table IV

Medication references.

Because headache is a common somatoform symptom,(16,17) consider the possibility of underlying mental health issues in the patient who presents with headache,(18,19) especially if the headaches are severe and chronic. When indicated, preventive treatment with tricyclic antidepressants(20,21) or beta-blockers(22) may be considered (Table IV). Start preventers at a low dose and escalate until adequate control is achieved. Patients should be counselled that preventive medications need time to take effect, and that treatment need not be lifelong.

Treatment of migraine

Simple analgesics may suffice as first-line treatment for acute migraine. Antiemetics may be considered if there is concomitant nausea and vomiting. Second-line treatments include triptans (serotonin 5-hydroxytryptamine type 1B/1D receptor agonists) and ergotamine derivatives (Table IV).(23) The combination of triptans and NSAIDs may be superior to either drug alone.(24) If symptoms are recurrent, search for underlying precipitating factors and/or psychiatric conditions. Preventive therapy is indicated if the migraine attacks are: (a) recurrent (> 3 days/month) and cause considerable disability despite optimal acute drug treatment; (b) recurrent with prolonged aura and/or hemiplegic migraine; (c) frequent and require medication usage at levels that risk bringing on medication overuse headache; and (d) recurrent and where acute treatment is contraindicated.

Preventive treatment options include beta-blockers, antidepressants and antiepileptics.(25) A 50% reduction of the episodic frequency of headache over 6–8 weeks is considered a reasonable treatment target. The long-term aims of preventive treatment are to reduce reliance on acute pharmacological treatment and to minimise the risk of chronic headache setting in. The decision to commence preventive therapy is highly individualised and should be based on the duration and severity of symptoms experienced by the patient, rather than solely on whether the disorder is episodic or chronic. When jointly agreed upon by both doctor and patient, preventive treatment should be initiated at a low dose and increased every 2–3 weeks until effective or dose-limiting side effects occur. Gradual withdrawal may be considered after 6–12 months of successful preventive therapy.

Treatment of medication overuse headache

Medication overuse headache is defined as a headache that arises from regular medication overuse of three months or more for a pre-existing headache (Box 3). NSAID and paracetamol usage of ≥ 15 days per month, and triptan and/or opioid usage ≥ 10 days per month is considered overuse.

Box 3

ICHD-3 diagnostic criteria for medication over headache.

Most patients with medication overuse headache have an underlying migraine or TTH that is masked by the presence of medication overuse. When suspected, avoid the use of preventive medication: they are generally ineffective and perpetuate medicine overprescription. Medication overuse headache requires deprescription of the overused medications, which for some patients may be achieved only with inpatient care. Evidence shows that for the majority of patients with medication overuse headache, responsiveness to preventive treatment improves after discontinuation of the overused medication.(26) Successful treatment requires careful management of expectations, close follow-up and is dependent on a trusting doctor-patient therapeutic relationship.