The first task in evaluating a headache patient is to identify or exclude secondary headache based on the history, the general medical examination, and the neurologic examination.

If suspicious features are present, diagnostic testing may also be necessary. Once secondary headaches are excluded, the task is to then diagnose one (or more than one) specific primary headache disorder.

In the initial evaluation the experienced physician looks for “headache alarms” that suggest the possibility of a secondary headache disorder.

Table 2-6 Cluster headache

3.1.1 Cluster headache

Diagnostic Criteria

A. At least 5 attacks fulfilling B-D

B. Severe unilateral orbital, supraorbital, and/or temporal pain lasting 15 to 180 minutes, untreated

• Conjunctival injection


• Lacrimation


• Nasal congestion


• Rhinorrhea


• Forehead and facial sweating


• Miosis


• Ptosis


• Eyelid edema

D. Frequency of attacks: from 1 every other day to 8/day

E. No evidence of organic disease

3.1.2 Episodic cluster headache

Diagnostic criteria

A. Criteria on cluster

B. At least 2 periods of headaches (cluster periods) lasting (untreated patients) from 7 days to 1 year, separated by remissions of at least 14 days

3.1.3 Chronic cluster headache

Diagnostic criteria

A. Criteria on cluster

B. Absence of remission phases for 1 year or more with remissions lasting <14 days

Source: Headache Classification Committee of the International Headache Society (1988).

Headache may arise in a number of metabolic disorders, particularly those that lead eventually to disordered cognitive states. These include, but are not limited to, hypernatremia, hyponatremia, acid-base abnormalities, and liver and kidney failure. Headache is usually a minor symptom in these conditions, which are marked by increasing irritability and weakness, confusion, disorientation, and eventually coma. As cerebral cortical functions deteriorate, headache is no longer a complaint. Exceptions to the rule are as follows:

• Hypercapnia: Some individuals with chronic respiratory failure, primarily those with hypercapnia, will develop severe headache. Marked dilation of cerebral vasculature may occur, and at times papilledema may result.


• Acidosis: Acidosis may be associated with headache. The cause is assumed to be the vasodilation that can occur as cerebral autoregulation is affected by the acidotic state.


• Hypoglycemia: Hypoglycemia is associated with a headache that is usually holocranial and may be steady or throbbing.


• Thyroid disease: Headache occurs particularly with hypothyroidism and generally disappears as the disturbance of metabolic function is corrected.


• Parathyroid disease: A particularly intense form of chronic headache is seen in patients with hyperparathyroidism. Generally, the pain is bilateral, and muscular tenderness may be present. The headache generally improves as the disease is corrected (usually by surgery), but this may take as long as 6 months to accomplish.

Editors: Silberstein, Stephen D.; Lipton, Richard B.; Dalessio, Donald J.