Headache Frequency
The frequency and pattern of headache may provide clues to the diagnosis. Cluster headache typically occurs in brief attacks, each lasting 30 to 90 minutes and recurring two to six times a day. Migraine may also occur at sporadic intervals and, thus, can mimic cluster headache. Episodic tension-type headaches occur fewer than 15 times a month; if they are more frequent, they are classified as chronic tension-type headache. Headache patterns may suggest useful preventive strategies. For example, menstrual migraines may respond to perimenstrual nonsteroidal anti-inflammatory medications. Nocturnal cluster attacks may be prevented by administering ergotamine at bedtime. Organic headaches may be episodic or daily and continuous. Headaches that are organic in origin do not occur with any set pattern and may mimic the known primary headaches, but if the frequency of headache increases, diagnostic evaluation is needed.
Onset, Duration, Character, and Severity
The severity of the pain and the rapidity of onset and resolution are diagnostically important. We advise using a 1 to 10 scale, where 1 represents minimal discomfort and 10 the most excruciating pain the patient can imagine. While these numbers may not be comparable across patients, they are very useful for charting individual improvements. As most headaches vary in intensity during an attack and across different attacks, it is also useful to inquire about the range of pain experienced during a headache. The pain of cluster headache is described as deep and boring, as if a hot poker were being driven into the eye. The headaches of fever, migraine, hemangiomatous tumors, and arterial hypertension are characteristically throbbing or pulsating in quality. The headaches of brain tumor and of meningitis, though occasionally pulsating, usually have a steady, aching quality. Tension-type headache is dull, nagging, and persistent and often described as feeling as though a band were wrapped around the head.
The most intense headaches are those associated with malignant hypertension and those due to meningitis, fever, migraine, and ruptured intracranial aneurysm. Beware of the acute-onset, “thunderclap” headache; it may be caused by a subarachnoid hemorrhage. Subarachnoid hemorrhage resulting from a ruptured intracranial aneurysm produces a headache that is sudden in onset, reaches great intensity in a very short time, and may be associated with unconsciousness or feelings of faintness. The onset of pain is soon followed by a stiff neck and blood in the lumbar spinal fluid. The intense headache of meningitis is accompanied by a stiff neck, which prevents passive flexion of the head on the chest, although the spasm of the neck muscles associated with migraine may also inhibit neck flexion.
Headaches associated with brain tumors, brain abscesses, sinus disease, tooth disease, and eye disease are usually only moderately severe. Hemorrhage into the parenchyma of the brain may not cause headache unless the hemorrhage breaks through into the ventricular or subarachnoid space or produces significant brain displacement; then, intense headache may result.
Headache Course
Beware the headache that progressively worsens; it may have an organic cause. The longer the headache has existed in its present form, the more likely it is to be benign. Cluster headache occurs in bouts that can last from 1 to 2 weeks or for as long as 4 to 5 months.
Editors: Silberstein, Stephen D.; Lipton, Richard B.; Dalessio, Donald J.