Mr. M is a 34-year-old man who comes to an outpatient practice complaining of intermittent headaches.
|What is the differential diagnosis of headache? How would you frame the differential?|
Headache is one of the most common physical complaints. Because less than 1% of all headaches are life-threatening, the challenge is to reassure and treat patients with benign headaches appropriately while finding the rare, life-threatening headache without excessive evaluation.
Headaches are classified as primary or secondary. Primary headaches are syndromes unto themselves rather than signs of other diseases. Although potentially disabling, they are reliably not life-threatening. Secondary headaches are symptoms of other illnesses. Unlike primary headaches, secondary headaches are potentially dangerous.
The distinction of primary and secondary headaches is useful diagnostically. Primary headaches are diagnosed clinically, sometimes using diagnostic criteria (the most commonly used are published by the International Headache Society, IHS). Traditional diagnostic studies cannot verify the diagnosis. Secondary headaches often can be definitively diagnosed by recognizing the underlying disease.
Clinically, primary and secondary headaches can be difficult to distinguish. The single most important question when developing a differential diagnosis for a headache is, “Is this headache new or old?” Chronic headaches tend to be primary, while new-onset headaches are usually secondary. This is the first and most important pivotal point in diagnosing headaches. This distinction is not perfect. There are some chronic headaches that are secondary headaches and even classic, primary headaches (such as migraines) can present as a new headache. The differentiation of old versus new also depends on how rapidly a patient brings his or her symptoms to medical attention. This being said, the following breakdown provides a clinically useful way of organizing headaches.
Cervical degenerative joint disease
Temporomandibular joint syndrome
Headaches associated with substances or their withdrawal
Analgesics (often presenting as chronic daily headaches)
Benign cough headache
Benign exertional headache
Headache associated with sexual activity
Benign thunderclap headache
Idiopathic intracranial hypertension (pseudotumor cerebri)
Upper respiratory tract infection
Subarachnoid hemorrhage (SAH)
Cavernous sinus thrombosis
Space occupying lesions
Medical morning headaches
Mr. M reports similar headaches for 10 years. He comes in now because while they used to occur 2–3 times a year, they have become more frequent, occurring 3–4 times a month. The headaches are so severe that he is unable to work while experiencing one. He describes them as a throbbing pain behind his right eye. (When describing the headache, he places the base of his hand over his eye with his fingers wrapping over his forehead.) The headaches are often associated with nausea and, in the last few ...