Why so many pains are centered in the head is a question of some interest. Several explanations come to mind. For one thing, the face and scalp are more richly supplied with pain receptors than many other parts of the body, perhaps to protect the precious contents of the skull. Also, the nasal and oral passages, the eye, and the ear—all delicate and highly sensitive structures—reside here and must be protected; when affected by disease, each is capable of inducing pain in its own way. Finally, there is great concern by patients about what happens to the head perhaps more than other parts of the body because headache raises the specter of brain tumor or other cerebral disease.
Semantically, the term headache encompasses all aches and pains located in the head, but in practice, its application is restricted to discomfort in the region of the cranial vault. Facial, lingual, and pharyngeal pains are discussed in the latter part of this chapter and separately in Chap. 44, because they pertain to the cranial nerves.
In the introductory chapter on pain, reference was made to the necessity, in dealing with any painful state, of determining its quality, severity, location, duration, and time course as well as the conditions that produce, exacerbate, or relieve it. In the case of headache, a detailed history following these lines will determine the diagnosis more often than will the physical examination or imaging. Nevertheless, a few aspects of the examination are worth emphasizing. For example, auscultation of the skull may rarely disclose a bruit (with large arteriovenous malformations); palpation may disclose the tender, hardened or elevated arteries of temporal arteritis; sensitive areas overlying a cranial metastasis or an inflamed paranasal sinus may be apparent; or there may be a tender occipital nerve. Examination of neck flexion may reveal meningitis; however, apart from such special instances, examination of the head itself, although necessary, seldom discloses the diagnosis.
The quality of cephalic pain is essential to diagnosis but the sensation may be difficult for the patient to describe. When asked to compare the pain to some other sensory experience, the patient may allude to tightness, aching, pressure, burning, bursting, sharpness, or stabbing. Among the most important aspects is whether the headache is pulsatile, usually implying migraine, but one must keep in mind that patients sometimes use the word throbbing to refer to a waxing and waning of the headache without any relation to the pulse, or use the term to transmit the severity of pain.
Similarly, statements about the intensity of the pain are inherently subjective, as they reflect as much the patient’s temperament, attitudes, and customary ways of experiencing and reacting to pain. One useful index of severity is the degree to which the pain has incapacitated the patient. A severe migraine attack seldom allows the migraineur to perform the day’s work. Other rough indices of the severity of headache are its propensity to awaken the patient from sleep or to prevent sleep, and autonomic reactions to the pain such as sweating and tachycardia. The most intense cranial pains are those associated with meningitis and subarachnoid hemorrhage, which can have grave consequences, but also migraine, cluster headache, or tic douloureux that do not have the same implications.