The mechanism and management of headache

Abstract

This article discusses the cause of headaches and the investigation and management of headaches. The first part of the article stresses that the pain sensitives structures of the cranium include the venous sinuses, great occipital, trigeminal, glossopharyngeal and vagus nerves as well as the intra and extracranial arteries. These structures may cause pain as a result of direct pressure on nerves or traction of the arteries, dilation of the arteries or dilation of the venous sinuses. Tension headaches are one of the most common headaches, but interestingly, these patients usually do not complain of true pain, but more often complain of a burning sensation, or pulsating warm sensation, or a sensation of pressure. Vascular headaches, which may be caused by migraine, cranial arteritis, hypertension or carotid artery insufficiency, usually result from dilation of intra- or extracranial arteries. The incidence of migraine has been estimated at between 5 and 10% of the population. Biochemical substances known to be associated with attacks of migraine include serotonin, tyramine, and neurokinin. The drug, methysergide, decreases the frequency of migraine headaches. The role of histamine in migraine attacks has been debated, but it is known that cluster headaches may be precipitated by histamine injection. Focal neurological disturbances such as hemiparesis and aphasia may be associated with attacks of migraine and although it is thought that these disturbances may be associated with vasoconstriction of major blood vessels, this has not been confirmed by arteriography. Migraine headaches may occur in patients taking oral contraceptives. The theories as to why this may occur are discussed. Cranial arteritis must be considered in elderly patients with headaches. The headaches are usually in the region of the temporal arteries, but not invariably. Headaches may occur following head injury and may be either psychoneurotic or possibly due to arachnoidal adhesions. Intracranial tumors may produce headaches by pressure or by local traction on pain sensitive structures. Extracranial lesions such as tumors of the cord, congenital anomalies, or cervical spondylosis may be responsible for headaches. The second portion of this article discusses the investigation and management of headaches. The authors stress that a careful history and examination is necessary before any further investigation is conducted. The most popular investigation in headache patients consists of routine skull films, but it is very rare that these will demonstrate the cause of the headaches. Electroencephalograms have not proved helpful, although in patients with migraine the incidence of electroencephalogram abnormality is probably a little higher than would be expected in the normal population. Radioisotope scans are likely to detect cerebral tumors, arteriovenous malformation, and hematomas. Radioisotope scans done on patients with the presenting symptoms of headaches in whom an intracranial abnormality is not suspected are usually normal. Echoencephalography is not recommended. Sedimentation rates are useful in those individuals in whom temporal arteritis is suspected and this test should be carried out routinely in patients over the age of 60. Lumbar punctures are justified only to exclude subarachnoid hemorrhage or meningitis. Cerebral angiography should not be recommended unless there is a specific indication for it. Cervical spondylosis is pointed out as an important cause of occipital headaches. It is also pointed out that the pre headache phenomena of migraine are associated with vasoconstriction, whereas the headache phase is associated with increased pulsation. (DeSaussure - Memphis, Tenn.)