This symptom is best analyzed by using anatomy, as seen in Tables 32 and 33, but differentiation by pathophysiology is interesting, particularly in muscle traction headaches and migraines.
Moving by layers from the skin to the center of the brain is the local application of the anatomic process. Thus, sunstroke is a cause of headache originating in the sunburnt skin, as is herpes zoster. Abscesses of the scalp are uncommon but significant causes of head pain. Moving to the muscles, one encounters the most common cause of headache, muscle traction headache, which may be secondary to other conditions (e.g., migraine or eyestrain), or primarily due to nervous tension or constantly holding the head in one position. Fibromyositis (usually of rheumatic etiology) may also cause a headache.
The next most common type of headache, migraine, originates from the superficial arteries. It usually involves the superficial temporal arteries, but it can involve the internal carotid arteries (Horton cephalalgia or cluster headaches), the occipital artery, and the intracranial arteries (e.g., hemiplegic migraine). Temporal arteritis and hypertension are two other important causes of headache originating from the extracranial arteries. The adjacent superficial nerves are a less common but important cause of headache. Occipital neuralgia may result from inflammation or compression of either the minor or major occipital nerve, and is often involved secondarily in muscle contraction headaches. This cause is established by blocking these two nerves (medially and laterally). Trigeminal neuralgia is no less important.
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TABLE 32. Headache—Extracranial and Cranial |
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Moving to deeper layers, one encounters the skull, where osteomyelitis (e.g., tuberculous or syphilitic), primary and metastatic carcinomas, cranial stenosis, Paget disease, and skull fractures are important causes of headache. The temporomandibular joint (TMJ) is the origin of headache in the TMJ syndrome (usually caused by malocclusion) and RA. Important causes of headache affect the cervical spine. Cervical spondylosis is a major cause in elderly persons, but RA, spondylitis, spinal cord tumors, and metastatic disease of the vertebrae are also etiologies to consider.
Several common causes of headache come to mind when considering the organs of the head. Thus, the eyes are affected by refractive errors, astigmatism, and glaucoma, all etiologies of headache. The ear is affected by otitis media, mastoiditis, acoustic neuromas, and cholesteatomas. The nose is affected by infectious rhinitis, allergic rhinitis, Wegener granulomatosis, nicotine toxicity, fractures, and deviated septum, all causes of headache. Sinusitis (both the purulent and the vacuum type), sinus polyps, and tumors make checking the nasal sinuses important in analyzing the cause of headaches.
Chronic sinusitis is almost never a cause of headache. Finally, the teeth should be investigated for caries, abscesses, and fillings that may be too close to the nerve root.
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TABLE 33. Headache—Intracranial |
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Intracranially there are very important but less common causes of headache. The meninges are the site of subarachnoid hemorrhages, subdural and epidural hematomas, meningitis, and hydrocephalus. Missing one of these causes is a grave error. The cerebral arteries are the site of cerebral hemorrhages, thrombosis, and emboli, as well as aneurysms and arteriovenous anomalies. The cerebral veins, especially the venous sinuses, may become inflamed and thrombosed, producing a headache. The cranial nerves are the site of trigeminal neuralgia mentioned above and glossopharyngeal neuralgia.
Although the brain itself is not tender, lesions of the brain cause increased intracranial pressure or traction on other painful structures, such as the intracranial arteries, venous sinuses, or nerves. A third of the cases of brain tumors present with a headache. Encephalitis produces a headache by the associated fever or meningeal irritation. Concussions, pituitary tumors, toxic encephalopathy from alcohol, bromides, and other substances are important causes, in addition to the cerebral hemorrhage, thrombosis, and emboli already mentioned. The various systemic diseases shown in Table 33 are too numerous to mention here, but fever of any etiology is an important cause and must not be forgotten, although this symptom is usually obvious.
Approach to the Diagnosis
The patient presenting with a history of headaches is an exciting diagnostic challenge. If one approaches the challenge simply on the basis of what is common, the patient most likely has migraine or muscle traction headache. But, wait a minute! Shouldn't we look for serious conditions such as brain tumor, meningitis, or subarachnoid hemorrhage to avoid a serious mistake and a malpractice suit? First, check for nuchal rigidity to rule out meningitis and subarachnoid headache. Next, do a careful neurologic examination to rule out a brain tumor or other space-occupying lesion. These steps are particularly important in a patient who is experiencing his or her first serious headache. If there is nuchal rigidity or focal neurologic signs, it is wise to immediately refer the patient to a neurologist or neurosurgeon for further workup and possible hospitalization. The specialist will probably order a CT scan of the brain and follow that with a spinal tap if a subarachnoid hemorrhage or meningitis is suspected. It is clear that a CT scan should be done prior to a spinal tap if there are focal neurologic signs or papilledema. One other condition that must be considered in acute headache (particularly in elderly persons) is temporal arteritis. A sedimentation rate will usually be positive, but a neurology consult is axiomatic so that steroids can be started immediately.
In the patient with chronic or recurring headaches and no neurologic findings, it is wise to see the patient during the attack. Migraine and histamine headaches can be diagnosed by the response to sumatriptan by mouth or injection. If the headaches are due to chronic allergic or infectious rhinitis, relief can be had by spraying the turbinates with phenylephrine. Muscle traction headaches will often be relieved by occipital nerve blocks supporting the diagnosis. Compression of the superficial temporal artery will often relieve migraine temporarily supporting that diagnosis. Compression of the jugular veins will often give relief to patients with post spinal tap headaches.
If the patient is seen between headaches, certain prophylactic measures may help establish the diagnosis. For migraine, β-blockers may be prescribed; if the headaches are prevented, there is good support for the diagnosis. A course of corticosteroids may be initiated in patients with histamine (cluster) headaches to help establish the diagnosis. Muscle relaxants and/or tricyclic drugs may be given to help diagnose muscle contraction headaches.
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Headache |
The diagnostic workup of chronic headaches might include a CT scan of the brain, x-rays of the sinuses, x-rays of the cervical spine, and routine blood work. Certainly if headache persists after careful follow-up, these need to be done.
Other Useful Tests
1. Neurology consult
2. Sedimentation rate (temporal arteritis)
3. X-ray of the teeth (dental abscess)
4. MRI of the brain (brain tumor)
5. Spinal fluid analysis (meningitis, subarachnoid hemorrhage)
6. 24-hour blood pressure monitoring (pheochromocytoma)
7. 24-hour urine catecholamines (pheochromocytoma)
8. Tonometry (glaucoma)
9. MRI of the TMJs (TMJ syndrome)
10. Allergy skin tests (allergic rhinitis)
11. Temporal artery biopsy (temporal arteritis)
Case Presentation #39
A 28-year-old white woman comes to your office with the chief complaints of continuous generalized headache and nausea for 3 days. The patient has also experienced occasional vomiting. She was seen in the emergency room the night before and was diagnosed with migraine, given a shot, and sent home.
Question #1. Utilizing anatomy, what is your differential diagnosis at this point?
On examination, the patient was found to have nuchal rigidity but no focal neurologic signs. Her temperature is 100.2°F, and her blood pressure is 110/70 mmHg.
Question #2. What is your diagnosis now?
