HEADACHE: DIAGNOSTIC WORKUP
To rule out severe anemia Routine diagnostic tests include a CBC, a sedimentation rate to rule out temporal arteritis, a chemistry panel to rule out liver and kidney disease, a VDRL test to rule out central nervous system syphilis, an x-ray of the sinuses to rule out sinusitis, and an x-ray of the cervical spine to exclude cervical spondylosis. A chest x-ray should also be done to rule out the possibility of metastatic neoplasm. A tonometry study may be done if glaucoma is suspected.
If there are focal neurologic signs, referral should be made to a neurologist or neurosurgeon as soon as possible. If one is not readily available, a CT scan or MRI may be done, the CT scan being the preferred procedure if the expense is a consideration.
If there is nuchal rigidity, a CT scan should be done to rule out a space-occupying lesion before proceeding with a spinal tap. If the CT scan is negative, a spinal tap can be done, and this will ascertain whether there is intracranial bleeding or meningitis. It is usually best to refer the patient to a neurologist or neurosurgeon if there is nuchal rigidity.
If the headaches are chronic and episodic, and there are no focal neurologic signs, papilledema, or nuchal rigidity, an imaging study can be postponed for a while until the response to treatment is evaluated. However, if the response to treatment is poor, one should not hesitate to order a CT scan or MRI.
Difficult cases of headache should also be studied with 24-hr blood pressure monitoring, a 24-hr urine for catecholamines, and lumbar puncture to diagnose central nervous system lues. Histamine phosphate 0.5 cc subcutaneously may help diagnose cluster headaches. Response to beta-blockers may help diagnose migraine.. Patients with chronic headache unresponsive to therapy should be referred to a psychiatrist. Cerebral angiography may be necessary to diagnose aneurysms and arteriovenous malformations
