What are the exams and tests for secondary headaches?
The patient history and physical examination provide the initial direction for determining the cause of secondary headaches. Therefore, it is extremely important that patients with a new, severe headache seek medical care and give their health care professional an opportunity to assess their condition. Tests that may be useful in making the diagnosis of the underlying disease causing the headaches will depend upon the doctor's evaluation and what specific disease, illness, or injury is being considered as the cause of the headaches (the differential diagnosis). Common tests that are considered include the following:
Specific tests will depend upon what potential issues the health care professional and patient want to address.
Blood tests provide helpful information in association with the history and physical examination in pursuing a diagnosis. For example, an infection or inflammation in the body may cause a rise in the white blood cell count, the erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP). These two tests are very nonspecific; that is, they may be abnormal with any infection or inflammation, and abnormalities do not point to a specific diagnosis of the cause of the infection or inflammation. The ESR is often used to make the tentative diagnosis of temporal arteritis, a condition that affects an older patient, usually over the age of 65, who presents with a sharp, stabbing temporal headache, due to inflammation of the arteries on one side of the head.
Blood tests may be used to assess electrolyte imbalance, and a variety of other potential problems involving organs like the liver, kidney, and thyroid.
Toxicology tests may be helpful if the patient is suspected of abusing alcohol, or prescription or other drugs of abuse.
Computerized tomography of the head
Computerized tomography (CT scan) is able to detect bleeding, swelling, and some tumors within the skull and brain. It also can show evidence of a previous stroke. With intravenous contrast injection (angiogram), it may also be used to look at the arteries of the brain for aneurysms.
Magnetic resonance imaging (MRI) of the head
MRI is able to show the anatomy of the brain and the layers that cover the brain and the spinal cord (meninges). It is more precise than computerized tomography. This type of scan is not available at all hospitals. Moreover, it takes much longer to perform, requires the patient to cooperate by holding still, and requires that the patients have no metal in their body (for example, a heart pacemaker or metal foreign objects in the eye).
Cerebrospinal fluid, the fluid that surrounds the brain and spinal cord, can be obtained with a needle that is inserted into the spine in the lower back. Examination of the fluid looks for infection (such as meningitis due to bacteria, virus, fungus, or tuberculosis) or blood from hemorrhage. In almost all cases, computerized tomography is done prior to lumbar puncture to make certain there is no bleeding, swelling, or tumor within the brain. Pressure within the space can be measured when the lumbar puncture needle is inserted. Elevated pressures may make the diagnosis of idiopathic intracranial hypertension (previously known as pseudotumor cerebri) in combination with the appropriate history and physical examination.