When a patient shows symptoms of a stroke, the physician will promptly evaluate the patient’s medical history and quickly run tests such as a computed axial tomography (CAT) scan. The CAT scan can help the physician determine whether the patient is having a cerebral hemorrhage or cerebral ischemia. This information determines the course of emergency treatment. The CAT scan may also help the physician locate the exact position of the damage.

Once the patient is stabilized, the complete evaluation can take several days. Tests that may be run during this time include:

• Physical examination. The carotid arteries will be examined with a stethoscope. If the physician hears an abnormal sound (a carotid bruit), there is a higher chance of finding atherosclerosis or carotid artery disease – conditions that increase the risk of stroke.
  
  
• A carotid ultrasound, or Duplex scanning. A painless strategy for assessing the presence of plaque in the carotid arteries. It uses high-frequency sound waves.
  
  
• Magnetic resonance angiography (MRA). A diagnostic test used to assess the degree of blockage in the carotid arteries. The MRA is a variation of the magnetic resonance imaging (MRI) scan, which is also very important in diagnosing a stroke.
  

  

• An electrocardiogram (EKG). Performed to identify any cardiac problems that may have led to the stroke, such as a prior heart attack.
  

  

• Blood tests, including a complete blood count (CBC) and a lipid profile (cholesterol test). By looking for risk factors that are associated with stroke, such as high cholesterol, the physician can design a long-term therapy that will reduce the risk of recurrent stroke.

Tests may also be done to assess overall brain functions, as measured by electrical activity. These tests can reveal how much neurological damage was inflicted by the stroke. One such test is the electroencephalogram (EEG). During this painless test, small metal devices electrodes are attached to the scalp. The electrodes are connected by wires (leads) to an electroencephalograph machine that charts the electrical activity of the brain. Physicians may also conduct an evoked-potential study where the brain's response to sight, hearing and touch are tested and measured.