How are stroke and transient ischemic attackes diagnosed?

Diagnosing Transient Ischemic Attacks (TIAs) and Determining Risk for Stroke

In people who experience transient ischemic attacks or small strokes, it is important to determine the source of these attacks in order to prevent a major stroke. A complete blood count, chest x-ray, and electrocardiogram are usually performed. Discouragingly, a 2001 study reported that over 30% of patients with TIA who called their primary care physician were neither evaluated nor sent to the hospital within the month after a first event.

Examining the Carotid Artery. The physician usually first examines the carotid artery to determine if it is severely narrowed. If it is, the patient is in danger of a major stroke. (The thickness of carotid artery is also proving to be a valuable indicator for long-term risks for stroke, as well as heart disease and mortality rates in general.)

The physician may use a number of approaches to determine the thickness of the artery:

• A clue to a blocked carotid artery is a bruit. This is a whooshing sound caused by blood flow turbulence in the narrowed artery. A physician may be able to hear a bruit using a stethoscope. Occasionally, even a patient can hear the sound. The presence of a bruit, however, is not necessarily a sign of an impending stroke, nor does the absence of a bruit indicate an unblocked artery.
  
• Carotid ultrasound is a very valuable tool for measuring the width of the artery. At this time, ultrasound is most useful in people between the ages of 40 and 60 years. It should be noted that severely blocked carotid arteries may distort some measurements, so other tests may be required to confirm the results.
  
• The blood pressure to the eye may also be measured. If blood flow to the eye is reduced, the physician estimates that the carotid artery is probably severely narrowed.
  

Other Imaging Techniques. Other imaging techniques may be useful for identifying small clots or other indicators of risk in the brain.

• Transcranial duplex sonography is an ultrasound technique that can identify tiny clots in the brain that do not produce symptoms but place patients at higher risk for TIAs or Stroke. In one study, the use of this technique to identify blockage in large arteries in the brain was very helpful in predicting the outlook for patients who had experienc ed an ischemic stroke. It may eventually prove to be useful in identifying unruptured aneurysms.