Stroke diagnostics

The Kompetenznetz Schlaganfall has also published a patient brochure on this topic: What tests are carried out after a stroke?

With a computer tomography (CT) scan of the head, the doctor can differentiate in the acute phase of the stroke whether the stroke is caused by a hemorrhage or a vascular occlusion (ischemia). Due to its wide availability, it is standard in acute diagnostics. In many hospitals today, simple native CT in acute stroke is supplemented by vascular imaging with CT (CT angiography) and blood flow measurement (CT perfusion). This allows further conclusions to be drawn about which blood vessel is blocked and to what extent the brain tissue is affected by the reduced blood flow.

In selected centers, magnetic resonance imaging (MRI) or magnetic resonance imaging is performed instead of CT. MRI can provide further useful information about the causes and progression of tissue damage in the event of a stroke. In addition, MRI is much better at visualizing small (so-called lacunae), older infarcts or additional damage (e.g. cerebral microangiopathy of the brain). The vessels (MR angiography) and blood flow (perfusion) can be reliably visualized. Unlike CT, MRI does not work with X-rays, but with magnetic waves. Examinations can therefore theoretically be repeated as often as required without having to reckon with long-term consequences for the patient. Patients with a pacemaker or other metal parts in their body cannot be examined.

Doppler and duplex sonography of the vessels supplying the brain can be used primarily to detect vascular calcification, calcareous (arteriosclerotic) deposits, narrowing of the blood vessels and thrombotic occlusions. The following applies: the greater the constriction of a neck vessel, the greater the risk of a stroke. With the relatively new, so-called transcranial Doppler and duplex sonography, vessels in the head can now also be visualized.

Sometimes it is necessary for the doctor to visualize the vessels with a so-called conventional angiography. During an angiography, the patient is injected with an X-ray contrast medium via a catheter and X-ray images of the head and its vessels are then taken.

Cardiac arrhythmias can be detected with the help of a simple ECG (electrocardiogram or cardiac current curve) and with a long-term or 24-hour ECG. These can lead to the formation of small blood clots that can be washed into the brain and block a vessel there (embolism). The doctor often recognizes these arrhythmias just by feeling the patient’s pulse or listening to the heart.

In addition to regular ECG check-ups, an ultrasound examination (echosonography) of the heart cavities should also be carried out before treatment with blood-thinning medication, for example. This allows other diseases that can lead to the formation of small blood clots, such as deposits on the heart valves or inflammatory vascular changes, to be detected. These examinations can describe the functioning of the heart and detect dangerous blood clots in the heart cavities. The ultrasound examination can be carried out from the outside through the chest (transthoracic echocardiography, TTE) or – more unpleasant but more accurate – through the esophagus (transesophageal echocardiography, TEE).