The diagnosis of a stroke is made on the details recounted by the patient and family and on the physical examination. The other tests such as brain scans help to confirm what is already suspected and can help differentiate whether the stroke was due to bleeding (Haemorrhagic) or not. The next step is to ask why a stroke has occurred. Even in young patients who have a stroke in about 30% of cases no real cause can be found. In some rare cases the cause of the symptoms is not actually a stroke but may be migraine or other neurological conditions. Some of the possible tests that are done are described dhere.
Blood Tests : These are useful to find out if you have an underlying medical condition which could have contributed to the stroke, for example, diabetes, high cholesterol or abnormal clotting problems.
Electrocardiogram (ECG ) : This test looks at the electrical activity of the heart and can tell us if you have an irregular heart beat (Atrial fibrillation), which can be a cause of stroke.
Computerised Tomography (CT ) : This is a form of brain scan using x-rays and all patients with a stroke will have one done as early as possible. In some cases a dye (Contrast) may need to be injected into a vein before the scan. It usually takes 5-10 minutes and is very quick and painless. The scan can help differentiate a haemorrhagic stroke where blood shows up as a white on a CT scan and a stroke due to cerebral infarction which appears darker than the surrounding brain.
Magnetic Resonance Imaging (MRI ) : This scan uses a magnetic field to image the brain and can give a more detailed picture than a CT scan. It is most useful for seeing strokes that at the back of the brain. However, It is very noisy and takes 20-30 minutes. Some patients find it a little claustrophobic. However it is highly informative and can provide crucial information It is not needed in all patients as the CT brain most often provides all the information needed about the type of stroke and where it is. The MRI scanner uses a very powerful magnet so cannot be done on patients with metal in their body eg pacemakers
24 hour tape: This is a small ECG recording device that you wear for a day and records and counts all your heart beats. It can be reasonably useful for picking up irregular heartbeats.
Carotid Doppler test : This test looks at the carotid arteries in the neck to see if there is any narrowing which may have caused the stroke. If there is narrowing we may consider referring you for an operation to prevent further strokes. It is only done on those in whom we would consider well enough to refer on for surgery called Carotid endarterectomy. Again it is a simple and painless test that takes 10-20 minutes.
Echocardiogram : This test looks at the heart and is sued to look for any possible causes of stroke. It is only done on selected patients where it will change treatment. It takes 20 minutes. Occasionally a bubble test is done along with the echocardigram to look for small holes in the heart which may be a rare cause of strokes.
Transoesophageal Echocardiogram : This is a more detailed heart scan and is done by putting a probe on the end of a scope which is then swallowed. The heart can be seen and any abnormalities recorded. It is only done on a small number of patients.
Thrombophilia screen: Is done when an inherited tendency to clot is suspected.
Lumbar puncture: This is done when we suspect that there may be some bleeding around the brain or we suspect there may be another neurological illness going on. It involves putting a needle into the back to take some spinal fluid. It is usually done with local anaesthesia and altogether takes 30 minutes.
