Stroke

As more knowledge is gained about the brain, the prognosis for stroke survivors becomes better. The clinical diagnosis of stroke is an essential part of the treatment process. When a patient arrives at the hospital, the first thing the doctor will do is assess his or her condition. A primary care doctor may be the first doctor one sees, but once a problem with the brain or nervous system is identified a specialist will be called. Neurologists are specialists who diagnose and treat conditions of the brain, but they do not perform surgery. Neurosurgeons perform surgery on the brain and other parts of the nervous system. Other medical specialists may be consulted if the problem involves their area of expertise.

After taking a verbal history, the physician conducts a physical exam. The physician may begin by evaluating muscle strength, reflexes, coordination, balance, capacity to hear, see, smell, and feel, and ability to speak. On the basis of physician’s findings, other diagnostic tests may be ordered.

An image of the brain is important in diagnosing a stroke. The physician is looking to see if there is blood on the brain, and if so, where it is. The physician is also trying to see if there is dead tissue (infarct) in the brain, and, if there is, to confirm that this is the result of a stroke (and not something that mimics stroke). Two main ways to get an image of the brain are computerized tomography scan (CT scan) and magnetic resonance imaging (MRI). During the CT scan, a painless procedure, the patient’s head is placed in a device that looks like a big salon hair dryer. The patient simply lies back and relaxes while X-rays are beamed to reveal the structure of the brain. The MRI may look more intimidating than the CT scan because the patient is put on a bed in a large machine, but it too, is a painless procedure. MRI uses radio frequencies to image the brain and the blood vessels in the head and in the neck. Because technology for the MRI is increasing at a rapid rate, and it is providing more information, it is becoming the diagnostic method of choice.

Ultrasonography has two uses: (1) to measure the speed of blood flow, which helps to determine where there are blockages in arteries; and (2) to produce an image of the blood vessel. The carotid Doppler test is done by moving a device up and down the neck to see if there is a narrowing of the arteries, and a transcranial Doppler test is an ultrasound technique that gives information about the blood flow in the main arteries of the brain.

Imaging of the brain can usually detect the presence of blood, but in some circumstances a spinal puncture, or spinal tap, will be performed to rule out the possibility. The procedure involves taking a small needle, inserting it between the vertebrae in the back, and taking a sample of cerebrospinal fluid to analyze.

Echocardiograms and electrocardiograms are the two types of tests used to detect any abnormalities in the heart that could have caused a stroke. In an echocardiogram, ultrasound creates an image of the heart from which the doctor can see if any blood clots are in pockets of the heart and if the valves of the heart are normal or abnormal. The electrocardiogram maps the heartbeat, making it possible to detect irregular heartbeats, insufficient blood supply, and damaged parts of the heart. Analyzing the heart is important because the heart can be a source for blood clots that break away and reach the brain.

Blood tests are generally done to identify problems that could complicate stroke. Depending on the patient’s medical history, liver and kidney tests may also be done to detect damage. All of these tests and procedures play a part in the physician’s diagnosis.