brain, spinal cord, and nerve disorders
Ischemic Stroke
Diagnosis of Ischemic Stroke
A doctor's evaluation Computed tomography and sometimes magnetic resonance imaging Laboratory tests, including those to measure blood sugar Doctors can usually diagnose an ischemic stroke based on the history of events and results of a physical examination. Doctors can usually identify which artery in the brain is blocked based on symptoms. For example, weakness or paralysis of the left leg suggests blockage of the artery supplying the area on the right side of the brain that controls the left leg’s muscle movements. Doctors often use a standardized set of questions and commands to determine how severe the stroke is, how well people are functioning, and how symptoms are changing over time. These test helps doctors evaluate the person's level of consciousness, ability to answer questions, ability to obey simple commands, vision, arm and leg function, and speech. Different areas of the brain control specific functions. Consequently, where the brain is damaged determines which function is lost. Doctors measure the blood sugar level. A low blood sugar level ( Hypoglycemia ) can cause similar symptoms. Computed tomography (CT) is usually done next. CT helps distinguish an ischemic stroke from a hemorrhagic stroke, a brain tumor, an abscess, and other structural abnormalities. However, during the first hours after some strokes, the CT scan may be normal or show only subtle changes. As a result, diagnosis may be delayed. So if available, Diffusion-weighted MRI (MRI), which can detect ischemic strokes within minutes of their start, may be done next. As soon as possible, doctors may also do other imaging tests ( CT angiography or Identifying the precise cause of an ischemic stroke is important. If the blockage is a blood clot, another stroke may occur unless the underlying disorder is corrected. For example, if blood clots result from an abnormal heart rhythm, treating that disorder can prevent new clots from forming and causing another stroke. Tests for causes may include the following: Electrocardiography (ECG) to look for abnormal heart rhythms Continuous Ambulatory Electrocardiography (done at home or in the hospital) to record the heart rate and rhythm continuously for 24 hours (or more), which may detect abnormal heart rhythms that occur unpredictably or briefly Echocardiography and Other Ultrasound Procedures to check the heart for blood clots, pumping or structural abnormalities, and valve disorders Imaging tests— Color Doppler ultrasonography , Blood tests to check for Overview of Anemia , Urine drug screen forcocaineand amphetamines Imaging tests enable doctors to determine how narrowed the carotid arteries are and thus to estimate the risk of a subsequent stroke or Transient Ischemic Attacks (TIAs) (TIA). Such information helps determine which treatments are needed. For cerebral angiography, a thin, flexible tube (catheter) is inserted into an artery, usually in the groin, and threaded through the aorta to an artery in the neck. Then, a substance that can be seen on x-rays (radiopaque contrast agent) is injected to outline the artery. Thus, this test is more invasive than other tests that provide images of the brain’s blood supply. However, it provides more information. Cerebral angiography is done before any endovascular procedure that uses a catheter to treat a blocked or narrowed arteries. Cerebral angiography is also done when Overview of Vasculitis is suspected. Because CT angiography is less invasive, it has largely replaced cerebral angiography done with a catheter. The exceptions are when endovascular procedures are planned. These procedures involve using instruments threaded through a catheter to physically remove a clot ( Mechanical thrombectomy ), to widen a narrowed artery (angioplasty), and/or to place a tube made of wire mesh (a stent) to keep the artery open. 