Brain scans
Imaging tests help doctors pinpoint areas of brain injury. Tests might include:
CT scan. This uses a series of X-rays to create a detailed image of the brain. A CT scan can show a brain hemorrhage, tumors, strokes and other conditions. This test is often used to diagnose and determine the cause of a coma.
MRI. This uses powerful radio waves and magnets to create a detailed view of the brain. An MRI can detect brain tissue damaged by an ischemic stroke, brain hemorrhages and other conditions. MRI scans are particularly useful for examining the brainstem and deep brain structures.
Electroencephalography (EEG). This measures the electrical activity inside the brain through small electrodes attached to the scalp. Doctors send a low electrical current through the electrodes, which record the brain’s electrical impulses. This test can determine if seizures might be the cause of a coma.