The two main types of stroke are ischemic, which is caused by an interruption in the brain's blood flow, and hemorrhagic, which is caused by blood leaking into the brain. The way a stroke affects someone depends largely on where in the brain the stroke takes place. The motor control areas of the brain affect the opposite side of the body, so the effects of right hemisphere stroke will affect the left side of the body.
A person who has a right hemisphere stroke will often have left-sided weakness. The level of weakness depends on the stroke's severity. It can range anywhere from minor muscle weakness, or left hemiparesis, to complete paralysis, or left hemiplegia. Hemiparesis and hemiplegia affect not only the arms and legs, but the muscles in the trunk and face as well. In addition to difficulty moving the left arm and leg, the left side of the face may appear droopy.
In addition to movement, a right hemisphere stroke can affect how a person feels on the left side. Medline Plus reports that tingling or numbness is common after a stroke. Some stroke patients experience problems with proprioception, which means they may not be able to tell where their left arm is without looking at it.
Because weakness can also affect the muscles on the left side of the mouth and tongue, some people may have slurred speech after a right hemisphere stroke. The National Institute of Neurological Disorders and Stroke reports that slurred speech, also called dysarthria, is also caused by decreased coordination of these oral motor muscles.
After a right hemisphere stroke, some people experience problems with their visual perception. They may lose the ability to see things on their left side, which is called a visual field cut, according to the National Stroke Association. These people often bump into things on the left or leave the left half of their plate untouched, simply because their brain does not see it. Some people also have trouble telling how far away an object is, or distinguishing top from bottom and left from right.
Changes in Behavior
After a right hemisphere stroke, some behavioral changes may be noted. The NINDS reports that depression is common after a stroke, along with other emotional changes. Some patients experience a flat affect, which means face and tone of voice do not show changes in emotion, whether they are telling a joke or discussing something sad. Stroke victims may also become more impulsive and act without thinking about the consequences. According to the NINDS, many people are unaware of their deficits after a right hemisphere stroke, which means they may require monitoring for potentially unsafe behaviors.
According to the National Stroke Association, short-term memory is often affected by a right hemisphere stroke. A person may have difficulty recalling events from one day to the next, though his memories of past experiences before the stroke are often intact. Because of this, it can be difficult to teach victims of a right hemisphere stroke how to compensate for their new challenges.