A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are metastatic, and they start somewhere else in the body and move to the brain. Brain tumors can cause many symptoms. Some of the most common are.
The definition of a restraint is something that restricts freedom or prevents someone from doing something. When someone is tied up and prevented from moving, this is an example of restraint.
It appears that constraint is something imposed from without, like laws or morals, but restraint is something a person imposed on her/himself. However, here are definitions of these words from the American Heritage Dictionary*. While there is a distinction between the two words, as in your definition, note that meaning # 4 under restraint, is constraint.. n. 1. The threat or use of force to prevent, restrict, or dictate the action or thought of others.