Stroke: a sudden attack of weakness usually affecting one side of the body. It is the consequence of the interruption to the flow of blood to the brain. (OxfordMed) 

In “medicine,” a loss of blood flow to part of the brain, which damages brain tissue. Strokes are caused by “blood clots” and broken “blood vessels” in the brain. Symptoms include dizziness, numbness, weakness on one side of the body, and problems with talking, writing, or understanding language. The risk of stroke is increased by high “blood pressure,” older age, smoking, “diabetes,” high “cholesterol,”  “heart disease,”  “atherosclerosis,” and a family history of stroke. (NCIt) The ideal treatment for stroke is to restore blood flow in blocked vessels. Drugs can be used to try to block the cascade of post-injury events. When the course of the stroke has led to dead brain tissue, the only treatments that can be beneficial are those that facilitate "plastic" changes in the brain. Examples are 'speech therapy' or 'physical therapy.’ (Kolb, 587) Also referred to as ‘cerebrovascular accident.’

Hemorrhagic Stoke: occurs when a blood vessel in part of the brain becomes weak and bursts open. This causes blood to leak into the brain. Some people have defects in the blood vessels of the brain that make this more likely. (PubMedHealth2)

Ischemic Stoke: an acute episode of focal cerebral, spinal, or retinal dysfunction caused by “infarction” of “central nervous system” “tissue.” (NCIt) Occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot. This may happen in two ways: a clot may form in an artery that is already very narrow; a clot may break off from another place in the blood vessels of the brain, or from some other part of the body, and travel up to the brain. (PubMedHealth2)

Stroke Caused Arm Paralysis: when a blood vessel supplying the brain gets clogged, the fibers that extend from the front part of the brain down to the spinal cord are deprived of oxygen and sustain damage, leaving the arm paralyzed. Most recovery from stroke-caused left hand paralysis occurs in the first few weeks. After this window of "plasticity" the left hand tends not to regain function. (Ramachandran, 119)