According to the World Health Organization (WHO), stroke is the "second leading cause of death and the third leading cause of disability" worldwide. A stroke occurs when the blood supply to a part of the brain is interrupted, either due to a blocked artery or a leaking blood vessel. The brain stem is located at the base of the brain and is responsible for receiving and relaying information throughout the body. The brain stem controls essential body functions, such as: breathing swallowing eye movement facial movement and sensation hearing heart rate blood pressure mplications. Types of strokes There are two main types of strokes, both of which can affect the brain stem: Ischemic stroke Ischemic strokes occur when blood clots form in the narrow arteries in the head or neck, cutting off the blood supply to an area of the brain. Ischemic strokes are the most common type, accounting for 87 percent of all strokes. Around 10 percent of all ischemic strokes affect the brain stem. A transient ischemic attack (TIA), also called a mini-stroke or a warning stroke occurs when the blood supply to the brain is interrupted briefly. TIAs cause milder symptoms than full ischemic strokes, and most symptoms go away within an hour. Hemorrhagic stroke Hemorrhagic strokes, or brain bleeds occur when a weak blood vessel leaks or breaks open, creating swelling and pressure. This pressure damages tissues and cells in the brain. Hemorrhagic strokes are less common than other types of stroke, but they account for 40 percent of all stroke deaths.