brain, spinal cord, and nerve disorders
Overview of Stroke
Symptoms of Stroke
Symptoms of a stroke or transient ischemic attack occur suddenly. They vary depending on the precise Brain Dysfunction by Location . Each area of the brain is supplied by specific arteries. For example, if an artery supplying the area of the brain that controls the left leg’s muscle movements is blocked, the leg becomes weak or paralyzed. If the area of the brain that senses touch in the right arm is damaged, sensation in the right arm is lost. Different areas of the brain control specific functions. Consequently, where the brain is damaged determines which function is lost. Strokes usually damage only one side of the brain. Because most of the nerves in the brain cross over to the other side of the body, symptoms appear on the side of the body opposite the damaged side of the brain. However, if the stroke damages the Brain stem and affects some of the Strokes usually damage only one side of the brain. Because most nerves in the brain cross over to the other side of the body, symptoms appear on the side of the body opposite the damaged side of the brain. Because early treatment of stroke can help limit loss of function and sensation, everyone should know what the early symptoms of stroke are. People who have any of the following symptoms should see a doctor immediately, even if the symptom goes away quickly: Sudden weakness or paralysis on one side of the body (for example, half of the face, one arm or leg, or all of one side) Sudden loss of sensation or abnormal sensations on one side of the body Sudden difficulty speaking, including difficulty coming up with words and sometimes slurred speech Sudden confusion, with difficulty understanding speech Sudden dimness, blurring, or loss of vision, particularly in one eye, and double vision Sudden dizziness or loss of balance and coordination, leading to falls One or more of these symptoms are typically present in both hemorrhagic and ischemic strokes. Symptoms of a transient ischemic attack are the same, but they usually disappear within minutes and rarely last more than 1 hour. Symptoms of a hemorrhagic stroke may also include the following: Sudden severe headache Nausea and vomiting Temporary or persistent loss of consciousness Very high blood pressure Other symptoms that may occur early include problems with memory, thinking, attention, or learning. People may be unable to recognize parts of the body and may be unaware of the stroke’s effects. The peripheral field of vision may be reduced, and hearing may be partially lost. Difficulty Swallowing , dizziness, and People may have difficulty controlling their bowels and/or bladder beginning several days or more after the stroke occurred. Loss of control may be permanent. Later symptoms may also include involuntary stiffening and spasms of the muscles (spasticity) and inability to control emotions. Many people become depressed because of the stroke. In most people who have had an ischemic stroke, loss of function is usually greatest immediately after the stroke occurs. However, in about 15 to 20%, the stroke is progressive, causing greatest loss of function after a day or two. This type of stroke is called an evolving stroke. In people who have had a hemorrhagic stroke, function usually is lost progressively over minutes to hours. Over days to months, some function is usually regained because even though some brain cells die, others are only stressed and may recover. Also, certain areas of the brain can sometimes switch to the functions previously done by the damaged part—a characteristic called plasticity. However, the early effects of a stroke, including paralysis, can become permanent. Muscles that are not used usually become permanently spastic and stiff, and painful muscle spasms may occur. Walking, swallowing, pronouncing words clearly, and doing daily activities may remain difficult. Various problems with memory, thinking, attention, learning, or controlling emotions may persist. Depression, impairments in hearing or vision, or vertigo may be continuing problems. When a stroke is severe, the brain swells, increasing pressure within the skull. Hemorrhagic strokes involve bleeding in the brain or in the tissues that cover it. This blood can increase pressure within the skull. Increased pressure can damage the brain directly or indirectly by forcing the brain sideways and downward in the skull. The brain may be forced through the rigid structures that separate the brain into compartments, resulting in a dangerous problem called Herniation: The Brain Under Pressure . The pressure affects areas that control consciousness and breathing in the brain stem (which connects the cerebrum with the spinal cord). Herniation can cause loss of consciousness, coma, irregular breathing, and death. The symptoms caused by a stroke can lead to other problems. If swallowing is difficult, people may inhale food, fluids, or saliva from the mouth into the lungs. Such inhalation (called aspiration) can cause Aspiration Pneumonia and Chemical Pneumonitis , which may be serious. Difficulty swallowing can also interfere with eating, resulting in undernutrition and dehydration. People may have difficulty breathing. Over time, not being able to move can result in Pressure Sores , muscle loss, permanent shortening of muscles (contractures), and the formation of blood clots in deep veins of the legs and pelvis ( If bladder control is impaired, Overview of Urinary Tract Infections (UTIs) are more likely to develop. 