Dictionary

acalculia: Loss of mathematical skills.

agnosia: Difficulty distinguishing sensory stimulations.

alexia: Loss of reading skills.

amaurosis fugax: Describes a sudden loss of vision in one eye caused by transient ischemic attack (TIA). Vision loss is temporary.

aphasia: Difficulties with speaking, reading and writing.

apraxia: Impairment in the ability to perform complex tasks.

ataxia: Loss of muscle coordination. Voluntary movements are disjointed or jerky. Ataxia can affect any area of the body, and is one of the symptoms associated with cerebellar stroke. Ataxia can affect vision and speech, depending on which muscles are involved. Ataxia may also cause dysphagia (difficulty swallowing).

basilar arteries: Part of the vertebrobasilar circulation system, located at the base of the skull. The two vertebral arteries connect to form a single basilar artery that provides the "vertebrobasilar territory" of the brain with oxygen. This territory includes the brain stem, cerebellum, and occipital lobes.

brain stem: Sometimes referred to as one of the "primitive" parts of the brain. Located at the top of the spinal column, the brain stem controls breathing, heart rate, blood pressure, and alertness. Brain stem strokes can disrupt breathing, causing sudden death.

brain stem stroke: Strokes that occur in the brain stem are especially devastating. The brain stem is the area of the brain that controls all of our involuntary, "life-support" functions, such as breathing rate, blood pressure and heartbeat. The brain stem also controls abilities such as eye movements, hearing, speech and swallowing. Since impulses generated in the brain's hemispheres must travel through the brain stem on their way to the arms and legs, patients with a brain stem stroke may also develop paralysis in one or both sides of the body.

carotid arteries: Run up both sides of the neck, and supply oxygen to the "carotid territory" of the brain. The carotid territory includes the frontal and temporal lobes.

cerebellar stroke: The cerebellum controls many of our reflexes and much of our balance and coordination. A stroke that takes place in the cerebellum can cause abnormal reflexes of the head and torso, coordination and balance problems, dizziness, nausea and vomiting.

cerebellum: Located behind the brain stem. While the frontal lobe controls movement, the cerebellum "fine-tunes" movement, this area of the brain controls fine motor movement, balance, and our brain's ability to determine limb position. A stroke in the cerebellum can lead to paralysis or "jerky" muscle movements.

cerebrum: The largest area of the brain. The cerebrum can be anatomically divided into two parts; the right and left hemispheres. The right hemisphere controls the left side of the body, and the left hemisphere controls the right side. This aspect of brain anatomy explains why stroke symptoms often only affect one side of the body. Four distinct lobes make up the cerebrum: the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe.

cholesterol plaques: These cholesterol plaques in the vertebral and carotid arteries, the arteries that feed the brain, may lead to an ischemic stroke. These cholesterol plaques contribute to strokes because the plaques cause narrowing of the arteries and significantly restrict blood flow.

dysarthria: Dysarthria refers to a speech difficulty. Rather than affecting the brain's language centers, dysarthria causes muscular weakness in the tongue muscles. Symptoms of dysarthria include slow, slurred speech. People suffering from dysarthria may benefit from speech therapy.

dysphagia: Refers to a difficulty in swallowing. A difficulty in swallowing may occur if the swallowing reflex is impaired, however dysphagia may also result from impaired muscular coordination of the tongue or throat muscles. A number of stroke events may result in dysphagia.