Stroke Dictionary

lacunar stroke: Generally more limited than anterior or posterior strokes. Lacunar stroke symptoms tend to affect only the brain's motor functions, without loss of "higher functions" such as speech, vision, or mental processes. Limited paresis (muscle weakness) is often one of the symptoms of lacunar stroke.

left-hemisphere stroke: The left hemisphere of the brain controls the movement of the right side of the body. It also controls speech and language abilities for most people. A left-hemisphere stroke often causes paralysis of the right side of the body. This is known as right hemiplegia.

mechanical thrombectomy: An intervention for acute ischemic stroke which involves removal of the offending thrombus directly. This is accomplished by inserting a catheter into the femoral artery, directing it up into the cerebral circulation, and deploying a corkscrew-like device to ensnare the clot.

miosis: Describes an involuntary contraction of the pupil. These features are illustrated in the left eye of the woman pictured here. The presence of either ptosis or miosis should lead to an investigation of a possible stroke.

motor control disorders: The inability to move muscles in a coordinated manner. Often impaired as a result of a stroke. Strokes usually occur on only one side of the brain, so decreased motor control usually develops on only one side of the body.

neglect: One of the most unusual symptoms of stroke: the individual cannot focus on half of his or her visual or physical world. When asked to draw a clock, people with neglect only draw half the clock face. Neglect usually affects the left side of the visual field.