Movement of the body is primarily controlled by the pyramidal (or corticospinal) tract, a pathway of neurons that begins in the motor areas of the brain, projects down through the internal capsule, continues through the brainstem, decussates (or cross midline) at the lower medulla, then travels down the spinal cord into the motor neurons that control each muscle. In addition to this main pathway, there are smaller contributing pathways (including the anterior corticospinal tract), some portions of which do not cross the midline. Because of this anatomy, injuries to the pyramidal tract above the medulla generally cause contralateral hemiparesis (weakness on the opposite side as the injury). Injuries at the lower medulla, spinal cord, and peripheral nerves result in ipsilateral hemiparesis. In a few cases, lesions above the medulla have resulted in ipsilateral hemiparesis: * In several reported cases, patients with hemiparesis from an old contralateral brain injury subsequently experienced worsening of their hemiparesis when hit with a second<unk>  in the ipsilateral brain. The authors hypothesize that brain reorganization after the initial injury led to more reliance on uncrossed motor pathways, and when these compensatory pathways were damaged by a second<unk> , motor function worsened further. * A case report describes a patient with a congenitally uncrossed pyramidal tract, who developed right-sided hemiparesis after a hemorrhage in the right brain.
symptom of Stroke
symptom of Intracerebral hemorrhage
symptom of Subarachnoid hemorrhage
symptom of Migraine
symptom of Brain tumor
symptom of Cerebral palsy
symptom of Lightheadedness
symptom of Burn