Stroke and Contralateral Weakness

Stroke Symptoms and Neuroanatomy

• Strokes typically cause contralateral (opposite side) weakness due to the decussation (crossing) of the corticospinal tract in the medulla oblongata 1
• The American Heart Association, as published in Circulation, notes that symptoms of stroke in the distribution of the right internal carotid artery or middle cerebral artery include left-sided weakness, left-sided sensory loss, and other left-sided deficits 1
• The International Journal of Stroke guidelines suggest that the classic presentation of stroke includes contralateral hemiparesis affecting the face, arm, and/or leg 2, 3
• Similarly, left hemisphere strokes typically cause right-sided weakness and sensory deficits, according to the American Heart Association, as published in Circulation 1

Clinical Implications

• The International Journal of Stroke recommends that when evaluating patients with suspected stroke, clinicians should recognize that unilateral weakness (face, arm, and/or leg) is a high-risk symptom requiring immediate assessment 2, 3