Brown-Séquard syndrome is a neurological condition that occurs when one side of the spinal cord is damaged. This damage can result from trauma, tumors, or diseases. The syndrome is characterized by a unique pattern of symptoms: loss of motor function and proprioception (awareness of body position) on the same side as the injury, and loss of pain and temperature sensation on the opposite side. The condition is named after Charles-Édouard Brown-Séquard, a 19th-century physiologist who first described it. Diagnosis typically involves a physical examination and imaging studies, while treatment focuses on managing symptoms and addressing the underlying cause of the spinal cord injury.