Brown-Séquard syndrome (BSS) is a rare neurological condition that happens when damage to your spinal cord causes muscle weakness or paralysis on one side of your body and a loss of sensation on the opposite side. The damage occurs on only one side of your spinal cord in a specific area. Your spinal cord is a cylindrical structure that runs through the center of your spine, from your brainstem to your low back. It’s a delicate structure that contains nerve bundles and cells that carry messages from your brain to the rest of your body and vice versa. Your spinal cord is one of the main parts of your nervous system. Brown-Séquard syndrome is considered an incomplete spinal cord injury (SCI), meaning there’s partial preservation of sensory function, motor function or a combination of both below where the injury occurred on your spinal cord. A complete SCI results in the loss of all sensory and voluntary motor functions below the level of the injury. BSS has several possible causes, but the most common cause is trauma — typically penetrating trauma such as a gunshot or stab wound. Inflammation or pinching of your spinal cord can also cause BSS occasionally. Brown-Séquard syndrome is named after scientist Charles-Édouard Brown-Séquard, who first described it in 1849. What is the difference between central cord syndrome and Brown-Séquard syndrome? Central cord syndrome (CCS) and Brown-Séquard syndrome (BSS) are both incomplete spinal cord injuries, but they’re distinct conditions. CCS is an incomplete traumatic injury to the center of your spinal cord, usually in your neck. This injury results in weakness in your arms that is worse than in your legs. BSS results from an incomplete spinal cord injury anywhere along your spine, and it causes weakness or paralysis on one side of your body and a loss of sensation on the other side below where the injury is. Who does Brown-Séquard syndrome affect? Brown-Séquard syndrome can affect anyone, though it’s a rare condition. It affects people assigned female at birth and people assigned male at birth in equal numbers. How common is Brown-Séquard syndrome? Brown-Séquard syndrome is a rare condition. Approximately 12,000 new cases of traumatic spinal cord injuries happen each year in the United States, and Brown-Séquard syndrome is estimated to result from 2% to 4% of these cases. SYMPTOMS AND CAUSES What are the symptoms of Brown-Séquard syndrome? Symptoms of Brown-Séquard syndrome (BSS) usually appear after you experience spinal cord injury that causes damage on only one side of your spinal cord in a specific area anywhere along your spine. The first symptoms of BSS are usually: Loss of voluntary motor function (muscle movement) on the same side of your body as the spinal cord damage below the level of the injury. This could present as weakness or paralysis. Loss of pain and temperature sensation on the other side of your body below the level of the injury. ...
