What is Brown-Séquard syndrome?

What is Brown-Séquard syndrome?

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.