A to Z of MS
Click on the relevant link for more information on a topic.
A to Z of MS Blood-brain barrier
The blood-brain barrier is a tightly packed layer of cells (called endothelial cells) that line the blood vessels in the brain and spinal cord. This barrier prevents large molecules, immune cells, and disease-causing organisms (eg viruses) from passing from the blood stream into the central nervous system (brain and spinal cord).
In multiple sclerosis, immune cells are able to enter the central nervous system, implying that the blood-brain barrier is damaged or compromised in some way. These immune cells attack the myelin in the brain and spinal cord, causing the lesions which lead to MS symptoms.
One of the disease modifying drugs, natalizumab (Tysabri), is thought to act by preventing the immune cells from passing into the central nervous system via the blood-brain barrier.