What is an MS relapse?
What is a relapse?
A relapse is an episode of neurological symptoms (caused by inflammation or demyelination) that happens at least 30 days after any previous episode began, lasts at least 24 hours and is not caused by an infection or other cause. A relapse is often described by other names, including an attack, exacerbation, flare-up, acute episode or clinical event.What happens in a relapse in the central nervous system?
In MS, relapses are caused by inflammation in the central nervous system (the brain and spinal cord). This inflammation is the body’s reaction when immune cells mistakenly attack the protective layer (myelin) that surrounds nerve fibres.When messages are blocked in an area with a specific function (for vision, movement or sensation, for example) then symptoms occur. When inflammation dies down, so too can the symptoms.
Inflammation may also damage some of the nerve fires (axons) themselves. Although it does not always happen, studies have shown that axons can be damaged even in the earliest stages of MS. The central nervous system can repair by itself some of the damage done to myelin (this is known as remyelination). Even when there is not complete remyelination, people can still recover from the symptoms of a relapse.
