Part 2 of 11
What is multiple sclerosis?
MS is a chronic illness involving the central nervous system. Theimmune system attacks myelin, which is the protective layer around nervefibers. This causes inflammation and scar tissue, or lesions. This can make ithard for your brain to send signals to the rest of your body. Types of MSinclude:
Relapsing-remitting MS (RRMS)
RRMS involves clear relapses of disease activity followed byremissions. Symptoms are mild or absent during remission, and there’s nodisease progression during the remission period. RRMS is the most common formof MS at onset.
Clinically isolated syndrome (CIS)
CIS involves one episode of symptoms that are due to demyelination inthe central nervous system. This episode must last for at least 24 hours.
The two types of episodes are monofocal and multifocal. A monofocalepisode means one lesion causes one symptom. A multifocal episode means youhave more than one lesion and more than one symptom.
Although these episodes are characteristic of MS, they aren’t enoughto prompt a diagnosis. If lesions similar to those that occur with MS arepresent, you’re more likely to receive a diagnosis of RRMS. If these lesionsaren’t present, you’re less likely to develop MS.
Primary-progressive MS (PPMS)
Neurological function becomes progressivelyworse from the onset of your symptoms if you have PPMS. However, short periodsof stability can still occur.
Progressive-relapsing MS was a term people previously used forprogressive MS with clear relapses. People now call it PPMS. The words “active”and “not active” are used to describe disease activity.
Secondary-progressive MS (SPMS)
SPMS occurs when RRMS transitions into theprogressive form. You may still have noticeable relapses, in addition to gradualworsening of function or disability.