About Multiple Sclerosis

Clinically isolated syndrome involves one episode of symptoms lasting at least 24 hours. These symptoms are due to demyelination in the central nervous system (CNS). Typical symptoms of CIS are optic neuritis (experienced by poor vision, blind spots, double vision), transverse myelitis (experienced by muscle weakness, numbness, tingling, bladder issues) and Lhermitte’s sign (experienced by an electric shock feeling in the neck). There are two types of CIS episodes: monofocal and multifocal. A monofocal episode means one lesion causes one symptom. A multifocal episode means the patient has more than one lesion and more than one symptom. 

Note: although these episodes are characteristic of MS, they aren’t enough to prompt a diagnosis of MS.

If lesions similar to those that occur with MS are present, a patient is more likely to receive a diagnosis of relapsing-remitting MS. If these lesions aren’t present, a patient is less likely to develop MS.

Relapsing-remitting MS involves clear relapses of disease activity followed by remissions. During remission periods, symptoms are mild or absent and there’s no disease progression. RRMS is the most common form of MS at onset and accounts for approximately 85% of all cases.

In people with PPMS, neurological function becomes progressively worse from the onset of symptoms. Over time it becomes increasingly difficult for signals from the brain to get through to the rest of the body. The rate of progression can vary. It’s possible for people to maintain a steady state without new or worsening symptoms for extended periods. There are no clear relapses and remissions like those of RRMS. Common early symptoms of PPMS include weakness in the legs and problems with walking.

Secondary progressive MS occurs when RRMS transitions into the progressive form. A patient may still have noticeable relapses in addition to disability or gradual worsening of function.