Understanding the Different Types of Multiple Sclerosis

Since MS does not progress in the same manner, professionals have divided the disease into four phenotypes based on the manner in which the disease progresses. The four types of multiple sclerosis are Clinically Isolated Syndrome, Relapsing-remitting Multiple Sclerosis, Primary Progressive Multiple Sclerosis, and also Secondary Progressive Multiple Sclerosis.

1) Clinically Isolated Syndrome (CIS)

 Clinically Isolated Syndrome is a first episode of neurologic symptoms. These symptoms are usually a result of inflammation and demyelination of the central nervous system. Not all people who have a CIS episode go on to have multiple sclerosis, however diagnosing a patient with CIS is the first step towards a future diagnosis of multiple sclerosis. Patients diagnosed with CIS are usually observed closely for a period of time to determine if the condition is ongoing and also if the condition becomes worse in any way.

Characteristics of CIS

• Episode must last for at least 24 hours
• Accompanied by lesions on the brain
• Episode does not yet meet the requirements to be diagnosed with MS

2) Relapsing-remitting Multiple Sclerosis (RRMS)

RRMS is the most common progression of multiple sclerosis. It is possible for patients diagnosed with Relapsing-remitting Multiple Sclerosis if they experience a time of remission. A patient in remission may experience no symptoms of the disease, other symptom may continue to affect the patient. A patient with RRMS is also diagnosed with a status based on test or confirmation a patient can be in a status of Active or Not Active and Worsening or Not Worsening.

Characteristics of RRMS

• Clearly defined attacks
• New or increasing neurologic symptoms
• Can be classified as active or non active
• Can have an active status of worsening or not worsening

3) Primary Progressive Multiple Sclerosis (PPMS)

The determination of PPMS is more complex than other types of multiple sclerosis, because it's an evaluation over time. Primary progressive multiple sclerosis is also unique, in that each patient has a different experience with PPMS. Similar to RRMS, Primary progressive multiple sclerosis is classified as active or not active. Tests are also used to determine whether a patient’s status is with progression or without progression.

Characteristics of PPMS

• Worsening neurologic function from the onset of symptoms
• Patient may experience brief periods of stability
• Can be classified as being active or not active
• Can be considered  to be with progression or without progression

4) Secondary Progressive Multiple Sclerosis (SPMS)

Most patients diagnosed with RRMS over time eventually transition into SPMS. Patients who have been diagnosed with SPMS may experience times of either relapse or stability. SPMS is also  progressive, which means it’s observed over a long period of time. Secondary progressive multiple sclerosis is also unique to each patient. Patients suffering from SPMS can be consider to be in an active or inactive state, with a status of with progression or without progression.

Characteristics of SPMS

• Worsening neurologic function from the onset of symptoms
• Patients may experience occasional relapse
• Gradual Worsening of Disability
• Condition can be classified as active or inactive
• The status of the condition can be with progression or without progression

While these four types of multiple sclerosis may be very similar in characteristics, it's important to understand that each diagnosis requires special observation as well as magnetic resonance imaging also known as an MRI. The phenotypes within multiple sclerosis are progressive, meaning that over time the type of MS you're diagnosed with may change depending upon the disease's progression.