There are at present 3 types of progressive MS. These are Primary Progressive, Progressive Relapsing and Secondary Progressive (with and without exacerbations).  There is also  a 4th which is a "category" rather than a type - this is called "Transitional Progressive" and is used by some researchers and some neurologists.

Primary progressive ms, is often thought of as the most severe form in the sense that from onset to total disability is the shortest time span. However, even within this category there are differences in both rate of progression and severity of progression.

Research has shown that MRI results indicate that people with primary progressive MS often have far more lesions and more widely spread throughout the CNS than any of the other types of MS - including SPMS.

PPMS is characterized by an increasing steady decline in motor and often cognitive abilities. There is none of the characteristic "remissions" as experienced by people with RRMS. At best there may be experienced a "plateau" where the individual does not get any better but for a time at least the current symptoms do not worsen. A plateau is usually short lived before the illness resumes the progressive process. Once symptoms appear they generally continue to become increasingly more frequent and severe.

For example, one may experience some "different" kinesthetic sensations - in other words feelings on the skin of the hands, arms, feet, legs etc., which the person describes as "unusual". These sensations over time may become more pronounced and are often identified as "tingles", then further along as "pins and needles". Sometimes the feelings then progress to either pain or numbness or both.

For other folks or even other areas of the body in the same person, the symptoms may begin as numbness or tingles or pins and needles - it depends on the extent of damage and location of damage to the myelin coating and or nerves themselves. Another example is with the arms or legs may feel "heavy" or swollen at first, then become increasingly unresponsive and may become paralyzed.

How quickly this all occurs differs from one person to another and even for an individual and while some situations, such as prolonged illness, intense stress or exhaustion, may hasten the process, no one is quite certain why. For example, some individuals, from diagnosis to total disability may be as quick as 2 years, others 4, or 10 or more.

Where the worst of the progressive symptomology appears, depends on where the lesions are located within the CNS. Naturally spinal lesions will result in a greater motor deficit. Because PPMS results in both a greater quantity of lesions and more widespread disbursement, people with PPMS accordingly show a greater range of symptomology than people with RRMS do.

That is, the most common symptoms reported by people with ms are fatigue, numbness, tingling, pins and needles, cramps, spasms, visual problems, memory problems and difficulty with concentration and attention, spatial orientation and coordination, bowel and bladder and sexual dysfunction. For people with RRMS, they may experience some of those symptoms, for PPMS folks they almost all develop all of the symptoms at some time. Consequently, total disability follows as more deficits occur.

Of all the types of MS, PPMS is the least common type and depending on who or what you read, the percentage changes also - for example 5% to 10% of all people are diagnosed PPMS.

While there are many drugs and treatments being trialed, there is to date no known totally effective treatment for PPMS. It is hoped that with the continued research that a drug or combination of drugs may be useful in halting or slowing the progression.

There have been some encouraging results with the use of chemotherapy (for example Cytoxan) and steroidal treatments in slowing the progression in some people. The theory for using chemotherapy is that MS is assumed to be caused by an over active immune system. By depleting the white blood cells, it is hoped that the immune response will either not occur, or not occur with as great a response. Therefore, minimizing the damage and slowing the progression of the disease.

TPMS

Transitional Progressive MS (TPMS) is a term sometimes used by researchers as the period of time during which a person is progressing from Relapsing Remitting MS (RRMS) to SPMS. Exacerbations still occur, however, rather than a complete or partial recovery with the symptoms remaining constant, the person begins to progress. Symptoms/disabilities "gained" in the exacerbation continue to worsen rather than remaining static. This period of transition may last weeks, months or most commonly 2 years.

SPMS
Secondary progressive MS (SPMS) is characterized by a pattern of Relapsing Remitting MS in the beginning. This may last for quite some years or only 2 years...again no one is able to predict how long a person may remain RRMS before progressing to SPMS.

Approximately 40 to 50% of the relapse remit type of MS sufferers go on to become secondary progressive. It is also not known what triggers cause the cessation of remission and the onset of the progression of the disease. Once an individual becomes SP, the pattern of symptoms, severity and disability is similar to that of Primary Progressive (for people without exacerbation).

People with SPMS who also have exacerbations do not have a remission period after exacerbations and show a pattern of progression between exacerbations.

If there is an "upside" to SPMS compared to PPMS, it is that it may take years of relatively uncomplicated, able living with the RR pattern before the onset of progression. Again it must be noted that people do vary in their rate of progression and severity of disability. Also the quantity and severity of relapses and time between "flares or attacks" also varies.

With the advent of the ABC drugs, it is hoped that less people will progress to SPMS, and that the deterioration and increase in symptomology will also be alleviated somewhat through treatment. In other words we hope that researchers may develop treatments to drastically slow the disease and thus increase the quantity of life while increasing the quality for the individuals.

New studies have also shown that the sooner an individual with SPMS is treated with Betaseron, the greater the potential there is to slowing the progression and subsequent disability.

PRMS
PRMS or progressive relapsing ms (like PPMS) is a relatively rare form of the disease. The individual is initially diagnosed as having PPMS and as much as up to 10 years later, may have an exacerbation.  It is characterized by the similar pattern of severe exacerbation, such as blindness or paralysis that people with RRMS experience. However, rather than returning to full recovery of functioning with some residual symptoms - such as tingles, numbness, as is the case with RRMS, the folks with PRMS show a pattern of progression between exacerbation's. It is probably best understood as being like PPMS only with the major exacerbations of RRMS