Relapsing/ remitting type of MS (RRMS) is most commonly diagnosed. Much of the research and drugs are approved for RRMS, I wonder what is actually happening in the body with progressive MS.
Multiple Sclerosis, often called MS, is a disease that affects the central nervous system (CNS): the brain, spinal cord, and optic nerves
I am not a scientist or even an educated researcher, I’m simply a woman living with MS. My almost 20 years of life with this condition has led me to many questions. Like many average people, I look online to have my questions answered. Wikipedia and YouTube have answers to many questions.
The problem is that one question leads to another.
What is actually happening in the body with progressive MS? One theory was shared by the MS society on YouTube is possibly if the myelin is the only part of the central nervous system being attacked then new myelin sheath can be formed but if the whole cell, the Oligodendrocytes is damaged then repair tends very poorly.
One Theory on Progressive MS – National MS Society
Oligodendrocytes are found only in the CNS. It sounds to me that the Oligodendrocytes form myelin. Wikipedia has a great write up about Oligodendrocytes and you can read it right here. http://en.wikipedia.org/wiki/Oligodendrocyte
Knowledge is important, and it helps to have an understanding about this MS condition.
Myelination is only prevalent in a few brain regions at birth and continues into adulthood. The entire process is not complete until about 25–30 years of age.
Oligodendrocyte formation in the adult brain is associated with glial-restricted progenitor cells, known as oligodendrocyte progenitor cells (OPCs). SVZ cells migrate away from germinal zones to populate both developing white and gray matter, where they differentiate and mature into myelin-forming oligodendroglia. However, it is not clear whether all oligodendroglial progenitors undergo this sequence of events. It has been suggested that some undergo apoptosis  and others fail to differentiate into mature oligodendroglia but persist as adult oligodendroglial progenitors.
An oligodendrocyte seenmyelinating several axons.
As part of the nervous system, oligodendrocytes are closely related to nerve cells, and, like all other glial cells, oligodendrocytes provide a supporting role for neurons. In addition, the nervous system of mammals depends crucially on myelin sheaths, which reduce ion leakage and decrease the capacitance of the cell membrane. Myelin also increases impulse speed, as saltatory propagation of action potentials occurs at the nodes of Ranvier in between Schwann cells (of the PNS) and oligodendrocytes (of theCNS). Furthermore, impulse speed of myelinated axons increases linearly with the axon diameter, whereas the impulse speed of unmyelinated cells increases only with the square root of the diameter. The insulation must be proportional to the diameter of the fiber inside. The optimal ratio of axon diameter divided by the total fiber diameter (which includes the myelin) is 0.6.
In contrast, satellite oligodendrocytes are functionally distinct from other oligodendrocytes. They are not attached to neurons and, therefore, do not serve an insulating role. They remain apposed to neurons and regulate the extracellular fluid. Satellite oligodendrocytes are considered to be a part of the gray matter whereas myelinating oligodendrocytes are a part of the white matter.
Myelination is an important component of intelligence. Neuroscientist Vincent J. Schmithorst found that there is a correlation with white matter and intelligence. People with greater white matter had higher IQ’s. A study done with rats by Janice M. Juraska showed that rats that were raised in an enriched environment had more myelination in their corpus callosum.