Multiple Sclerosis (MS) is a disease affecting the central nervous system. It rarely affects people in exactly the same way, and over time, several types have been identified. As well as the four main types of this condition, there are numerous subtypes that may be used to describe different forms of the disease. The four main types are relapsing/remitting, secondary progressive, progressive relapsing, and primary progressive.
Relapsing/remitting multiple sclerosis is defined by the patient having relapses or episodes of the disease. Slightly over 80% of those suffering from MS begin with this type. During a relapse, patients may experience symptoms not shown before, and may also see other symptoms experienced before either worsen, change or not be present. During the remission phase, the symptoms lessen, and the effects caused by symptoms such as disabling of the limbs may also lessen or may completely disappear. Periods of remission greatly vary. Some will experience only a few days of remission, while others may experience months or years of remission.
Secondary progressive multiple sclerosis is usually a second stage of relapsing/remitting MS. About 90% of those with that type will progress to this type. Remissions are characterized by worsening of the disease, so that relapses become more severe. Generally, after a while there are very few relapses while the condition simply worsens until the central nervous system is completely impacted. This process, however, can take many years, and many with this type can still live fairly normal and active lives because the progression is not sudden.
Progressive relapsing multiple sclerosis is characterized by acute attacks, with little recovery during relapses, which are few. Meanwhile, the relapses do not represent the recovery of the central nervous system, but simply a break prior to more significant attacks. Roughly 5% of those with MS have this type.
Primary progressive multiple sclerosis occurs in about 10% of those with MS. The body becomes gradually disabled, but the person tends not to suffer from acute attacks. This type may be more difficult to diagnose because there are no attacks to herald the disease. However, gradual impairment of movement, and increased disability usually helps diagnose the disease within a few years of development.
Subtypes of multiple sclerosis come down to fine details. One subtype called Devic’s Disease attacks the spinal column and particularly the eyes. This may result in pain in the eyes, blurred vision, and acute loss of vision. Some may lose color differentiation in vision.
Benign MS is a subtype of relapse/remission. Usually a person has a single attack, and then the disease goes into remission for an extended period of time, sometimes a decade or more. Malignant multiple sclerosis, on the other hand, is very serious, and fortunately rare. The disease progresses at an extremely fast rate, and is most likely to cause significant disability within a year of onset. This subtype may also be called acute MS or Marburg’s variant.