Progression of Multiple Sclerosis

A younger age of onset appears to be associated with a slower progression although there is considerable variation as with all aspects of the disease.

A study undertaken in 2000 suggested that progression to moderate disability is often slower in patients with relapsing-remitting disease compared to patients with chronic progressive disease. However, in both types of MS the disease eventually worsens at the same rate.

Generally therefore the ability to predict the development of disability in MS is a major challenge. Although unfavourable prognostic features have been recognised, they cannot be used in individual casesto provide an accurate prognosis.

These unfavourable factors may include:

• Male sex,
• Sphincter symptoms at onset,
• Motor or cerebellar signs at onset (weakness, inco-ordination, nystagmus etc),
• Incomplete recovery from the first attack,
• Short interval between initial and second attack (i.e. high relapse rate in early years),
• Incomplete remission after first relapses,
• Early disability,

• High lesion load detected by early MRI scan of the brain.

The most supported tool for the grading of functional effects of MS is the (Expanded) Disability Status Scale ((E)DSS). The scale ranges from 1 (least severe) to 10 (death from MS). However, the scale is not ideal because there is a bias towards the physical effects of the disease (particularly walking) rather than the cognitive effects and the scale is therefore not used universally. There are several other disability scales used by health professionals and for research purposes but these are not often recorded on a routine basis for most patients.

Amended April 2008