Disease course of PPMS

In response to the previous comment from the MS'ers with PPMS, who needed a walking aid within 4years of disease onset and malignant MS. 

The following is the survival curve in relation to PPMS. As you can see only ~8% of MS'ers with PPMS need a walking stick within 4 years (red); this is twice the progression rate of the average, i.e. 50% require a walking aid within 8 years (blue).


Source: Cottrell et al. The natural history of multiple sclerosis: a geographically based study. 5. The clinical features and natural history of primary progressive multiple sclerosis. Brain. 1999 Apr;122 ( Pt 4):625-39.

This study reports the natural history of 216 MS'ers with PPMS defined by at least 1 year of attack-free progression at onset. This represents 19.8% of a largely population-based patient cohort having a average follow-up of 23 years.

This subgroup of PP-multiple sclerosis patients had a average age of onset of 38.5 years, with females predominating by a ratio of 1.3:1.0. 

Disease course:
  1. The rate of deterioration from disease onset was substantially more rapid than for RRMS, with a median time to EDSS 6 (cane) and EDSS 8 (restricted mobility) of 8 and 18 years, respectively
Examination of the early disease course revealed two groups with adverse outcomes
  1. A shorter time to reach EDSS 3 (moderate disability, though fully ambulatory) from onset adversely influenced time to EDSS 8. 
  2. Involvement of three or more neurological systems at onset resulted in a median time to EDSS 10 (death) of 13.5 years in contrast to PPMS patients with one system involved at onset where median time to death from MS was 33.2 years. 
  3. Age, gender and type of neurological system involved at onset appeared to have little influence on prognosis. 
Life expectancy:
  1. Cause of death and familial history profile were similar in PPMS and relapse-onset MS. 
PPMS vs. SPMS:
  1. From clinical onset, rate of progression was faster in the PPMS than in the SPMS. 
  2. However, when the rates of progression from onset of the progressive phase were compared, SPMS had a more rapid progressive phase. 
Relapses:
  1. A substantial minority (28%) of the PPMS'ers had a distinct relapse even decades after onset of progressive deterioration. 
"Apologies, if some of you find these figures grim reading. Unfortunately, as you know, MS is a bad disease, particularly PPMS, and these figures make that very clear. This why we are spending a large amount of time working on progressive disease; how to stop or slow it down or in the case of relapse-onset MS prevent it from starting in the first place."

Additional reading: EDSS