Age at Onset Predicts Disease Progression in MS

Primary progressive multiple sclerosis (PPMS), the least common MS disease course, carries the worst prognosis. In this study,¹ researchers investigated factors associated with disability accumulation in PPMS.

The researchers identified 500 patients with PPMS in their patient database in Canada. They investigated the influence of sex, age at disease onset, and onset symptoms on time to, and age at, Expanded Disability Status Scale (EDSS) 4 and 6, as well as the time from EDSS 4 to 6 in patients with PPMS using standard survival methods. Median times to EDSS 4 and EDSS 6 were found to be 5 and 9 years. The median ages at EDSS 4 and EDSS 6 were 51 years and 55 years, respectively.

Older age at onset and bilateral motor onset symptoms were independently associated with a shorter time to both EDSS 4 and EDSS 6. Only age at onset was significantly associated with the time from EDSS 4 to EDSS 6.

In conclusion, age at disease onset is the most important predictor of disability accumulation in PPMS. Bilateral motor onset symptoms also were associated with quicker disease progression.

The above paper demonstrates that the prognosis for PPMS is poor and that age at disease onset is the most important risk factor predicting outcome. More than 50% of patients with PPMS need a walking stick within 10 years of disease onset. Treatments are urgently needed to prevent or delay the rapid disease progression in these patients. Age predicting disease progression is now a common theme in MS and needs future research attention.

References:

1. Koch MW, Greenfield J, Javizian O, et al. The natural history of early versus late disability accumulation in primary progressive MS. J Neurol Neurosurg Psychiatry. 2014 Aug 4. pii: jnnp-2014-307948. doi: 10.1136/jnnp-2014-307948.