Pattern of spread and prognosis in lower limb-onset ALS

Abstract

Our objective was to establish the pattern of spread in lower limb-onset ALS (contra- versus ipsi-lateral) and its contribution to prognosis within a multivariate model. Pattern of spread was established in 109 sporadic ALS patients with lower limb-onset, prospectively recorded in Oxford and Sheffield tertiary clinics from 2001 to 2008. Survival analysis was by univariate Kaplan-Meier log-rank and multivariate Cox proportional hazards. Variables studied were time to next limb progression, site of next progression, age at symptom onset, gender, diagnostic latency and use of riluzole. Initial progression was either to the contralateral leg (76%) or ipsilateral arm (24%). Factors independently affecting survival were time to next limb progression, age at symptom onset, and diagnostic latency. Time to progression as a prognostic factor was independent of initial direction of spread. In a regression analysis of the deceased, overall survival from symptom onset approximated to two years plus the time interval for initial spread. In conclusion, rate of progression in lower limb-onset ALS is not influenced by whether initial spread is to the contralateral limb or ipsilateral arm. The time interval to this initial spread is a powerful factor in predicting overall survival, and could be used to facilitate decision-making and effective care planning.

Key words::

• Epidemiology
• prognostic
• survival

Acknowledgements

We would like to thank all the staff of the Oxford and Sheffield MND Care and Research Centres (who both receive funding from the UK MND Association), for their ongoing work in the care of ALS patients. MRT is supported by the MRC/MNDA Lady Edith Wolfson Clinician Scientist Fellowship, and AB is supported by an NIHR Clinical Training Lectureship.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.