Disability progression in aggressive multiple sclerosis.
OBJECTIVE
To examine disease progression in 'aggressive' multiple sclerosis (MS), British Columbia, Canada (1980-2009).


METHODS
Aggressive (or 'malignant') MS was defined as Expanded Disability Status Scale (EDSS) ⩾6 within 5 years from onset. The first EDSS ⩾6 was termed 'baseline'. Within 2, 3 and 5 years post-baseline, patients were categorized as follows: 'worsened' or 'improved', relative to baseline EDSS (the remainder exhibited no change or had no new scores). The associations between patient characteristics (sex, relapsing onset/primary progressive, onset age, onset symptoms, disease duration, cumulative prior relapses and baseline EDSS) and worsening in disability were examined longitudinally using logistic regression.


RESULTS
Of the 225/4341 (5.2%) aggressive/malignant MS patients, 134 (59.6%) were female, 167 (74.2%) were relapsing onset, 94 (41.8%) had received disease-modifying drugs at some point and the mean follow-up was 8.7 years. The proportion of patients who 'worsened' increased from 40.4% to 57.8%, while those who 'improved' varied little (range, 8.9%-10.2%). The odds of worsening increased with disease duration (adjusted odds ratio (AOR) = 1.36; 95% confidence interval (CI) = 1.22-1.52) and the presence of primary progressive (vs relapsing-onset) MS (AOR = 1.85; 95% CI = 1.01-3.38).


CONCLUSIONS
Apart from disease duration and a primary progressive course, no clinically useful associations of subsequent disease worsening in patients with aggressive/malignant MS were identified.
Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada/Division of Neurology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
Suresh
S
Menon
Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
Feng
F
Zhu
Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
Afsaneh
A
Shirani
Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
Joel
J
Oger
The Ottawa Hospital Research Institute and University of Ottawa, Ottawa, ON, Canada.
Mark S
MS
Freedman
Division of Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
Helen
H
Tremlett
D000328:Adult; D001955:British Columbia; D015331:Cohort Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000503:physiopathology*; D012008:Recurrence
Multiple sclerosis; epidemiology; neuroepidemiology