October 22, 2007 (Prague) — The majority of patients
diagnosed with benign multiple sclerosis (MS), based on an
Expanded Disability Status Scale (EDSS) score of 3 or less
after a disease duration of 10 years, continue to progress
after an additional 20 years, according to a new long-term
study.
The study also found, however, that these patients tend to
live significantly longer than those diagnosed with more
serious forms of the disease.
The study was presented here by lead author Lisa Costelloe,
MD, from St. Vincent’s University Hospital in Dublin, Ireland,
at the 23rd Congress of the European Committee for the
Treatment and Research in Multiple Sclerosis (ECTRIMS).
Follow-Up of 21 Years
The study enrolled 436 patients diagnosed with possible MS,
including 53 benign patients, in 1985, and their charts were
reviewed 21 years later with regard to outcome. The indicators
of benign MS in the initial 1985 cohort and in the survivors
in 2006 were determined. In addition, the disability of
surviving patients was recorded using the EDSS, and survival
from disease onset was calculated.
The investigators reported that the original diagnosis of
MS turned out to be incorrect in 41 of 397 (10%) patients: 17
(4%) had a clinically isolated syndrome and 24 (6%) had
alternative diagnoses. An analysis of the data also showed
that median survival for the 1985 cohort of 356 MS patients
was 43.6 years from disease onset.
Of the original 53 benign patients, 47 were followed up in
2006 (4 were lost to follow-up and 2 did not have MS). Of the
47 benign cases, 7 remained benign, 18 had died, and 22 had
secondary progressive MS (mean EDSS 7.4).
Median survival for those who were deemed benign in 1985
was significantly better than for those who were not benign at
the time (52.1 vs. 41.6 years; HR 0.47; P = .008). In
2006, 40 of 356 (11%) patients had a benign outcome at a mean
follow-up of 26.1 years. Characteristics significantly
associated with a long-term benign course included female sex,
younger age at disease onset, and absence of motor symptoms at
presentation.
Hospital-Based Sample
"Our study is one of few studies to follow up a large
benign MS cohort over 20 years after they were originally
assessed, in order to determine the long-term outcome of this
MS subtype," Dr. Costelloe told Medscape Neurology &
Neurosurgery. "We have found that with lengthy follow-up,
the majority of our benign MS patients went on to develop
significant disability and, in fact, only 15% of them remained
benign," she added.
"We also found that in patients who have a more benign
course after 10 years of disease, there was a trend toward
longer survival, compared with those who were more progressive
after 10 years," Dr. Costelloe noted. She pointed out that the
following 3 factors at presentation were predictive (albeit
weakly) of a benign course in the long-term: female sex,
younger age at onset of disease, and absence of pyramidal
involvement at presentation.
"There have been few long-term follow-up studies of benign
MS after 20 years, and the research by Dr. Costelloe and
colleagues is a careful, conscientious study," said Stanley A.
Hawkins, MD, a clinical neurologist from Queen’s University in
Belfast, Northern Ireland, who was not associated with the
study. "Perhaps 1 weakness, though, is that the sample was
clinic-based and not population-based," Dr. Hawkins added.
In an interview with Medscape Neurology & Neurosurgery,
Dr. Costelloe acknowledged that the research was
hospital-based and therefore may not have captured some benign
cases who may not be admitted to the hospital. However, she
stressed, "It is hospital-based MS patients whom we
as clinicians deal with on a daily basis, and as such it is
useful data to apply to the patient group we diagnose and care
for in the long-term."
23rd Congress of the European Committee for the Treatment
and Research in Multiple Sclerosis: Parallel session 7 (85).
Presented October 13, 2007.
