New Criteria Aids In Multiple Sclerosis Diagnosis
From Single Clinical Episode of Demyelination
A DGReview of :"Application
of the new McDonald criteria to patients with clinically isolated syndromes
suggestive of multiple sclerosis"
Annals of Neurology
By Veronica Rose
Patients presenting with single clinical episodes of demyelination can now be
positively diagnosed with multiple sclerosis earlier due to new criteria.
This finding was presented in 2001 by the newly formed International Panel of
MS Diagnosis, a team of experts headed by Professor Ian MacDonald.
Previously, diagnosis had proved impossible for those identified with these
clinically isolated syndromes. Using the new criteria has resulted in more
than doubling the diagnostic rate within a year.
The new criteria integrates magnetic resonance imaging with clinical
diagnostic methods. It also facilitates the diagnosis of MS in patients who
present with signs and symptoms suggestive of the disease. These include
monosymptomatic disease, disease with a typical relapsing-remitting course or
insidious progression but no clear attacks and remissions.
Neurologists at the Institute of Neurology in Queen Square, London, England,
undertook an evaluation of the application of the new criteria. They
established the frequency of developing MS from clinical and MRI examinations
which were prospectively performed at baseline, then at follow -up periods of
three months, one, and three years. The frequency was also determined by
applying the new McDonald and the Poser criteria for clinically definite MS.
Researchers then assessed the specificity, sensitivity, positive and negative
predictive value, and accuracy of the new criteria for a clinically positive
diagnosis. They established that 20 of 95 patients were confirmed MS using the
McDonald criteria, but only seven from 95 had developed clinically definite MS
at three months.
A year later the corresponding figures were 38 from 79 (48 percent) and 16 of
79 (20 percent). After three years the figures were 29/ 50 (58 percent)and 19
from 50 (38 percent).
Neurologists concluded that the development of MS using the new MRI criteria
offered a high sensitivity (83 percent) specificity (83 percent), positive
predictive value (75 percent), negative predictive value (89 percent) and
accuracy (83 percent) after a year for clinically definite MS at three years