TORONTO—Severe onset, involvement of more than two functional systems, and polylesional presentation predict poor recovery from an initial demyelinating event, according to researchers at the University of California, San Francisco (UCSF), who asserted that these predictors may represent targets “for earlier and more aggressive therapies.” The investigators reported their findings at the 129th Annual Meeting of the American Neurological Association.

DOES SEVERITY PREDICT RECOVERY?

Polylesional presentation could characterize as many as 21% to 32% of initial demyelinating events; these patients may not recover well and could have earlier ambulatory limitations, related Timothy West, BS, lead author of the UCSF study. With the exception of patients with optic neuritis, recovery after an initial demyelinating event is relatively unknown. Among patients with optic neuritis, 80% of those with mild presentation experience complete recovery within six months, while only 33% of patients who present with severe optic neuritis have complete recovery in that period. This association led Mr. West and colleagues to hypothesize that the severity of an initial demyelinating event is predictive of recovery.

The investigators analyzed a cohort of 163 patients with multiple sclerosis (MS) (110 women) at the UCSF MS Center. The mean age at onset for the cohort was 34 years; 130 patients were white, 12 were African-American, nine were Hispanic, eight were Asian, and four were of unreported ethnicity. Onset location of the initial demyelinating event was the spinal cord for 43% of patients, the brain stem/ cerebellum for 28% of patients, the optic nerve for 16% of patients, and polylesional for 13% of patients.

THREE PREDICTORS OF POOR OUTCOME

Initial demyelinating event severity was scored at the first clinical visit within one month of onset or was extrapolated from hospital discharge summaries and other sources for patients whose first visit was outside of UCSF, the investigators said. Recovery was defined as the lowest Expanded Disability Status Scale score from two to 12 months after onset. Across the cohort, 48% of patients had moderate severity of onset, 39% had mild severity, and 13% had severe onset; severity was similar across age, gender, and ethnicity. Fifty-four percent of onsets were monolesional; 14% of presentations were polylesional, Mr. West noted. Complete recovery was reported in 36% of patients, fair recovery in 41%, and poor recovery in 23%; recovery was also similar across age, gender, and ethnicity.

After statistical analysis, Mr. West and colleagues reported that “onset severity predicts initial demyelinating event recovery. In our cohort, patients with a mild onset were 12 times more likely to completely recover than those with severe onset.” Mild:severe onset also had an odds ratio of 6.2 for fair:poor recovery, while mild:moderate onset had an odds ratio of 9.5 for complete:poor recovery and an odds ratio of 4.2 for fair:poor recovery.

In addition, more than 60% of patients with a polylesional onset had a poor prognosis for recovery (patients with polylesional presentation were four times less likely to recover than those with monolesional presentation). Polylesional presentation was also predictive of poor recovery; as the number of functional systems affected increased, the likelihood of a poor recovery from an initial demyelinating event also increased. That finding was unique to the UCSF study, Mr. West noted. The investigators plan to analyze these predictors as they relate to time of a second event and disability at year 2 and to investigate genetic factors that may play a role in predicting recovery.

NR

—C. Justin Romano

Suggested Reading
Hickman SJ, Toosy AT, Miszkiel KA, et al. Visual recovery following acute optic neuritis: a clinical, electrophysiological and magnetic resonance imaging study. J Neurol. 2004;251:996-1005.

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