Do motor impairments detected on onset of multiple sclerosis suggest an early second attack? A prospective study

BACKGROUND: Factors determining the clinically isolated syndrome (CIS) patient's likelihood of developing multiple sclerosis (MS) are important for the clinician who needs to identify patients warranting immunomodulatory treatments. OBJECTIVE: To determine whether motor abnormalities found during the initial demyelinating event imply an increased risk of a second event within the first year. METHODS: Fifty-two early onset CIS patients, volunteered to participate in the prospective study. Motor parameters collected at onset included gait, balance, lower limb peak isometric strength and fatigue index parameters. At the end of one year, patients were subdivided into two groups, those who had experienced a second demyelinating attack suggestive of MS and those who maintained their clinical status. RESULTS: Forty-nine patients were included in the final analysis. Within the first year, 24 patients experienced a second attack, while 25 maintained their neurological status. Patients who suffered a second demyelinating attack, demonstrated reduced overall lower limb peak strength compared with patients who maintained their clinical status (411.9 (S.E. = 32.1) vs. 514.8 (S.E. = 34.1). No differences were observed between groups in gait and balance parameters. CONCLUSION: An initial demyelinating event characterized by reduced lower limb strength can possibly suggest an increased risk of an early second attack.