Motor impairments at presentation of clinically isolated syndrome suggestive of multiple sclerosis: Characterization of different disease subtypes

Objectives: To evaluate the frequency of motor impairments in patients with recently diagnosed clinically isolated syndrome (CIS) suggestive of MS. Methods: Following a neurological examination, patients with CIS were subdivided into two groups according to the number of functional systems involved at onset. Groups consisted of monosymptomatic (n=35, mean EDSS=1. 3 ± 0. 2) and polysymptomatic (n=17, mean EDSS=2. 6 ± 0. 1) patients. Motor assessment included peak isometric torque and fatigue index (FI) measured at the knee and ankle bilaterally and spatiotemporal parameters of gait and postural control. Lesion load and atrophy were measured on a 3. 0T brain MRI using MSAnalyze computerized software. Twenty eight age- and gender-matched healthy subjects served as controls for motor assessment. Results: Polysymptomatic patients demonstrated reduced peak strength and FI, slower gait velocity, narrower base of support and increased sway rate compared to healthy subjects and mono-symptomatic patients. Furthermore, polysymptomatic and monosymptomatic patient median score in T2-weighted volume lesions (mm^{3}) was 4875 and 1628, respectively. Conclusions: Evidence of two subtypes of CIS was established in context with MRI findings and motor deficits. Differentiating between these groups can potentially improve management of MS patients at the initial stages of the disease process.