Subtle Upper Limb Impairment in Radiological Isolated Syndrome Subjects

Objective: Spatial dissemination of focal white matter brain lesions, highly suggestive of multiple sclerosis (MS) in subjects without clinical neurological symptoms, is referred to as radiological isolated syndrome (RIS). The aim of this study was to demonstrate that kinematic parameters are able to measure motor performance and to identify subtle symptoms undetectable with the clinical examination. Methods: We investigated the clinical, kinematic motor performance in 6 subjects following conventional brain MRI (1.5-T). Subjects had a negative neurological examination and fulfilled the diagnostic criteria for RIS proposed by Okuda. Results: Subjects were 4 females and 2 males with a mean age of 39.5 years. 2 subjects performed all kinematic parameters in the range of HC/M, 1 subject resulted with one parameter above the range of HC/M group, 3 subjects had more than 2 kinematic parameters above the range of HC/M. The mean nine-hole peg test (9HPT) score was 18 seconds ± 1. 2 subjects had spinal cervical cord lesions and oligoclonal bands were detected in other 2 patients. VEP were negative in all subjects. No case showed dissemination in time (no new T2 lesions at the 6 month MRI). Of the kinematic parameters used, the integral of the norm of the third derivative-jerk-of the hand path was the most sensitive parameter (four of six subjects), Remarkably the technique appears to be able to detect subtle differences between some subjects with RIS and control subjects. Conclusion: We believe that this type of instrumental assessment can help in identifying subjects with RIS with a high risk for developing MS.