Nine Hole Peg Test asymmetry in refining upper limb assessment in multiple sclerosis.

•Upper limb function in multiple sclerosis is scored using mean right-left 9-HPT.•Upper limb 9-HPT asymmetry is define as the inter-arm 9-HPT score difference.•Upper limb asymmetry is prevalent in higher disability multiple sclerosis subjects.•Not considering asymmetry in the evaluation of upper limb provide misleading results.•Subjects with same 9-HPTmean show different EDSS depending on upper limb asymmetry.