International audienceCognitive impairment is frequent in patients with multiple sclerosis (PwMS). The cognitive deficits could worsen along the disease contributing to significant disability taking into account some heterogeneity among PwMS. However, the possibility of acute cognitive change has been reported during relapse, which includes physical symptoms, with full or partial recovery. 1-3 Besides, the concept proposed by Pardini et al. 4 relating to 'Isolated Cognitive Relapses' (ICRs)-with no physical worsening-based on a transient decrease of the Symbol Digit Modalities Test (SDMT) in PwMS is debated. The SDMT assessing mainly information processing speed has been well validated in MS, and its clinically meaningful change has been proposed based on ecological endpoint. 5 Nevertheless, Pardini et al. 4 acknowledged some limitations concerning the choice of this definition of ICRs only based on one neuropsychological (NP) assessment. They underlined that ICRs were not self-identified, but they highlighted the value of informant versions of the Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ). 6 Interestingly, Pardini et al. 4 also supported the clinical relevance of ICRs due to their association with cognitive daily functioning and further cognitive decline in PwMS
