Cognitive changes in early MS: a call for a common framework.

Cognitive dysfunction is among the main symptoms of multiple sclerosis (MS) and adversely affects patients' quality of life. The occurrence of cognitive impairment early in the disease process raises crucial issues related to definition of the impairment and its magnitude as well as to the tools applied to the assessment. To date there is little evidence concerning the reliability and validity of cognitive measures in early MS and their predictive long-term role. As MS is a complex disease, multidimensional approaches should be further developed and validated to study the cognitive sphere in the early stages of the disease. Considering that none of the available tests performed in isolation is able to provide a complete picture of the cognitive impairment in early MS, this calls for the definition of phase duration, impairment and tools appropriate for use by clinicians and researches. The present review proposes a framework aimed to help neurologists in approaching cognitive impairment in early MS and stimulate discussions and evaluations of the suggested recommendations.