Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system (CNS) characterized by progressive axonal degeneration (Correa et al., 2016; Kuhmann et al., 2002) that affects approximately 2.8 million people worldwide (Walton et al., 2020). MS affects between 11 % and 20 % of the Mexican population (Arrambide et al., 2004; Velazquez et al., 2002). It is more common in women and primarily affects young people between the ages of 20 and 40 years (Aguirre et al., 2011). Individuals with MS exhibit common clinical features, including motor, cognitive and neuropsychiatric problems (Brassington et al., 1998).

Investigations conducted in MS patients have allowed to establish the frequency of cognitive impairment (Chiaravalloti and DeLuca., 2008; Peyser et al., 1990; Rao et al., 1991). Cognitive impairment can be identified in both the early and later stages of MS (Oreja et al., 2019; Ruano et al., 2017) and significantly interferes with various aspects of quality of life, including the ability to work and socialize (Mitchell et al., 2005). Cognitive deficits are present in 43–70 % of patients, representing one of the main features of MS (Ruano et al., 2017). Several studies conducted in this population have demonstrated different cognitive alterations, including impairments in processing speed, attention, memory and learning (including immediate and delayed recall and recognition) and executive function (Benedict et al., 2020; DeLuca et al., 2004; Eijlers et al., 2018; Ferreira., 2010).

Some researchers have recommended clinical tools for assessing cognitive impairment in MS patients (Artemiadis et al., 2021; Benedict et al., 2003, 2006, 2017; Kalb et al., 2018; Matías-Guiu et al., 2020; Morrow et al., 2010; Rao et al., 2017; Rivera et al., 2022; Strober et al., 2019). An expert committee of neurologists and neuropsychologists recommended the Brief International Cognitive Assessment for MS (BICAMS) as an international measure for routinely screening and monitoring cognitive functions in MS patients (Corfield et al., 2018; Langdon et al., 2011). This instrument primarily assesses information processing speed, verbal memory and visual memory (Langdon et al., 2012) and has been validated and standardized in many countries (Betscher et al., 2021; Darwish et al., 2022; Filser et al., 2018; Maubeuge et al., 2021; O´Connell et al., 2015; Orchard et al., 2013; Potticary et al., 2023; Sousa et al., 2018; Spedo et al., 2015; Walker et al., 2016). In Latin America (LATAM), the BICAMS has only been validated for Brazilian, Argentinian and Colombian populations (Alarcon et al., 2020; Spedo et al., 2015; Vanotti et al., 2016). In Mexico, there have been no validity studies of the BICAMS. Therefore, the objective of this study was to validate and assess the reliability of the BICAMS in a Mexican population with MS and provide regression-based norms.