Alexithymia in radiologically isolated syndrome

Alexithymia refers to difficulty identifying (DIF) and describing (DDF) feelings and externally oriented thinking (EOT). Its prevalence remains unknown in the radiologically isolated syndrome (RIS), the preclinical multiple sclerosis (MS) phase.

Alexithymia was measured with the Toronto Alexithymia Scale (TAS-20) in 29 RIS and age and gender-matched healthy controls and relapsing-remitting (RR) MS with an EDSS <3. All participants completed evaluations of cognition (BCCOG-SEP), depression (Fast-BDI), fatigue (EMIF), and quality of life (SEP-59).

The level of alexithymia was significantly different between the three groups, with the higher score in the RRMS group (mean score of 54.5, SD: 12,3) compared to RIS (mean score of 47.2, SD: 14.8) and in healthy controls (mean score of 41.9, SD:12.8). 34 % of RIS participants showed a pathological level of alexithymia. The proportions were 21.7 % in the healthy controls and 51.7 % in the RRMS-matched groups. The difference was mainly significant for the DIF factor, p<.001. No significant correlations were observed between alexithymia and the different measures of cognition. In the RIS group, alexithymia was strongly linked to the levels of depression and cognitive fatigue. Furthermore, alexithymia was related to decreased mental quality of life.

The study revealed that one-third of subjects with radiologically isolated syndrome show signs of alexithymia. Interestingly, no cognitive measure was found to be correlated with the level of alexithymia, which is consistent with previous research findings. Alexithymia and mainly difficulty identifying feelings in RIS are associated with depression but also relate to cognitive fatigue and reduced mental quality of life. This could impact the daily interactions of RIS subjects.