Objective: The aim of the present study was to investigate the process of understanding social inferences and metaphors and the pragmatic use of language through emotion recognition and social inference tests in patients diagnosed with Primary Progressive Multiple Sclerosis (PPMS) mainly characterized by neurodegeneration. Additionally, we tried to identify a cerebrospinal fluid (CSF) biomarker correlated with the degree and rate of cognitive decline in progressive MS patients.
Method: For the purpose of the present study 25 patients, aged 20 up to 55 years, with PPMS were evaluated. All patients were admitted in the First Department of Neurology, AHEPA Hospital of Thessaloniki. The control group was 30 healthy individuals which participated in the study voluntarily. The groups were matched for age, gender, years of education and intelligence.
Instruments: Social inference was examined with the Awareness of Social Inference Test (TASIT). The TASIT consists of two different parts. The "Tasit Part I: Emotion Evaluation Task (EET - FORM A). The EET is the first part of a broader audiovisual tool designed for the clinical assessment of social perception that is called "The Awareness of Social Inference Test (TASIT)". The second Part of the test TASIT - Social Inference examines the viewer's ability to determine the speaker's meaning and intentions based upon the dialogue, emotional expression, and paralinguistic cues.
Results: The findings indicate that patients with PPMS show decline in emotion recognition and social inference abilities, as compared with the control group. More specifically, PPMS patients have problems to understand the affective state of the others mirroring a specific problem in ToM.
Conclusion: The level of Theory of Mind in the form of sarcasm understanding decreases significantly in MS patients compared with healthy group potentially mirroring impairment in ToM in general. The results indicate that MS group is not resilient to understand metaphoric speech. More specifically, their pathology seems to be able to affect complex ToM abilities.