An Investigation of the Difference in Reaction Time to Visual and Auditory Stimuli in Two Groups of Patients with Multiple Sclerosis and Healthy People

Multiple sclerosis (MS), is an inflammatory chronic disease of the central nervous system, usually starting in the most productive years of the patient’s life, and its cognitive consequence may affect on patient’s behavior, social functions, daily life, and occupation. One of the most important cognitive variables, which may be affected through MS, is reaction time. The aim of this study was to investigate the reaction time of patients with MS (SPMS and RRMS types) toward visual and auditory stimuli.

The study design was a retrospective, causal-comparative type, in which the sample was selected through an accessible and purposive sampling method from the patients who were referred to the MS center and MS institute of Isfahan, Iran. The control group was selected from the healthy patient’s family members or their relatives. A total of 159 subjects participated in this study, each group consisted of 53 subjects. The reaction time of the three groups toward the visual and auditory stimuli was measured. The instruments comprised a reaction timer and a multiple sclerosis impact scale.

The results showed that the reaction time in the patients was significantly slower than in healthy people. Furthermore, it was revealed that patients with SPMS type were slower in reaction time in comparison to RRMS patients.

The speed of information processing in patients with MS, has become slower, due to the slowing of the conduction through nerve pulses, which is due to demyelination in damaged pathways. The decrease in processing speed may lead to an inability of the patients to accomplish mental and cognitive tasks, and this deficit is finally depicted in the inability of MS patients in responding to visual and auditory stimuli.