Cognitive deficits are estimated to appear in 30–70% MS patients. Cognitive deficit is often characterized as slight cognitive dysfunction and is usually leading to loos one's job.

To find out range and rate of the cognitive changes in MS patients and whether complaints are in accordance with objectively found results.

Neuropsychological methods was used for finding out objective changes in the field of cognitive functions, clinical interview was used to assess subjective experiencing. the test group: 35 patients (therefore 25 women), aged 23 – 66.

In patients whose IQ is higher than 100, it has been found out that 16.6% of them have no difficulties related to cognitive functions, 53.33% have executive functions disorder and 25.00% have other disorders. in patients whose IQ is lower than 99, it has been found out that 72.2% of the patients have no complaints related to cognitive functions, 18.8% have executive functions impairment and 9.09% have other impairments. Besides that the coherence between level of IQ and objective findings and/or subjective experiencing was investigated.

The patients whose IQ is higher than 100 feel do not complain (50%); unlike the patients whose IQ is lower than 100, only 25% do not refer to any complaints. Objective findings show the same tendency. Our hypothesis says that the patients whose IQ is higher than 100 have better compensation ability in the range of mild cognitive deficit than the patients whose IQ is lower than 100.