Leukoaraiosis is a change in brain white matter with characteristic manifestation in MR and CT head scans. Common leukoaraiosis risk factors include aging and arterial hypertension. A quarter of symptomatic ischemic infarcts belongs to small blood vessel disease group and could be presented as lacunar infarcts. These two crucial pathophysiological mechanisms are in the root of cognitive dysfunction related to small blood vessel disease. 60 lacunar infarct patients were examined and parameters for groups with and without leukoaraiosis were determined. It was found that leukoaraiosis incidence was highest in the group of women older than 70. Neurological assessment was scored on NIH-NINDS scale, functional status was scored with Barthelo index, and cognitive status was determined using Mini Mental State Examination (MMSE) and Alzheimer Disease Assessment Scale Late (ADAS-L). Correlation analysis of these parameters on significance level of *p<0.05, **p<0.01, suggests decrease in neurological status and cognitive performance.

One of the best-studied responses of cognitive evoked potentials is a so-called “P300”, the late positive wave complex that occurs about 300-500 ms after the stimulus. It is obtained when the subject’s attention is focused on a signal that is rare, especially if the signal has a motivational or emotional meaning. In the study of P300 potential, we followed the variations of potential amplitude and latency, so the objective was to examine whether there is a difference in Fz and Cz amplitudes of auditory induced cognitive evoked P300 potential depending on the performance of oddball tasks, both in male and female subjects. The study included 60 subjects (30 female respondents and 30 male respondents). P300 potential is induced by the auditory "oddball" paradigm with 80% of non-target and 20% of target stimuli that are presented to the patient through headphones. The target tones are high tones of 2000 Hz. The standard, 1000 Hz tones the respondent should ignore but when he hears the target tones the respondent should press the button on the special handle. The value of Fz and Cz amplitudes both in male and female subjects obtained in the classical "oddball" paradigm when the subject reacted to the signal by pressing the key with the dominant (right) arm were statistically significantly lower (p>0,05) than the values of Fz and Cz amplitudes obtained when the key was pressed by the non-dominant hand. Based on this experiment it can be concluded that both in male and female subjects the performance of oddball tasks does not affect the amplitude of P300 cognitive evoked potentials.