Correlation of the Somatosensory Evoked Cerebral Potentials of Median Nerve Between Healthy and Respondents with Multiple Sclerosis

GOAL: To determine correlation between wavesr amplitudes in SSEP of median nerve, with special focus on waves N19 and P22 of the somatosensory evoked cerebral potentials (SSEP) in healthy individuals and patients with multiple sclerosis (MS). MATERIAL AND METHODS: This research involved 100 respondents divided into two groups: first group (experimental) us consisted of 50 respondents with the verified multiple sclerosis treated at the Neurology Clinic in Sarajevo, second group (control) is consisted of 50 respondents, healthy volunteer. Research is conducted in time period from August 1st 2006 until August 1st 2007. All respondents underwent Somatosensory evoked potentials evaluation of the median nerve. The tested amplitudes were in waves N19 and P22. All values was statistically processed based on percent, crosstabs, mean, standard deviation, standard error of mean, Chi-square test, Student t-test, at the referent significance level of p 0.05. RESULTS: Within baseline there was no statistically significant difference according to gender and age of the respondents from control and experimental group. Mean age in the control group is 35.28 years SD ± 10.49 and in experimental 34.9 years, SD ± 8.57. In group of respondents with MS the amplitude of wave N19 in 88% was in range 0.1-5 μV while in the control group it was 94%. In experimental group 6% of patients had amplitude with values 0.1-1 μV. Shown results indicates statistically significant decrease of N19 wave amplitude in experimental compared to the control group. (X2=6,198, p 0.05). Amplitude of wave P22 for 14% of respondents with MS was 0.1-1 μV, the number of patients with the amplitude 1-5μV in the experimental group was lower by 12% and by 3% smaller number of patients with the amplitude 5-10 μV compared to the control group. Shown results indicated statistically significant difference of decreased values for the P22 wave in experimental compared to the control group. ( X2=109,896 p 0.01). CONCLUSION: In our research values of the cortical waves N19 and P22 amplitudes was significantly decreased among patients with MS compared to healthy respondents. This parameter of measuring evoked response besides prolonged latency can be considered significant as proof of pathological waves in SSEP among patients with multiple sclerosis especially during the acute phase of illness