Asymmetry of magnetic motor evoked potentials recorded in calf muscles of the dominant and non-dominant lower extremity.
The aim of the study was to determine the applicability of magnetic stimulation and magnetic motor evoked potentials (MEPs) in motor asymmetry studies by obtaining quantitative and qualitative measures of efferent activity during low intensity magnetic stimulation of the dominant and non-dominant lower extremities. Magnetic stimulation of the tibial nerve in the popliteal fossa was performed in 10 healthy male right-handed and right-footed young adults. Responses were recorded from the lateral head of the gastrocnemius muscles of the right and left lower extremities. Response characteristics (duration, onset latency, amplitude) were analyzed in relation to the functional dominance of the limbs and in relation to the direction of the current in the magnetic coil by use of the Wilcoxon pair sequence test. The CCW direction of coil current was related to reduced amplitudes of recorded MEPs. Greater amplitudes of evoked potentials were recorded in the non-dominant extremity, both in the CW and CCW coil current directions, with the statistical significance of this effect (p=0.005). No differences in duration of response were found in the CW current direction, while in CCW the time of the left-side response was prolonged (p=0.01). In the non-dominant extremity longer onset latencies were recorded in both current directions, but only for the CW direction the side asymmetries showed a statistical significance of p=0.005. In the dominant extremity the stimulation correlated with stronger paresthesias, especially using the CCW direction of coil current. The results indicate that low intensity magnetic stimulation may be useful in quantitative and qualitative research into the motor asymmetry.
Department of Theory and Methodology of Physical Education, Academy of Physical Education, ul. Mikolowska 72a, 40-058 Katowice, Silesia, Poland. d.olex@awf.katowice.pl
Dorota
D
Olex-Zarychta
Robert
R
Koprowski
Grzegorz
G
Sobota
Zygmunt
Z
Wróbel
D004576:Electromyography; D019054:Evoked Potentials, Motor; D007839:Functional Laterality; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology; D013997:Time Factors; D004561:Transcutaneous Electric Nerve Stimulation; D055815:Young Adult