Research Of Late Components P60 Of Motor Evoked Potential

BackgroundThe physiological basis of long lantence reflex,which can be effected by all kinds of physiological and pathological factors,is polysynaptic reflex.Studying long lentence reflex is very importent to research the effection of nervous system disease and physiological factor to nerve function.But util now,we only studyed the late components R2 of blink reflex, research about the long lantence reflex of motor evoked potential was rare.PurposeTo explore the late components P60 of motor evoked potential(MEP) and the possible pathway.MethodsWe collected the cases at the neuroelectrophysilogical room in henan province people's hospital between November of 2008 to November of 2009. Forty-five cases of normal motor evoked potential result, were stimulated motor area cortex, cervical and lumbar vertebrae respectively in relaxation state and contraction state, and were recorded wave on the bilateral upper limbs thenar and wrist extensor. At the same time,in order to explore the possible pathway,Another ten subjects were stimulated deviating from the point of electrical stimulation.Results(1).We can recorde the later components P60 of MEP in the upper limb by stimulating the cortex, cervical and lumbar, which is waveform variability and process variation, the lantency is longer than the contralateral MEP;(2).The occurrence rate of late components P60 is different in different stimulate parts,the late components can be recorded in the cortex ipsilateral and contralateral when stimulating the motor cortex,but the the emergence of ipsilateral cortex was significantly higher than the contralateral cortex;(3).The waveform of late components P60 of MEP is discrete and time-difference large;(4).Compared with the relaxed state,the lantence is shortened and amplitude is increased when the target musle is contract state;(5).The latence increas gradually when stimulate ipsilateral cortex,cervical and lumbar vertebrae;(6).As the deviation from the stimulus-point,the MEP waveform gradually disappeared while the late components still exist. Conclusions(1).Late components P60 of motor evoked potential exists, is a long-term multi-synaptic reflex with repeatability and stability;(2).Late components P60 of motor evoked potential can be recorded commenly in the cortex ipsilateral, The waveform is discrete and has a longer lantency, There is the phenomenon of facilitation.(3). Late components P60 of motor evoked potential is a complete reflex through cortex,the afferent fibre is peripheral sensory fibres and the efferent fibre comes from primary motor cortex,premotor cotex or complement motor cotex.(4).Studying the late components P60 has important effect,through which we can explore the influence of pathological factors(such as central nerve system disease,neurological degenerative disease and so on)and physiological factors(such as anxious,depression and so on) to nerve function.