Tentative Study On The Effect Of Contact Heat Evoked Potentials On The Function Of Spinothalamic Tract Of Patients With Thalamic Infarction

Objectives:Thalamic infarction is one of the common diseases encountered by department of neurology clinically.Although the imaging examinations as MRI can shows a precise localization diagnosis related to anatomy,they are unable to carry out a quantitative analysis on the function of spinothalamic tract of patients.By using the stimulator whose temperature can be elevated rapidly within a certain range to stimulate the nociceptor of skin,the contact heat evoked potentials(CHEPs)is able to selectively identify and stimulate the nociceptive sensory transmission function of thinly-myelinated sheath A? fiber and unmyelinated C fiber,which is an objective,relatively new and non-invasive method of examining the algesia disorder and the function of spinothalamic tract.This paper applied the technical study on CHEPs to evaluate the function of spinothalamic tract of Nociceptive afferent pathway of patients with thalamic infarction,exploring the application of CHEPs detectiontechnique and A ? fiber conduction velocity in thalamic infarction,providing a reference for the electrophysiological diagnosis of thalamic infarction.Methods:A total of 55 cases of subject admitted in China-Japan Fellowship Hospital from Jan,2014 to Dec,2016 had been collected in accordance with the following inclusion and exclusion criteria,among them there were 24 cases of pure thalamic infarction,9 cases of thalamic infarction complicated with diabetes,12 cases of pure diabetes and 10 cases of normal control that were free of thalamic infarction and diabetes.The CHEP stimulator was used to carry out a heat-pain stimulation to the skin of palm-lateral proximal end at 1/3 of forearm of upper extremities,the cervical C7 spinous process,the T12 spinous process of thoracic vertebra and shank with a constant stimulative temperature of 54.5?,after 3-5seconds of stimulation,the stimulus intensity of subjects was graded(grade 1-10)in accordance with visual analogue scale(VAS).The recording location point of CHEPs was Fz,Cz and Pz,where the latent period of CHEPs was recorded,and the A?fiber conduction velocity was calculated.Meanwhile,the included patients were measured in terms of SCV and MCV,and the patient information like age,height and weight was recorded,of which the result was compared and analyzed with CHEPs.Results:1.CHEPs waveform can be elicited steadily,and the difference of CHEPs abnormal rate among different groups has statistical significance(P<0.05).The different groups of C7 has no statistical significance(P>0.05).2.The difference of CHEPs latency stage among different groups has statistical significance: DM group,thalamic lesions + DM group,the thalamic infarction group,in the inside of the forearm or tibial anterior lateral is extended,the difference has statistical significance(P < 0.05).The difference among thalamic infarction group,CHEPs latency stage and thalamic infarction on patients with compared with the lateral thalamus infarction has no statistical significance(P>0.05).3.The conduction velocity of spinal segments and peripheral nerve about A? fiber on the DM group,thalamic lesions + DM group,has no statistical significance(P>0.05).4.The CHEPs abnormal rate of the DM group is significantly greater than the MCV group,the difference has statistical significance(P<0.05).The difference of among different MCV groups has statistical significance: the median nerve amplitude,the tibial nerve conduction speed,and the tibialnerve amplitude of DM group,thalamic lesions + DM group,and the normal group is lower or slower,the difference has statistical significance(P<0.05),the comparative difference of the thalamus infarction group and the normal group has no statistical significance(P>0.05).5.The VAS difference before treatment among different groups has statistical significance: the VAS of the thalamic infarction group,thalamic lesions + DM group,and DM group before treatment is lower than normal group,the difference has statistical significance(P<0.05).The VAS difference after treatment among different groups has statistical significance(P>0.05).The change of VAS before and after treatment of the patients with normal CHEPs waveform is more prominent than the patients with abnormal CHEPs waveform,the difference has statistical significance(P<0.05).Conclusion:1.The function of spinothalamic tract of Nociceptive afferent pathway is involved by thalamic diseases,but spinal segment and peripheral segment of nociceptive afferent pathway are not involved,the central segment is involved.2.Fixed-point(internal lateral forearm,anterior external lateral shank)CHEPs measurement contributes to the judgment of damage to function of spinothalamic tract.3.CHEPs can serve as an objective indicator for sensory disturbance,which contributes to the identification and judgment of thalamic disease and local nervous disease and to the discovery of subclinical lesion.4.The effect of early treatment to the thalamus infarction patients is evidently related to the abnormal rate of CHEPs,the patients who have a generally normal CHEPs waveform are less pain pathway injury,as well as a better Treatment effect.