A Study Of Brain Stem Trigeminal Evoked Potentials In Patients With Primary Trigeminal Neuralgia

Objective To establish and optimize the clinical detection method of trigeminal nerve evoked potentials and the normal reference value of BTEP,and to evaluate the changes of BTEP in patients with primary trigeminal neuralgia and its relationship with microvascular decompression and complications Correlation.Methods A total of 80 patients having the brainstem trigeminal evoked potentials monitored at Lanzhou University Second Hospital from December 2015 to March 2017,of which 25 cases accompanied with primary trigeminal neuralgia(PTN),50 patients with hemifacial spasm(HFS)and 5 cases with glossopharyngeal pain(GPN).First of all,51 patients with HFS and 4 patients with GPN were divided into the navigation group(30 cases)and freehand group(25 cases).The supraorbital nerve,infraorbital nerve and mental nerve were stimulated respectively,and the drawing rate of BTEP of two way of puncture methods were detected and compared.Both groups were separately measured about the BTEP rate,and the latency of W1,W2 and W3 and amplitude of W2 and W3 were tested,To establishment the normal reference value.Then 25 patients with PTN underwent microvascular decompression were recorded and compared with the BTEP indexes before and after operation,and the clinical evaluation was carried out.Results The incidence of BTEP in the supraorbital nerve was low(50% vs 18%)in the navigation group and the freehand,but the rate of lead in the navigation group was significantly higher(?2 = 12.20,P <0.05),and the positive rate of BTEP in the infraorbital nerve was higher(96.7% vs 88%),and the application of navigation leads to the trend rate of increase,but there were no statistically significant(2=3.04,P>0.05),lower rate of BTEP leads to stimulation of mental nerve after(16.7% vs 8%),even after the application of navigation hasn't been improved(?2=1.84,P>0.05).Study on 25 cases of PTN showed trigeminal neuralgia patients before BTEP W2 and W3 showed prolonged latency and(or)waveform disappear,BTEP and contralateral had significant difference(P>0.05),with the change of BTEP after the symptoms of the patients,23 patients can recover the trigeminal nerve conduction function after operation.The symptom of pain disappeared after surgery,no facial numbness,2 cases of patients with postoperative W2 and W3 waveform did not recover,although postoperative facial pain symptoms disappeared,but the emergence of facial numbness.Conclusions Stimulate the infraorbital nerve,stimulus intensity in the 1mA ~ 5 mA,the drawing rate is high,and the waveform is stable.BTEP normal reference value can be established for Primary trigeminal neuralgia diagnosis;MVD after BTEP W2,W3 wave significantly improved to support the vascular compression caused by the theory of trigeminal neuralgia;BTEP help determine whether the trigeminal nerve conduction function abnormalities,Can be used to guide the operation to avoid nerve damage,assess the decompression is sufficient,while the prognosis can be evaluated.