The Comparative Research Of Treating Classic And Atypical Trigeminal Neuralgia With Microvascular Decompression

Since microvascular compression is the international consebsus of it's importance in the etiology of trigeminal neuralgia(TN), micorvascular decompression(MVD) is now the most prevailing treatment of TN. In this operation, retrosigmoid approach is the common way and the key step is exposing the cerebellopontine angle(CPA) and the root entry zone(REZ) of the trigeminal nerve. In order to reducing the complications of MVD, no tractive operating technique is necessarily emphasized during operation. Comparing with the traditional operative microscope, neuroendoscope has superiority in drilling the bone, protecting the cerebellum and producing clearer surgical field of the REZ and its surrodings.Though good effect of microvascular decompression on treating TN has been widely accepted, it's deficient effect on pain relief recurrence sometimes still confused some patients,especially in ones suffering from atypical trigeminal nreuralgia(ATN) other than classic trigeminal neurgalgia(CTN). In fact, basides the efficency of MVD, some other clinical characters between classic trigeminal CTN and ATN are quite different. So, first, to explore the advantages of neuroendoscopein in MVD and second, to explore the difference between the clinicals characters and there correlations to the effects of MVD, we did the mimic operation of them on cadaver heads and did a retrospective analysis of 65 patients with CTN or ATN in the following two parts:PART ONE Endoscopic Anatomy of Cerebellopontine angle through Microvascular DecompressionObjective To observe the difference between neuroendoscope and microscope in mimic operation of MVD and the anatomic characteristics of the REZ of trigeminal nerve and it's surroding structures in CPA.Materials and Methods We simulated the retrosigmoid approach in 3(6sides) adults' cadaveric heads and obsered the trigeminal nerve and other structures arounding it under a 0° neuroendoscope.Results The trigeminal nerve can be observed by neuralendoscope without any injury of nerve and cerebellum when the diameter of the bone hole is about 20 mm. If the diameter less than 20 mm, it is difficult to expose the nerve and have a obvious nerve injury.Conclusions 1.The trigeminal nerve and surrounding structures can be observed clearly under neuroendoscope. 2.It lowers the needs of the head position and the diameter of the bone hole under neuroendoscope, so it can reduce the difficulty of the operation.PART TWO Difference Between Clinical and Atypical Trigeminal Neuralgia in MVD: analysis of 65 casesBackground and Objective Trigeminal neuralgia(TN) is a severe acute paroxysmal pain which involves the distribution of unilateral trigeminal nerve. It is often attack females more than 40 years old. According to the characteristics of pain, the trigeminal neuralgia can be classified as classic trigeminal neuralgia(CTN) and atypical trigeminal neuralgia(ATN).The difference between them is that the former has the trigger point and complete period of remission.To explore the difference between the classic trigeminal neuralgia(CTN) and atypical trigeminal neuralgia(ATN).Materials and Methods We retrospectively analyzed 65 patients diagnosed as trigeminal neuralgia and received microvascular decompression(MVD) in our department from January 2013 to January 2015. Their clinical characters including age, gender, history, severity of pain, sides, history of medicine, the maximum dose of cabamazepine, preoperative findings in MRI images, the length, width, thickness, cross-section area of intra cistern part of the nerve in the plan, parasagittal and coronal scan in FIESTA phase, visible displacement and compression of trigeminus in MRI scanning, intra-operational findings, following result in 1 year were recorded and statistical analyzed.ResultsAll patients had difference of the area and length of trigeminal nerve between the affected and the normal side. If patients were classified as CTN and ATN according to their registered symptoms, they were different in history, history of medicine, deformation of trigeminal nerve, length of trigeminal nerve in cerebellopontine angle cistern, offending arteriosclerosis and operative results(p < 0.05). If they were classified according to their primary symptoms, they had only difference in history and operative results(p<0.05). If they were classified according to the natural history of pain, CTN and TTN were different in history, history of medicine and offending arteriosclerosis.ATN and TTN were different in operative results(p=0.05). Relation of Magnetic Resonance Imaging(MRI) results and operative results revealed that the suspected offend arteries were highly correlated with deformation of trigeminal nerve, intra-operative findings and operative results. In patients with ATN, if MRI results presented deformation of the nerve, the results of MVD also showed optimistic.Conclusions 1.According to our results, we concluded that CTN and ATN are different in history, history of medicine, deformation of trigeminal nerve, offend arteriosclerosis and operative results. 2.Whenever the MRI results of a patients with CTN suggested that arterial compression was exit, MVD is the optimal choice. MVD is a acceptable treatment when a ATN patient has accurate deformation of trigeminal nerve in MRI scanning.