Correlated Anatomy And Comparative Study Of Treatment For Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a sort of recurrent paroxysmal transient megalgia on the face of the trigeminal nerves areal area. According to our national statistics, the incidence rate of TN is 1.82‰, and it is the most common neuropathic disease. TN usually falls ill after the middle age. The incidence rate of female is higher than that of male. The pain usually located in the single lateral, the right is more than the left, and the bilaterality pain is little. The pain usually appears on the branch II III of the trigeminal nerves, and little on the branch I . In the clinic, TN is divided to primary trigeminal neuralgia and secondary trigeminal neuralgia. The secondary TN is usually caused by some parenchymal diseases of encroaching on the root of trigeminal nerve. The primary trigeminal neuralgia does not present neurologic sign, and with no apparente structural disease or functional disease by various kinds of imaging examination.Facial pain is the most outstanding clinical manifestation of the primary trigeminal neuragia. Facial pain often suddenly attacks absence of aura, as if lance, cauterization, acupuncture or lightning stroke, and lasting 1-2 min suddenly to stop. Between the two attacks , facial sense is normal without pain, and natural intermission may last several months or even several years. Along with prolongation of course, seizure frequency of facial pain may increase, degree of facial pain may aggravate, and nature intermission may shorten so that facial pain last from morning till night. More than half patients may have the painful trigger point that causes facial pain to break out if it is touched lightly. It is usually located at upper lip, ala nasi, angle oris, cuspid teeth, palate, and buccal mucosa. In addition, facial mechanical stimulation such as talking, eating, facewashing, toothbrushing, or windblown may cause facial pain. Some simultaneous phenomena such as dacryorrhea, dribble and facial vellicate may appear when facial pain breaks out.The pathogenesy of trigeminal neuralgia is unknown.There are several hypotheses, but still lack of a hypothesis to explain all the symptoms of trigeminal neuralgia integratedly.According to the recent research, multiple factors instead of single factor participate to the disease. Hypothesis about pathogenesy includes central mechanism and peripheral mechanism,and there is evidence manifesting immunity and biochemistry mechanism are associated with trigeminal neuralgia.There are many kinds of treatment methods for the primary trigeminal neuralgia. Drugs therapy is the treatment to be chosen first. Up to date, carbamazepine is the most widespread application and the most effective drug. But many patients taken this drug may have acquired pharmacal tolerance. Operation treatment have many kinds, for instance ethanol or butanol injecting trigeminal ganglion, glycerine injecting trigeminal cistern, peripheral neurotomy, percutaneous radiofrequency thermocoaglation(PRFT), microvascular decompression(MVD), radicotomy, percutaneous microballoon compression(PMC), Stereotactic radiosurgy Gamma knife (GK). Radicotomy may cure TN thoroughly, but partial facial anaesthesia may followed and complications are serious. MVD has already performed for several decades. It can relief pain, but the trauma is larger. PRFT has good early curative effects, but it's recurrence rate is high. Second therapy is still effective for recurrent patients. PMC is a new operative method with microinvasion in our country. It can keep physiological structure integrality of trigeminal nerves, with no nervers damage,and can keep normal facial senses. Stereotaxic radiosurgery gamma knife is an effective treatment for TN for several years. Although it has higher recurrence rate, it also has high curative rate, with mild trauma, and it can be performed repeatedly.This study,began with the anatomy research, investigated anatomical factors associated with trigeminal nerve. Meanwhile, this study investigated four clinical treatment methods for TN according to the effectiveness,,in order to provide theoretical guidance for clinical practice.In the anatomy parts, this study investigated the relationship between trigeminal nerve and peripheral vessels by dissectting the root of trigeminal nerve and acroteric structure. Bilateral roots of trigeminal nerve of 10 adult normal head samples were dissectted ecto-entad under the operating microscope. To observehe Meckel cavity, the relation between the root of trigeminal nerve and the peripheral blood vessels, and to observe the shape of foramen ovale and to measure its correlated anatomy data. The study manifested the closed relationship and multiformity between the root of trigeminal nerve and peripheral vessels including the superior cerebellar artery (SCA), anterior inferior cerebellar artery (AICA),and the petrosal vein(PV).The study suggested that the operator should explore strictly during the microvascular decompression operation and to avoid the omission of offending vessel. (2)Foramen ovale is much varied in different individual,the acupuncture should be guided by imagingtechnology to increase accuracy and to decrease complication.In the clinical parts, this study estimated the current therapeutical methods forthe primary trigeminal neuralgia,including PMC,PRFT,GK,and MVD for elder TN,from therapeutical method, effectiveness,recurrence rate and complications. The results showed that PMC is the simple and effective treatment for TN,especially for patients involved in branch I and branch I+II. PRFT showed good early therapeutic effects, and X-ray and 3D-CT location can increase the accuracy of foramen oval puncture and decrease complication. It had high academic value and can be popularized in clinical practice. GK is an effective and safety therapeutic method with potential advantage.. MVD can be performed for the elder TN patients under strict monitore and the operation style depended on the exploration results during operations.Conclusion: (1)The root of trigeminal nerve is related closely to the peripheral vessels, the operator should explore strictly during the microvascular decompression operation to avoid the omission of offending vessel. (2)Foramen ovale is much varied in different individual,the puncture should be guided by imaging technology to increase accuracy and to decrease complication.(3)All the four therapeutical methods showed good effects on the treatment for TN. PMC is more effective than PRFT and GK for TN involved in branch Land branch I+II. PRFT had good early effect with slight adverse effect. MVD can be performed on elder TN under strict monitored,and the therapeutic effect is confirmed. GK is an effective and safety therapeutic methodwith potential advantage for TN.