| Background:Primary trigeminal neuralgia (TN) is also called tic douloureux, which is characterized by stereotyped attacks of paroxysmal pain lasting from a split second up to 2 minutes and located in the distribution. TN incidence is 180/10 Million that is a common disease in middle-aged and aged people in China. The start of TN pain is located in the one side of distribution in V3 or V2, and the pain could spread to two or three branches in the face. With the development of course of the disease in TN that the clinical presentation is typical turn into atypical. This disorder is characterized by episodes of intense facial pain that last from a few seconds to several minutes or hours. The episodes of intense pain may occur paroxysmally. To describe the pain sensation, patients may describe a trigger area on the face so sensitive that touching or even air currents can trigger an episode; however, in many patients the pain is generated spontaneously without any apparent stimulation. It affects lifestyle as it can be triggered by common activities such as eating, talking, shaving and brushing teeth. Wind, high pitched sounds, loud noises such as concerts or crowds, chewing, and talking can aggravate the condition in many patients. The attacks are said by those affected to feel like stabbing electric shocks, burning, pressing, crushing, exploding or shooting pain that becomes intractable.The therapeutic method of TN has 4 types:microvascular decompression (MVD), trigeminal nerve root selective partial amputation, drug therapy and nerve block, the basis therapy is drug which give priority to with carbamazepine. Since the great professor of Dandy proposes the neuro-vascular conflict theory (NVC) is the causes of TN, the MVD is widely used in clinic. What is more, the first choice for treat TN is MVD that is only for cause. The curative effect of MVD is excellent, which effective rate as high as 85%. However, with the extended post-MVD time that the recurrence rate to increase gradually. Barke and Jannetta found that the recurrence rate is 30% at post-MVD time in 6.2 years though the study that 1145 TN patients took MVD were statistical analysis, and the most of recurrence is happen within 2 years in post-MVD time. In addition, the effect of MVD is better with the offending vessel is artery than vein and composite conflict. There is a great challenge that the recurrence of TN patients after MVD. Meanwhile, it is a difficult problem to reduce the rate of recurrence for the general neurosurgeons. Matsushima found that the severe arachnoid adhesion is existence in patients who take MVD once again. The adhesion lie in the patient who takes MVD again has enough attention by neurosurgeon. On the contrary, it is unknown the relationship that between the arachnoid and the effect or recurrence in patients after MVD. The first and second chapters of paper are concentration on the arachnoid that influence the effect of MVD and the mechanism of TN, and for detailed study in fibrosis of arachnoid. The anomalous change that in arachnoid such as thickening, adhesion as well as the cistern whether could tested by imageology. In recently, with the rapidly development of MRI, especially in the sequence of three-dimensional MRI (3D-MRI), for instance 3D fast imaging employing steady-state acquisition(3D-FIESTA),3D MR angiography(3D MRA),3D constructive interference in steady state(3D CISS and 3D spoiled gradient recalled (3D SPGR). The positional relation between nerve and vessel can be clearly shows in MRI. The trigeminal nerve and the arteries were identified on both 3D FIESTA and MR angiographic images (3D-MRA)for both the pathologic and normal sides, but the veins were only identifiable on the 3D FIESTA images. It has been reported that NVC caused by the arteries could be evaluated by using the source images of MR angiography, including 3D fast imaging with steady-state precession or 3D spoiled gradient-recalled acquisition in the steady state. Since an artery with a fast blood flow is shown as a structure of high signal intensity and a nerve is shown as a structure of intermediate signal intensity, the responsible artery could be identified by using MR angiography. At MR angiography, however, the contrast resolution between the cerebrospinal fluid and the nerve is somewhat unclear. Further-more, the depiction of the vein is impossible with MR angiography because of the slow blood flow in the vein. There is a hot study that uses the 3D-MRI sequence to show the pathogenesis of TN.The MRI thin slice scan that could not only exclude the secondary trigeminal neuralgia but also show the relationship between the nerve and the vessel has become a routine examination in pre-MVD. There is a important significance that definite the relationship between the imaging factors (such as cistern area, nerve root size and angle) and the effect of MVD. It is could help to make operation plan and improve the efficacy. The third and fourth chapters of study are concentration on the relationship between imaging factors and the effect of MVD.The first part, related factors of primary trigeminal neuralgia recurrence after microvascular decompressionObjective To evaluate related factors of the recurrence of primary trigeminal neuralgia after microvascular decompression.Methods 147 patients with initial primary trigeminal neuralgia treated with microvascular decompression in Departerment of Neurosurgery, Nanfang Hospital were retrospectively analyzed.Preoperative treatment, clinical presentation, operative findings and postoperative outcome was recorded from the follow-up borad.The related factors of recurrence was statically analyzed.Results The mean follow-up time was 38 months and recurrence rate is 11.6%(17/147). The univariate analysis showed the duration of disease (P=0.016), clinical presentation (P= 0.026), offending artery (P<0.001),compression degree (P=0.003) decompression degree (P<0.001), the outer arachnoid (P<0.001), arachnoid compression (P<0.001) and arachnoid adhesion (P<0.001) was statically related to recurrence. After Logistic regression analysis, the outer arachnoid (P=0.033), arachnoid trabecula compression (P=0.008), offending artery (P=0.002), decompression degree (P=0.004) were the predictors of recurrence.Conclusions The microvascular decompression remains significant in treating primary trigeminal neuralgia,and the arachnoid factors may play an important role in the pathogenesis of trigeminal neuralgia and microvascular decompression.The second part, the study of fibrosis in cerebellopontine angle cistem arachnoidObjective To confirm the fibrosis actually existence in cerebellopontine angle cistern arachnoid with TN patients, and provide the new proof with pathogenesis for TN.Methods The cerebellopontine angle cistern arachnoid that come from TN patients took the first MVD and cerebral trauma patients was collected during January 2013-December 2014 in Departerment of Neurosurgery, Nanfang Hospital. The specimen of both group were HE stain and picro-sirus red stain in order to compare with the thickness in collagen fiber. And all date was statistical analysis use SPSS 13.Results The 21 TN patients and 22 cerebral trauma patients in all were included studies. For TN patients arachnoid, the full-thickness of mean is 87.86±9.34μm and the collagen fiber thickness of mean is 53.95±8.90μm; for trauma patients, the full-thickness of mean is 62.55±1.55μm and the collagen fiber thickness of mean is 33.50±3.60um. The comparison in thickness of arachnoid (P<0.001) and collagen fiber (P<0.001) were statistically significant.Conclusions There has fibrosis in cerebellopontine angle cistem arachnoid with TN patients. The pathogenesis of TN that significant cause is the fibrosis arachnoid.The third part, the Relationship between Preoperative MRI Characteristics and Short-term Effects of Microvascular Decompression in Primary Trigeminal NeuralgiaObjective To evaluate the relationship between preoperative MRI characteristics and perioperative effects of microvascular decompression in primary trigeminal neuralgia. Methods To analyze the relationship between preoperative MRI characteristics and perioperative effects of 103 primary trigeminal neuralgia patients who had suffered microvascular decompression in Nanfang Hospital. The MRI related factors included the ratio of CPA area, TGN cross-sectional area, TGN length. Besides that, the TGN oppression distance, the position of TGN, the position of basilar artery and the type of offending vascular were also enrolled. The surgical effects were divided into disappear, remission and ineffective.Results Univariate analysis showed that the oppression orientation (P=0,017), oppression distance (P<0.001), offending vascular type (P= 0.016), TGN cross-sectional area ratio (P<0.001) were the influencing factors of perioperative effects, logistic regression analysis showed that the offending vascular type (P= 0.002)and TGN cross-sectional area ratio (P=0.020) were the main predictive factors of perioperative microvascular decompression effects.ConclusionsPreoperative thin slice MRI scanning showed that the offending artery, non-atrophy nerve roots, far distance from oppression point to brainstem would bring microvascular decompression patients better perioperative effects.The fourth part,the relationship between postoperative recurrence of microvascular decompression and the radiological factors of trigeminal neuralgiaObjective:To evaluate the radiological factors about the recurrence of primary prosopalgia treated by microvascular decompression (MVD).Methods:To analyze the relationship between postoperative recurrence and preoperative MRI features of the 107 patients who were treated by MVD in Nanfang hospital. The radiological characteristics of trigeminal nerve (TGN) included the sectional area ratio, length ratio, intersection angle ratio, compression distance and orientation of TGN. Besides that, the radiological features also included the area ratio of cerebellopontine angle (CPA), location of basilar artery and the types of offending vascular.Results:The result of Kaplan-Meier analysis showed the duration of disease (P=0.039), clinical presentation (P=0.049),the area ratio of cerebellopontine angle (P=0.003), types of offending vascular (P=0.000), sectional area ratio of TGN (P=0.036) and compression distance of TGN (P= 0.045) were related to the postoperative recurrence. The Cox Regression showed that the area ratio of CPA (P=0.049), duration of disease (P=0.002),offending vascular types (P=0.000) and sectional area ratio of TGN (P=0.019) were the main influencing factors of postoperative recurrence.Conclusions:The MRI characteristics of TGN demonstrated that the CPA cistern without stenosis, the offending vascular being artery and the nerve root without atrophy will not easily lead to the postoperative recurrence of MVD. |
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