Ying Chai

Predicting the outcome of microvascular decompression for primary trigeminal neuralgia by the use of magnetic resonance tomographic angiography.

Background Microvascular decompression (MVD) has been the available method to cure trigeminal neuralgia (TN), and several factors have been discussed as significant predictors of excellent outcome after MVD. Objective This study aimed to find out the value of magnetic resonance tomographic angiography (MRTA) in predicting the outcome of MVD for TNs. Method A total of 157 cases of TNs who underwent MVD have taken MRTA preoperatively and postoperatively and then were followed up for 5 years. The possible prognostic factors were analyzed by &khgr;2 test and Kaplan-Meier survival analysis. Result Five years after MVD, 83.4% (131 cases) gave excellent, 10.2% (16 cases) gave good, and 6.4% (10 cases) gave poor results. A significant difference was found between the severity of postoperative neurovascular compression (&khgr;2 = 16.307, P < 0.01)/the relief rate of neurovascular compression (NVC) (&khgr;2 = 17.221, P < 0.01) and the outcome after MVD. However, no significant correlation was found between the severity of preoperative NVC and the outcome (&khgr;2 = 6.275, P = 0.329). The Kaplan-Meier survival curves showed that lower degree of postoperative NVC severity group and higher relief rate group had better pain relief after MVD. Conclusions Postoperative MRTA can help us predict the outcome of MVD; less severity of postoperative NVC and more relief of compression could be possible prognostic factors.

Withdrawal reaction of carbamazepine after neurovascular decompression for trigeminal neuralgia: A preliminary study☆

OBJECTIVE To evaluate the representations and the relevant factors of carbamazepine-associated withdrawal reaction (CAWR) after microvascular decompression (MVD) to treat trigeminal neuralgia (TN). METHODS The present series included 90 patients who were referred from September 2010 to January 2013 and diagnosed with classical TN. The carbamazepine (CBZ) serum level was tested twice at 24h pre- and 24h post-operation by using HPLC analysis. The analysis of correlating selected factors and CAWR was performed. RESULTS Among 90 patients, 26 (28.9%) suffered from post-operative CAWR for 3 days after MVD. The symptoms of CAWR include overexcitement, e.g. insomnia, dysphoria, hand fremitus, hallucination and severe headache. The history of CBZ therapy before MVD, pre-operative dosage of CBZ, and the D-value of CBZ blood concentrations demonstrated statistic differences between the patients with CAWR and those without CAWR. Patient characteristics such as gender, age, and duration of neuralgia, neuralgia-related factors including neuralgia extent and neurovascular compression severity, and operation conditions including duration of MVD procedure, effect of MVD and complication of MVD had no influence on the occurrence of CAWR. CONCLUSION It is strongly suggested that CAWR is dependent on the pre-operative dosage and the changing rate of pre- and post-operative CBZ blood concentrations.

Preoperative evaluation of the neurovascular compression using magnetic resonance tomographic angiography: our radiologic indications for microvascular decompression to treat trigeminal neuralgia.

Purpose The aim of this study was to introduce our classification of the neurovascular compression (NVC) in trigeminal neuralgia and the radiologic indications for microvascular decompression (MVD) based on magnetic resonance tomographic angiography. Methods From 2003 to 2011, 322 patients with primary trigeminal neuralgia were treated with MVD. The score of NVC was from 0 to 3. Three scores, separately from axial, oblique sagittal, and coronal images, were added together. The degree of NVC was classified as follows: grade 0 (0–1), grade 1 (2–3), grade 2 (4–6), and grade 3 (7–9). Results In summary, 88.3% (182/206) patients with absolute indication, 78.3% (65/83) patients with relative indication, and 90.9% (30/33) without indication showed excellent results. Among the 27 patients with good result, 13 patients (48.1%) were in grade 1, and 3 (11.1%) were in grade 0. Among the 18 patients with poor result, 5 patients (27.8%) were in grade 1 preoperatively. Five patients with severe complications were all in grade 0 with vague NVC. Conclusion The patients with grades 2 and 3 (absolute indications) NVC were recommended with MVD.

Somatotopic organization of trigeminal ganglion: three-dimensional reconstruction of three divisions.

Abstract Clearing the somatotopic organization of trigeminal ganglion can help us to improve the precision of treatment for trigeminal neuralgia. The distribution of primary afferent perikarya of 3 branches of trigeminal nerve in the trigeminal ganglion was investigated in the rabbit, and 3D model was reconstructed then. After application of wheat germ agglutinin-horseradish peroxidase and DiI to the cut endings of the 3 branches of trigeminal nerve, ophthalmic cells were found in the anteromedial part of the trigeminal ganglion, mandibular cells in the posterolateral part, and maxillary cells in the middle part. The results suggest that the somatotopic organization of the ganglion in rabbits is a mediolateral direction reflecting the mediolateral order of the ophthalmic, maxillary, and mandibular nerves.

Trigeminal Neuralgia: Evaluation of the Relationship Between the Region of Neuralgic Manifestation and the Site of Neurovascular Compression Under Endoscopy.

AbstractThis study aimed to evaluate the relationship among the pain region, branches of trigeminal nerve, and the neurovascular compression (NVC) location. A total of 123 consecutive patients with trigeminal neuralgia (TN) underwent endoscope-assisted microvascular decompression according to positive preoperative tomographic angiography. V2 alone was in 51 cases and V3 alone was in 64 cases. The location of NVC was classified into cranial, caudal, medial, or lateral sites. Some patients with multiple regions were recorded as medial + cranial, lateral + cranial, medial + caudal, and lateral + caudal. Twenty-eight (71.8%) of 39 patients with TN (V2) had their NVC at the medial site of the nerve. Twenty-seven (64.3%) of 42 patients with TN (V3) had their NVC at the lateral site of the nerve. There was a statistically significant difference (P = 0.0011 < 0.01, &khgr;2 test). Sixteen (69.6%) of 23 patients with TN(V2) had their NVC at the cranial site of the nerve. Thirty-four (69.4%) of 49 patients with TN (V3) had their NVC at the caudal site of the nerve. There was no statistical difference (P = 0.3097 > 0.01). Evaluation of the relationship between the pain region and the NVC location by endoscopic images during microvascular decompression is more accurate. The second branch is mostly distributed in the medial area, and third branch is mainly distributed in the lateral area.

Etiologic exploration of magnetic resonance tomographic angiography negative trigeminal neuralgia

Our objective was to explore the etiologic factors involved in trigeminal neuralgia with negative magnetic resonance tomographic angiography (MRTA) results. Clinical data from 341 patients with idiopathic trigeminal neuralgia who were treated with neurovascular decompression between March 2003 and December 2011 were retrospectively analyzed. The etiologic causes of preoperative MRTA-negative trigeminal neuralgia were categorized based on comparisons between preoperative MRTA and intraoperative endoscopic images. MRTA was highly sensitive (92.4%, 291/315) to neurovascular compression, whereas its specificity was 65.4% (17/26). Among the 24 false-negative cases, there were nine patients with petrosal vein compression, 12 with superior cerebellar artery compression, two with superior cerebellar arterial branch compression, and one patient with anterior inferior cerebellar artery compression. Among the 17 true-negative cases, three patients had arachnoid adhesions, one had a protruding temporal eminence, five had micro-cholesteatomas, and eight patients exhibited no compression. The factors responsible for the MRTA-negative results included small-diameter arterial vessels, veins with slow blood flow, arachnoid adhesions, protruding temporal eminences, micro-cholesteatomas, and other pathologies such as multiple sclerosis. Preoperative diagnoses of MRTA-negative patients need to integrate the MRI results from multiple sequences to discriminate between arteriolar compression, venous compression, and small compressive lesions. When narrow cerebellopontine angles are shown in MRTA, arachnoid adhesion and temporal eminence compression should be considered.

Three-Dimensional Reconstruction of the Distribution of Neurons Contributing to Ophthalmic, Maxillary, and Mandibular Nerves in the Trigeminal Ganglion of Experimental Model

Abstract The authors introduce a new method to build a three-dimensional (3D) model of the 3 branches of the trigeminal nerve in the trigeminal ganglion of rabbit with 3 different kinds of fluorescence. Ten adult New Zealand rabbits of both sexes weighing between 2.0 and 3.0 kg were used in the experiment. Then through an operation under general anesthesia, the maxillary and mandibular nerves were exposed, and red and gold fluorescence were applied to investigate the neurons of the maxillary and mandibular nerves. Subsequently, DiI was used as a marker for the ophthalmic neuron for the other side of the same rabbit. After receiving images of the 3 branches under a fluorescence microscope, a 3D model of the 3 branches of the trigeminal nerve could be built. The authors obtained an image of the 3 branches of neurons in the trigeminal ganglion, and a 3D model of the 3 branches of the trigeminal nerve in the trigeminal ganglion was reconstructed. In the trigeminal ganglion, ophthalmic neurons were concentrated in the anteromedial section, the maxillary division in the middle, and the mandibular division posterolaterally. Overlap was observed between the ophthalmic and maxillary neurons, and also for the maxillary and mandible neurons.

Does Idiopathic Bone Cavity Involving Mandibular Condyle Need Surgical Intervention of Bone Cavity Filling

Abstract Idiopathic bone cavity (IBC) is a rare, asymptomatic, unilateral, oval-shaped radiolucent defect in the mandible. It is extremely rare that IBC occurs in the mandibular branch and condylar process. This article presents a 16-year-old male with IBC occuring in the mandibular branch.

Surgical Therapy for Pure Trigeminal Motor Neuropathy Accompanied by Limited Mouth Opening: A Retrospective Study

Purpose: This study aims to find out if there is any new manifestation of pure trigeminal motor neuropathy and evaluated the long-term results of surgery for its treatment. Patients and methods: The present study includes 10 patients referred from December 2003 to June 2014. The clinical manifestation investigations were recorded and 3 patients with limited mouth-opening were operated. The longterm follow-up result was performed. Results: Among 10 patients, 6 suffered from limited mouth opening, the other 4 jaw deviation. Among patients who had difficulty in mouth-opening, 3 patients chose surgery to improve the situation, the others just follow-up. At the final follow-up, the average maximum mouth opening of operated patients totally increased by 180%. For non-operated patients, no obvious improvement of mouth opening was observed. Conclusion: Limitation on mouth-opening is another manifestation of pure trigeminal motor neuropathy and surgery can effetely improve the situation.