Carnosine regulation of intracellular pH homeostasis promotes lysosome-dependent tumor immunoevasion.

Tumor cells and surrounding immune cells undergo metabolic reprogramming, leading to an acidic tumor microenvironment. However, it is unclear how tumor cells adapt to this acidic stress during tumor progression. Here we show that carnosine, a mobile buffering metabolite that accumulates under hypoxia in tumor cells, regulates intracellular pH homeostasis and drives lysosome-dependent tumor immune evasion. A previously unrecognized isoform of carnosine synthase, CARNS2, promotes carnosine synthesis under hypoxia. Carnosine maintains intracellular pH (pHi) homeostasis by functioning as a mobile proton carrier to accelerate cytosolic H+ mobility and release, which in turn controls lysosomal subcellular distribution, acidification and activity. Furthermore, by maintaining lysosomal activity, carnosine facilitates nuclear transcription factor X-box binding 1 (NFX1) degradation, triggering galectin-9 and T-cell-mediated immune escape and tumorigenesis. These findings indicate an unconventional mechanism for pHi regulation in cancer cells and demonstrate how lysosome contributes to immune evasion, thus providing a basis for development of combined therapeutic strategies against hepatocellular carcinoma that exploit disrupted pHi homeostasis with immune checkpoint blockade.

Non-canonical phosphoglycerate dehydrogenase activity promotes liver cancer growth via mitochondrial translation and respiratory metabolism.

Phosphoglycerate dehydrogenase (PHGDH) is a key serine biosynthesis enzyme whose aberrant expression promotes various types of tumors. Recently, PHGDH has been found to have some non-canonical functions beyond serine biosynthesis, but its specific mechanisms in tumorigenesis remain unclear. Here, we show that PHGDH localizes to the inner mitochondrial membrane and promotes the translation of mitochondrial DNA (mtDNA)-encoded proteins in liver cancer cells. Mechanistically, we demonstrate that mitochondrial PHGDH directly interacts with adenine nucleotide translocase 2 (ANT2) and then recruits mitochondrial elongation factor G2 (mtEFG2) to promote mitochondrial ribosome recycling efficiency, thereby promoting mtDNA-encoded protein expression and subsequent mitochondrial respiration. Moreover, we show that treatment with a mitochondrial translation inhibitor or depletion of mtEFG2 diminishes PHGDH-mediated tumor growth. Collectively, our findings uncover a previously unappreciated function of PHGDH in tumorigenesis acting via promotion of mitochondrial translation and bioenergetics.

MYC promotes cancer progression by modulating m6 A modifications to suppress target gene translation.

The MYC oncoprotein activates and represses gene expression in a transcription-dependent or transcription-independent manner. Modification of mRNA emerges as a key gene expression regulatory nexus. We sought to determine whether MYC alters mRNA modifications and report here that MYC promotes cancer progression by down-regulating N6-methyladenosine (m6 A) preferentially in transcripts of a subset of MYC-repressed genes (MRGs). We find that MYC activates the expression of ALKBH5 and reduces m6 A levels in the mRNA of the selected MRGs SPI1 and PHF12. We also show that MYC-regulated m6 A controls the translation of MRG mRNA via the specific m6 A reader YTHDF3. Finally, we find that inhibition of ALKBH5, or overexpression of SPI1 or PHF12, effectively suppresses the growth of MYC-deregulated B-cell lymphomas, both in vitro and in vivo. Our findings uncover a novel mechanism by which MYC suppresses gene expression by altering m6 A modifications in selected MRG transcripts promotes cancer progression.

PGAM5 deacetylation mediated by SIRT2 facilitates lipid metabolism and liver cancer proliferation.

Tumor metabolic reprogramming and epigenetic modification work together to promote tumorigenesis and development. Protein lysine acetylation, which affects a variety of biological functions of proteins, plays an important role under physiological and pathological conditions. Here, through immunoprecipitation and mass spectrum data, we show that phosphoglycerate mutase 5 (PGAM5) deacetylation enhances malic enzyme 1 (ME1) metabolic enzyme activity to promote lipid synthesis and proliferation of liver cancer cells. Mechanistically, we demonstrate that the deacetylase SIRT2 mediates PGAM5 deacetylation to activate ME1 activity, leading to ME1 dephosphorylation, subsequent lipid accumulation and the proliferation of liver cancer cells. Taken together, our study establishes an important role for the SIRT2-PGAM5-ME1 axis in the proliferation of liver cancer cells, suggesting a potential innovative cancer therapy.

Microvascular decompression for pediatric onset trigeminal neuralgia: patterns and variation.

OBJECTIVES: Pediatric trigeminal neuralgia has been rarely reported in the literature, which were only 28 cases. Although microvascular decompression (MVD) has been widely accepted as effective therapy for trigeminal neuralgia, the etiology and surgical treatment of pediatric ones are seldom addressed. We report our experience with MVD for pediatric trigeminal neuralgia patients with emphasis on the vascular conflict patterns and surgical skills. METHODS: This retrospective report included 11 pediatric TN patients, who underwent MVD and were followed for 3-86 months. The data were retrospectively analyzed with emphasis on the clinical features. RESULTS: This series included 4 boys and 7 girls with average age of 13 ± 3.4 years old, their onset age were from 7 to 18 years old. The singular vein and combined artery/vein conflictions account for 7/11. 9 (81.8%) patients achieved immediate excellent outcomes. One recurrence was observed after 5 months and refused the second surgery. CONCLUSIONS: The etiology of pediatric onset trigeminal neuralgia is still vascular conflict, whose patterns are different from adults, of which combined artery/vein and singular venous compression patterns have a much more higher proportion. Because of the smaller operative space and fragile-thin venous wall with adhesion to other structures, it is much more difficult to decompress the trigeminal nerve among pediatric patients. Sufficient arachnoid release, full exploration, and decompression along the trigeminal nerve were necessary, which will increase the excellent rate among pediatric patients.

Microvascular Decompression Alone without Rhizotomy Is an Effective Way of Treating Glossopharyngeal Neuralgia: Clinical Analysis of 46 Cases.

BACKGROUND: Microvascular decompression (MVD) has been the right choice for glossopharyngeal neuralgia (GPN) patients. However, whether glossopharyngeal/vagal nerve root rhizotomy should be combined with MVD is still controversial. OBJECTIVE: To evaluate whether glossopharyngeal/vagal nerve root rhizotomy during MVD is necessary for the treatment of GPN. METHODS: We performed a retrospective study of 46 GPN patients who underwent MVD surgery alone in our hospital, and their patient demographics, clinical presentations, and intraoperative findings are shown. The immediate and long-term follow-up outcomes were investigated to show the treatment's efficiency and safety; the outcome was also compared with our previous study. The relevant literature was reviewed to show complications for GPN patients undergoing glossopharyngeal/vagal nerve root rhizotomy with MVD. RESULTS: The most common offending vessel was the posterior inferior cerebellar artery (60.9%). 100% of the patients were pain-free (score of I on the Barrow Neurological Institute pain intensity [BNI-P] scale) immediately after MVD surgery, while 1 patient relapsed with occasional pain 12 months after the operation (score of III on the BNI-P scale). Poor wound healing and hearing loss were found in 1 case each. No complications related to the glossopharyngeal nerve/vagal nerve were reported. Some surgical techniques, such as thorough exploration of the CN IX-X rootlets, full freeing from arachnoid adhesions, and usage of a moist gelatin sponge, can improve the success rate of the operation. CONCLUSIONS: MVD alone without rhizotomy is an effective and safe method for patients with GPN.

Fully endoscopic microvascular decompression of the hemifacial spasm: our experience.

PURPOSE: Microvascular decompression (MVD) surgery has been accepted as a potentially curative method for hemifacial spasm (HFS). The primary cause of failure of MVD is incomplete decompression of the offending vessel due to inadequate visualization. This study is aimed at evaluating the benefit of endoscopic visualization and the value of fully endoscopic MVD. METHODS: From March 2016 to March 2018, 45 HFS patients underwent fully endoscopic MVD in our department. From opening the dura to preparing to close, the assistant held the endoscope and the surgeon operated. Abnormal muscle response (AMR) and brainstem auditory evoked potentials (BAEP) were monitored. For every patient, the offending vessel was transposed or interposed and achieved complete decompression. AMR was used to evaluate the adequacy of decompression at the end of the surgery. The intra-operative findings and postoperative outcomes and complications were analyzed. RESULTS: Immediately after surgeries, 39 patients (86.7%) achieved excellent result; 2 cases (4.4%) had good result. So the postoperative effective rate was 91.1% (41/45). During 12-36 month follow-up, the outcomes were excellent in 42 cases (93.3%) and good in 2 cases (4.4%), and the effective rate reached to 97.8% (44/45). No recurrence was noted. The postoperative complications were found in 2 patients (4.4%). One patient (2.2%) showed delayed facial palsy on the tenth day but was fully recovered 1 month later. Intracranial infection was noticed in 1 patient (2.2%) and was cured by using intravenous antibiotics for 2 weeks. There was no hearing impairment, hoarseness, or other complications. CONCLUSIONS: Fully endoscopic MVD is both safe and effective in the treatment of HFS. Electrophysiological monitoring is helpful to gain a good result and reduce hearing impairment.

Prediction of calcification tendency in pediatric cystic adamantinomatous craniopharyngioma by using inflammatory markers, hormone markers, and radiological appearances.

PURPOSE: To compare the different levels of inflammatory markers, hormone markers, and radiological appearances between PCACP with and without calcification so as to explore the relationships between these markers and calcification. METHODS: The inflammatory markers, hormone markers, and radiological appearances were compared not only between PCACP with and without calcification, but also among its different forms of calcification. The receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic significance of all markers between these groups. RESULTS: It was showed that the white blood cell (WBC) count, neutrophil count, monocyte count, prognostic nutritional index (PNI), prolactin (PRL), and T1WI signal of cysts were higher in PCACP with calcification than in PCACP without calcification. The neutrophil count was significantly higher in PCACP with eggshell calcification than in other groups. The PCACP with mixed calcification had the highest PRL level in all kinds of PCACP with calcification. Only the area under curve (AUC) values of neutrophil count and PRL level were greater than 0.8. CONCLUSION: It is found that inflammation and hormone are related to PCACP's calcification. High neutrophil count and PRL level may indicate possible calcification tendency in PCACP. Improved intracystic therapies based on these results may help to inhibit the formation of calcification in PCACP in future.

The diagnostic value of preoperative inflammatory markers in craniopharyngioma: a multicenter cohort study.

To compare the different levels of preoperative inflammatory markers in peripheral blood samples between craniopharyngioma (CP) and other sellar region tumors so as to explore their differential diagnostic value. The level of white blood cell (WBC), neutrophil, lymphocyte, monocyte, platelet, albumin, neutrophil lymphocyte ratio (NLR), derived NLR (dNLR), platelet lymphocyte ratio (PLR), monocyte lymphocyte ratio (MLR) and prognostic nutritional index (PNI) were compared between the CP and other sellar region tumors. A receiver operating characteristics (ROC) curve analysis was performed to evaluate the diagnostic significance of the peripheral blood inflammatory markers and their paired combinations for CP including its pathological types. Patients with CP had higher levels of pre-operative WBC, lymphocyte and PNI. The papillary craniopharyngioma (PCP) group had higher neutrophil count and NLR than the adamantinomatous craniopharyngioma (ACP) and healthy control groups whereas the ACP group had higher platelet count and PNI than the PCP and healthy control groups. There were not any significant differences in preoperative inflammatory markers between the primary and recurrent CP groups. The AUC values of WBC, neutrophil, NLR + PLR and dNLR + PLR in PCP were all higher than 0.7. Inflammation seems to be closely correlated with CP's development. The preoperative inflammatory markers including WBC, neutrophil, NLR + PLR and dNLR + PLR may differentially diagnose PCP, pituitary tumor (PT) and Rathke cleft cyst (RCC). In addition, some statistical results in this study indirectly proved previous experimental conclusions and strictly matched CP's biological features.

Microvascular decompression for glossopharyngeal neuralgia: a retrospective analysis of 228 cases.

BACKGROUND: Glossopharyngeal neuralgia (GPN) is an uncommon craniofacial pain syndrome caused by neurovascular conflict. Compared to trigeminal neuralgia or hemifacial spasm, the incidence of GPN was very low. Until now, little is known about the long-term outcome following microvascular decompression (MVD) process. METHODS: Between 2006 and 2016, 228 idiopathic GPN patients underwent MVD in our department. Those cases were retrospectively reviewed with emphasis on intraoperative findings and long-term postoperative outcomes. The average period of follow-up was 54.3 ± 6.2 months. RESULTS: Intraoperatively, the culprit was identified as the posterior inferior cerebellar artery (PICA) in 165 cases (72.3%), the vertebral artery (VA) in 14 (6.1%), vein in 10 (4.4%), and a combination of multiple arteries or venous offending vessels in 39 (17.2%). The immediately postoperative outcome was excellent in 204 cases (89.5%), good in 12 (5.3%), fair in 6 (2.6%) and poor in 6 (2.6%). More than 5-year follow-up was obtained in 107 cases (46.9%), which presented as excellent in 93 (86.9%), good in 6 (5.6%), fair in 3 (2.8%) and poor in 5 (4.7%). Thirty-seven (16.2%) of the patients experienced some postoperative neurological deficits immediately, such as dysphagia, hoarseness and facial paralysis, which has been improved at the last follow-up in most cases, except 2. CONCLUSIONS: This investigation demonstrated that MVD is a safe and effective remedy for treatment of GPN.

Posterior Fossa Re-Exploration for Recurrent Trigeminal Neuralgia: Operative Findings and Surgical Techniques.

OBJECTIVE: Microvascular decompression (MVD) is considered the first choice for the surgical treatment of trigeminal neuralgia (TN). However, recurrence after MVD is still a problem and a challenge for neurosurgeons. In this study, we share our experience in the posterior fossa re-exploration of the recurrent cases. METHODS: From January 2014 to January 2015, 15 recurrent TN patients who received fossa re-exploration were retrospectively studied. Surgeries were performed by retrosigmoid suboccipital approach. Brainstem auditory evoked potentials (BAEP) were monitored throughout the operation. Intraoperative findings and surgical techniques were recorded. Postoperative outcomes and complications were analyzed. RESULTS: Among the 15 patients, Teflon adhesion was found in 14. Teflon felt displacement was found in 4 patients, and additional Teflon felt was used to interpose. New offending vessels were found in 5 patients. Three of them were small arteries and the other 2 were petrosal veins. After dissected, small pieces of wet gelatin sponge and Teflon felt were implanted respectively to ensure complete decompression. The remaining 6 patients had no vascular compression except severe adhesion, and nerve combing was performed. After surgery, 12 achieved complete pain relief, 2 gained partial pain relief, and 1 failed. Six patients experienced facial numbness postoperatively. There was no hearing impairment or other complications. During the mean 26-month follow-up, no recurrence occurred and all of 6 cases with facial numbness after surgery improved. CONCLUSIONS: Teflon adhesion is a significant cause of recurrent TN. Wet gelatin-assisted method is good for Teflon interposition. If no vascular compression is found during re-exploration, trigeminal nerve combing can be used. Intraoperative BAEP monitoring is helpful to reduce the incidence of hearing loss.

Bell's Palsy: Clinical Analysis of 372 Cases and Review of Related Literature.

OBJECTIVE: To analyze some clinical and epidemiologic aspects of Bell's palsy (BP) and to develop relevant correlations between existing data in literature and those obtained in this research. METHODS: From January 2012 to December 2014, 372 consecutive patients diagnosed with BP were studied retrospectively. We reviewed the patients' data including gender, age, occupation, clinical manifestations, comorbid disease, and the rate of recurrence. RESULT: The highest incidence was identified in those between 39 and 50 years of age. BP was more frequent in warm seasons (spring and summer) with its incidence reaching a peak value in September. The seasonal incidence of BP was significantly higher in summer (p < 0.05). In addition, diabetes mellitus was the most common accompanying comorbid condition. CONCLUSION: The peak age when BP showed up was in the fourth decade of life and 55.1% of patients belonged to the male gender. BP has been observed to have the highest incidence during warm seasons (spring and summer). Diabetes mellitus was the most common comorbid condition accompanying BP. In addition, a recurrence was more likely to occur in the first 1.5 years after its first incidence.

Fatal complications following microvascular decompression: could it be avoided and salvaged?

Although the microvascular decompression (MVD) surgery has become an effective remedy for cranial nerve rhizopathies, it is still challengeable and may result in a fatal sequel sometimes. Therefore, the operative skill needs to be further highlighted with emphasis on the safety and a preplan for management of postoperative fatal complications should be established. We retrospectively analyzed 6974 cases of MVD. Postoperatively, 46 patients (0.66 %) presented decline in consciousness with a positive finger-nose test (or failure to be tested) after wake up from the anesthesia, whom were focused on in this study. Their surgical findings and intraoperative manipulation as well as computer tomography (CT) delineation were reviewed in detail. These cases consisted of trigeminal neuralgia in 37 and hemifacial spasm in 9. All these patients underwent an immediate CT scan, which demonstrated cerebellar hemorrhages in 38 and epidural hematomas in 6. A later magnetic resource image delineated cerebral infarctions in basal ganglia in 2. Eventually, 15 (0.2 %) died and 31 survived. Data analysis showed that the mortality is significantly higher in trigeminal cases with cerebellar hematoma and an immediate hematoma evacuation plus ventricular drainage could give the patient more chance of survival (p < 0.05). It appeared that the cerebellar hemorrhage was the predominant cause contributable to the postoperative consciousness decline, which occurred more often in trigeminal cases. To have a safe MVD, an appropriate surgical technique is the priority. It is very important to create a satisfactory working space before decompression of the cranial nerve root, which is obtained by a patient microdissection of the arachnoids rather than blind retraction of the cerebellum and hotheaded sacrifice of the petrous vein. Once a cerebellar hematoma is confirmed, an emergency surgery should not be hesitated. A prompt evacuation of the hematomas followed by a dual ventricular drainage via both the frontal horns may save the patient.

Combination of Magnetic Resonance Imaging and Electrophysiological Studies in Lumbar Disc Herniation.

Objective We aimed to study the clinical value of magnetic resonance imaging (MRI) and electrophysiological studies in the diagnosis of lumbar disc herniation and in the evaluation of the therapeutic effect of discectomy. Methods In this study, 265 patients with LDH were treated with discectomy after assessment by the Japanese Orthopedic Association (JOA) score, MRI, and electrophysiological studies. All the patients were followed-up for 6 years. The effects of the operation were assessed by determining the angle between the nerve root canal and disc protrusion (AN value), the stenotic ratio of the spinal canal, the width of the lateral recess, motor conduction velocity (MCV), sensory conduction velocity (SCV), and nerve action potential (NAP) before and after operation. Results The AN value, stenotic ratio of the spinal canal, and the width of the lateral recess of protruding intervertebral discs showed significant differences from these values for the patients' unaffected intervertebral discs (P < 0.05). The MCV, SCV, and NAP of the affected limb showed significant differences from these values for the patients' unaffected limbs (P < 0.05). In all the patients the values for these indicators showed significant differences before and after operation (P < 0.05). Conclusion MRI and electrophysiological studies can be used in the diagnosis of lumbar disc herniation, and in the evaluation of the effect of surgery.

The Significance of Abnormal Muscle Response Monitoring During Microvascular Decompression for Hemifacial Spasm.

BACKGROUND: Despite the wide adoption of the abnormal muscle response (AMR) to electrical stimulation of the facial nerve during microvascular decompression (MVD) surgery, the value of AMR in the prognosis of the postoperative outcome is still controversial. In order to better use this intraoperative electrophysiology, it is necessary to further address the relationship between AMR and postoperative results. METHODS: Three hundred and thirty-two patients with hemifacial spasm (HFS) in whom MVD surgery was performed and in whom AMR was available were finally enrolled in this study. The intraoperative AMR changes were classified as amplitude ≥ 50 %, <50 %, and disappearance. These changes were retrospectively analyzed in association with intraoperative findings and postoperative outcomes. The follow-up period ranged from 11 to 62 months, with an average of 34.1 months. RESULTS: Among the 332 patients with a typical AMR wave recorded at the beginning of the operation, the AMR disappeared in 305, and amplitude was <50 % in 11 and ≥50 % in 16. Of those with AMR disappearance plus those with amplitude < 50 %, 98.4 % achieved relief on the first postoperative day and at the latest follow-up, while of those with amplitude ≥50 %, 18.8 % and 25 %, respectively, achieved relief on the first postoperative day and at the latest follow-up (P < 0.01). Accordingly, a more than 50 % decrease of AMR amplitude may predict a good prognosis. The accuracy, sensitivity, and specificity of AMR monitoring were 97.5 %, 99 %, and 72.2 %, respectively. CONCLUSIONS: AMR could be a good tool for successful MVD in patients with HFS when a rational analysis is conducted in association with the intraoperative findings. Persistence of AMR may imply that the real offending vessel was missed. If the entire facial nerve root is cleared of any vessel, a remaining AMR amplitude of less than 50 % might be acceptable. Otherwise, neurocombing is suggested before finishing the operation.

Surgical Treatment of Hemifacial Spasm Caused by the Compression of Internal Auditory Canal of Facial Nerve.

OBJECTIVE: To make out the way to distinguish the offending vessels compressed the internal auditory canal part of the facial nerve. METHODS: The hemifacial spasm patients were treated of microvascular decompression surgery with neurophysiologic monitoring. The patients were found that the internal auditory canal of the facial nerves was fully compressed, and the records of surgery monitoring were analyzed. RESULTS: All the patients were recorded the delay incubation period in electromyography monitoring, and all patients were hemifacial spasm free finally. CONCLUSION: Some hemifacial spasms were caused by internal auditory canal compression, so during the operation, the authors should explore the whole course of the facial nerve and compress the internal auditory canal part with the aid of neurophysiologic monitoring.

Utility of Brainstem Trigeminal Evoked Potentials in Patients With Primary Trigeminal Neuralgia Treated by Microvascular Decompression.

OBJECTIVE: To investigate the characteristics of brainstem trigeminal evoked potentials (BTEP) waveform in patients with and without trigeminal neuralgia (TN), and to discuss the utility of BTEP in patients with primary TN treated by microvascular decompression (MVD). METHODS: A retrospective review of 43 patients who underwent BTEP between January 2016 and June 2016, including 33 patients with TN who underwent MVD and 10 patients without TN. Brainstem trigeminal evoked potentials characteristics of TN and non-TN were summarized, in particular to compare the BTEP changes between pre- and post-MVD, and to discover the relationship between BTEP changes and surgical outcome. RESULTS: Brainstem trigeminal evoked potentials can be recorded in patients without trigeminal neuralgia. Abnormal BTEP could be recorded when different branches were stimulated. After decompression, the original W2, W3 disappeared and then replaced by a large wave in most patients, or original wave poorly differentiated improved in some patients, showed as shorter latency and (or) amplitude increased. Brainstem trigeminal evoked potentials waveform of healthy side in patients with trigeminal neuralgia was similar to the waveform of patients without TN. In 3 patients, after decompression the W2, W3 peaks increased, and the latency, duration, IPLD did not change significantly. Until discharge, 87.9% (29/33) of the patients presented complete absence of pain without medication (BNI I) and 93.9% (31/33) had good pain control without medication (BNI I-II). CONCLUSION: Brainstem trigeminal evoked potentials can reflect the conduction function of the trigeminal nerve to evaluate the functional level of the trigeminal nerve conduction pathway. The improvement and restoration of BTEP waveforms are closely related to the postoperative curative effect.

Teflon Might Be a Factor Accounting for a Failed Microvascular Decompression in Hemifacial Spasm: A Technical Note.

BACKGROUND: Although Teflon is widely adopted for microvascular decompression (MVD) surgery, it has never been addressed for failure analysis. This study analyzed the reasons for failed MVDs with emphasis on the Teflon sponge. METHODS: Among the 685 hemifacial spasm cases between 2010 and 2014, 31 were reoperated on within a week because of unsatisfactory outcome, which was focused on in this study. Intraoperative findings regarding Teflon inserts of these repeat MVDs were reviewed. RESULTS: Among the 38 without satisfactory outcomes, 31 underwent repeat MVDs, and they were all spasm free afterwards. Eventually, the final cure rate was 99.2%. It was found in the repeat MVDs that the failure was attributable to the Teflon insert in most of the cases (74.2%) directly or indirectly. It was caused by improper placement (47.8%), inappropriate size (34.8%) and unsuitable shape (17.4%) of the Teflon sponge. CONCLUSION: Although it is not difficult for an experienced neurosurgeon to discover a neurovascular conflict during the MVD process, the size, shape and location of the Teflon sponge should not be ignored. Basically, the Teflon insert is used to keep the offending artery away from the facial nerve root rather than to isolate it. Therefore, the ideal Teflon sponge should be just small enough to produce a neurovascular separation.

Management of symptomatic hemifacial spasm or trigeminal neuralgia.

Hemifacial spasm (HFS) or trigeminal neuralgia (TN) is a kind of hyperactivity disorder of cranial nerves caused by vascular compression. However, sometimes, the disease may arise from nerve damage produced by tumors, which was called as symptomatic HFS/TN. Until now, little is known about the exact mechanism and the necessity of microvascular decompression (MVD) regarding the tumor-induced HFS/TN, which is necessary to be retrospectively analyzed in a considerable sample. Among the 4021 patients who underwent MVD in our department between 2006 and 2014, 44 were finally diagnosed as symptomatic HFS or TN. These patients were focused in this study and their clinical features as well as intraoperative findings and postoperative outcomes were retrospectively investigated. Data analysis exhibited the symptomatic HFS/TN cases accounted for 1.1 % in the study, which were caused by epidermoid in 18 (40.9 %) and meningioma in 15 (34.1 %) followed by neuroma in 7 (15.9 %) as well as aneurysm in 2 (4.5 %) and arteriovenous malformation in 2 (4.5 %). Compared to those with idiopathic HFS/TN, younger females were more susceptible (p < 0.05). After resection of the neoplasm, the offending vessel was identified in 26 (59.1 %), which were followed by MVD process. Postoperatively, the symptoms relief rate was 88.6 %. Our study showed that surgical management of patients with symptomatic HFS/TN may lead to a satisfactory result, yet those primary lesions should be removed firstly. In some cases, a microvascular decompression process might be unnecessary afterward, but the entire nerve root should be checked to exclude any vessel in contact with.

Delayed relief of hemifacial spasm after microvascular decompression: can it be avoided?

BACKGROUND: Although microvascular decompression (MVD) surgery has been widely accepted as an effective treatment for hemifacial spasm (HFS), delayed relief cases have been frequently reported. Therefore, the value of an immediate redo MVD should be discussed. METHODS: This study included 1,435 HFS patients who underwent MVD with intraoperative abnormal muscle response (AMR) monitoring from 2011 through 2013 at XinHua Hospital. These cases were analyzed retrospectively with emphasis on the postoperative outcomes and introaperative findings. RESULTS: After MVD, 1,384 HFS patients obtained relief immediately. The 51 unrelieved patients underwent AMR monitoring again the next day; this was positive in 48 and negative in 3 patients. These three patients with negative AMR obtained relief spontaneously within a week. Among the 48 positive patients, 31 and 11 were underwent redo MVD within a week and 5-22 months, respectively, and all achieved relief after the second operation. Of the six remainig patients, two obtained relief within 2 months and 4 remained unchanged in the up-to-3-year's follow-up period. In redo MVDs, insufficient decompression of the facial nerve accounted for the failure. Finally, in this database, the immediate postoperative cure rate was 96.4 %; with earlier redo MVD, the final cure rate could be increased to 99.9 %. CONCLUSIONS: Despite being a reasonable remedy for HFS in the hands of an experienced neurosurgeon, sometimes small vessels can be missed while managing the main offending arteries during MVDs, which might account for the delayed relief. Therefore, reexamination of the AMR is necessary for unimproved patients; if a positive result is recorded, an immediate redo MVD is suggested.