Heng Zhang

The long-term outcome predictors of pure microvascular decompression for primary trigeminal neuralgia.

OBJECTIVE The aim of this study is to provide credible and comparable evidence on the efficacy and safety of pure microvascular decompression (MVD) for primary trigeminal neuralgia (TN), and also to find out the possible prognostic factors of excellent long-term outcome after the surgery. METHODS A prospective cohort study was conducted, involving the patients who met the diagnostic criteria of primary TN (both typical and atypical). The cohort patients underwent pure MVD, and then were followed up by independent neurologists. The possible prognostic factors were analyzed by the logistic method. RESULTS All 154 consecutive primary TN patients (98 typical, 56 atypical) underwent pure MVD from January 2001 to November 2005. The patients were followed up for median 5.6 years (10 lost in 5 years). Respective initial and 5-years complete pain-free without medication (Barrow Neurological Institute pain score, I) rates were 84% and 72% for total primary TN, 87% and 80% for typical TN, and 79% and 54% for atypical TN. The Kaplan-Meier survival curves of 5 years demonstrated different long-term outcomes in different groups (typical TN vs. atypical TN). The typical symptoms (odds ratio [OR], 2.776), preoperative magnetic resonance indicating vessel compression (OR, 2.950), and obvious vessel compression found during operation (OR, 3.219) were proved to have a positive effect on long-term pain relief without medication. CONCLUSIONS This is a perspective cohort study of pure MVD, which confirms the long-term effectiveness and safety of the surgery for primary TN. Patients with typical symptoms, positive magnetic resonance findings, or obvious vessel compressions might have better long-term prognosis.

Application of covered stent grafts for intracranial vertebral artery dissecting aneurysms

OBJECT Utilization of covered stent grafts in treating neurovascular disorders has been reported, but their efficacy and safety in vertebral artery (VA) dissecting aneurysms needs further investigation. METHODS Six cases are presented involving VA dissecting aneurysms that were treated by positioning a covered stent graft. Two aneurysms were located distal to the posterior inferior cerebellar artery, and 4 were located proximal to the posterior inferior cerebellar artery. Aspirin as well as ticlopidine or clopidogrel were administered after the procedure to prevent stent-related thrombosis. All patients were followed up both angiographically and clinically. RESULTS Five of the 6 patients underwent successful placement of a covered stent graft. The covered stent could not reach the level of the aneurysm in 1 patient with serious vasospasm who died secondary to severe subarachnoid hemorrhage that occurred 3 days later. Patient follow-up ranged from 6 to 14 months (mean 10.4 months), and demonstrated complete stabilization of the obliterated aneurysms, and no obvious intimal hyperplasia. No procedure-related complications such as stenosis or embolization occurred in the 5 patients with successful stent graft placement. CONCLUSIONS Although long-term follow-up studies using a greater number of patients is required for further validation of this technique, this preliminary assessment shows that covered stent graft placement is an efficient, safe, and microinvasive technique, and is a promising tool in treating intracranial VA dissecting aneurysms.

Quantitative Study of Posterior Fossa Crowdedness in Hemifacial Spasm

OBJECTIVE To quantitatively study the degree of posterior fossa crowdedness (PFC) in patients with hemifacial spasm (HFS) and to further investigate whether overcrowding in posterior fossa affects the efficacy and safety of microvascular decompression. METHODS We conducted a prospective case-control study of patients diagnosed with HFS and sex- and age-matched healthy control patients. All subjects underwent high-resolution, 3-dimensional magnetic resonance imaging, and posterior fossa crowdedness index (PFCI) and cerebrospinal fluid volume (CSFV) were measured. Patients with HFS underwent primary microvascular decompression and long-term follow-up. Associations of PFCI and other factors with operative outcomes and complications were analyzed. RESULTS The study enrolled 153 subjects: 102 patients and 51 control subjects. Compared with control subjects, patients had a more PFC (PFCI: 83.2% vs. 80.2%; P = 0.005) and smaller posterior fossa CSFV (16,248.0 mm(3) vs. 20,054.0 mm(3); P = 0.001). The mean effective space of posterior fossa cerebrospinal fluid in patients with HFS was 11.8% smaller than in control subjects (P = 0.004). Compared with men, women showed larger PFCI (83.6% vs. 82.2%; P = 0.012) and smaller PF CSFV (16,027.5 mm(3) vs. 17,299.5 mm(3); P = 0.009). Sixty-one patients (59.8%) were spasm-free immediately postoperatively, and 95 (93.1%) were spasm-free at follow-up. Complication rates were 9.8% in the short term, and 2.9% at follow-up. Lower PFCI (odds ratio [OR] 0.63; P = 0.019) and severe indention (OR 1.41; P = 0.027) were significantly associated with better short-term outcomes. Greater PFCI (OR 2.05, P = 0.008) was associated with greater early complication incidence. CONCLUSION Patients with HFS had more PFC. PFC potentially leads to cranial nerve and vascular structure crowding, which may increase HFS risk. PFC was significantly associated with poor short-term outcomes and greater incidence of early complications but not long-term outcomes and complications.

Association of polymorphisms in the elastin gene with sporadic ruptured intracranial aneurysms and unruptured intracranial aneurysms in Chinese patients

It has been suggested that the elastin gene is a candidate gene for the development of intracranial aneurysms (IAs). We investigated the association of single-nucleotide polymorphisms (SNPs) in the elastin gene in sporadic subarachnoid hemorrhage and in patients with unruptured aneurysms in China. We genotyped 446 (47.9%) IA patients (308 ruptured and 138 unruptured) and 485 (52.1%) control subjects for seven exonic and intronic SNPs in the elastin gene and then evaluated their allelic associations with sporadic ruptured and unruptured IAs. We found that IA is associated with two SNPs in the elastin gene: rs2071307 (odds ratio 2.87; 95% confidence interval, 2.26–3.64; p < 0.001) and rs2856728 (odds ratio 2.12; 95% confidence interval, 1.71–2.62; p < 0.001). Furthermore, the minor allele of rs2071307 (allele A) was also associated with IA rupture; 31.3% of patients with ruptured IAs were carriers of the minor allele, whereas only 23.2% of patients with unruptured IAs carried the minor allele (odds ratio 1.51; 95% confidence interval, 1.09–2.10; p = 0.013). In conclusion, our study indicates that the elastin gene may be associated with the formation of IAs, and importantly, that it may also be associated with the rupture of IAs.

Effects of microvascular decompression on depression and anxiety in trigeminal neuralgia: A prospective cohort study focused on risk factors and prognosis

OBJECTIVE Patients with trigeminal neuralgia (TN) often develop a terrible fear of triggering pain, which may lead to depression and anxiety, exerting a negative effect on their quality of life. This study aimed to investigate the prevalence and risk factors of depression and anxiety in TN patients, and further to investigate the effects of microvascular decompression (MVD) on these psychiatric disorders. PATIENTS AND METHODS A prospective cohort study was conducted, patients with TN who underwent MVD in our department between 2013 and 2015 were included. Visual analogue scale (VAS) score was used to measure the severity of pain. Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) were used to evaluate depression and anxiety disorders before and 6-month after MVD. The clinical data of these patients were collected prospectively and statistically analyzed. RESULTS A total of 128 study subjects comprising 70 women and 58 men with a mean age of 47.5±11.2years were included in this study. The mean VAS score was 7.7±1.5. Eighty-three patients (64.8%) had depression and 24 patients (18.8%) suffered anxiety. Multivariate logistic regression analysis revealed that female gender (OR=2.4, P=0.036), high pain intensity (OR=3.25, P=0.027) and ineffective medicine treatment (OR=1.89, P=0.041) were associated with depression, and female gender (OR=3.45, P=0.034) and high pain intensity (OR=2.88, P=0.022) were also associated with anxiety. There were significant improvements in depression and anxiety symptoms between pre- and postoperative responses. CONCLUSIONS Depression and anxiety are prevalent in patients with idiopathic TN. Female gender, high pain intensity and ineffective medicine treatment are risk factors. MVD not only provides high pain-relief rate, but also leads to significant improvements in the depression and anxiety symptoms.

Microvascular decompression for trigeminal neuralgia in patients with failed gamma knife surgery: Analysis of efficacy and safety.

OBJECTIVE Though it is usually successful, failure or delayed pain recurrence may occur after gamma knife surgery (GKS) in patients with trigeminal neuralgia (TN), and additional intervention may be required. This study aimed to investigate whether the safety and efficacy of microvascular decompression (MVD) were influenced by prior GKS. PATIENTS AND METHODS The authors retrospectively evaluated 36 consecutive TN patients who underwent MVD after failed GKS from January 2012 to June 2013. The clinical features, operative findings and surgical outcomes were reviewed and statistically analyzed, and the operation results were further compared with a cohort of 60 patients with no prior GKS. RESULTS At surgery, atrophy of the trigeminal nerve was observed in 13 patients (36.1%), arachnoid thickening in 6 patients (16.7%), adhesions between vessels and the trigeminal nerve in 8 patients (22.2%), and atherosclerotic plaque in the offending vessels in 3 patients (8.3%). The complete pain relief rates were 83.3% immediately after MVD and 72.2% at last follow-up, which showed no statistical difference when compared with patients without GKS. New or worsened facial numbness occurred in 7 patients (19.4%), which was significantly higher than those without GKS (p=0.02). Univariate analysis suggested that a positive pain response to the prior GKS correlated with better long-term outcome (p=0.015), and the existence of arachnoid adhesions correlated with higher risk of facial numbness (p=0.03). CONCLUSIONS MVD remains an appropriate and effective alternative therapy for patients with failed GKS, with no added technical difficulty. However, the risk of facial numbness seems to be higher than those with MVD alone.

Primary trigeminal neuralgia is associated with posterior fossa crowdedness: A prospective case-control study

Neurovascular conflict (NVC) has been postulated to be the underlying cause of trigeminal neuralgia (TN). Does the posterior fossa crowdedness increase the chance of NVC? The aim of this study was to quantitatively measure the posterior fossa crowdedness in patients with TN and to perform a comparison with healthy controls. We conducted a prospective case-control study of 46 patients diagnosed with primary TN and 46 sex- and age-matched healthy controls. All subjects underwent high-resolution three-dimensional MRI, and the 3D Slicer software was used to measure the posterior fossa volume (PFV) and hindbrain volume (HBV). The posterior fossa crowdedness index (PFCI) was calculated as HBV/PFV × 100%. The results showed that patients with TN had a larger HBV (155.4 ± 23.2 cm3 versus 152.9 ± 13.5 cm3, P = .16) and a smaller PFV (182.7 ± 18.3 cm3 versus 186.1 ± 11.7 cm3, P = .42) as compared to control subjects, but these values were not significantly different. The mean PFCI was significantly higher in patients with TN than in controls (85.1% ± 3.4% versus 82.2% ± 5.3%; P = .03). Women had a more crowded posterior fossa than men (85.8% ± 2.1% versus 84.1% ± 2.6%; P = .023) in patients with TN. The correlation analysis showed that a higher PFCI was associated with younger age (P = .02), woman (P = .014), and TN disease (P = .001). From this study, we conclude that patients with TN have a more crowded posterior fossa than healthy subjects. Women, younger age and TN disease are associated with a higher PFCI. The posterior fossa crowdedness may be a risk factor of NVC, and thus more likely to result in the genesis of TN.

Surgical management of hemifacial spasm associated with chiari I malformation: analysis of 28 cases

OBJECTIVE Hemifacial spasm (HFS) associated with Chiari I malformation (CIM) is rare. This study aimed to analyze the frequency of HFS associated with CIM in our department and further to investigate the clinical characteristics, treatment strategies, and outcomes of these cases. METHODS Twenty-eight of 831 patients with HFS who fulfilled the criteria for CIM were analyzed retrospectively. In this series, microvascular decompression (MVD) was performed in 23 patients (82.1%). The remaining 5 patients (17.9%) with obvious symptoms attributable to CIM were treated only with foramen magnum decompression. The mean follow-up period was 41 ± 21.7 months. RESULTS The frequency of HFS associated with CIM was 3.4%. There were 19 women (67.9%) and 9 men (32.1%) with a mean age of 36.4 ± 7.5 years. The most common symptoms were headache, paraesthesias, and muscular weakness with the exception of typical HFS. Seventeen patients (73.9%) experienced immediate postoperative spasm relief, and 21 patients (91.3%) were spasm relief at discharge after MVD. However, 3 patients (14.3%) experienced delayed recurrence of HFS after successful MVD in the follow-up. After foramen magnum decompression, 3 of 5 patients experienced complete relief of the spasm, and 4 patients showed improvement in the CIM-related symptoms. CONCLUSIONS The results suggest that MVD can still be an effective treatment for HFS when it coexists with CIM. Furthermore, posterior fossa crowdedness may be a common risk factor for the 2 diseases, and foramen magnum decompression should be considered as the primary procedure in patients with HFS and symptomatic CIM.

Potential regulation of glioma through the induction of apoptosis signaling via Egl‑9 family hypoxia‑inducible factor 3

Glioma is an aggressive form of brain cancer that occurs following the abnormal proliferation of glial cells. Although glioma cannot spread to other organs, the morbidity and mortality rates of the disease are high, even following surgery, radiotherapy and chemotherapy. The function of Egl-9 family hypoxia-inducible factor 3 (Egln3) in cancer is controversial, and it is debated as to whether Egln3 positively or negatively regulates tumors. In the present study, a mouse model of low-grade glioma was successfully established. Through the use of immunohistochemical and western blot analyses, it was demonstrated that Egln3 expression in glioma tissue performed an important role in regulation by amplifying the signals for apoptosis, as determined by an increase in DNA fragments. Furthermore, Egln3 expression was inhibited by the administration of dimethyloxalylglycine, and the downregulated expression of Egln3 had marked effects on the regulation of glioma through apoptosis. The present study therefore provides evidence of an association between Egln3 expression and apoptosis in low-grade glioma.

Anticonvulsant effect of piperine ameliorates memory impairment, inflammation and oxidative stress in a rat model of pilocarpine-induced epilepsy

The primary active component of black pepper is piperine, which is purified and used to treat epilepsy, achieving higher efficiency when purified. The present study was conducted to evaluate whether the anticonvulsant effect of piperine ameliorates pilocarpine-induced epilepsy, and to investigate the mechanism underlying these effects. Epilepsy was induced in Sprague Dawley rats using pilocarpine. Pilocarpine-induced epilepsy in the rats was treated with 40 mg/kg piperine for 45 consecutive days. Status epilepticus and a Morris water maze test were used to analyze the anticonvulsant effects of piperine in the epileptic rats. Inflammation and oxidative stress were then measured using commercially-available kits following piperine treatment. Lastly, the activity of caspase-3 and the protein expression levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were evaluated using commercially-available kits and western blot analysis, respectively. The results demonstrated that treatment with piperine was able to reduce the status epilepticus and prevented memory impairment following pilocarpine-induced epilepsy in rats. The anticonvulsant effects of piperine decreased inflammation and oxidative stress following pilocarpine-induced epilepsy in rats. The upregulated activity of caspase-3 and expression levels of Bax/Bcl-2 were suppressed following treatment with piperine in the rats with pilocarpine-induced epilepsy. These results suggest that the anticonvulsant effects of piperine ameliorate memory impairment, inflammation and oxidative stress in a rat model of pilocarpine-induced epilepsy.