Trigemino-cardiac reflex: the trigeminal depressor responses during skull base surgery.

OBJECTIVE: To observe and analyze the occurrence and management of the trigemino-cardiac reflex (TCR) defined as the phenomenon of abrupt drops in heart rate (HR) and blood pressure during skull base surgery. METHOD: One hundred patients underwent skull base surgery for various lesions were recruited and great attention was paid to heart rate and blood pressure throughout the surgical procedure to screen intraoperative TCR. RESULT: Twelve patients had TCR intro-operatively, all patients showed abrupt drops in HR of 38% from a mean of 78 beats/min to a mean of 49 beats/min, mean arterial blood pressure (MABP) decreased 33% from a mean of 93 mmHg to a mean of 60 mmHg, respectively. TCR was resolved spontaneously in eight patients, but had to be offset by intraoperative administration of relatively higher dose atropine in another four patients. CONCLUSION: (1) Manipulation at or near the trigeminal nerve during the skull base surgery may cause TCR, even if premedication with anticholinergic drug is used; (2) cessation of irritation from surgical manipulation to disrupt the reflex is the most important step to offset TCR; (3) continuous, especially repeated TCR in some rare cases occasionally necessitates the administration of high dose atropine.

Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of intractable trigeminal neuralgia.

BACKGROUND: Percutaneous radiofrequency thermocoagulation of the trigeminal ganglion (PRTTG) is regarded as the first choice for most patients with trigeminal neuralgia (TN) because of its safety and feasibility. However, neuronavigator-guided PRTTG has been seldom reported. The purpose of this study was to assess the safety and efficacy of neuronavigator-guided PRTTG for the treatment of intractable TN. METHODS: Between January 2000 and December 2004, 54 patients with intractable TN were enrolled into this study and were randomly divided into two groups. The patients in navigation group (n = 26) underwent PRTTG with frameless neuronavigation, and those in control group (n = 28) received PRTTG without neuronavigation. Three months after the operation, the efficacy, side effects, and complications of the surgery were recorded. The patients in the control group were followed up for 10 to 54 months (mean, 34 +/- 5), and those in the navigation group were followed up for 13 to 58 months (mean, 36 +/- 7). Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data, and the log-rank test was used to compare survival curves of the two groups. RESULTS: The immediate complete pain-relief rate of the navigation group was 100%, whereas it was 95% in the control. The proportion of sustained pain-relief rates at 12, 24 and 36 months after the procedure were 85%, 77%, and 62% in the navigation group, and 54%, 40%, and 35% in the control. Recurrences in the control group were more common than that in the navigation group. Annual recurrence rate in the first and second years were 15% and 23% in the navigation group, and 46%, 60% in the control group. No side-effect and complication was noted in the navigation group except minimal facial hypesthesia. CONCLUSION: Neuronavigator-guided PRTTG is a safe and promising method for treatment of intractable TN with better short- and long-term outcomes and lower complication rate than PRTTG without neuronavigation.

[Microsurgical treatment of trigeminal neurinomas with middle fossa extradural approach].

OBJECTIVE: To investigate the effect of microsurgical treatment of trigeminal neurinomas with middle fossa extradural approach. METHODS: Between January 1996 and December 2005, 27 patients with trigeminal schwannomas were treated by middle fossa extradural approach. The clinical data were retrospectively analyzed. RESULTS: Total resection was achieved in 25 patients and subtotal resection in the other 2 patients. The cranial nerve deficits were improved in 18 patients, unchanged in 4 patients and worsened in 5 patients postoperatively. New Incomplete paralysis of cranial nerve were observed in 4 patients. Cerebrospinal fluid leakages and bacterial meningitis occurred in 2 cases, which were cured by lumber draining and antibiotic therapy. There was not operative mortality. Twenty six patients were followed up for 6 - 48 months. Tumor recurrence was found in 1 case after 40 months and was excised again. CONCLUSION: This approach can provide better exposure of these tumors and multiple working angles with minimal brain retraction and can improve the surgical results in terms of increased complete tumor resection rate and reduced complications rate.

Association between XRCC1 Arg399Gln polymorphism and glioma risk in a Chinese population: a case-control study.

AIM: In China, the incidence rates of glioma tend to be increased, however, the genetic contribution to its etiology is not well-understood. The aim of this study is to evaluate the association of XRCC1 Arg399Gln polymorphism with glioma risk in a Chinese population. MATERIALS AND METHODS: We conducted a case-control study on 387 patients with glioma and 400 cancer-free controls between 2004 and 2014. Peripheral blood samples of both groups were processed for DNA extraction and genotyping of the XRCC1 Arg399Gln polymorphism using PCR-RFLP. Comparison of the distribution of Arg399Gln genotypes in the study groups was performed by means of 2-sided contingency tables using the χ(2) test. Hazard ratios (HRs) were estimated by Cox proportional hazard regression model. RESULTS: When the AA genotype was used as the reference group, the GG genotype was associated with significantly increased risk for glioma (adjusted OR = 3.18, 95% CI = 1.38-3.88; P = 0.017). Under the dominant model of inheritance, the AG + GG genotype was associated with significantly increased risk for glioma (adjusted OR =2.33, 95% CI = 1.12-5.81; P = 0.023). When the A allele was used as the reference group, the G allele was associated with increased glioma risk (adjusted OR, 2.44, 95% CI, 1.76-4.18; P = 0.003). CONCLUSION: Our data suggests that XRCC1 Arg399Gln polymorphism contribute to increased risk of glioma, which may be susceptibility biomarkers for glioma.

Cardiovascular responses during percutaneous radiofrequency thermocoagulation therapy in primary trigeminal neuralgia.

Our objective was to observe and document cardiovascular side effects of radiofrequency thermocoagulation of the trigeminal ganglion. Forty-eight patients with primary trigeminal neuralgia were enrolled into this study. Continuous electrocardiogram, heart rate, cardiac rhythm changes, and systemic blood pressure were monitored during the procedure of oval foramen puncture, electrode needle stimulation, and lesion production. Oval foramen puncture led to decreases in heart rate in 6 patients, increases in heart rate in another 42 patients, and significant elevation of mean arterial blood pressure in all 48 patients. The frequency (50 Hz) of prelesion electrical stimulation caused slight pressor responses, and radiofrequency thermocoagulation caused marked pressor responses. The correlation between the intensity of the stimulus and the magnitude of the pressor response was positive when temperature during radiofrequency thermocoagulation was below 75 degrees C. That correlation became negative when the temperature exceeded 75 degrees C. We conclude that greater anticipatory awareness should be directed toward pressor than depressor responses during the procedures of percutaneous radiofrequency thermocoagulation therapy in primary trigeminal neuralgia.