A novel scoring system as a preoperative predictor for pain-free survival after microsurgery for trigeminal neuralgia.

OBJECTIVEPain relief following microvascular decompression (MVD) for trigeminal neuralgia (TN) may be related to pain type, degree of neurovascular conflict, arterial compression, and location of compression. The objective of this study was to construct a predictive pain-free scoring system based on clinical and radiographic factors that can be used to preoperatively prognosticate long-term outcomes for TN patients following surgical intervention (MVD or internal neurolysis [IN]). It was hypothesized that contributing factors would include pain type, presence of an artery or vein, neurovascular conflict severity, and compression location (root entry zone).METHODSAt the authors' institution 275 patients with type 1 or type 2 TN (TN1 or TN2) underwent MVD or IN following preoperative high-resolution brain MRI studies. Outcome data were obtained retrospectively by chart review and/or phone follow-up. Characteristics of neurovascular conflict were obtained from preoperative MRI studies. Factors that resulted in a probability value of < 0.05 on univariate logistic regression analyses were entered into a multivariate Cox regression analysis in a backward stepwise fashion. For the multivariate analysis, significance at the 0.15 level was used. A prognostic system was then devised with 4 possible scores (0, 1, 2, or 3) and pain-free survival analyses conducted.RESULTSUnivariate predictors of pain-free survival were pain type (p = 0.013), presence of any vessel (p = 0.042), and neurovascular compression severity (p = 0.038). Scores of 0, 1, 2, and 3 were found to be significantly different in regard to pain-free survival (log rank, p = 0.005). At 5 and 10 years there were 36%, 43%, 61%, and 69%, and 36%, 43%, 56%, and 67% pain-free survival rates in groups 0, 1, 2, and 3, respectively. While TN2 patients had worse outcomes regardless of score, a subgroup analysis of TN1 patients with higher neurovascular conflict (score of 3) had significantly better outcomes than TN1 patients without severe neurovascular conflict (score of 1) (log rank, p = 0.005). Regardless of pain type, those patients with severe neurovascular conflict were more likely to have arterial compression (99%) compared to those with low neurovascular conflict (p < 0.001).CONCLUSIONSPain-free survival was predicted by a scoring system based on preoperative clinical and radiographic findings. Higher scores predicted significantly better pain relief than lower scores. TN1 patients with severe neurovascular conflict had the best long-term pain-free outcome.

Sex-dependent posterior fossa anatomical differences in trigeminal neuralgia patients with and without neurovascular compression: a volumetric MRI age- and sex-matched case-control study.

OBJECTIVE: The pathophysiology of trigeminal neuralgia (TN) in patients without neurovascular compression (NVC) is not completely understood. The objective of this retrospective study was to evaluate the hypothesis that TN patients without NVC differ from TN patient with NVC with respect to brain anatomy and demographic characteristics. METHODS: Six anatomical brain measurements from high-resolution brain MR images were tabulated; anterior-posterior (AP) prepontine cistern length, cerebellopontine angle (CPA) cistern volume, nerve-to-nerve distance, symptomatic nerve length, pons volume, and posterior fossa volume were assessed on OsiriX. Brain MRI anatomical measurements from 232 patients with either TN type 1 or TN type 2 (TN group) were compared with measurements obtained in 100 age- and sex-matched healthy controls (control group). Two-way ANOVA tests were conducted on the 6 measurements relative to group and NVC status. Bonferroni adjustments were used to correct for multiple comparisons. A nonhierarchical k-means cluster analysis was performed on the TN group using age and posterior fossa volume as independent variables. RESULTS: Within the TN group, females were found to be younger than males and less likely to have NVC. The odds ratio (OR) of females not having NVC compared to males was 2.7 (95% CI 1.3-5.5, p = 0.017). Patients younger than 30 years were much less likely to have NVC compared to older patients (OR 4.9, 95% CI 1.3-18.4, p = 0.017). The mean AP prepontine cistern length and symptomatic nerve length were smaller in the TN group than in the control group (5.3 vs 6.5 mm and 8.7 vs 9.7 mm, respectively; p < 0.001). The posterior fossa volume was significantly smaller in TN patients without NVC compared to those with NVC. A TN group cluster analysis suggested a sex-dependent difference that was not observed in those without NVC. Factorial ANOVA and post hoc testing found that findings in males without NVC were significantly different from those in controls or male TN patients with NVC and similar to those in females (female controls as well as female TN patients with or without NVC). CONCLUSIONS: Posterior fossa volume in males was larger than posterior fossa volume in females. This finding, along with the higher incidence of TN in females, suggests that smaller posterior fossa volume might be an independent factor in the pathophysiology of TN, which warrants further study.

Pain-free survival after vagoglossopharyngeal complex sectioning with or without microvascular decompression in glossopharyngeal neuralgia.

OBJECTIVE: Glossopharyngeal neuralgia (GN) is a rare pain condition in which patients experience paroxysmal, lancinating throat pain. Multiple surgical approaches have been used to treat this condition, including microvascular decompression (MVD), and sectioning of cranial nerve (CN) IX and the upper rootlets of CN X, or a combination of the two. The aim of this study was to examine the long-term quality of life and pain-free survival after MVD and sectioning of the CN X/IX complex. METHODS: A combined retrospective chart review and a quality-of-life telephone survey were performed to collect demographic and long-term outcome data. Quality of life was assessed by means of a questionnaire based on a combination of the Barrow Neurological Institute pain intensity scoring criteria and the Brief Pain Inventory-Facial. Kaplan-Meier analysis was performed to determine pain-free survival. RESULTS: Of 18 patients with GN, 17 underwent sectioning of the CN IX/X complex alone or sectioning and MVD depending on the presence of a compressing vessel. Eleven of 17 patients had compression of CN IX/X by the posterior inferior cerebellar artery, 1 had compression by a vertebral artery, and 5 had no compression. One patient (6%) experienced no immediate pain relief. Fifteen (88%) of 17 patients were pain free at the last follow-up (mean 9.33 years, range 5.16-13 years). One patient (6%) experienced throat pain relapse at 3 months. The median pain-free survival was 7.5 years ± 10.6 months. Nine of 18 patients were contacted by telephone. Of the 17 patients who underwent sectioning of the CN IX/X complex, 13 (77%) patients had short-term complaints: dysphagia (n = 4), hoarseness (n = 4), ipsilateral hearing loss (n = 4), ipsilateral taste loss (n = 2), and dizziness (n = 2) at 2 weeks. Nine patients had persistent side effects at latest follow-up. Eight of 9 telephone respondents reported that they would have the surgery over again. CONCLUSIONS: Sectioning of the CN IX/X complex with or without MVD of the glossopharyngeal nerve is a safe and effective surgical therapy for GN with initial pain freedom in 94% of patients and an excellent long-term pain relief (mean 7.5 years).

Deep Brain Stimulation-Related Infections: Analysis of Rates, Timing, and Seasonality.

BACKGROUND: Infection is one of the most common complications of deep brain stimulation (DBS). Long-term infection rates beyond the immediate postoperative period are rarely evaluated. OBJECTIVE: To study short- and long-term DBS-related infection rates; to evaluate any potential seasonality associated with DBS-related infections. METHODS: We retrospectively reviewed all DBS surgeries performed in a 5-yr period at 1 hospital by a single surgeon. Infection rates and clinical characteristics were analyzed. Postoperative "infections" were defined as occurring within 6 mo of implantation of DBS hardware, while "erosions" were defined as transcutaneous exposure of hardware at ≥6 mo after implantation. Based on the date of surgery preceding an infection, rates of infection were calculated on a monthly and seasonal basis and compared using Chi square and logistic regression analyses. RESULTS: A total of 443 patients underwent 592 operations; 311 patients underwent primary DBS placement with 632 electrodes. Primary DBS placement infection incidence was 2.6%. DBS procedure infection and infection rate by electrode were 2.9% and 3.2%, respectively. Infectious complications presented later than 6 mo postoperatively in 38% of infected patients Summer (July-September) infection rate was significantly higher than other seasons (P = .002). The odds ratio of an infection related to a surgery performed in August was found to be 4.15 compared to other months (P = .021). CONCLUSION: There is a persistent risk of DBS infection and erosion beyond the first year of DBS implantation. Start of the academic year was associated with increased infection rate at our institution.

Application of Lean Principles to Neurosurgical Procedures: The Case of Lumbar Spinal Fusion Surgery, a Literature Review and Pilot Series.

BACKGROUND: Delivery of higher value healthcare is an ultimate government and public goal. Improving efficiency by standardization of surgical steps can improve patient outcomes, reduce costs, and lead to higher value healthcare. Lean principles and methodology have improved timeliness in perioperative medicine; however, process mapping of surgery itself has not been performed. OBJECTIVE: To apply Plan/Do/Study/Act (PDSA) cycles methodology to lumbar posterior instrumented fusion (PIF) using lean principles to create a standard work flow, identify waste, remove intraoperative variability, and examine feasibility among pilot cases. METHODS: Process maps for 5 PIF procedures were created by a PDSA cycle from 1 faculty neurosurgeon at 1 institution. Plan, modularize PIF into basic components; Do, map and time components; Study, analyze results; and Act, identify waste. Waste inventories, spaghetti diagrams, and chartings of time spent per step were created. Procedural steps were broadly defined in order to compare steps despite the variability in PIF and were analyzed with box and whisker plots to evaluate variability. RESULTS: Temporal variabilities in duration of decompression vs closure and hardware vs closure were significantly different (P = .003). Variability in procedural step duration was smallest for closure and largest for exposure. Wastes including waiting and instrument defects accounted for 15% and 66% of all waste, respectively. CONCLUSION: This pilot series demonstrates that lean principles can standardize surgical workflows and identify waste. Though time and labor intensive, lean principles and PDSA methodology can be applied to operative steps, not just the perioperative period.

Use of Risk Model for Assessment of Residents' Perception of Complexity of Surgical Steps: Example of Modular Component Steps of Lumbar Spinal Fusion Surgery.

BACKGROUND: Quality improvement projects increasingly emphasize standardization of surgical work flow to optimize operative room efficiency. Removing special cause variability resulting from nonsurgical waste is an obvious target; however, resident surgical education must be maintained, even in the setting of process improvement. OBJECTIVE: To describe the impact of resident-identified "risky" or "uncomfortable" procedural steps on operative time during transforaminal lumbar interbody fusion (TLIF). METHODS: TLIF procedure steps were defined. An 8 2-part questions survey regarding comfort level and perceived risk assessment at each step was developed and completed by junior (17) and senior residents (10), and by faculty (6) from orthopedic, and neurological surgery. A risk matrix was constructed defining 2 zones: a "danger zone"; responses were high risk (3-5) and low comfort (1-3), and a "safe zone"; responses were low risk (1-2) and high comfort (4-5). One-tailed Chi-square with Yates correction was performed. RESULTS: Risk matrix analysis showed a statistical difference among "danger zone" respondents between junior resident and faculty groups for exposure, pedicle screw placement, neural decompression, interbody placement, posterolateral fusion, and hemostasis. A radar graph identifies percent of respondents who fall within the "danger zone". CONCLUSION: Resident perception of surgical complexity can be evaluated for procedural steps using a risk matrix survey. For TLIF, residents may assign more risk and may be less comfortable performing steps in a training-level-dependent manner. Identification of particular high-risk or uncomfortable steps should prompt strict faculty oversight to improve patient safety, monitor resident education, and reduce operative time.

Inverse effects of oxytocin on attributing mental activity to others in depressed and healthy subjects: a double-blind placebo controlled FMRI study.

BACKGROUND: Oxytocin is a stress-attenuating and pro-social neuropeptide. To date, no study has looked at the effects of oxytocin in modulating brain activity in depressed individuals nor attempted to correlate this activity with attribution of mental activity in others. METHOD: We enrolled 10 unmedicated depressed adults and 10 matched healthy controls in a crossover, double blind placebo controlled fMRI 40 i.u. intra-nasal oxytocin study (20 i.u. per nostril). Each subject performed reading the mind in the eyes task (RMET) before and after inhalation of oxytocin or placebo control for a total of 80 scans. RESULTS: Before oxytocin administration, RMET engaged the medial and lateral prefrontal cortex, amygdala, insula and associative areas. Depressed subjects showed increased anterior ventral activation for the RMET minus gender identification contrast whereas matched controls showed increased dorsal and frontal activity. Compared to placebo, oxytocin in depressed subjects showed increased activity in the superior middle frontal gyrus and insula, while controls exhibited more activity in ventral regions. Oxytocin also led to inverse effects in reaction times on attribution task between groups, with controls getting faster and depressed individuals slower to respond. CONCLUSION: Depression is associated with increased paralimbic activity during emotional mental attribution of others, appearing to be distinctly modulated by oxytocin when compared to healthy controls. Further studies are needed to explore long-term exposure to pro-social neuropeptides on mood in depressed populations and assess their clinical relevance.