Minimally invasive endoscopic evacuation with the novel, portable Axonpen neuroendoscopic system for spontaneous intracerebral hemorrhage

Minimally invasive surgeries have shown potential to improve mortality and clinical outcomes of spontaneous intracerebral hemorrhage (ICH). The present study assessed the first-in-human outcomes of a novel, portable neuroendoscopic system for ICH evacuation at our single center. This neuroendoscopic system integrates real-time visualization into a handpiece which has controllable suction, irrigation, and coagulation to allow a neurosurgeon to conduct minimally invasive ICH evacuation independently with bimanual dexterity. Pre- and postoperative data of ten patients who had spontaneous basal ganglia hemorrhage (mean: 46.5 ± 12.2 mL) and underwent evacuation with the specified neuroendoscopic system were collected prospectively. The mean time to receive surgery was 12.1 ± 7.6 h. Mean operative time was 3.4 ± 0.9 h. The mean hematoma volume decreased to 6.0 ± 3.9 mL at postoperative 6 h, resulting in a mean volume reduction of 86.0 ± 11.2% (P = 0.005). The median length of intensive care unit stay was 3 days (IQR, 3-4 days). At discharge, the median Glasgow Coma Scale (GCS) score significantly improved to 11.5 (IQR, 11-15; P = 0.016), and the median modified Rankin Scale (mRS) score was 4 (IQR, 4-5). Six patients (60%) showed a favorable mRS score of ≤ 3 on their last return visit. Neither death nor rebleeding occurred during the follow-up periods. Integrated design of the innovative device is valuable to optimize minimally invasive endoscopic ICH evacuation procedure. Further studies are needed to clarify long-term benefits from such type of the innovative device to early intervention of ICH.

Focused ultrasound combined with radiotherapy for malignant brain tumor: a preclinical and clinical study

INTRODUCTION

Blood-brain barrier (BBB) remains to be the major obstacle to conquer in treating patients with malignant brain tumors. Radiation therapy (RT), despite being the mainstay adjuvant modality regardless of BBB, the effect of radiation induced cell death is hindered by the hypoxic microenvironment. Focused ultrasound (FUS) combined with systemic microbubbles has been shown not only to open BBB but also potentially increased regional perfusion. However, no clinical study has investigated the combination of RT with FUS-BBB opening (RT-FUS).

METHODS

We aimed to provide preclinical evidence of RT-FUS combination in GBM animal model, and to report an interim analysis of an ongoing single arm, prospective, pilot study (NCT01628406) of combining RT-FUS for recurrent malignant high grade glioma patients, of whom re-RT was considered for disease control. In both preclinical and clinical studies, FUS-BBB opening was conducted within 2 h before RT. Treatment responses were evaluated by objective response rate (ORR) using magnetic resonance imaging, progression free survival, and overall survival, and adverse events (AE) in clinical study. Survival analysis was performed in preclinical study and descriptive analysis was performed in clinical study.

RESULTS

In mouse GBM model, the survival analysis showed RT-FUS (2 Gy) group was significantly longer than RT (2 Gy) group and control, but not RT (5 Gy) group. In the pilot clinical trial, an interim analysis of six recurrent malignant high grade glioma patients underwent a total of 24 RT-FUS treatments was presented. Three patients had rapid disease progression at a mean of 33 days after RT-FUS, while another three patients had at least stable disease (mean 323 days) after RT-FUS with or without salvage chemotherapy or target therapy. One patient had partial response after RT-FUS, making the ORR of 16.7%. There was no FUS-related AEs, but one (16.7%) re-RT-related grade three radiation necrosis.

CONCLUSION

Reirradiation is becoming an option after disease recurrence for both primary and secondary malignant brain tumors since systemic therapy significantly prolongs survival in cancer patients. The mechanism behind the synergistic effect of RT-FUS in preclinical model needs further study. The clinical evidence from the interim analysis of an ongoing clinical trial (NCT01628406) showed a combination of RT-FUS was safe (no FUS-related adverse effect). A comprehensive analysis of radiation dosimetry and FUS energy distribution is expected after completing the final recruitment.

Long-term follow-up and comparison of programmable and non-programmable ventricular cerebrospinal fluid shunts among adult patients with different hydrocephalus etiologies: a retrospective cohort study

BACKGROUND

Programmable valve (PV) has been shown as a solution to the high revision rate in pediatric hydrocephalus patients, but it remains controversial among adults. This study is to compare the overall revision rate, revision cause, and revision-free survival between PV and non-programmable valve (NPV) in adult patients with different hydrocephalus etiologies.

METHOD

We reviewed the chart of all patients with hydrocephalus receiving index ventricular cerebrospinal fluid (CSF) shunt operations conducted at a single institution from January 2017 to December 2017. Patients included in the study were followed up for at least 5 years. Statistical tests including independent t-test, chi-square test, and Fisher's exact test were used for comparative analysis, and Kaplan-Meier curve using log-rank test was performed to compare the revision-free survival between the PV and NPV groups.

RESULTS

A total of 325 patients were included in the study, of which 181 patients were receiving PVs and 144 patients receiving NPV. There were 23 patients (12.8%) with PV and 22 patients (15.3%) with NPV receiving initial revision. No significant statistical difference in the initial revision rate was observed between the two groups (p = 0.52). No survival difference was found between the PV and NPV groups. However, better revision-free survival was noted in the PV group among idiopathic normal pressure hydrocephalus (iNPH) (p = 0.0274) and post-traumatic hydrocephalus (p = 0.017).

CONCLUSIONS

The combination of the different etiologies of hydrocephalus and the features of PV and NPV results in different outcomes-revision rate and revision-free survival. PV use might be superior to NPV in iNPH and post-traumatic hydrocephalus patients. Further studies are needed to clarify the indications of PV use in adult hydrocephalus patients.

Correlation between initial tumor enlargement and magnetic resonance imaging characteristics following linear accelerator-based stereotactic radiosurgery for acoustic neuromas

BACKGROUND

Initial tumor enlargement (or pseudoprogression) instead of true tumor progression is a common phenomenon in patients with acoustic neuromas who are treated with stereotactic radiosurgery (SRS). This phenomenon can affect clinical decision-making and patient management. This study assessed the correlation between initial tumor enlargement and magnetic resonance imaging characteristics in patients with acoustic neuromas who were treated with linear accelerator (LINAC)-based SRS. The long-term tumor control outcomes were also analyzed.

MATERIALS AND METHODS

In total, 330 patients with sporadic acoustic neuromas who were treated with LINAC SRS between March 2006 and March 2020 were retrospectively evaluated to assess their initial tumor enlargement. The tumors were divided into homogeneously enhanced, heterogeneously enhanced, and cystic types based on the morphological characteristics noted on magnetic resonance images. Tumor control was assessed in 275 patients with a follow-up duration of more than 2 years.

RESULTS

Initial enlargement was observed in 137 of 330 (41.5%) tumors as early as 3 months after LINAC SRS. Data analysis revealed that postoperative tumors with a residual volume lower than 2.5 cm3 had a lower incidence of initial enlargement (p = 0.039). No correlation was noted between the initial enlargement and morphological characteristics of tumors. In patients with a mean follow-up duration of 82.8 ± 37.2 months, heterogeneously enhanced tumors exhibited a lower control rate than homogeneously enhanced and cystic tumors (p = 0.045). No correlation was noted between initial enlargement and tumor control.

CONCLUSION

Initial enlargement can occur as early as 3 months after SRS. Postoperative residual tumors with a volume lower than 2.5 cm3 exhibit a lower incidence of initial enlargement. Heterogeneously enhanced tumors have a lower local control rate.

Risk factors for peritumoral edema after radiosurgery for intracranial benign meningiomas: a long-term follow-up in a single institution

OBJECTIVE

Peritumoral edema (PTE) is recognized as a complication following stereotactic radiosurgery (SRS). The aim of this paper was to evaluate the risk of post-SRS PTE for intracranial benign meningiomas and determine the predictive factors.

METHODS

Between 2006 and 2021, 227 patients with 237 WHO grade I meningiomas were treated with Novalis linear accelerator SRS. All patients were treated with a single-fraction dose of 11–20 Gy (median 14 Gy). The median tumor volume was 3.32 cm3 (range 0.24–51.7 cm3).

RESULTS

The median follow-up was 52 months (range 12–178 months). The actuarial local tumor control rates at 2, 5, and 10 years after SRS were 99.0%, 96.7%, and 86.3%, respectively. Twenty-seven (11.9%) patients developed new or worsened post-SRS PTE, with a median onset time of 5.2 months (range 1.2–50 months). Only 2 patients developed post-SRS PTE after 24 months. The authors evaluated factors related to new-onset or worsened PTE after SRS. In univariate analysis, initial tumor volume > 10 cm3 (p = 0.03), total marginal dose > 14 Gy (p < 0.001), preexisting edema (p < 0.0001), tumor location (p < 0.001), parasagittal location (p < 0.0001), superior sagittal sinus (SSS) involvement (p < 0.0001), and SSS invasion (p < 0.015) were found to be significant risk factors. In multivariate analysis, total marginal dose > 14 Gy (HR 3.38, 95% CI 1.37–8.33, p = 0.008), preexisting SRS edema (HR 12.86, 95% CI 1.09–4.15, p < 0.0001), tumor location (HR 2.13, 95% CI 1.04–3.72, p = 0.027), parasagittal location (HR 8.84, 95% CI 1.48–52.76, p = 0.017), and SSS invasion (HR 0.34, 95% CI 0.13–0.89, p = 0.027) were significant risk factors. Twelve (5.3%) patients were symptomatic. Ten of 27 patients had complete resolution of neurological symptoms and edema improvement with steroid treatment. Steroid treatment failed in 2 patients, who subsequently required resection for PTE.

CONCLUSIONS

Radiosurgery is a safe and effective method of treating benign intracranial meningiomas according to long-term follow-up. We also identified total marginal dose > 14 Gy, preexisting PTE, parasagittal location, and SSS invasion as predictors of post-SRS PTE. Risk factors for post-SRS PTE should be considered in meningioma treatment.

Prognostic Factors Analysis for Intracranial Cavernous Malformations Treated with Linear Accelerator Stereotactic Radiosurgery

Stereotactic radiosurgery (SRS) is generally considered a substitute for cranial cavernous malformations (CCMs). However, prognostic factors for post-radiosurgery CCM rebleeding and adverse radiation effects have not been well evaluated, and the effect of timing and optimal treatment remains controversial. Therefore, this study evaluated prognostic factors for post-radiosurgical rebleeding and focal edematous changes in 30 patients who developed symptomatic intracranial hemorrhage due to solitary non-brainstem CCM and received linear accelerator (LINAC) SRS in a single medical center from October 2002 to June 2018. An overall post-radiosurgical annual hemorrhage rate with 4.5% was determined in this study. In addition, a higher marginal dose of >1600 centigray and earlier LINAC SRS intervention were correlated with a significantly lower post-radiosurgical annual hemorrhage rate. A lesion size larger than 3 cm3 and a coexisting developmental venous anomaly were significant risk factors for post-radiosurgical focal brain edema but mostly resulted in no symptoms and were temporary. This study demonstrated the efficacy of LINAC SRS in preventing CCM rebleeding and suggests that earlier radiosurgery treatment with a higher dose for non-brainstem symptomatic CCMs be considered.

Robot-Assisted Radiofrequency Ablation Combined with Thermodynamic Simulation for Epilepsy Reoperations

Repeat craniotomies to treat recurrent seizures may be difficult, and minimally invasive radiofrequency ablation is an alternative therapy. On the basis of this procedure, we aimed to develop a more reliable methodology which is helpful for institutions where real-time image monitoring or electrophysiologic guidance during ablation are not available. We used simulation combined with a robot-assisted radiofrequency ablation (S-RARFA) protocol to plan and execute brain epileptic tissue lesioning. Trajectories of electrodes were planned on the robot system, and time-dependent thermodynamics was simulated with radiofrequency parameters. Thermal gradient and margin were displayed on a computer to calculate ablation volume with a mathematic equation. Actual volume was measured on images after the ablation. This small series included one pediatric and two adult patients. The remnant hippocampus, corpus callosum, and irritative zone around arteriovenous malformation nidus were all treated with S-RARFA. The mean error percentage of the volume ablated between preoperative simulation and postoperative measurement was 2.4 ± 0.7%. No complications or newly developed neurologic deficits presented postoperatively, and the patients had little postoperative pain and short hospital stays. In this pilot study, we preliminarily verified the feasibility and safety of this novel protocol. As an alternative to traditional surgeries or real-time monitoring, S-RARFA served as successful seizure reoperation with high accuracy, minimal collateral damage, and good seizure control.

Phase IB trial of pegylated arginine deiminase (ADI-PEG 20) plus radiotherapy and temozolomide in patients with newly diagnosed glioblastoma

2057

Background: ADI-PEG 20 exploits the different metabolic ability for synthesizing arginine (Arg) between normal and neoplastic cells to reduce tumor cell growth. Preclinical and clinical studies have shown that cancers which are either Arg auxotrophic, with silencing of argininosuccinate synthetase ( ASS1), or Arg non-auxotrophic, respond to ADI-PEG 20 monotherapy or ADI-PEG 20 combined with various chemotherapies, respectively. ADI-PEG 20 has shown efficacy as monotherapy in ASS1 negative mouse glioblastoma (GBM) models and the combination of ADI-PEG 20 with temozolomide (TMZ) and with radiation (RT) in both ASS1 negative and ASS1 positive mouse GBM models. Based on these rationales, ADI-PEG 20 was added to standard RT + TMZ in patients with newly diagnosed GBM. This is the first clinical trial combining ADI-PEG 20 with RT. Methods: This phase IB, open-label, single-arm, standard 3+3 dose escalation with a recommended phase 2 dose (RP2D) expansion study (NCT04587830) was initiated in June 2020. Weekly ADI-PEG 20 is added to concurrent RT + TMZ and to 6 cycles of adjuvant TMZ (Stupp protocol). ADI-PEG 20 could be continued for up to 2 years. RANO criteria are used to determine response by evaluating MRI at 1, 3 and 6 months after RT, and every 3 months thereafter. Major eligibility criteria are age 20-75 years with newly diagnosed, histologically confirmed GBM with Karnofsky performance status ≥ 60. Endpoints include safety, pharmacodynamics, immunogenicity, progression free survival (PFS) and overall survival (OS). Results: Cohorts 1 (18 mg/m2) and 2 (36 mg/m2) were completed without dose limiting toxicity (DLT). Enrollment to cohort 3 (RP2D phase, 36 mg/m2) is ongoing with 23/26 patients. The major adverse events (AEs) were fatigue (52%), constipation (39%) and neutrophil decrease (39%). Dermatologic or allergic reactions occurred in 12/23 (52%), and all were grade 1-2 except for anaphylactic shock in 1 and vasculitis/rash in 1. 22/23 are alive, with median PFS = 9.5 months. The first 6 study patients are all alive for at least 11 months, with the longest at 1.5 years. 10 are off treatment due to progressive disease in 6, severe AE in 2, consent withdrawal in 1, and medical decision in 1. Mean peripheral blood Arg levels were suppressed ( < 10uM) for 4-6 weeks in most subjects, with a reciprocal elevation of citrulline levels. Anti-ADI-PEG 20 antibodies tended to increase as peripheral Arg levels increased. Conclusions: The addition of ADI-PEG 20 to RT + TMX was safe, and no DLT was observed. The RP2D of ADI-PEG 20 was determined to be 36mg/m2. AEs were those typically seen with RT + TMZ, with perhaps an increase in rash reported with the addition of ADI-PEG 20. Anaphylaxis and vasculitis were seen (1 subject with each), and have been observed previously with ADI-PEG 20. The preliminary OS data are encouraging. A registration phase 2/3 trial of this triplet is being considered. Clinical trial information: NCT04587830.

A manzamine-derived compound as a potential therapeutic agent for glioma by inducing apoptosis and cell cycle arrest

Glioma is a severe disease with a poor prognosis despite aggressive surgical resection and traditional chemotherapies. Therefore, new anti-neoplastic drugs are urgently needed. Bioactive compounds from natural products are potential sources of antiproliferative molecules, among which manzamine compounds extracted from the Formosan marine sponge Haliclona sp. have shown considerable promise as anticancer drugs. In the present study, the anti-neoplastic effect and mechanism of the manzamine derivative 1-(9'-propyl-3'-carbazole)-1, 2, 3, 4-tetrahydro-β-carboline (PCTC) were investigated using in vitro cell lines and an in vivo subcutaneous animal model. Both cytotoxic and anti-proliferative effects were shown in human and murine glioma cell lines (A172, U87MG, and GL261), together with enhanced expressions of apoptotic enzymes and intracellular reactive oxygen species, and blockage of the G1/S phase of the cell cycle. In addition, combined treatment of GL261 cells with PCTC and temozolomide had a synergic antiproliferative effect. Significant safety, efficacy, and survival benefits were also demonstrated with PCTC treatment in the murine subcutaneous GL261 model. In conclusion, PCTC could effectively promote cell death through apoptosis and cell cycle arrest in glioma cell lines, and provide survival benefits in the animal model. Therefore, PCTC may be a clinically beneficial therapy for glioblastoma.

Surgical Outcome and Evaluation of Strategies in the Management of Growth Hormone-Secreting Pituitary Adenomas After Initial Transsphenoidal Pituitary Adenectomy Failure

Acromegaly is a systemic disease that requires multidisciplinary treatment to achieve the best clinical outcome. This study aimed to evaluate the outcomes of the endoscopic transsphenoidal approach (TSA) as the primary treatment for somatotroph adenomas and further investigate patients who had suboptimal surgical results. This retrospective study included 83 patients with somatotroph adenomas treated by TSA at our institution from 1999 to 2010. Biochemical remission was defined as hGH <1 and <2.5 ng/ml. Factors associated with failure of TSA and strategy of secondary treatments for refractory and recurrent disease were analyzed. The mean age of patients was 41.1 ± 11.3 years, and the mean follow-up time was 54.2 ± 44.3 months. Approximately 44.5% of patients had residual tumors after TSA. Larger tumor size, higher GH level before the operation, and the existence of residual tumors were associated with TSA failure. Forty-one patients had an inadequate response to TSA or a recurrent lesion, and of these patients, 37 had residual tumor after TSA. Octreotide results in good outcomes in the treatment of DGSA patients, and SRS/EXRT generates good results in treating patients who receive second treatments when remission cannot be reached 6 months after TSA operation.

Safety and tolerability of asunercept plus standard radiotherapy/temozolomide in Asian patients with newly-diagnosed glioblastoma: a phase I study

Asunercept (company code APG101 [Apogenix AG]; company code CAN008 [CANbridge Pharmaceuticals]) is a novel glycosylated fusion protein that has shown promising effectiveness in glioblastoma. This Phase I study was initiated to evaluate the tolerability and safety of asunercept in combination with standard radiotherapy and temozolomide (RT/TMZ) in Asian patients with newly diagnosed glioblastoma. This was the Phase I portion of a Phase I/II open label, multicenter trial of asunercept plus standard RT/TMZ. Adults with newly-diagnosed glioblastoma received surgical resection followed by standard RT/TMZ plus asunercept 200 mg/week (Cohort 1) or 400 mg/week (Cohort 2) by 30-min IV infusion. The primary endpoint was the safety and tolerability of asunercept during concurrent asunercept and RT/TMZ; dose-limiting toxicities were observed for each dose. Secondary endpoints included pharmacokinetics (PK) and 6-month progression-free survival (PFS6). All patients (Cohort 1, n = 3; Cohort 2, n = 7) completed ≥ 7 weeks of asunercept treatment. No DLTs were experienced. Only one possibly treatment-related treatment emergent adverse event (TEAE), Grade 1 gingival swelling, was observed. No Grade > 3 TEAEs were reported and no TEAE led to treatment discontinuation. Systemic asunercept exposure increased proportionally with dose and showed low inter-patient variability. The PFS6 rate was 33.3% and 57.1% for patients in Cohort 1 and 2, respectively. Patients in Cohort 2 maintained a PFS rate of 57.1% at Month 12. Adding asunercept to standard RT/TMZ was safe and well tolerated in patients with newly-diagnosed glioblastoma and 400 mg/week resulted in encouraging efficacy.

Trial registration NCT02853565, August 3, 2016.

Incidence and Factors Associated with Postoperative Delayed Hyponatremia after Transsphenoidal Pituitary Surgery: A Meta-Analysis and Systematic Review

INTRODUCTION

Postoperative delayed hyponatremia is a complication associated with transsphenoidal pituitary surgery. Due to a wide spectrum of symptoms, the reported incidence and predictors of postoperative delayed hyponatremia vary among studies, and this deserves to be reviewed systematically.

METHODS

PubMed, EMBASE, and CENTRAL databases were searched until September 1, 2020. Studies were included when (1) the event number of delayed hyponatremia after transsphenoidal pituitary surgery was reported, or (2) the associated factors of such complication were evaluated.

RESULTS

A total of 27 studies were included for meta-analysis. The pooled incidence of overall and symptomatic delayed hyponatremia was 10.5% (95% confidence interval (CI) = 7.4-14.7%) and 5.0% (95% CI = 3.6-6.9%), respectively. No overt variations of the pooled estimates were observed upon subgroups stratified by endoscopic and microscopic procedure, publication year, and patients' age. In addition, 44.3% (95% CI = 29.6-60.2%) of unplanned hospital readmissions within 30 days were caused by delayed hyponatremia. Among the predictors evaluated, older age was the only significant factor associated with increased delayed hyponatremia (odds ratio = 1.16, 95% CI = 1.04-1.29, P = 0.006).

CONCLUSION

This meta-analysis and systematic review evaluated the incidence of postoperative delayed hyponatremia and found it as a major cause of unplanned readmissions after transsphenoidal pituitary surgery. Older patients are more prone to such complications and should be carefully followed. The retrospective nature and heterogeneity among the included studies and the small number of studies used for risk factor evaluation might weaken the corresponding results. Future prospective clinical studies are required to compensate for these limitations.

The Merits of Awake Craniotomy for Glioblastoma in the Left Hemispheric Eloquent Area: One Institution Experience

OBJECTIVE

Awake craniotomy (AC) with intraoperative stimulation mapping is the standard treatment for gliomas, especially those on the eloquent cortex. Many studies have reported survival benefits with the use of AC in patients with glioma, however most of these studies have focused on low-grade glioma. The aim of this study was to evaluate the experience of one treatment center over 10 years for resection of left hemispheric eloquent glioblastoma.

METHODS

This retrospective analysis included 48 patients with left hemispheric eloquent glioblastoma who underwent AC and 61 patients who underwent surgery under general anesthesia (GA) between 2008 and 2018. Perioperative risk factors, extent of resection (EOR), preoperative and postoperative Karnofsky Performance Score (KPS), progression-free survival (PFS) and overall survival (OS) were assessed.

RESULTS

The postoperative KPS was significantly lower in the GA patients compared to the AC patients (p = 0.002). The EOR in the GA group was 90.2% compared to 94.9% in the AC group (p = 0.003). The mean PFS was 18.9 months in the GA group and 23.2 months in the AC group (p = 0.001). The mean OS was 25.5 months in all patients, 23.4 months in the GA group, and 28.1 months in the AC group (p < 0.001). In multivariate analysis, the EOR and preoperative KPS independently predicted better OS.

CONCLUSION

The patients with left hemispheric eloquent glioblastoma in this study had better neurological outcomes, maximal tumor removal, and better PFS and OS after AC than surgery under GA. Awake craniotomy should be performed in these patients if the resources are available.

Treatment of intracranial meningioma with single-session and fractionated radiosurgery: a propensity score matching study

Single-session stereotactic radiosurgery (SSRS) is recognized as a safe and efficient treatment for meningioma. We aim to compare the long-term efficacy and safety of fractionated stereotactic radiotherapy (FSRT) with SSRS in the treatment of grade I meningioma. A total of 228 patients with 245 tumors treated with radiosurgery between March 2006 and June 2017were retrospectively evaluated. Of these, 147 (64.5%) patients were treated with SSRS. The remaining 81 patients (35.5%) were treated with a fractionated technique. Protocols to treat meningioma were classified as 12-16 Gy per fraction for SSRS and 7 Gy/fraction/day for three consecutive days to reach a total dose of 21 Gy for FSRT. In univariate and multivariate analyses, tumor volume was found to be associated with local control rate (hazard ratio = 4.98, p = 0.025). The difference in actuarial local control rate (LCR) between the SSRS and FSRT groups after propensity score matching (PSM) was not statistically significant during the 2-year (96.86% versus 100.00%, respectively; p = 0.175), 5-year (94.76% versus 97.56%, respectively; p = 0.373), and 10-year (74.40% versus 91.46%, respectively; p = 0.204) follow-up period. FSRT and SSRS were equally well-tolerated and effective for the treatment of intracranial benign meningioma during the10-year follow-up period.

Using cortical function mapping by awake craniotomy dealing with the patient with recurrent glioma in the eloquent cortex

Background

Methods

Results

Conclusion

Brain computerized tomography reading in suspected acute ischemic stroke patients: what are essentials for medical students?

BACKGROUND

Few systematic methods prioritize the image education in medical students (MS). We hope to develop a checklist of brain computerized tomography (CT) reading in patients with suspected acute ischemic stroke (AIS) for MS and primary care (PC) physicians.

METHODS

Our pilot group generated the items indicating specific structures or signs for the checklist of brain CT reading in suspected AIS patients for MS and PC physicians. These items were used in a modified web-based Delphi process using the online software "SurveyMonkey". In total 15 panelists including neurologists, neurosurgeons, neuroradiologists, and emergency department physicians participated in the modified Delphi process. Each panelist was encouraged to express feedback, agreement or disagreement on the inclusion of each item using a 9-point Likert scale. Items with median scores of 7-9 were included in our final checklist.

RESULTS

Fifty-two items were initially provided for the first round of the Delphi process. Of these, 35 achieved general agreement of being an essential item for the MS and PC physicians. The other 17 of the 52 items in this round and another two added items suggested by the panelists were further rated in the next round. Finally, 38 items were included in the essential checklist items of brain CT reading in suspected AIS patients for MS and PC physicians.

CONCLUSIONS

We established a reference regarding the essential items of brain CT reading in suspected AIS patients. We hope this helps to minimize malpractice and a delayed diagnosis, and to improve competency-based medical education for MS and PC physicians.

CCM1 and CCM2 variants in patients with cerebral cavernous malformation in an ethnically Chinese population in Taiwan

Cerebral cavernous malformation (CCM) is a vascular malformation characterized by clustered enlarged capillary-like channels in the central nervous system. The genes harboring variants in patients with CCM include CCM1/Krev interaction trapped-1, CCM2/MGC4607, and CCM3/programmed cell death protein 10. We aimed to identify pathogenic variants in an ethnic Chinese population in Taiwan. We recruited 95 patients with multiple CCMs or a single lesion with a relevant family history. Sanger sequencing was performed for 41 patients. Variants were identified using sequence alignment tools, and the clinical significance of these variants was determined using American College of Medical Genetics and Genomics standards and guidelines. Several pathogenic variants were found in six patients, including three unrelated patients and three affected members of one family. Two novel pathogenic variants leading to early truncation comprised a deletion variant in exon 18 of CCM1 (c.1846delA; p.Glu617LysfsTer44) and an insertion variant in exon 4 of CCM2 (c.401_402insGCCC; p.Ile136AlafsTer4). One novel pathogenic splice site variant was c.485 + 1G > C at the beginning of intron 8 of CCM1. In this study, we identified novel variants related to CCM in an ethnically Chinese population in Taiwan.

Adjuvant Radiation Therapy Compared with Observation Alone for Postoperative Residual Nonfunctional Pituitary Adenomas

OBJECTIVE

The management of residual nonfunctional pituitary tumors after surgical resection remains controversial. In this study, we compared the prognosis of postoperative radiation therapy and observation only in patients with residual nonfunctional pituitary adenoma and reviewed the long-term complications after radiation therapy.

METHODS

We retrospectively analyzed 90 patients who underwent surgery for nonfunctional pituitary adenomas from January 2008 to April 2012. Residual tumors were classified by size, location, and pathologic staining. Tumor progression was defined as volume progression ≥15% with or without clinical symptoms. Postoperative radiation therapy was performed <1 year after the last surgery. We compared the progression and 3-year and 5-year progression-free survival between the observation group and postoperative radiation therapy group. Postradiation complications including hypopituitarism, diabetes insipidus, deterioration in visual field or acuity, cranial nerve palsy, and hydrocephalus were also analyzed.

RESULTS

More of the patients who received postoperative radiation therapy had a tumor progression-free survival of ≥3 years than did those who did not receive postoperative radiation therapy. Postoperative radiation therapy was significantly beneficial for the patients with a tumor size ≥3 cm or with tumors in the cavernous sinus. The most frequent complication after radiation therapy was hypopituitarism and a few cases had third cranial nerve palsy; however, there were no significant relationships with radiation therapy.

CONCLUSIONS

In this study, immediate radiation therapy after tumor resection was an effective and relatively safe treatment for residual or progressive nonfunctional pituitary adenomas. Moreover, the long-term complications of radiation therapy were mild.

Previous Antithrombotic Therapy, Particularly Anticoagulant, Is Associated with Unfavorable Outcomes in Patients with Primary Spontaneous Intracerebral Hemorrhage Receiving Craniotomy: A Nationwide Population-Based Cohort Study

OBJECTIVE

The impact of antithrombotic agents on patients with primary intracerebral hemorrhage (ICH) remains controversial, especially patients who require emergent craniotomy. This study was undertaken to evaluate clinical outcomes in operated patients with ICH with and without previous antithrombotic agents.

METHODS

This is a retrospective cohort study. Between January 2001 and December 2013, all patients with ICH who received emergent craniotomy and who were present in Taiwan's National Health Insurance Research Database were screened and divided into those with previous antiplatelet therapy, anticoagulant therapy, and nonantithrombotic therapy according to their health care claims data within 3 months of index admission. The primary end points included in-hospital mortality and complications and short-term outcome.

RESULTS

Of 18,872 eligible patients, 16,251 (87.1%) did not receive any antithrombotic therapy, 2267 patients had antiplatelet therapy, and 354 patients had anticoagulation therapy. After propensity score matching, significantly more blood transfusions and craniectomies were identified in the patients with previous antithrombotic treatment compared with those undergoing nonantithrombotic therapy. Compared with the nonantithrombotic treatment cohort, patients under previous anticoagulant treatment had significantly higher in-hospital mortality (odds ratio, 2.12; 95% confidence interval, 1.45-3.10). Furthermore, during the 6-month follow-up period, previous anticoagulant therapy was independently associated with a greater risk of all-cause mortality (P = 0.001). The in-hospital and 6-month all-cause mortality of patients with previous antiplatelet treatment was not significantly different from patients with nonantithrombotic treatment.

CONCLUSIONS

These findings suggested an increased risk of in-hospital mortality and poor short-term outcome among operated patients with ICH with previous antithrombotic therapy, particularly anticoagulant therapy, but not with antiplatelet therapy.

The rs16906252:C>T SNP is not associated with increased overall survival or temozolomide response in a Han-Chinese glioma cohort

The methylation status of O-6-methylguanine-DNA methyltransferase (MGMT) is associated with the prognosis in gliomas and in other cancers. Recent studies showed that rs16906252, an SNP in the MGMT promoter, is associated with promoter methylation and is a predictor of the overall survival time (OST) and the response to temozolomide (TMZ) treatment. However, these findings haven’t been systematically investigated in the Han-Chinese population. We analyzed the relevance between rs16906252 polymorphisms, the MGMT methylation status, and the OST in 72 Han-Chinese gliomas patients. The MGMT promoter methylation was measured by bisulfite conversion followed by pyro-sequencing, while rs16906252 was measured by restriction endonuclease digestion. Contrary to the previous findings, we found no association between rs16906252 genotypes and promoter methylation on MGMT. The lower-grade glioma (LGGs) patients carrying the C allele with rs16906252 showed a surprisingly better OST (P = 0.04). Furthermore, the LGG patients carrying hypo-methylated MGMT promoter and rs16906252 T allele showed significantly poorer prognosis. The prognostic benefit of MGMT promoter methylation and genotypes on gliomas patients is marginal. A new molecular stratified patient grouping of LGGs is potentially associated with poorer OST. Active MGMT might have a protective role in LGG tumors, enabling evolution to severe malignancy.

Evaluating the impact of hippocampal sparing during whole brain radiotherapy on neurocognitive functions: A preliminary report of a prospective phase II study

BACKGROUND

Whole brain radiotherapy (WBRT) is the treatment of choice for patients with brain metastases. However, neurocognitive functions (NCFs) decline due to impaired hippocampal neurogenesis might occur thereafter. It is hypothesized that conformal hippocampal avoidance during the course of WBRT (HA-WBRT) might provide meaningful NCF preservation. Our study aims to demonstrate the impact of delivering HA-WBRT on NCF changes in patients receiving WBRT.

METHODS

Twenty-five patients who were referred for prophylactic cranial irradiation (PCI) or treating oligometastatic brain disease were enrolled in the study. Before the HA-WBRT course, all participants should receive baseline neurocognitive assessment, including memory, executive functions, and psychomotor speed. The primary endpoint was delayed recall, as determined by the change/decline in verbal memory [Wechsler Memory Scale - 3rd edition (WMS III)- Word List score] from the baseline assessment to 4 months after the start of HA-WBRT.

RESULTS

Only three patients belonged to the clinical setting of PCI; the remaining 22 patients had oligometastatic brain disease. Regarding neurocognitive outcomes, no statistically significant differences were found between various NCF scores obtained at baseline and at post-radiotherapy intervals, in immediate verbal memory and non-verbal memory, except for delayed recall memory on Word List (F = 5.727, p = 0.048).

CONCLUSIONS

Functional preservation by hippocampal sparing during WBRT could largely be achieved in this study, which also suggests that HA-WBRT should be a feasible technique preserving neurocognitive functions while maintaining intracranial control.

Comparing the outcomes of different postgraduate year training programs in Taiwan

BACKGROUND

Postgraduate year training programs play an important role in the development of a comprehensive medical education. The goal of these training programs is to inculcate in physicians the expected level of skill in patient care. After the initiation of such programs in the USA, Europe, and Japan, studies were conducted in Taiwan to investigate relevant training methods, and a training system was established in 2003. Beginning with 3-month programs, followed by 6-month programs, the programs were constantly modified and enhanced by the establishment of the 1-year training program in 2011. This year was the transition period from the 6-month programs to the 1-year programs.

METHODS

We used a 50-item multiple choice question (MCQ) test and six 10-min stations for objective structured clinical examination (OSCE), which was composed of four stations relating to standardized patients and two stations concerning the clinical skill evaluation, to evaluate the learning results of the trainees. The trainees were divided into four groups according to the training program.

RESULTS

There was no significant difference between the performance of the 6 months and 1-year groups. The p values were 0.424 in the MCQ test and 0.082 in the OSCE evaluation.

CONCLUSION

A well-designed postgraduate training program should develop trainees' competencies. The results of this study may provide useful insight for ways to improve the design of training programs. Further investigation to better understand the impact of different programs is warranted.

Corpus callosum involvement and postoperative outcomes of patients with gliomas

Corpus callosum involvement is associated with poorer survival in high grade glioma (HGG), but the prognostic value in low grade glioma (LGG) is unclear. To determine the prognostic impact of corpus callosum involvement on progression free survival (PFS) and overall survival (OS) in HGG and LGG, the records of 233 glioma patients treated from 2008 to 2011 were retrospectively reviewed. Preoperative magnetic resonance (MR) images were used to identify corpus callosum involvement. Age, sex, preoperative Karnofsky performance scale, postoperative Eastern Cooperative Oncology Group (ECOG) score and extent of resection (EOR) were evaluated with respect to PFS and OS. The incidence of corpus callosum involvement was similar among HGG (14 %) and LGG (14.5 %). Univariate analysis revealed that PFS and OS were significantly shorter in both WHO grade II and grade IV glioma with corpus callosum involvement (both, p < 0.05). Multivariate analysis showed that grade II glioma with corpus callosum involvement have shorter PFS (p = 0.03), while EOR, instead of corpus callosum involvement (p = 0.16), was an independent factor associated with PFS in grade IV glioma (p < 0.05). Corpus callosum involvement was no longer significantly associated with OS after adjusting age, gender, EOR, preoperative and postoperative performance status (p = 0.16, 0.17 and 0.56 in grade II, III and IV gliomas, respectively). Corpus callosum involvement happened in both LGG and HGG, and is associated with lower EOR and higher postoperative ECOG score both in LGG and HGG. Corpus callosum involvement tends to be an independent prognostic factor for PFS in LGG, but not for OS in LGG or in HGG.

Transglutaminase 2 expression is increased as a function of malignancy grade and negatively regulates cell growth in meningioma

Most meningiomas are benign, but some clinical-aggressive tumors exhibit brain invasion and cannot be resected without significant complications. To identify molecular markers for these clinically-aggressive meningiomas, we performed microarray analyses on 24 primary cultures from 21 meningiomas and 3 arachnoid membranes. Using this approach, increased transglutaminase 2 (TGM2) expression was observed, which was subsequently validated in an independent set of 82 meningiomas by immunohistochemistry. Importantly, the TGM2 expression level was associated with increasing WHO malignancy grade as well as meningioma recurrence. Inhibition of TGM2 function by siRNA or cystamine induced meningioma cell death, which was associated with reduced AKT phosphorylation and caspase-3 activation. Collectively, these findings suggest that TGM2 expression increases as a function of malignancy grade and tumor recurrence and that inhibition of TGM2 reduces meningioma cell growth.

Linear accelerator stereotactic radiosurgery in the management of intracranial arteriovenous malformations: long-term outcome

BACKGROUND

Arteriovenous malformation (AVM) is one of the cerebrovascular diseases that bear a high risk of hemorrhage. The treatment modalities include microsurgical resection, endovascular embolization, stereotactic radiosurgery, or combinations that vary widely. Several large series have been reported, while data from Asian populations were few. The aim of this study was to examine the efficacy of linear accelerator stereotactic radiosurgery (LINAC SRS) for the treatment of intracranial AVMs, to evaluate the hemorrhage rate and to analyze associated factors.

METHODS

One hundred and sixteen patients with AVM were treated with LINAC SRS in a single institute between September 1994 and May 2005 and were retrospectively evaluated. The demographics of patients, clinical characteristics of AVM, the treatment modalities, and the parameters of the LINAC SRS were analyzed. Delayed toxicity and hemorrhage rate after treatment were also evaluated. The AVM obliteration and bleed rates were calculated using the Kaplan-Meier method and Cox regression analyses.

RESULTS

The efficacy rate with total obliteration after treatment was 81.9% (95 of 116 patients). The median interval to achieve total obliteration was 49 months. Microsurgical resection combined with SRS for residual AVMs achieved better obliteration rates compared to SRS alone (statistically significant, p = 0.001), while no significant difference was found between the embolization group and the group with no prior treatment (p = 0.895). The Spetzler-Martin grade of AVM is a relative factor of obliteration, higher grades resulting in a worse outcome (p = 0.009). Obliteration was significantly influenced by AVM volume in univariate analysis (p = 0.034), and volume <5 cm(3) contributed to improved obliteration (p = 0.01). There was no statistically significant difference in the hemorrhagic rate and the complication rate between ruptured and unruptured AVMs, while the unruptured group had a higher obliteration rate (p = 0.024). The annual hemorrhage rate after LINAC SRS treatment was 1.9%. The bleeding rate was 3.3% in the first year after radiosurgery, 2.1% in the second year, 1.9% between the second and fifth year, and 1.5% between the fifth and tenth year. Patients with hemorrhagic events before radiosurgery appeared to have a higher rebleeding risk during the latency period. Twenty-three patients (19.8%) had late adverse effects with regard to posttreatment radiological follow-up, but only 1 (0.8%) had newly developed neurological deficits.

CONCLUSION

LINAC SRS achieved a high obliteration rate and reduced the risk of hemorrhage effectively in ruptured and unruptured intracranial AVMs. Prior microsurgical resection provided better outcome, while embolization showed no benefit. Adverse effects after treatment are acceptable and require long-term follow-up.

Fractionated stereotactic radiosurgery using the Novalis system for the management of pituitary adenomas close to the optic apparatus

Radiosurgery has been proven to be an effective treatment for residual or recurrent pituitary adenomas after surgery. However, it causes severe complications when the optic apparatus is irradiated over the tolerance dose. In this study, we analyzed the feasibility of fractionated stereotactic radiosurgery to treat pituitary tumors close to the optic apparatus. Thirty-four patients from June 2006 to June 2011 with recurrent or residual pituitary adenomas close to (<3 mm) the optic apparatus were treated with fractionated stereotactic radiosurgery. Three fractions with a total dose of 2100 cGy were applied to the tumors. Imaging, examination of vision, and estimation of hormone level were regularly performed before and after radiosurgery. The mean tumor volume before fractioned stereotactic radiosurgery was 5.06±3.08 cm3 (range: 0.82-12.69 cm3). After a mean follow up of 36.8±15.7 months (range: 16-72 months), tumor size was reduced in seven (20.6%) patients and remained the same in the other 27 (79.4%) patients. Vision was improved in one patient and remained stable in the rest. Only one patient developed transient post-treatment diplopia. This study suggests that fractionated stereotactic radiosurgery is safe for treating pituitary adenomas close to the optic apparatus. Studies with more patients and longer follow-up are required to draw definite conclusions.

Non-invasive synergistic treatment of brain tumors by targeted chemotherapeutic delivery and amplified focused ultrasound-hyperthermia using magnetic nanographene oxide

The combination of chemo-thermal therapy is the best strategy to ablate tumors, but how to heat deep tumor tissues effectively without side-damage is a challenge. Here, a systemically delivered nanocarrier is designed with multiple advantages, including superior heat absorption, highly efficient hyperthermia, high drug capacity, specific targeting ability, and molecular imaging, to achieve both high antitumor efficacy and effective amplification of hyperthermia with minimal side effects.

Focused ultrasound-induced blood-brain barrier opening to enhance temozolomide delivery for glioblastoma treatment: a preclinical study

The purpose of this study is to assess the preclinical therapeutic efficacy of magnetic resonance imaging (MRI)-monitored focused ultrasound (FUS)-induced blood-brain barrier (BBB) disruption to enhance Temozolomide (TMZ) delivery for improving Glioblastoma Multiforme (GBM) treatment. MRI-monitored FUS with microbubbles was used to transcranially disrupt the BBB in brains of Fisher rats implanted with 9L glioma cells. FUS-BBB opening was spectrophotometrically determined by leakage of dyes into the brain, and TMZ was quantitated in cerebrospinal fluid (CSF) and plasma by LC-MS\MS. The effects of treatment on tumor progression (by MRI), animal survival and brain tissue histology were investigated. Results demonstrated that FUS-BBB opening increased the local accumulation of dyes in brain parenchyma by 3.8-/2.1-fold in normal/tumor tissues. Compared to TMZ alone, combined FUS treatment increased the TMZ CSF/plasma ratio from 22.7% to 38.6%, reduced the 7-day tumor progression ratio from 24.03 to 5.06, and extended the median survival from 20 to 23 days. In conclusion, this study provided preclinical evidence that FUS BBB-opening increased the local concentration of TMZ to improve the control of tumor progression and animal survival, suggesting its clinical potential for improving current brain tumor treatment.

Long-term follow-up of patients with surgical intractable acromegaly after linear accelerator radiosurgery

BACKGROUND/PURPOSE

Radiotherapy is a crucial treatment for acromegalic patients with growth hormone (GH)-secreting pituitary tumors. However, its effect takes time. We retrospectively reviewed the long-term outcome of linear accelerator stereotactic radiosurgery (LINAC SRS) for patients with acromegaly from the perspective of biochemical remission and associated factors.

METHODS

Twenty-two patients presenting with residual or recurrent (GH)-secreting functional pituitary tumor between 1994 and 2004 who received LINAC SRS were enrolled and followed up for at least 3 years. Residual or recurrent tumor was defined as persistent elevated GH or insulin-like growth factor-1 (IGF-1) level and image-confirmed tumor after previous surgical treatment. Biochemical remission was defined as fasting GH less than 2.5 ng/mL with normal sex-and-age adjusted IGF-1.

RESULTS

The mean follow-up period was 94.7 months (range 36-161 months). Overall mean biochemical remission time was 53 months (median 30 months). Biochemical control was achieved in 15 patients (68.2%) over the follow up period. One patient experienced recurrence after SRS and underwent another operation. Initial GH at diagnosis and pre-SRS GH correlated with biochemical control (p = 0.005 and p < 0.0001, respectively). Further evaluation demonstrated that biochemical control stabilized after 7.5 years. Overall post-SRS hormone deficit persisted in five patients (22.7%).

CONCLUSION

In comparison to other radiosurgery modalities, LINAC radiosurgery also provides a satisfactory outcome. SRS has maximum effect over the first 2 years and stabilizes after 7.5 years. Moreover, SRS elicits long-term biochemical effects and requires longer follow-up for better biochemical remission.

Brain surgery in patients with liver cirrhosis

OBJECT

Liver cirrhosis was identified as an independent predictor of poor outcomes in patients suffering trauma and in those undergoing major surgeries. The aim of this study was to report the authors' experiences treating patients with cirrhosis who undergo brain surgeries.

METHODS

Between 2004 and 2009, 121 consecutive patients with cirrhosis underwent 144 brain procedures. Patients were categorized as Child-Turcotte-Pugh (referred to as "Child") Class A, B, or C. The patient profiles, including the severity of cirrhosis, reason for surgery, complications, and prognosis factors, were analyzed.

RESULTS

In this retrospective study, the overall surgical complication rate for patients with cirrhosis was 52.1% and the mortality rate was 24.3%. For patients with acute traumatic brain injury (TBI), the complication, rebleeding, and mortality rates reached 84.4%, 68.8%, and 37.5%, respectively. Surgery for TBI was a significant risk factor for postoperative complications (p = 0.0002) and postoperative hemorrhage (p < 0.0001). Otherwise, according to the Child classification, the complication rate increased in a stepwise fashion from 38.7% to 60% to 84.2%, the rebleeding rate from 29.3% to 48.0% to 63.2%, and the mortality rate from 5.3% to 38% to 63.2% for Child A, B, and C, respectively. The Child classification was associated with higher risk of complications-Child B vs A OR 2.84 (95% CI 1.28-6.29), Child C vs A OR 5.39 (95% CI 1.32-22.02). It was also associated with risk of death-Child C vs A OR 30.43 (95% CI 7.71-120.02), Child B vs A OR 10.88 (95% CI 3.42-34.63).

CONCLUSIONS

Liver cirrhosis is a poor comorbidity factor for brain surgery. The authors' results suggest that the Child classification used independently is a poor prognostic factor; in addition, grave outcomes were observed in patients with TBI.

Multifaceted effects of rapamycin on functional recovery after spinal cord injury in rats through autophagy promotion, anti-inflammation, and neuroprotection

BACKGROUND

Spinal cord injuries (SCIs) are serious and debilitating health problems that lead to severe and permanent neurological deficits resulting from the primary mechanical impact followed by secondary tissue injury. During the acute stage after an SCI, the expression of autophagy and inflammatory responses contribute to the development of secondary injury. In the present study, we examined the multifaceted effects of rapamycin on outcomes of rats after an SCI.

MATERIALS AND METHODS

We used 72 female Sprague-Dawley rats for this study. In the SCI group, we performed a laminectomy at T10, followed by impact-contusion of the spinal cord. In the control group, we performed only a laminectomy without contusion. We evaluated the effects of rapamycin using the Basso, Beattie, and Bresnahan scale for functional outcomes, Western blot analyses for analyzing LC3-II, tumor necrosis factor expression, and p70S6K phosphorylation, and an immunostaining technique for localization and enumeration of microglial and neuronal cells.

RESULTS

Basso, Beattie, and Bresnahan scores after injury significantly improved in the rapamycin-treated group compared with the vehicle group (on Day 28 after the SCI; P < .05). The Western blot analysis demonstrated that rapamycin enhanced LC3-II expression and decreased p70S6K phosphorylation compared with the vehicle (P < .01), which implies promotion of autophagy through mammalian target of rapamycin inhibition. Furthermore, rapamycin treatment significantly attenuated tumor necrosis factor production and microglial expression (P < .05). Immunohistochemistry of NeuN (antibodies specific to neurons) showed remarkable neuronal cell preservation in the rapamycin-treated group compared with the vehicle-treated group (P < .05), which suggests a neuroprotective effect of rapamycin.

CONCLUSIONS

Rapamycin is a novel neuroprotectant with multifaceted effects on the rat spinal cord after injury. Use of such a clinically established drug could facilitate early clinical trials in selected cases of human SCIs.

Outcomes of 75 patients over 12 years treated for acoustic neuromas with linear accelerator-based radiosurgery

The aim of this study was to investigate the efficacy of linear accelerator (LINAC)-based radiosurgery in the treatment of acoustic neuromas. In this retrospective study, we enrolled 75 patients with non-neurofibromatosis type 2 acoustic neuromas who were followed-up for more than 5years. The 75 patients were divided into 3 groups: patients with a newly diagnosed tumor; those with a residual tumor; and those with a recurrent tumor. The average follow-up period was 97.8months. The overall tumor progression-free rate was 92%, and corresponding rates among those with newly diagnosed tumors was 100%, residual tumors was 84.4%, and recurrent tumors was 92.8% (p=0.028). Lesion localization using CT scans correlated with a higher tendency for tumor progression than lesion localization using CT-MRI fusion images (15.6% versus 2.4%, respectively). Residual tumors treated with radiosurgery have a higher progression rate, and careful lesion localization using CT-MRI image fusion is required.

Electrocorticographic monitoring as an alternative tool for the pre-surgical evaluation of patients with bi-temporal epilepsy

BACKGROUND

To analyze the surgical outcomes of patients with temporal lobe epilepsy with bilateral foci after one-week bilateral subdural strip electrocorticographic (ECoG) recording.

METHODS

We retrospectively evaluated 12 patients with bilateral epileptic foci after scalp electroencephalography examination who underwent ECoG between May 1995 and July 2000. Subdural strips were implanted in the bilateral subtemporal regions for a one-week ECoG recording.

RESULTS

All but one of the patients exhibited unilateral dominance of epileptogenic discharges (> 65%) and, following an anterior temporal lobectomy, the majority of patients (8 of 11) enjoyed a seizure-free life during the ensuing 3 years. No mortality or morbidity such as intracranial hemorrhage or wound infection was noted.

CONCLUSIONS

The dominance of an epileptic focus in patients with bitemporal epileptogenic discharges can thus be successfully recorded by electrocorticographic monitoring prior to anterior temporal lobectomy.

Interhemispheric comparisons of cerebral blood flow velocity changes during mental tasks with transcranial Doppler sonography

OBJECTIVE

The purpose of this study was to evaluate hemispheric asymmetry of cerebral blood flow changes during various mental tests by applying transcranial Doppler sonography (TCD) to simultaneously monitor bilateral cerebral blood flow velocity changes.

METHODS

Twenty-one participants without cerebrovascular disease performed 3 left hemispheric tasks (reading, calculation, and color scaling) and 3 right hemispheric tasks (face recognition, space imagination, and line orientation).

RESULTS

Mean velocities of the rest and performing periods did not differ significantly between the left and right hemispheric tasks. Although greater acceleration of blood flow velocity was observed on the left than on the right in most of the 6 tasks except line orientation (mean left - right ratio difference [D(l-r)] ranged from -0.018 to 0.071), this difference was larger for left hemispheric tasks (mean D(l-r) ranged from 0.050 to 0.071) than right hemispheric tasks (mean D(l-r) ranged from -0.018 to 0.034; P < .001). Further comparisons of each pair of (ie, left and right) hemispheric tasks revealed that the most suitable left and right hemispheric tasks to show hemispheric asymmetry were reading and line orientation, respectively (P < .001).

CONCLUSIONS

Hemispheric asymmetry of cerebral blood flow changes during mental tests is demonstrable with TCD only when comparing the D(l-r) in response to suitable paired left and right hemispheric tasks.

Stereotactic brain biopsy: Single center retrospective analysis of complications

OBJECTIVE

Stereotactic biopsy is a widely used surgical technique for the histological diagnosis of intracranial lesions. Potential risks of this procedure, such as hemorrhage, seizure, and infection have been established, and different risk factors have been characterized. However, these risks have been addressed by only few studies conducted in Asian countries.

MATERIALS AND METHODS

The study group is comprised of 299 consecutive stereotactic biopsy procedures by 11 neurosurgeons between 2004 and 2007. The pre-operative medical conditions, methods of biopsy and postoperative complications were analyzed.

RESULT

The overall diagnostic yield was 90.64%. Complications were observed in 7.36% of the cases, with symptomatic hemorrhages occurring in 4.35% of the cases, and the overall mortality rate in this study population was 1.34%. Patients with liver cirrhosis were at a higher risk of hemorrhage. Other clinical, radiological, or histological variables were not associated with an increased risk of complications.

CONCLUSION

Stereotactic brain biopsy is a safe and reliable way to obtain a histological diagnosis. Based on our recent clinical experiences, the data suggests that more attention should be paid to liver cirrhotic patients, since the chance on hemorrhage is significantly larger.

Ultrastructural observations on the progress of nerve degeneration and regeneration at the suture site following vagal-hypoglossal nerve coaptation in cats

Nerve degeneration and regeneration have been investigated at the suture site following proximal-to-distal vagal-hypoglossal nerve coaptation (VHC) in cats at different time points (from 3 to 315 days postoperatively; dpo). Massive axonal degeneration and myelin breakdown and removal of degraded neural debris were observed during the first 2 weeks postoperatively. This was followed by active Schwann cell multiplication and inflammatory cell invasion at 14 dpo. Schwann cells appeared mobile, and were guided to the newly developed growth cones, dividing them into axonal sprout clusters. At 18 dpo, the migrating Schwann cells were confined to the preexisting basal lamina scaffolds, forming bands of Bungner. It is suggested that the latter may play a key role in navigating the regenerating axons to their newly acquired target organ at 22 dpo. Remyelination of axons was not observed till 46 dpo. Compared with the rapid axonal reaction in other models of nerve injury, the degeneration process in VHC was protracted and, furthermore, regeneration and remyelination were delayed. The subtle remodeling of the nerve in cross-coaptation may be far greater than previously recognized, and this may have clinical importance since patients undergoing nerve crossover microsurgery exhibit delayed motor rehabilitation, apparently as a direct result of a change in target innervation. Defining the mechanisms underlying the neuroplastic program could thus potentially improve the prognosis of crossover of two different peripheral nerves.

"Migration" of traumatic subarachnoid hematoma? A case report

BACKGROUND

Traumatic spinal SAH with neurologic deficits is rare and easily misdiagnosed, especially after traumatic intracranial hemorrhage.

CASE DESCRIPTION

We report a case of spinal SAH with root compression occurring after a scooter accident.

CONCLUSIONS

Physicians should be aware of descending migration of intracranial SAH as a possible cause of spinal cord or root compression, especially in the patient with late onset spinal symptoms.

Treatment of Epileptogenic Cavernomas: Surgery versus Radiosurgery

BACKGROUND

Epilepsy is the most common symptom of cavernoma. Although microsurgery is the mainstay treatment for epileptogenic cavernoma, this procedure may cause severe complications for some lesions. This report aimed to study if linear accelerator (LINAC) radiosurgery was an alternative treatment modality for epileptogenic cavernoma.

METHODS

In this retrospective study, 29 patients were diagnosed with epileptogenic cavernomas from September 1995 to March 2005. Fifteen patients were treated with surgical excision and 14 with LINAC radiosurgery. The evaluation of epilepsy control was according to Engel's classification.

RESULTS

In the surgical group, 13 (86.7%) of 15 patients had a class I seizure-free outcome. In the radiosurgery group, class I control was achieved in 9 (64.3%) of 14 patients. However, there was no significant difference in the results of treatment between the two groups.

CONCLUSIONS

LINAC radiosurgery is an alternative treatment for epileptogenic cavernomas, especially when the lesions are located in the central regions or eloquent areas of the brain.

Dynamic recording of irrigating fluid distribution in root canals using thermal image analysis

AIM

To investigate the influence of the size and the depth of insertion of irrigating needles, and the diameter of the master apical file on flow distribution during fluid irrigation in root canals.

METHODOLOGY

Stepback canal instrumentation was employed on seven extracted human single canal teeth. The size of the master apical files ranged from sizes 25, 30, 35, 40, 45, 50 to size 80 within the seven teeth, respectively. A thermal imaging system (ThermaCAM; National Instruments Co., Austin, TX, USA) was used to record the dynamic fluid distribution following root canal preparation. The dynamic fluid distribution was analysed during irrigation by insertion of different irrigating needle tips (23, 25 and 27 gauge) at various depths (3, 6 and 9 mm) from the root apex. The whole process of irrigation was recorded by a video camera and analysed by two observers separately. The success of the irrigation process was defined when the irrigant was able to flow into to the apical region immediately after injection.

RESULTS

The aqueous irrigant was flushed into the apical region when a size 27 gauge irrigating needle was placed into a size 30 canal at a point 3 mm from the apical stop. When the same needle tip was placed 6 mm from the root canal apex, successful irrigation was achieved only in the canals prepared to size 50 or larger. When a size 25 gauge irrigating needle was placed 3 mm from the working length, the canal size had to be no <45 to allow for successful irrigation. When a size 23 gauge needle was placed at the same position, the canal needed to be prepared to size 50 to allow thorough irrigation of the apex. At 9 mm from the apical stop, none of the irrigating needles could achieve successful irrigation of any canal size.

CONCLUSION

The flow distribution of root canal irrigation can be affected adversely by large diameter irrigating needles, by greater distances between the needle tip and the apical stop, and by narrow root canals.

LINAC radiosurgery for intracranial cavernous malformation: 10-year experience

BACKGROUND

The annual hemorrhage rate of intracranial cavernous malformation (CM) is reported to range from 0.23% to 1.1%. Because of the low hemorrhage rate, operating on a deep symptomatic lesion with or without hemorrhage is considered controversial. For the prevention of hemorrhage, radiosurgery is an alternative method, targeting smaller lesions and delivering higher doses of radiation. Linear accelerator (LINAC) radiosurgery, aside from the gamma knife (GK), is not often discussed in the treatment of CM.

PATIENTS AND METHODS

From 1995 to 2005, 30 patients presenting with hemorrhage or seizures, aged 14-79 years (mean 24.0 years) with single (27 patients) or multiple (three patients) CMs received LINAC radiosurgery at our institute. Six patients received LINAC radiosurgery following craniotomy for residual lesions revealed by the follow-up MRI. The temporal lobe was the most common site for CM in this series (n=8), followed by the brain stem (n=7). Thirty patients received 34 radiosurgery treatments with peripheral doses ranging from 800 cGy to 2200 cGy. The mean follow-up time was 59.9 months (range 1-122 months).

RESULTS

One patient re-bled post-radiosurgery (0.67% in 149.75 observation-years). Two patients had asymptomatic post-LINAC edema (6.7%). Those three patients were symptom-free during the follow-up period.

CONCLUSION

We suggest that LINAC radiosurgery is a relatively safe technique for treating deep or residual CM, although the actual effectiveness for CM obliteration is not known.

Surgical treatment for severe visual compromised patients after pituitary apoplexy

BACKGROUND

Pituitary apoplexy is a rare neurovascular insult. Early surgical decompression is the most effective treatment, especially for rapid deterioration of visual acuity or for altered consciousness. The timing of rapidly expanded mass was strongly related to the treatment outcome.

METHODS

Thirteen patients who presented with severe visual defect after pituitary apoplexy were enrolled retrospectively. Six patients without severe underlying diseases were considered non-complicated and were treated early. Another seven patients who received delayed treatment after medical problems were stabilized and/or conservative management failed were considered to be complicated. The visual acuity of each individual eye was evaluated and organized into six grades based on visual acuity. Twelve patients received transsphenoidal surgery and one craniotomy was performed for tumor removal.

RESULTS

The delay of surgical treatment was 3.5 days and 8.7 days in the two groups, respectively. Overall, 19 out of 26 eyes (73%) improved after surgery; 100% in non-complicated group and 50% in complicated group. The average grade of visual improvement was 2.66 vs. 0.71 by each individual eye, and the difference was statistically significant (P<0.000). The ratio of regained useful vision was significant in non-complicated patients (P<0.000). The incidence of requirement long-term hormone replacement was high in the complicated group (2/6 vs. 6/7). The resection rate was total in 8 patients, subtotal in 3, partial in 1, with one loss of image follow-up.

CONCLUSIONS

Early decompression significantly improved visual outcomes and the need for hormone replacement was minimal. We postulated old age, underlying malignant diseases, and coagulation disorders played the predisposing factors of poor outcome in these cases.

Traumatic internal carotid artery dissection

Traumatic internal carotid artery dissection is a serious condition that may cause ischemic stroke in young patients. It has been under-diagnosed in the past. We present three cases of traumatic internal carotid artery dissection. The clinical manifestations include hemicrania, hemiparesis, partial Horner's syndrome and cranial nerve palsy. Diagnosis is with carotid color Doppler ultrasound, CT angiography of the neck and conventional angiography. The outcome may be poor with hemiparesis, persistent vegetative state and death. We review the literature and discuss the clinical presentation, diagnosis, grading and treatment choices for traumatic internal carotid artery dissection and stroke.

Symptomatic hematoma of cervical ligamentum flavum: case report

STUDY DESIGN

A case of symptomatic hematoma of cervical ligamentum flavum.

OBJECTIVE

To report the first ligamentum flavum hematoma in the cervical spine and review the reported cases.

SUMMARY OF BACKGROUND DATA

A herniated nucleus pulposis, spondylosis, epidural hematoma or abscess, neoplasm, or some pathology of the ligamentum flavum, such as hypertrophy, ossification, or calcification, are the most common causes of spinal cord and nerve root compression. A ligamentum flavum hematoma has also been reported as a cause of compression of the cauda equina and lumbar nerve roots but has never been found in the cervical spine.

METHODS

A 72-year-old man presented with left upper arm pain and left hemiparesis following traditional massage therapy. Admission magnetic resonance images showed a posterior oval-shaped mass that was continuous with the ligamentum flavum at C3-C4 level.

RESULTS

A C3-C4 laminectomy for decompression and resection of the lesion was performed. One year after surgery, the patient remained neurologically intact and symptom-free.

CONCLUSIONS

Hematoma of the ligamentum flavum occurring in the cervical spine has never been reported previously. Repeated trivial injury on a degenerative ligamentum flavum might be the leading predisposing factor. Spine surgeons should be aware of a hematoma in the ligamentum flavum as a possible cause of spinal cord or root compression, especially in the mobile cervical and lumbar spine.