Electrical cortical stimulation for treatment of intractable epilepsy originating from eloquent cortex: surgical accuracy and clinical efficacy.

BACKGROUND: Electrical cortical stimulation is shown effective in treating patients with drug-resistant epilepsy. We demonstrated how detailed procedures of pre- and intra-operative planning of cortical stimulation implantation may influence the results of seizure reduction rate. METHODS: To confirm the precision of subdural grids covering the epileptogenic foci in the eloquent regions, pre- and intra-operative video-electroencephalography (VEEG) were performed in patients with drug-resistant epilepsy during a 4-day 24-h monitoring. The localization of the grid was determined via 3D reconstruction imaging of subdural electrodes co-registered onto the patient's cortex. A final quadripolar lead in cyclic stimulation mode was then placed and secured on the target cortex area. Post-operative 3D CT ensured the accurate location of stimulation lead without any misplacement. Bipolar cyclic stimulation and post-implantation VEEG were performed for 7 days. Patients were discharged and followed up regularly for parameters adjustment and recording of seizure outcomes. RESULTS: Eight patients received chronic cortical stimulation implantations between February 2003 and December 2017. The mean age of these patients was 21.1 years old and the average post-operative follow-up was 77.3 months. Comparisons of their seizure frequency at baseline and during the postoperative period revealed a mean reduction in seizures of 60.4% at the first year and 65.6% at the second year. CONCLUSIONS: Pre-surgical planning enhanced the accuracy of electrode placement and led to a favorable seizure reduction rate. Our report confirms that electrical cortical stimulation with detailed implantation procedures is safe and effective for patients with drug-resistant epilepsy originating from eloquent cortex.

A Scoping Review of Medical Education Research in Neurosurgery.

BACKGROUND: Little is known about the state of medical education (ME) research in neurosurgery. As ME started to develop in neurosurgery in recent years, it is important to understand the current status and develop the theory for advancement in neurosurgery. The aim of this study was to undertake a scoping review of neurosurgery literature on ME research. METHODS: MEDLINE, SCOPUS, and PubMed databases were searched. Inclusion criteria were full-text articles in English published from January 2006 to December 2017. Research aspects included country of publication, annual number of publications, journal types, type of participants, frequently researched topics, and research design. Search terms included neurosurgery, medical education, teaching, training, learning, and curriculum. RESULTS: A total of 9863 references were found across 3 databases. After duplicate removal and further screening, 533 references remained for coding analysis. ME research activity in neurosurgery is increasing and commonly observed in Western countries. Identified articles were mostly quantitative, with curriculum, assessment (especially simulation), and teaching and learning being the most dominant research themes. CONCLUSIONS: This study highlights the need for enhanced quantity and quality of ME research in neurosurgery. It identifies areas of highest priority and aspects to be improved and provides us with a rationale for future development in ME in neurosurgery. These findings reveal future education research direction and programmatic research areas, while also establishing a benchmark to assess changes in educational scholarship over time.

Electrical cortical stimulation for refractory focal epilepsy: A long-term follow-up study.

OBJECTIVE: To report the long-term seizure control and safety of open-loop electrical cortical stimulation in patients with refractory focal epilepsy of diverse etiologies. METHODS: Six patients who received a therapeutic trial of cortical stimulation were included retrospectively. The frequency of seizures was recorded before and after implantation. Surgical procedure- and stimulation-related adverse effects were also recorded. RESULTS: The mean reductions in seizures were 61% at 1 year, 68% at 2 years, and 80% at 3-7 years post-implantation. The median follow-up time was 54 months (range 36-156 months). The etiologies of epilepsy included polymicrogyria in two patients, post-traumatic in one patient, and periventricular heterotopia, post-encephalitis, and familial lateral temporal lobe epilepsy in the remaining three patients. Status epilepticus stopped immediately after stimulation in three patients with focal status epilepticus or epilepsia partialis continua at baseline, with a long-term reduction in seizures of more than 90% and improvements in conscious level. Tissue incompatibility with the connection wire was noted in one patient, which subsided after the system was removed. CONCLUSIONS: Open-loop cortical stimulation of epileptic foci improved seizure control in our patients with refractory focal epilepsy of diverse etiologies. Electrical cortical stimulation stopped epilepsia partialis continua/focal status epilepticus immediately after the intervention and exhibited a sustained effect in reducing seizures. No procedure-related complications were observed. Further case cohort studies are needed to clarify which patients respond to open-loop cortical stimulation.

Indirect Targeting of Subthalamic Deep Brain Stimulation Guided by Stereotactic Computed Tomography and Microelectrode Recordings in Patients With Parkinson's Disease.

Objective: Magnetic resonance imaging fusion techniques guided by frame-based stereotactic computed tomography and microelectrode recordings are widely used to target the subthalamic nucleus. However, MRI is not always available. The aim of this study was to determine whether the indirect targeting of the subthalamic nucleus for deep brain stimulation using frame-based stereotactic computed tomography and microelectrode recording guidance in patients with advanced idiopathic Parkinson's disease was an effective and safe treatment and to determine the factors that contributed to outcome. Methods: Thirty-four consecutive patients with Parkinson's disease who were treated from 2010 to 2012 were enrolled in this retrospective cohort study. The patients were assessed with the Unified Parkinson's Disease Rating Scale-part III (UPDRS-III) and other clinical profiles peri- and post-operatively. The horizontal and vertical distances between the midpoint of the head frame and the brain midline at the septum pellucidum level and the upper edge of the bilateral lens, respectively, on a thin-section brain computed tomography scan were defined as the horizontal and vertical deviations, respectively. Results: After the deep brain stimulation surgery, the patients' UPDRS-III scores improved 48 ± 2.8% (range, 20-81%) compared to the patients' baseline off-levodopa scores. No surgery-associated complications were found. The mean recorded length difference of the subthalamic nucleus between the initial and final single microelectrode recording trajectories was 5.37 ± 0.16 mm (range, 3.99-7.50). Multiple linear regression analyses revealed that the increased lengths of the vertical (regression coefficient [B]: -0.0626; 95% confidence interval [CI]: -0.113 to -0.013) and horizontal deviations (B: -0.0497; 95% CI: -0.083 to -0.017) were associated with less improvement in the patients' UPDRS scores. Conclusion: These results showed that the indirect targeting of the subthalamic nucleus for deep brain stimulation using frame-based stereotactic computed tomography and microelectrode recording guidance in patients with advanced idiopathic Parkinson's disease was effective and safe. Greater symmetry of the head frame fixation resulted in better outcomes of the deep brain stimulation of the subthalamic nucleus in patients with Parkinson's disease, especially when the horizontal deviation was 2 mm or less and the vertical deviation was 1 mm or less.

Efficacy of limited hippocampal radiofrequency thermocoagulation for mesial temporal lobe epilepsy.

OBJECTIVE: Radiofrequency thermocoagulation (RFTC), which has been developed for drug-resistant epilepsy patients, involves less brain tissue loss due to surgery, fewer surgical adverse effects, and generally good seizure control. This study demonstrates the effectiveness of RFTC performed at limited hippocampal locations. METHODS: Daily seizure diaries were prospectively maintained for at least 6 months by 9 patients (ages 30-59 years) with drug-resistant mesial temporal lobe epilepsy (MTLE) before treatment with RFTC. The limited target for stereotactic RFTC was chosen based on intraoperative electroencephalography (EEG) recording and was initially tested with a Radionics electrode at a low temperature, 45°C, for 60 seconds. The therapeutic RFTC heating parameters were 78°C-80°C for 90 seconds. All patients who received the RFTC treatment underwent both MRI and EEG recording immediately postoperatively and at the 3-month follow-up. Monthly outpatient clinic visits were arranged over 6 months to document seizure frequency and severity to clarify the changes noted in imaging studies and EEG patterns. RESULTS: Two patients were excluded from our analysis because one had undergone multiple seizure surgeries and the other had a poor recording of seizure frequency, before the RFTC surgery. Five and two patients underwent left-sided and right-sided RFTC, respectively. None of the patients had generalized tonic-clonic attacks postoperatively, and no adverse effects or complications occurred. According to MRI data, the effect of coagulation was limited to less than 1.0 cm in diameter and perifocal edema was also in limited range. The seizure frequency within 6 months decreased postoperatively with a mean reduction in seizures of 78% (range 36%-100%). Only two patients had a temporary increase in seizure frequency within 2 weeks of the surgery, and over 50% of all patients showed a decrease in average seizure frequency. CONCLUSIONS: The study results confirm that limited RFTC provides a more effective surgery with similar seizure control but fewer complications than resective surgery for drug-resistant MTLE patients.

Correlations between clinical hormone change and pathological features of pituicytoma.

PURPOSE: Pituicytoma is a rare low-grade glioma arising from the pituicytes of the posterior pituitary. To date, the clinical and pathological correlates of pituicytoma have not been investigated. This study was thus designed to examine the correlation between pituicytoma and the normal pituitary gland. METHODS: The records of patients who underwent pituitary surgery at Chang Gung Memorial Hospital in Linkou, Taiwan between 2000 and 2016 were reviewed. Patients who received a pathological diagnosis of pituicytoma were included; however, those with inadequate specimens for pathological study were excluded. Clinical information, including patients' presenting symptoms, serum hormone levels, neuroimages, and specimens, were collected. Hematoxylin and eosin stains and immunohistochemical (IHC) stains were performed for differential diagnosis. RESULTS: Among the 1532 patients who underwent pituitary surgery, nine (0.59%) received a pathological diagnosis of pituicytoma. Two patients were excluded due to inadequate specimens. Among the seven remaining patients, six presented with hormone changes. The IHC stains revealed that pituicytoma has no secretory function; however, the resected pituitary glands showed positive results for hormone change. Coexisting pituicytoma and adrenocorticotropic hormone adenoma were identified in one patient with a diagnosis of Cushing disease. CONCLUSIONS: Pituicytoma revealed a negative endocrine secretory function through IHC staining. Additionally, pituicytoma is associated with hypersecretion of the pituitary gland both clinically and pathologically. Diagnosing pituicytoma before pathological confirmation is difficult because the tumour may present with hormone dysfunction. Therefore, IHC staining of specimens is useful to exclude the possibility of coexisting pituicytoma and pituitary adenoma.

Effect of ventilation rate on air cleanliness and energy consumption in operation rooms at rest.

The interrelationships between ventilation rate, indoor air quality, and energy consumption in operation rooms at rest are yet to be understood. We investigate the effect of ventilation rate on indoor air quality indices and energy consumption in ORs at rest. The study investigates the air temperature, relative humidity, concentrations of carbon dioxide, particulate matter (PM), and airborne bacteria at different ventilation rates in operation rooms at rest of a medical center. The energy consumption and cost analysis of the heating, ventilating, and air conditioning (HVAC) system in the operation rooms at rest were also evaluated for all ventilation rates. No air-conditioned operation rooms had very highest PM and airborne bacterial concentrations in the operation areas. The bacterial concentration in the operation areas with 6-30 air changes per hour (ACH) was below the suggested level set by the United Kingdom (UK) for an empty operation room. A 70% of reduction in annual energy cost by reducing the ventilation rate from 30 to 6 ACH was found in the operation rooms at rest. Maintenance of operation rooms at ventilation rate of 6 ACH could save considerable amounts of energy and achieve the goal of air cleanliness.

Long-Term Outcomes for Patients With Stroke After Coronary and Valve Surgery.

BACKGROUND: Postoperative stroke is one of the most devastating complications of cardiac surgery. When life-threatening situations such as large infarction and hemorrhage occur, neurosurgical procedures may be performed. In this study, we analyzed the long-term medical and surgical outcomes of stroke after cardiac surgery. METHODS: We conducted a retrospective, nationwide, population-based study. All enrolled patients underwent first-time cardiac surgery and were further divided into the subgroups of nonstroke, stroke with medical treatment, and stroke with neurosurgical treatment. All-cause mortality, recurrent stroke, and readmission were analyzed. RESULTS: We included 67,051 patients in this study. Patients with postoperative stroke (2.6%, n = 1,731) exhibited an in-hospital mortality rate of 12.3% (n = 213) and a 5-year mortality rate of 49.1% (n = 850). Unprecedentedly, the 83 patients who underwent neurosurgical procedures exhibited an in-hospital mortality of 16.9%; this rate increased to 65.1% at the 5-year follow-up. This neurosurgical subgroup exhibited the highest rate of long-term mortality (p < 0.001). In the neurosurgical subgroup, age was the risk factor for all-cause mortality (hazard ratio, 2.60; 95% confidence interval, 1.60-4.24; p < 0.001). CONCLUSIONS: Postoperative stroke often leads to high mortality and poor long-term outcomes. Patients who experienced a severe stroke and underwent neurosurgical procedures also exhibited poor outcomes. Patients and their families should be informed of relatively high mortality and poor long-term outcomes before neurosurgical operation.

Outcomes of chronic subdural hematoma in patients with liver cirrhosis.

OBJECTIVE: Burr hole craniostomy is an effective and simple procedure for treating chronic subdural hematoma (CSDH). However, the surgical outcomes and recurrence of CSDH in patients with liver cirrhosis (LC) remain unknown. METHODS: A nationwide population-based cohort study was retrospectively conducted using data from the Taiwan National Health Insurance Research Database. The study included 29,163 patients who underwent first-time craniostomy for CSDH removal between January 1, 2001, and December 31, 2013. In total, 1223 patients with LC and 2446 matched non-LC control patients were eligible for analysis. All-cause mortality, surgical complications, repeat craniostomy, extended craniotomy, and long-term medical costs were analyzed. RESULTS: The in-hospital mortality rate (8.7% vs 3.1% for patients with LC and non-LC patients, respectively), frequency of hospital admission, length of ICU stay, number of blood transfusions, and medical expenditures of patients with LC who underwent craniostomy for CSDH were considerably higher than those of non-LC control patients. Patients with LC tended to require an extended craniotomy to remove subdural hematomas in the hospital or during long-term follow-up. The surgical outcome worsened with an increase in the severity of LC. CONCLUSIONS: Even for simple procedures following minor head trauma, LC remains a serious comorbidity with a poor prognosis.

The venous delay phenomenon in computed tomography angiography: a novel imaging outcome predictor for poor cerebral perfusion after severe aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Diverse treatment results are observed in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH). Significant initial perfusion compromise is thought to predict a worse treatment outcome, but this has scant support in the literature. In this cohort study, the authors correlate the treatment outcomes with a novel poor-outcome imaging predictor representing impaired cerebral perfusion on initial CT angiography (CTA). METHODS: The authors reviewed the treatment results of 148 patients with poor-grade aSAH treated at a single tertiary referral center between 2007 and 2016. Patients with the "venous delay" phenomenon on initial CTA were identified. The outcome assessments used the modified Rankin Scale (mRS) at the 3rd month after aSAH. Factors that may have had an impact on outcome were retrospectively analyzed. RESULTS: Compared with previously identified outcome predictors, the venous delay phenomenon on initial CTA was found to have the strongest correlation with posttreatment outcomes on both univariable (p < 0.0001) and multivariable analysis (OR 4.480, 95% CI 1.565-12.826; p = 0.0052). Older age and a higher Hunt and Hess grade at presentation were other factors that were associated with poor outcome, defined as an mRS score of 3 to 6. CONCLUSIONS: The venous delay phenomenon on initial CTA can serve as an imaging predictor for worse functional outcome and may aid in decision making when treating patients with poor-grade aSAH.

Different perceptions of narrative medicine between Western and Chinese medicine students.

BACKGROUND: Western medicine is an evidence-based science, whereas Chinese medicine is more of a healing art. To date, there has been no research that has examined whether students of Western and Chinese medicine differentially engage in, or benefit from, educational activities for narrative medicine. This study fills a gap in current literature with the aim of evaluating and comparing Western and Chinese Medicine students' perceptions of narrative medicine as an approach to learning empathy and professionalism. METHODS: An initial 10-item questionnaire with a 5-point Likert scale was developed to assess fifth-year Western medical (MS) and traditional Chinese medical (TCMS) students' perceptions of a 4-activity narrative medicine program during a 13-week internal medicine clerkship. Exploratory factor analysis was undertaken. RESULTS: The response rate was 88.6% (412/465), including 270 (65.5%) MSs and 142 (34.5%) TCMSs, with a large reliability (Cronbach alpha = 0.934). Three factors were extracted from 9 items: personal attitude, self-development/reflection, and emotional benefit, more favorable in terms of enhancement of self-development/reflection. The perceptions of narrative medicine by scores between the two groups were significantly higher in TCMSs than MSs in all 9-item questionnaire and 3 extracted factors. CONCLUSIONS: Given the different learning cultures of medical education in which these student groups engage, this suggests that undertaking a course in Chinese medicine might enhance one's acceptance to, and benefit from, a medical humanities course. Alternatively, Chinese medicine programmes might attract more humanities-focused students.

Does One Size Fit All? Examining the Application of Neurosurgery Residency Milestones Developed in the United States to a Taiwanese Culture.

BACKGROUND: The Milestone Project was launched in 2009, charging specialties to develop specific educational accomplishments required to establish clinical competency. The milestone assessment method was first introduced to Taiwan in 2013 and before applying milestone assessments to our medical education system, the validity and reliability of these questionnaires needed to be evaluated. METHODS: Twenty neurosurgical faculty members representing 3 clinical divisions and all 4 branch institutes completed milestone questionnaires for 26 residents semiannually, resulting in 435 resident assessments being collected and analyzed. RESULTS: Cronbach's α, Kuder-Richardson Formula 20, and Kendall's W were used to show acceptable reliability and validity. Rater consistencies for nonskilled parts found that rater consistency progressively improved with time. Not all raters were able to assess the residents for the skilled parts resulting in nonassessable rates ranging from 9.5%-89.4%. For nonskilled and skilled items, milestone level as assessed by the staff improved as the resident progressed from residency year 3 (R3) to R6 in the residency program and showed that the milestone achievement level for an R3 was lower than that of an R6. CONCLUSIONS: Milestone assessments have high reliability and may be a helpful assessment tool. Although milestone assessment can provide thorough feedback concerning performance and the content of the training program, they may not perfectly suit all residency-training programs, especially in different countries or different cultures. Modifications should be done before applying milestones to different areas; therefore the results can truly reflect the progress and condition of the training and learning process.

Different Volumetric Measurement Methods for Pituitary Adenomas and Their Crucial Clinical Significance.

Confirming the status of residual tumors is crucial. In stationary or spontaneous regression cases, early treatments are inappropriate. The long-used geometric calculation formula is 1/2 (length × width × height). However, it yields only rough estimates and is particularly unreliable for irregularly shaped masses. In our study, we attempted to propose a more accurate method. Between 2004 and 2014, 94 patients with pituitary tumors were enrolled in this retrospective study. All patients underwent transsphenoidal surgery and received magnetic resonance imaging (MRI). The pre- and postoperative volumes calculated using the traditional formula were termed A1 and A2, and those calculated using the proposed method were termed O1 and O2, respectively. Wilcoxon signed rank test revealed no significant difference between the A1 and O1 groups (P = 0.1810) but a significant difference between the A2 and O2 groups (P < 0.0001). Significant differences were present in the extent of resection (P < 0.0001), high-grade cavernous sinus invasion (P = 0.0312), and irregular shape (P = 0.0116). Volume is crucial in evaluating tumor status and determining treatment. Therefore, a more scientific method is especially useful when lesions are irregularly shaped or when treatment is determined exclusively based on the tumor volume.

Neurosurgical robotic arm drilling navigation system.

BACKGROUND: The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process. METHODS: The system comprised neurosurgical robotic arm navigation combining robotic and surgical navigation, 3D medical imaging based surgical planning that could identify lesion location and plan the surgical path on 3D images, and automatic bone drilling control that would stop drilling when the bone was to be drilled-through. Three kinds of experiment were designed. RESULTS: The average positioning error deduced from 3D images of the robotic arm was 0.502 ± 0.069 mm. The correlation between automatically and manually planned paths was 0.975. The average distance error between automatically planned paths and risky zones was 0.279 ± 0.401 mm. The drilling auto-stopping algorithm had 0.00% unstopped cases (26.32% in control group 1) and 70.53% non-drilled-through cases (8.42% and 4.21% in control groups 1 and 2). CONCLUSIONS: The system may be useful for neurosurgical robotic arm drilling navigation.

The Clinical Value of Intraoperative Mobile Computed Tomography in Managing High-Risk Surgical Patients with Traumatic Brain Injury-A Single Tertiary Trauma Center Experience.

OBJECTIVE: A subset of surgically treated patients with traumatic brain injury (TBI) cannot be stabilized by initial surgery. Mobile computed tomography (CT) provides real-time information for diagnosis in these TBI surgically high-risk (TBI-SHR) patients. The objective of this study was to analyze a 5-year series of TBI-SHR patients to evaluate the impact of intraoperative mobile CT (imCT) on prognosis. METHODS: Of 1017 surgically treated patients with TBI retrospectively reviewed over a 5-year period (2009-2013), 59 patients required second operations within 72 hours of their initial surgery because of progressive or delayed hematomas (TBI-SHR group). Their clinical, radiographic, and intraoperative findings were compared among 19 patients who received imCT versus 40 patients who received fixed-unit CT. RESULTS: Our TBI-SHR group accounted for 5.8% of all surgically treated patients with TBI. The use of imCT led to a change in surgical plan in 56% of patients with TBI intraoperatively. Younger patients (≤55 years; P < 0.05) with multifocal hemorrhage on preoperative CT (P = 0.033) and with an intraoperative unexpected event such as intraoperative intracranial pressure >20 mm Hg or acute brain swelling after adequate decompression (P = 0.003 and 0.004, respectively) significantly benefited from imCT in the TBI-SHR group. imCT also provided a quicker diagnosis (P < 0.001), led to a trend toward shorter intensive care unit stays (P = 0.077), and was associated with better neurologic outcomes at discharge days (P = 0.044). CONCLUSIONS: The use of imCT is associated with better neurologic outcomes at discharge days compared with the use of fixed-unit CT in TBI-SHR patients.

Successful Treatment of Refractory Status Epilepticus Using Anterior Thalamic Nuclei Deep Brain Stimulation.

BACKGROUND: Refractory status epilepticus (RSE) is considered a medical emergency in neurology and is related to high mortality. We report a successfully treated case of RSE using deep brain stimulation (DBS) at the anterior thalamic nuclei (ATN) in a 17-year-old woman. RESULTS: This patient developed RSE as a result of progressive seizure activity. RSE with generalized tonic-clonic seizures was noted 2 weeks before admission. Video electroencephalography monitoring showed continuous 3-Hz generalized spike-and-wave complexes with higher amplitude over bilateral frontal. Four weeks after RSE onset, bilateral DBS of the ATN was started. This treatment was immediately followed by the disappearance of tonic-clonic seizures and spike-and-wave complexes, suggesting resolution of the RSE. Significant clinical improvement was noted 1 week after DBS implantation. CONCLUSIONS: DBS at the ATN significantly improved both the electroencephalography and clinical presentation in the patient with RSE. DBS at the ATN should be considered as a possible treatment choice once a patient develops RSE.

Long Term Surgical Outcome and Prognostic Factors of Atypical and Malignant Meningiomas.

Atypical and malignant meningiomas are rare. Our aim was to examine the treatment outcomes following surgical resection, and analyze associations between clinical characteristics and overall survival (OS) or relapse free survival (RFS). 102 patients with atypical or malignant meningiomas underwent microsurgical resection between June 2001 and November 2009 were analyzed retrospectively. We compared demographics, clinical characteristics, treatment, and complications. The five-year and ten-year overall survival rates were 93.5% and 83.4%, respectively. Three factors significantly reduced OS: Malignant meningiomas (p < 0.001), which also decreased RFS (p < 0.001); female patients (p = 0.049), and patients with Karnofsky Performance Status (KPS) < 70 at diagnosis (p = 0.009). Fifty two patients (51%) experienced tumor relapse. Total resection of tumors significantly impacted RFS (p = 0.013). Tumors located at parasagittal and posterior fossa area lead to higher relapse rate (p = 0.004). Subtotal resection without adjuvant radiotherapy lead to the worst local control of tumor (p = 0.030). An MIB-1 index <8% improved OS and RFS (p = 0.003). Total resection of atypical and malignant meningiomas provided better outcome and local control. Adjuvant radiation therapy is indicated for patients with malignant meningiomas, with incompletely excised tumors; or with tumors in the parasagittal or posterior fossa area. The MIB-1 index of the tumor is an independent prognostic factor of clinical outcome.

Neurenteric Cyst or Neuroendodermal Cyst? Immunohistochemical Study and Pathogenesis.

BACKGROUND: Neurenteric cysts are rare central nervous system lesions derived from an endodermal origin. There is no consensus concerning pathogenesis because of the paucity of occurrences. We report an immunohistochemical study of 10 cases with neurenteric cysts and postulate its pathogenesis. METHODS: Ten patients underwent surgical treatment for neurenteric cysts from 1995 to 2015. We retrospectively reviewed clinical, radiologic, operative, and pathologic findings for these patients. Immunohistochemical stains were completed in all cases to distinguish cell type and origin. RESULTS: Three cell types were identified: pseudostratified-ciliated, goblet-columnar, and simple cuboidal cells. All cases were positive for cytokeratin 7, and negative for cytokeratin 20, caudal-type homeobox 2, mucin 2, thyroid transcription factor 1, human chorionic gonadotropin, placental alkaline phosphatase, and cluster of differentiation 31. Four of them had positive staining for mucin 5AC, with expression only in goblet-columnar cells. According to the immunohistochemical results, the cells resembled the respiratory tract (pseudostratified-ciliated), stomach (goblet-columnar), and respiratory bronchioles (simple cuboidal). Seventy-five percent of cases with recurrence had a goblet-columnar component, emphasizing the importance of total resection of the cyst and complete pathologic examination. CONCLUSIONS: We postulate that the cystic tumor was derived from multipotent endodermal cells that migrated and traveled along the neuroectoderm, with incomplete differentiation into various cell types as a result of an unsuitable microenvironment. Because the neurenteric canal was only the channel of migration rather than a component of the cysts, the term neuroendodermal cysts is more precise in presenting the embryopathogenesis.

Seizure Freedom After Limited Hippocampal Radiofrequency Thermocoagulation.

BACKGROUND: Surgical interventions are often used for freedom from seizure in patients with drug-resistant mesial temporal lobe epilepsy. A patient with seizure foci in the left mesiotemporal region underwent limited-size stereotactic radiofrequency thermocoagulation (RF-TC) over the left hippocampus. CASE DESCRIPTION: A 37-year-old woman with febrile convulsion in her childhood was admitted to our neurologic department with complex partial seizure with secondary generalization. Electroencephalography showed epileptogenic focus mainly from the left mesiotemporal region, and magnetic resonance imaging confirmed a left hippocampal atrophy. Because of failure to control seizure after use of several antiepileptic drugs, drug-resistant mesial temporal lobe epilepsy was diagnosed. RF-TC was done in the left hippocampus. Unique features of our technique include intraoperative electroencephalography recordings directly from electrodes on the left hippocampus, an aura sensation provoked during the low-temperature test thermocoagulation, and therapeutic thermocoagulation performed via a Radionics radiofrequency lead. In the 16-week period following the surgery, the patient experienced no seizure attacks and no significant postoperative adverse effects or memory impairments. Compared with other reports using RF-TC, our case demonstrates a 1-step minimally invasive surgery that reduces hippocampal volume loss, shortens the length of hospital stay, decreases the occurrence of postoperative infection, and achieves good outcomes for epilepsy control. CONCLUSIONS: Favorable seizure control was achieved with minimally invasive RF-TC. Further use of this technique is warranted in cases of drug-resistant mesial temporal lobe epilepsy.

Neurenteric cysts: risk factors and management of recurrence.

BACKGROUND: Neurenteric cysts are rare central nervous system lesions with excellent outcome after total excision. The authors report their experience in the management of these lesions, especially if recurrence occurs. Risk factors of recurrence were analyzed, which have never been reported according to the literature review. METHODS: Twelve patients underwent surgical treatment for neurenteric cysts from April 1998 to July 2015. We retrospectively reviewed the clinical, radiological, operative, and pathological findings for these patients. Correlations between clinical characteristics and recurrence were analyzed. RESULTS: This series included six intracranial and six intraspinal cases. Total resection was achieved in 4 of the 12 cases and partial resection in 8. Six of the patients that underwent partial resection suffered from recurrence, and an additional operation was needed in five. Three of the recurrent intracranial lesions had refractory symptoms and were finally controlled through cyst-peritoneal or ventricle-peritoneal shunts. Risk factors of recurrence were revealed as age ≦30 years old (p = 0.02), subtotal resection in the first operation (p = 0.01), and size of supratentorial NECs >30 ml (p = 0.04). Two-thirds of recurrences occurred in the first 2 years after treatment. CONCLUSIONS: NECs express high recurrence rates when total excision cannot be achieved. The preoperative diagnosis error plays a major role leading to an incorrect surgical strategy and recurrence. MRI with FLAIR and DWI is recommended to improve the preoperative diagnosis. Although timely reoperation is indicated for symptomatic recurrence, adhesion may cause reoperation to become more challenging. C-P or V-P shunts are suggested as the second-line treatment, resulting in excellent prognosis. Patients with mucin-secreting cells noted histologically are susceptible to recurrence.