Objective: We focused on the hypothesis that overexpression of the inwardly rectifying potassium channel 2.1 (Kir2.1) gene could inhibit motor neuron activity and, therefore, be therapeutically used in gene-based neuromodulation.

Methods: In order to induce expression of the Kir2.1, the inducible RheoSwitch(TM) promoter was used and controlled by ligand. In vivo gene expression was accomplished by an adenoviral vector to deliver unilaterally into the lumbar spinal cord of rats.

Results: Behavioral assays demonstrated that neuromuscular inhibition was exclusive to rats that received the ligand. Histological analysis also showed evidence of some motor neuron loss in these animals. Behavioral effects of Kir2.1 expression were completely reversible, arguing that the behavioral effect did not result from motor neuron death.

Conclusion: Delivery of the gene for Kir2.1 inhibits neurons by resisting depolarization to the action potential threshold. Regulated neuronal expression of Kir2.1 may provide an elegant means for neuromodulation in a selected neuronal population.

From: Regulated Neuronal Neuromodulation via Spinal Cord Expression of the Gene for the Inwardly Rectifying Potassium Channel 2.1 (Kir2.1) by Boulis et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background and Importance

Clinical Presentation: A boy presented with gonadotropin-independent precocious puberty at 6 years and 10 months of age. Although a slight elevation of [beta]-human chorionic gonadotropin[beta]-HCG) suggested that a small pineal cystic lesion observed on magnetic resonance imaging might be an HCG-producing tumor, it was not clear whether the mass was truly a GCT. Accordingly, we followed the pineal lesion and serum pituitary-gonadotropin levels for approximately 7 years. After this period without essential tumor growth, the pineal tumor suddenly showed rapid enlargement, which prompted treatment. A histopathological investigation revealed a mixed GCT with a germinoma and an immature teratoma. Serum pituitary-gonadotropin levels at 5 years after the first examination had increased to normal pubertal ranges. Although the pituitary-gonadotropin levels had remained low during the period with no tumor growth, the gonadotropin levels were elevated and had continued to increase at least 2 years before the rapid enlargement of the tumor.

Conclusion: These phenomena suggest that levels of neuroendocrinological parameters, such as pituitary-gonadotropin, at puberty might affect the enlargement of pineal region GCTs, which might account for the natural history of GCTs, i.e., their frequent detection at puberty.

From: A Pineal Region Germ Cell Tumor with Rapid Enlargement After a Long-term Follow-up by Jinguji et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To evaluate the clinical outcome and risk factors for in-stent restenosis (ISR) after treatment of ICAS with a Wingspan stent.

Methods: Seventy-seven patients with 79 total target ICAS > 60% (mean, 79.9 +/- 8.4%; symptomatic ICAS, 96.2%) underwent attempted treatment with Wingspan stenting between March 2010 and March 2011. A retrospective review of the prospectively registered data was conducted to assess the risk factors for ISR as well as the clinical outcomes of these patients.

Results: The 30-day TIA/stroke and death rates were 5.3% (95% CI, 0.1% to 10.5%) and 0%, respectively. All patients but one were followed clinically for a mean of 18.9 months (range, 12-23 months). During the period, cumulative TIA/stroke and death rates were 8.1% (95% CI, 1.7% to 14.5%) and 0%, respectively. Only one patient suffered a disabling stroke (subarachnoid hemorrhage), which was associated with retreatment of an ISR using a drug-eluting balloon-expandable stent. Follow-up angiography was available in 69 treated vessels (89.6%) at 3-24 months (median: 12 months). Binary ISR rate was 24.6%, of which 17.6% (3 of 17 cases) were symptomatic. Rapid balloon inflation (95% CI, 5.490 to 530.817) and longer length of stenosis (95% CI, 1.093 to 1.891) were independent risk factors for ISR.

Conclusion: Wingspan stenting may be effective for appropriately selected ICAS patients. Rapid balloon inflation and longer lengths of stenosis were independent risk factors for ISR.

From: Wingspan Stenting for Intracranial Atherosclerotic Stenosis: Clinical Outcomes and Risk Factors for In-stent Restenosis by Shin et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To establish a simple, short fMRI task that reliably localizes crucial language areas in individual patients who undergo respective surgery.

Methods: fMRI was measured during an 8-minute auditory semantic decision task in 28 healthy controls and 35 consecutive patients suffering from focal epilepsy or from brain tumor. Nineteen underwent resective surgery. Group and individual analyses were performed. Results in patients were compared to postsurgical language outcome and to electrocortical stimulation (ECS) when available.

Results: BOLD clusters concordant with the anterior and posterior language areas were activated in 96% and 89% of the controls, respectively. The anterior and posterior language areas were both activated in 93% of the patients. These results were concordant with ECS results in five patients. Transient post-surgical language deficits were found in two patients in whom surgery was performed in the vicinity of the fMRI activations or who had post-surgical complications implicating areas of fMRI activations.

Conclusion: The proposed fast fMRI language protocol reliably localized the most relevant language areas in individual subjects. It appears to be a valuable complementary tool for surgical planning of epileptogenic foci and of brain tumors.

From: Non-invasive Language Mapping in Patients with Epilepsy or Brain Tumors by Genetti et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To present a safe, relatively easy, and effective treatment option for very rare intrasellar arachnoid cysts (IAC).

Methods: We performed a prospective study of intrasellar cystic lesions without a solid portion. Endoscopic exploration and fenestration were performed for all lesions under neuronavigational guidance. We analyzed presenting symptoms, endocrinological status, and magnetic resonance images (MRI).

Results: There were two male and four female patients with a mean age of 45 years (range, 27-67 years). All patients presented with the visual disturbance of bitemporal hemianopsia. Four patients had endocrinological symptoms including galactorhea, dysmenorrhea, and diabetes insipidus. Endoscopic fenestration of the cyst was successfully performed in all patients. All patients were confirmed to have a pure cystic lesion, namely an arachnoid cyst. The follow-up period was 10 months on average (range, 6 – 12 months). Visual disturbance improved in five patients. Endocrinological problems persisted in all patients for 3 months and then normalized except for the patient with diabetes insipidus. There was no evidence of recurrence in any of the six patients in the 12-month postoperative imaging studies (median follow-up of 10 months). Two patients showed syndrome of inappropriate antidiuretic hormone (SIADH) at 2 and 4 weeks after the operation, but these recovered to normal levels after this time point.

Conclusion: Endoscopic fenestration of an intrasellar arachnoid cyst is a safe and simple procedure without serious complications.

From: Transventricular Endoscopic Fenestration of Intrasellar Arachnoid Cyst by Shim et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Objective: To evaluate cognitive outcome after coil embolization of asymptomatic UIA and its relationship with CSIL after the procedure.

Methods: We prospectively enrolled 40 UIA patients who showed no new focal neurological deficit after coil embolization. CSIL were assessed with diffusion-weighted imaging (DWI) within 1 day after the procedure. A battery of neuropsychological tests was performed three times: preoperatively and postoperatively at 1 and 4 weeks after coil embolization.

Results: The incidence of cognitive impairment after coiling in patients with UIAs was 44% (17/39) at 1 week and 19% (7/37) at 4 weeks after coil embolization. DWI within 1 day after coil embolization revealed that 60% (24/40) of patients showed CSIL. However, no significant difference was found in any mean cognitive scores as well as the number of cognitively impaired variables between patients with and without CSIL at weeks 1 and 4. Additional correlation analysis revealed no correlations between the number of CSIL on DWI and the cognitive sum z-score at both 1 and 4 weeks.

Conclusion: Exhaustive neuropsychological evaluation of UIA patients who underwent coil embolization demonstrated recovery or improvements from baseline cognitive function after 4 weeks, although some patients still showed cognitive deficits at 4 weeks after the procedure. However, we found no statistically significant relationship between the presence and the number of CSIL on DWI and cognitive changes after the procedure.

From: Cognitive Outcome and Clinically Silent Thromboembolic Events after Coiling of Asymptomatic Unruptured Intracranial Aneurysm by Kang et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Objective: To assess whether subsidence rates differ between static and expandable cages, and identify independent risk factors for subsidence and extent of subsidence when present.

Methods: A consecutive population of patients who underwent corpectomy between 2006 and 2009 was identified. Subsidence was assessed via x-ray at 1-month and 1-year follow-ups. In addition to cage type, demographic, medical, and cage-related covariates were recorded. Multivariate models were employed to assess independent associations with rate, odds, and extent of subsidence.

Results: Of 91 patients, 44.0% had expandable and 56.0% had static cage. One-month subsidence rate was 36.3%, and 51.6% at 1 year. Expandable cages were independently associated with higher rates and odds of subsidence compared to static cages. Infection, trauma, and footplate-to-vertebral body endplate ratio of less than 0.5 were independent risk factors for subsidence. Presence of prongs on cages and posterior fusion 2 or more levels above and below corpectomy level had lower rates and odds of subsidence. Infection and cage placement in the thoracic or lumbar region had greater extent of subsidence when subsidence was present.

Conclusion: Expandable cages had higher rates and risk of subsidence compared to static cages. When subsidence was present, expandable cages had greater magnitudes of subsidence. Other factors including footplate-to-vertebral body endplate ratio, prongs, extent of supplemental posterior fusion, spinal region, and diagnosis also impacted subsidence.

From: Radiologic Outcomes of Static Versus Expandable Titanium Cages After Corpectomy: A Retrospective Cohort Analysis of Subsidence by Lau et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To evaluate the effect of ignoring small vessels and SW vs. stringent BIF labeling on SR ruptured aneurysm detection performance in borderline aneurysms with small branches, and to reconcile SR-based labeling with clinical SW/BIF classification.

Methods: Catheter rotational angiographic datasets of 134 consecutive aneurysms (60 ruptured) were automatically measured in 3-D. Stringent BIF labeling was applied to clinically labeled aneurysms, with 21 aneurysms switching label from SW to BIF. Parent vessel size was evaluated both taking into account, and ignoring, small vessels. SR was defined accordingly, as the ratio between aneurysm and parent vessel sizes. Univariate and multivariate statistics identified significant features. The square of the correlation coefficient (R-square) was reported for bivariate analysis of alternative SR calculations.

Results: Regardless of SW/BIF labeling method, SR was equally significant in discriminating aneurysm ruptured status (p-value <0.001). Bivariate analysis of alternative SR had a high correlation of R-square=0.94 on the whole dataset, and R-square=0.98 on the 21 borderline aneurysms.

Conclusion: Ignoring small branches from SR calculation maintains rupture status detection performance, while reducing post-processing complexity and removing labeling ambiguity. Aneurysms adjacent to these vessels can be considered sidewall for morphometric analysis. It is reasonable to use the clinical SW/BIF labeling when employing SR for rupture risk evaluation.

From: Size Ratio Performance in Detecting Cerebral Aneurysm Rupture Status is Insensitive to Small Vessel Removal by Lauric et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Available now online are the newest Academic Medicine articles addressing a number of the most pressing issues facing the academic medicine community. Keep reading for more details.

Perspectives

Creating a Longitudinal Environment of Awareness: Teaching Professionalism Outside the Anatomy Laboratory
Jones, from his perspective as a medical student, describes the goal of incorporating professionalism into all basic science courses—the creation of a longitudinal, cohesive environment of awareness.

Balancing Personalized Medicine and Personalized Care
Cornetta and Brown discuss how new genetic technologies promise to revolutionize medical care, but raise issues regarding patients’ expectations of personalized care. They make recommendations regarding personalized medicine.

Articles

A Multi-Institutional Medical Educational Collaborative: Advocacy Training in California Pediatric Residency Programs
Chamberlain and colleagues describe a successful educational collaborative that disseminates educational resources and provides faculty development to advance residents’ training in advocacy and other areas.

MiPLAN: A Learner-Centered Model for Bedside Teaching in Today’s Academic Medical Centers
Stickrath and colleagues describe this three-part model that is designed to enable clinical teachers to provide care to patients while assessing learners, determining high-yield teaching topics, and providing feedback to learners.

Employee Health Benefit Redesign at the Academic Health Center: A Case Study
Marshall and colleagues describe an employee health benefit redesign implemented at Penn State Hershey Medical Center that has led to reduced costs, increased use of the Penn State network, and increased employee utilization of wellness and preventive programs.

The Community Leaders Institute: An Innovative Program to Train Community Leaders in Health Research
Crosby and colleagues describe a program designed to enhance academic-community research, integrate the interests of community leaders and AHC researchers, and build research capacity and competencies within the community.

Creating “Innovator’s DNA” in Health Care Education
Armstrong and Barsion discuss how health care educator development programs can use the five innovator’s skills (associating, questioning, observing, networking, and experimenting) to produce change agents and change in medicine.

Research Reports

Training in Urban Medicine and Public Health: TRIUMPH
Haq and colleagues report that early, short-term outcomes confirm that the University of Wisconsin’s Training in Urban Medicine and Public Health program is achieving its desired goals: attracting and preparing medical students to work with urban underserved communities.

Medical Students’ Experiences with Authorship in Biomedical Research: A National Survey 
Karani and colleagues explored authorship issues related to medical students’ research projects, assessed their knowledge about authorship issues in biomedical research, and determined their interest in learning about authorship guidelines.

Estimating Learning Outcomes from Pre- and Posttest Student Self-Assessments: A Longitudinal Study 
Schiekirka and colleagues’ evaluation strategy may assist medical teachers in identifying strengths and weaknesses of a particular course regarding specific learning objectives.

Can Incorporating Inpatient Overnight Work Hours into a Pediatric Clerkship Improve the Clerkship Experience for Students?
Talib and colleagues, using a historical controls study and a brief survey, studied the effects of overnight work hours on medical students’ perceptions of and performance in an internal medicine clerkship.

If Every Fifth Physician Is Affected by Burnout, What About the Other Four? Resilience Strategies of Experienced Physicians
Zwack and Schweitzer interviewed 200 German physicians to identify the strategies they used to promote health and foster resilience.

Developing a Unified List of Physicians’ Reasoning Tasks During Clinical Encounters
Goldszmidt and colleagues developed a unified list of physicians’ reasoning tasks, or what they reason about, during clinical encounters to provide a common language for discussing, teaching, and researching clinical reasoning. 

How Do Social Networks and Faculty Development Courses Affect Clinical Supervisors’ Adoption of a Medical Education Innovation? An Exploratory Study
Jippes and colleagues argue that a clinical supervisor’s social network may be as important as faculty development course participation in determining whether the supervisor adopts an educational innovation.

“URM Candidates Are Encouraged to Apply”: A National Study to Identify Effective Strategies to Enhance Racial and Ethnic Faculty Diversity in Academic Departments of Medicine
Peek and colleagues analyzed URM faculty rank by demographics and diversity best practices for 66 schools. Their interviews showed that institutional leadership and human capital were associated with higher URM rank.

The Construct and Criterion Validity of the Mini-CEX: A Meta-Analysis of the Published Research
Al Ansari and colleagues report that the construct and criterion validity of the mini-CEX were supported, indicating it is an important instrument for the direct observation of trainees’ clinical performance.

A Bibliometric Analysis of Evaluative Medical Education Studies: Characteristics and Indexing Accuracy
Sampson and colleagues analyzed records of articles published in five medical education and five general and internal medicine journals to determine types of research, learner levels, and indexing accuracy.

Background

Objective: To study the role of the left basal occipito-temporal area and its white matter pathways.

Methods: Three patients underwent awake surgery for lesions in the left basal postero-temporal region with intraoperative electrostimulations. Intraoperative testing consisted of naming, reading, and recognition of symbols. Location of the stimulation sites was obtained by comparing the surgical cavity in the postoperative MRI to the tags precisely located in each one of these sites seen on intraoperative photographs.

Results: A double dissociation was elicited, inducing specific visual recognition and reading disturbances during stimulation in the left postero-basal temporal cortex, without naming impairment. Stimulation of the inferior part of the sagittal stratum (inferior longitudinal fascicle) generated the same response, while a specific picture naming impairment, consisting of semantic paraphasias, was obtained when stimulating superiorly to this fascicle, over the lateral wall and roof of the ventricle (inferior fronto-occipital fascicle).

Conclusion: We propose the existence of a dual visuo-language route in the left dominant hemisphere. The first pathway seems to run basally, from the occipital lobe to the postero-basal temporal cortex, mediated by the left inferior longitudinal fascicle, sub-serving visual recognition. The second pathway might run superiorly and more medially, from the occipital pole directly to the frontal areas, and could be underlain by the inferior fronto-ocipital fascicle, involved in naming (semantic processing). Such a model might have both fundamental and clinical implications for the selection of the tasks during awake mapping as well as for postsurgical rehabilitation.

From: Double Dissociation Between Visual Recognition and Picture Naming: A Study of the Visual-language Connectivity Using Tractography and Brain Stimulation by Gil-Robles et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Objective: To evaluate the patient’s sense of smell and mucociliary clearance time (MCT) after skull base surgery.

Methods: Patients with pituitary adenoma underwent a Transnasal Transphenoidal Endoscopic Approach (TTEA Group, N=36), while patients with other benign parasellar tumors underwent an Expanded Endonasal Approach (EEA Group, N=14) with a vascularized septal flap (VSF). Assessment of symptoms (Visual Analogue Scale, VAS), olfactometry (Barcelona Smell Test, BAST-24), and MCT (Saccharin test) were performed before and 3 months after surgery.

Results: Before surgery, patients reported poorer BAST-24 scores on detection, identification, and forced choice than the healthy population, while both study groups had similar sinonasal symptoms, BAST-24, and MCT scores. After surgery, no changes in symptom scores (VAS) were observed except for the loss of smell (26.7+/-30.5 mm, p<0.05) and posterior nasal discharge (29.7+/-30.3 mm, p<0.05) compared to baseline (5.2+/-11.3, 19.1+/-25.3, respectively). EEA patients reported higher loss of smell and posterior nasal discharge compared to TTEA. TTEA and EEA groups had similar scores on post-operative BAST-24. After surgery, however, patients showed prolonged Saccharin test (15.6+/-10.8 min, p<0.05) compared to baseline (8.4+/-4.4 min). In addition, EEA reported longer MCT than TTEA patients.

Conclusion: EEA but not TTEA has a short-term (3 months) negative impact on patient’s olfaction and mucociliary clearance. Patients should be informed about smell loss as a consequence of skull base surgery to prevent legal claims. Likewise, further research and some modifications on reconstruction flaps are encouraged to avoid damaging the olfactory neuroepithelium.

From: Impairment of Olfaction and Mucociliary Clearance After Expanded Endonasal Approach Using Vascularised Septal Flap Reconstruction for Skull Base Tumors by Alobid et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To examine the anatomy of the MOCR and outline its role as a “key landmark” for approaches to the sellar and suprasellar regions.

Methods: Ten silicone-injected, cadaveric specimens and 96 dry skulls were examined. Dissections were done endoscopically and microscopically.

Results: The lateral tubercular recess (LTR) is an osseous depression located at the lateral edge of the tuberculum when viewed from the sphenoid sinus. Intracranially, it corresponds to the lateral tubercular crest (LTC); a ridge situated at the superomedial aspect of the carotid sulcus. The MOCR is a teardrop shaped osseous indentation formed at the medial junction of the paraclinoid carotid canal and the optic canal. Dorsally, it is represented by a teardrop shaped area with vertices at the inferior aspect of the LTC, the medial aspect of the junction of the superior and posterior surfaces of the optic strut, and the superolateral aspect of the tuberculum. The middle clinoid process is situated inferior to the LTC. The distal osseous arch (DOA) of the carotid sulcus connects the lateral opticocarotid recess (LOCR) to the LTR and is a landmark for the paraclinoid ICA. Only 44% of the specimens had middle clinoid processes.

Conclusion: The MOCR and middle clinoid process are distinct structures. Because of its location at the confluence of the optic canal, the carotid canal, the sella, and the anterior cranial base, the MOCR is a “key landmark” for endoscopic approaches.

From: The Medial Opticocarotid Recesss: An Anatomical Study of an Endoscopic “Key Landmark” to the Ventral Cranial Base by Labib et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To analyze the subcortical anatomy of a specific region within the parietal and temporal lobes where seven long-distances tracts intersect, i.e. the temporo-parietal fiber intersection area (TPFIA).

Methods: Four postmortem human hemispheres were dissected, and four healthy hemispheres were analyzed using DTI-based tractography software. The different tracts that intersect at the posterior temporal and parietal lobes were isolated and the relations with the surrounding structures analyzed.

Results: Seven tracts pass through the TPFIA: horizontal portion of the superior longitudinal fasciculus, arcuate fasciculus, middle longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, optic radiations, and tapetum. The TPFIA was located deep to the angular gyrus, posterior portion of the supramarginal gyrus, and posterior portion of the superior, middle, and inferior temporal gyri.

Conclusion: The TPFIA is a critical neural crossroad, as it is traversed by seven white matter tracts that connect multiple areas of the ipsilateral and contralateral hemisphere. It is also a vulnerable part of the network, as a lesion within this area will produce multiple disconnections. This is valuable information when planning a surgical approach through the parieto-temporo-occipital junction. In order to decrease the surgical risks, a detailed DTI tractography reconstruction of the TPFIA should be performed and intraoperative electrical stimulation should be strongly considered.

From: Fiber Dissection and DTI Tractography Study of the Temporo-parietal Fiber Intersection Area by Martino et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Clinical Presentation: Case 1: An 87-year old woman presented with acute onset left 3rd nerve palsy. Work-up demonstrated an 18 mm left posterior carotid wall aneurysm with a large daughter aneurysm on its dome. Endovascular access was complicated by a type III aortic arch with a hyper-acute angle at the origin of the left common carotid artery. An 8 French Simmons II shaped guide formed a stable platform, allowing successful PED delivery.

Case 2: A 76-year old woman experienced a transient ischemic attack. She harbored a right-sided 20 mm cavernous internal carotid artery (ICA) aneurysm. She was treated with two PEDs deployed via a transradial approach.

Conclusion: Transradial access or guide support with the 8 French Simmons II catheter grants stable access for curative embolization with the PED in elderly patients with large intracranial aneurysms and a complex aortic arch.

From: Transradial Access or Simmons Shaped 8 French Guide Enable Delivery of Flow-diverters in Patients with Large Intracranial Aneurysms and Type III Aortic Arch by Dietrich et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background and Importance

Clinical presentation: A 36 year-old woman presented with headache, multiple cranial nerve palsies, visual hallucinations, confusion, hemiparesis, hemihipoestesia, episodes of disconnection and toxic syndrome. MR and PET-scan revealed leptomeningeal carcinomatosis in the brain stem, the cerebellum and along the whole spinal cord. Various nodular, intradural extramedullary lesions were present at multiple dorsal and lumbar levels. Metastatic bone disease affected all the vertebral bodies and various extra-spinal bones. An intradural and bone biopsy was performed at L4, providing the diagnosis of anaplastic ependymoma (WHO grade III) with focal neuronal differentiation. Despite chemotherapy, the patient’ symptoms quickly progressed, and she died 7 weeks after diagnosis.

Conclusion: To our knowledge, there are no previous descriptions of ependymomas with this extensive leptomenineal, spinal, intracranial and extraneural dissemination at clinical onset. Bone metastases in spinal ependymoma have not been previously reported.

From: Anaplastic Ependymoma with Holocordal and Intracranial Meningeal Carcinomatosis and Holospinal Bone Metastases by Pérez-Bovet et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

From: The Contribution of Carlo Giacomini (1840-1898): The Limbus Giacomini and Beyond by Perrini et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To assess the incidence, clinical significance, predictors, and outcomes of in-stent stenosis (ISS).

Methods: Angiographic studies and hospital records were retrospectively reviewed for 435 patients treated between 2005-2011 in our institution. A multivariable regression analysis was conducted to determine predictors of ISS.

Results: The Neuroform stent was used in 264 (60.7%) patients and the Enterprise in 171 (39.3%). A total of 11 (2.5%) patients demonstrated some degree of ISS during the follow-up period at a mean time point of 4.2 months (range 2-12 months). The stenosis was mild (<50%) in 8 (1.8%) patients, moderate (50-75%) in 2 (0.5%), and severe (>75%) in 1 (0.2%). None were symptomatic or required further intervention. There was complete ISS resolution in 2 patients, partial resolution in 2, and no change in 5 on follow-up angiography. Patients developing ISS were significantly younger than those without ISS (40.3 vs. 54.9 yrs, p<0.001). ISS rates were 2.7% with the Neuroform and 2.3% with the Enterprise stent (p= 0.6). In multivariable analysis, younger patient age (OR=0.92; p=0.008), carotid ophthalmic aneurysm location (OR=7.7; p=0.01), and carotid terminus aneurysm location (OR=8.1; p=0.009) were strong independent predictors of ISS. The type of stent was not a predictive factor.

Conclusion: Neuroform and Enterprise ISS is an uncommon, often transient and clinically benign complication. Younger patients and those harboring anterior circulation aneurysms located at ophthalmic and carotid terminus locations are more likely to develop ISS.

From: In-Stent Stenosis Following Stent-Assisted Coiling: Incidence, Predictors and Clinical Outcomes of 435 Cases by Chalouhi et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To review the outcomes of patients with giant MCA aneurysms not amenable to clipping or vessel reconstruction treated with extracranial-intracranial (EC-IC) bypass and vessel sacrifice.

Methods: We retrospectively reviewed a database of aneurysms treated at our institution between 1983 and 2011.

Results: Sixteen patients (11 males, 5 females) were identified. There were 10 saccular, 4 fusiform, and 2 serpentine aneurysms. The aneurysms predominantly involved the M1 segment in 5 cases, M2 in 9 cases, and both M1 and M2 in 2 cases. The EC-IC bypasses performed included 13 STA-MCA, 1 saphenous vein graft (SVG-MCA), and 2 radial artery grafts (RAG-MCA). Postoperative bypass patency rate was 93.8% (15/16). There were three cerebrovascular accidents (18.8%), but no perioperative deaths (0% mortality). The mean follow-up was 58.4 months (range, 1-265; median, 23.5 months). In 75% (12/16) of cases the aneurysms were occluded successfully. A small residual was noted in three cases using this treatment strategy and they were retreated. In a fourth case treated with partial distal occlusion, reduced flow through the aneurysm was noted postoperatively, but the patient did not undergo further treatment. The mean modified Rankin scale (mRS) and mean Glasgow Outcome Scale (GOS) scores at last follow-up were 1.6 (range 1-4, median 1) and 4.8 (range 3-5, median 5), respectively.

Conclusion: Giant MCA aneurysms are challenging lesions. EC-IC bypass with parent vessel occlusion can provide a durable form of treatment with acceptable rates of morbidity and mortality.

From: Extracranial-intracranial Bypass and Vessel Occlusion for the Treatment of Unclippable Giant Middle Cerebral Artery Aneurysms by Kalani et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: We studied the expression pattern of HMGB-1 in the cerebellum.

Methods: We studied congenital hydrocephalic H-Tx rats aged 1 day and 7 days along with age-matched non-hydrocephalic H-Tx and Sprague Dawley (SD) rats as controls. Gene and protein expressions of HMGB-1 in the cerebellum were assayed by real-time polymerase chain reaction and western blotting, respectively; further, immunohistochemical analyses were performed using HMGB-1 (indicator of apoptosis), single-stranded DNA (ssDNA); adhesion factor related with cell migration, HNK-1; and the Purkinje cell-specific antibody, calbindin.

Results: Cytoplasmic HMGB-1 expression observed in Purkinje cells in the 1-day-old hydrocephalic group was stronger than that in the non-hydrocephalic and SD groups. Double fluorescent staining with ssDNA confirmed that Purkinje cells were undergoing apoptosis. HNK-1 expression was lower in the Purkinje cell layer in the 7-day-old rats in the hydrocephalic group, and Purkinje cells were disrupted in comparison to the control groups. Morphological changes in the cerebellum were observed in the 7-day-old rats in the hydrocephalic group as compared to the control groups.

Conclusion: Our results suggest that cerebellar neuronal cell damage in the early postnatal period may be related to the higher expression of HMGB-1 in the Purkinje cells.

From: Cerebellar Purkinje Cells Exhibit Increased Expression of HMGB-1 and Apoptosis in Congenital Hydrocephalic H-Tx Rats by Watanabe et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To compare the safety, efficacy, and 1-year clinical outcome of supra-orbital keyhole and standard pterional approaches for ruptured anterior circulation aneurysms.

Methods: A total of 87 patients underwent surgical clipping, 40 through the pterional and 47 through the supra-orbital keyhole approach. Baseline demographics, operative time, procedural complications, and 1-year patient outcome were retrospectively compared.

Results: The two groups were comparable with respect to baseline characteristics with the exception of a higher proportion of small aneurysms (<7mm) in the supra-orbital group (70.2% vs. 37.5%, p=.002). Total operative time was significantly shorter in the supra-orbital group (205 minutes, p<.001) compared with the pterional group (256 minutes). The rate of procedural complications was lower in patients treated through the pterional (17.5%) versus the supra-orbital approach (23.4%, p=.4). Intra-operative aneurysm ruptures occurred more frequently in the supra-orbital group (10.6% vs. 2.5%). No patient experienced early or late rebleeding in either group. One year after treatment, 75% (30/40) of patients achieved a favorable outcome (GOS IV or V) in the pterional group versus 76.6% (36/47) in the supra-orbital group (p=.8).

Conclusion: The rate of procedural complications may be higher with the supra-orbital keyhole approach, but overall patient outcomes appear to be comparable. The pterional approach is a simple, reliable, and efficient procedure. The keyhole approach may be an acceptable alternative for neurosurgeons who have gained sufficient experience with the technique, especially for small non-complex aneurysms.

From: Surgical Treatment of Ruptured Anterior Circulation Aneurysms: Comparison of Pterional and Supra-Orbital Keyhole Approaches by Chalouhi et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Available now online are the newest Academic Medicine articles addressing a number of the most pressing issues facing the academic medicine community. Keep reading below for more details.

Perspectives

Reconsidering the Focus On “Outcomes Research” In Medical Education: A Cautionary Note
Cook and West discuss issues–such as dilution, feasibility, failure to establish a causal link, potentially biased outcome selection, and teaching to the test–that challenge the overuse of patient outcomes in medical education research. 

Environment, Biodiversity, and the Education of the Physician of the Future
Gómez and colleagues discuss the declining environmental conditions that create health threats and worsen noncommunicable conditions. They argue that physicians must be educated as intermediaries between science and the public and to engage in environmental policy discussions.

Articles

The Creation and Impact of a Dedicated Section on Quality and Patient Safety in a Clinical Academic Department
Boudreaux and Vetter describe how a formal, structured Section on Quality and Patient Safety has promoted a culture of patient care and safety, improved performance metrics, and set the standard for other departments within their health system.

Building Interdisciplinary Biomedical Research Using Novel Collaboratives
Ravid and colleagues offer the work of the Evans Center for Interdisciplinary Biomedical Research as a productive model for leveraging discovery, as universities seek to stimulate interdisciplinary research.

Fostering Creativity: How the Duke GME Quasi-Endowment Encourages Graduate Medical Education Innovation
Andolsek and colleagues describe a “grass-roots” innovation fund and how it has made possible demonstrable sustainable impacts on teaching and learning, and increased morale and scholarly recognition.

YouTube as a Platform for Publishing Clinical Skills Training Videos
Topps and colleagues, with the goal of disseminating their educational videos to a broader audience, considered several platforms. Here they discuss their decision to use YouTube and present some outcomes.

Creating a Virtual Pharmacology Curriculum in a Problem-based Learning Environment: One Medical School’s Experience
Karpa and Vrana describe the Pennsylvania State University College of Medicine’s virtual pharmacology curriculum, which includes learning objectives, study guides, and examination questions corresponding to each PBL case, and faculty-led review sessions.

Advanced Ultrasound Training for Fourth-Year Medical Students: A Novel Training Program at the Ohio State University College of Medicine
Bahner and Royall describe this program, which provides training in focused ultrasound for fourth-year students, reducing educational burdens for residency programs, although advanced ultrasound training usually occurs during residency or later.

Research Reports

Improving Student Selection Using Multiple Mini Interviews with Multi-faceted Rasch Modeling
Till and colleagues report on using the multiple mini-interview selection process at the University of Dundee Medical School, which reliably separated the candidates into four statistically distinct levels of noncognitive ability.

Deafness Among Physicians and Trainees: A National Survey
Moreland and colleagues examined the characteristics and accommodations used by the deaf and hard-of-hearing (DHoH) physician and trainee population and whether these individuals were more likely to care for DHoH patients.

Making July Safer: Simulation-Based Mastery Learning During Intern Boot Camp
Cohen and colleagues describe a simulation-based mastery learning boot camp that allows for individualized training, assessment, and documentation of competence before interns begin providing medical care.

“Being the Best We Can Be”: Medical Students’ Reflections on Physician Responsibility in the Social Media Era
Lie and colleagues, before and after an educational intervention on professionalism, examined medical students’ attitudes, self-reported behaviors, and intended actions related to their online social media use.

Gauging Events that Influence Students’ Perceptions of the Medical School Learning Environment: Findings from One Institution
Shochet and colleagues argue that the learning environment influences students’ professional development. At JHUSOM, understanding the phenomena that influence students’ perceptions can inform how meaningful learning occurs and professional behaviors are formed.

Construction and Validation of the Nijmegen Evaluation of the Simulated Patient (NESP): Assessing Simulated Patients’ Ability to Role Play and Provide Feedback to Students
Bouter and colleagues developed a feasible, valid, and reliable instrument that could be used at different medical schools to assess the performance of individual simulated patients.

The Objective Assessment of Experts’ and Novices’ Suturing Skills Using An Image Analysis Program
Frischknecht and colleagues objectively assessed and compared the suturing performance of experts and novices using an image analysis program to provide validity evidence for this assessment method.

Premedical Students’ Exposure to the Pharmaceutical Industry’s Marketing Practices
Hodges and colleagues found that the majority of medical students have interacted with the pharmaceutical industry even before entering medical school so they argue that interventions should be considered to enhance students’ awareness of marketing on prescribing practices.

A National Survey of Academic Emergency Medicine Leaders on the Physician Workforce and Institutional Workforce and Aging Policies
Takakuwa and colleagues, as part of the Aging and Generational Issues Taskforce of the Society for Academic Emergency Medicine, describe the policies, practices, and attitudes of academic emergency medicine leaders regarding workforce issues, shift work, and accommodating the academic and personal needs of aging physicians.

Medical Education in the Caribbean: Quantifying the Contribution of Caribbean-Educated Physicians to the Primary Care Workforce in the United States
van Zanten and Boulet found that more than half of the Caribbean-educated physicians involved in U.S. direct patient care are practicing in primary care specialties, thereby making an important contribution to the workforce.

Measuring Medical Student Attitudes and Beliefs Regarding Patients Who Are Obese
Ip and colleagues found that the Nutrition, Exercise, and Weight Management (NEW) Attitudes Scale is valid and reliable and may be used in future studies of medical school students’ attitudes and beliefs regarding obese patients.

Background

Objective: To perform a biomechanical analysis of instrumented reconstruction configurations used after axial spondylectomy and demonstrate safe use of a novel construct in a patient case report.

Methods: Several different published and novel reconstruction configurations were inserted into 7 occipitocervical spines that underwent axial spondylectomy. A biomechanical analysis of the constructs’ stiffness in flexion and extension, lateral bending, and rotation was performed. A patient then underwent a posterior-only approach for axial spondylectomy and circumferential reconstruction.

Results: Biomechanical analysis of different constructs demonstrated that anterior column reconstruction with bilateral cages spanning C1 lateral mass to C3 facet in combination with occipitocervical instrumentation was superior in flexion-extension and equivalent in lateral bending and rotation to currently used constructs. In the patient in which this construct was placed via a posterior-only approach for axial spondylectomy and instrumentation, the patient remained at neurological baseline and demonstrated no recurrence of local disease or failure of instrumentation to date.

Conclusion: When comparing C1 lateral mass to C3 facet bilateral cage plus occipitocervical instrumentation to existing anterior and posterior constructs, this novel reconstruction is biomechanically equivalent if not superior in performance. In a patient, the posterior-only approach for C2 spondylectomy with the novel reconstruction was safe, durable, and avoided the morbidity of the anterior approach.

From: Axial Spondylectomy and Circumferential Reconstruction via a Posterior Approach by Jandial et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: To evaluate the usefulness of 5-ALA fluorescence-guided resection of intramedullary ependymoma for achieving maximum tumor resection.

Methods: This study included 10 patients who underwent surgical resection of an intramedullary ependymoma. Nine patients were orally administered 5-ALA (20 mg/kg) 2 hours before the induction of anesthesia. 5-ALA fluorescence was visualized using an operating microscope. Tumors were removed in a standardized manner with electrophysiological monitoring. The extent of resection was evaluated on the basis of intraoperative findings and postoperative magnetic resonance imaging. Histopathological diagnosis was established according to World Health Organization 2007 criteria. Cell proliferation was assessed by Ki-67 labeling index (LI).

Results: 5-ALA fluorescence was positive in 7 patients (6 grade II and 1 grade III) and negative in 2 patients (grade II). Intraoperative findings were dichotomized: tumors covered by the cyst were easily separated from the normal parenchyma; whereas tumors without the cyst appeared to be continuous to the spinal cord. In these cases, 5-ALA fluorescence was especially valuable in delineating the ventral as well as cranial and caudal margins. Ki-67 LI was significantly higher in 5-ALA positive cases compared to 5-ALA negative ones. All patients neurologically improved or stabilized after surgery.

Conclusion: 5-ALA fluorescence was useful for detecting tumor margins during surgery for intramedullary ependymoma. When combined with electrophysiological monitoring, fluorescence-guided resection could help to safely achieve maximum tumor resection.

From: 5-aminolevulinic Acid Fluorescence-guided Resection of Intramedullary Ependymoma: Report of 9 Cases by Inoue et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Background

Objective: We describe 9 cases of EVD-related vascular trauma: 7 arteriovenous fistulae and 2 traumatic aneurysms.

Methods: During a 3-year period, 299 patients had EVDs placed. Eight patients (2.75%), 3 male and 5 female, mean age 48 +/- 20 years, developed vascular lesions associated with EVDs. Six patients developed arteriovenous fistulae (AVFs) and 2 patients developed a traumatic aneurysm. The arterial feeders of five superficial draining fistulae arose from the middle meningeal artery, and the arterial feeder of a deep draining fistula originated from a lenticulostriate artery. One traumatic aneurysm arose from a distal branch of the anterior cerebral artery, and the second from a branch of the superficial temporal artery. Four of the superficial fistulae were treated with transarterial embolization.

Results: Two superficial fistulae and the deep draining fistula spontaneously resolved after EVD removal. The intracranial aneurysm was embolized with Onyx18, and the superficial temporal artery aneurysm was managed conservatively. There were no hemorrhages associated with any of these vascular lesions, and no complications following treatment.

Conclusion: Our data suggest that iatrogenic vascular trauma associated with EVD insertions (2.75%) may be more common than is currently appreciated. Endovascular treatment is effective and may be necessary when these lesions do not spontaneously resolve.

From: Iatrogenic Vascular Complications Associated with External Ventricular Drain Placement: A Report of Eight Cases and Review of the Literature by Kosty et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.

Objective: To analyze complications from the microsurgical treatment of VS by an expert surgical team and to propose strategies for minimizing such complications.

Methods: Surgical outcomes and complications were evaluated in a consecutive series of 410 unilateral VSs treated from 2000 to 2009. Clinical status and complications were assessed postoperatively (within 7 days) and at the time of follow-up (range: 1 to 116 months; mean: 32.7 months).

Results: Follow-up data were available for 357 of the 410 patients (87.1%). Microsurgical tumor resection was performed through a retrosigmoid (RS) approach in 70.7% of cases. Thirty-three patients had intrameatal tumors (8%) and 204 (49.8%) had less than 20 mm tumors. Gross total resection (GTR) was performed in 306 patients (74.6%). Hearing preservation surgery (HPS) was attempted in 170 patients with tumors smaller than 20 mm and good hearing was preserved in 74.1%. The main neurological complication was facial palsy (H-B grade III-VI), observed in 14% (56 cases) of patients postoperatively; however, 59% of them improved during the follow-up period. Other neurological complications were: disequilibrium in 6.3%, facial numbness in 2.2%, and lower cranial nerve (LCN) deficit in 0.5%. Non-neurologic complications included: cerebrospinal fluid (CSF) leaks in 7.6%, wound infection in 2.2%, and meningitis in 1.7%.

Conclusion: Many of these complications are avoidable through further refinement of operative technique, and strategies for complication avoidance are proposed.

From: Contemporary Surgical Management of Vestibular Schwannomas: Analysis of Complications and Lessons Learned Over the Past Decade by Nonaka et al.

Full article access for Neurosurgery subscribers at Neurosurgery-Online.com.