Posterior vascular anatomy of the encephalon: a comprehensive review

PURPOSE

This article presents a comprehensive exploration of neurovascular anatomy of the encephalon, focusing specifically on the intricate network within the posterior circulation and the posterior fossa anatomy; enhancing understanding of its dynamics, essential for practitioners in neurosurgery and neurology areas.

METHOD

A profound literature review was conducted by searching the PubMed and Google Scholar databases using main keywords related to neurovascular anatomy. The selected literature was meticulously scrutinized. Throughout the screening of pertinent papers, further articles or book chapters were obtained through additional assessment of the reference lists. Furthermore, four formalin-fixed, color latex-injected cadaveric specimens preserved in 70% ethanol solution were dissected under surgical microscope (Leica Microsystems Inc, 1700 Leider Ln, Buffalo Grove, IL 60089, USA), using microneurosurgical as well as standard instruments, and a high-speed surgical drill (Stryker Instruments 1941 Stryker Way Portage, MI 49002, USA). Ulterior anatomical dissection was performed.

RESULTS

Detailed examination of the basilar artery (BA), a common trunk formed by the union of the left and right vertebral arteries, denoted a tortuous course across the basilar sulcus. Emphasis is then placed on the Posterior Inferior Cerebellar Artery (PICA), Anterior Inferior Cerebellar Artery (AICA) and Superior Cerebellar Artery (SCA). Each artery's complex course through the posterior fossa, its divisions, and potential stroke-related syndromes are explored in detail. The Posterior Cerebral Artery (PCA) is subsequently unveiled. The posterior fossa venous system is explained, categorizing its channels. A retrograde exploration traces the venous drainage back to the internal jugular vein, unraveling its pathways.

CONCLUSION

This work serves as a succinct yet comprehensive guide, offering fundamental insights into neurovascular anatomy within the encephalon's posterior circulation. Intended for both novice physicians and seasoned neuroanatomists, the article aims to facilitate a more efficient clinical decision-making in neurosurgical and neurological practices.

Technical evolution of pediatric neurosurgery: the evolution of intraoperative imaging

Imaging has always been fundamental to neurosurgery, and its evolution over the last century has made a dramatic transformation in the ability of neurosurgeons to define pathology and preserve normal tissue during their operations. In the mid-70 s, the development of computerized cross-sectional imaging with CT scan and subsequently MRI have revolutionized the practice of neurosurgery. Later, further advances in computer technology and medical engineering have allowed the combination of many modalities to bring them into the operating theater. This evolution has allowed real-time intraoperative imaging, in the hope of helping neurosurgeons achieve accuracy, maximal safe resection, and the implementation of minimally invasive techniques in brain and spine pathologies. Augmented reality and robotic technologies are also being applied as useful intra-operative techniques that will improve surgical planning and outcomes in the future. In this article, we will review imaging modalities and provide our institutional perspective on how we have integrated them into our practice.

Standardized reporting of complications of epilepsy surgery and invasive monitoring: A single-center retrospective study

OBJECTIVE

Monitoring adverse effects related to epilepsy surgery is essential for quality control and for counseling patients prior to the procedure. The aim of this study was to analyze the rates of complications related to epilepsy surgery following invasive monitoring and to classify them according to the recently proposed protocol by the E-pilepsy consortium.

METHODS

This is a retrospective study of collected data extracted from our routinely updated epilepsy surgery database which consisted of 173 surgical procedures: 89 surgeries for insertion of subdural grids, strips, and/or depth electrodes, and 84 resective surgeries. According to the protocol, complications were defined as unexpected postoperative adverse events and were stratified into transient (lasting less than 6 months) and permanent deficits (lasting 6 months or longer). In addition, we reported patients with postoperative psychiatric disturbances and calculated the rates of transient and permanent postoperative sequelae which were defined as expected postoperative deficits deemed inherent to the surgical procedure.

RESULTS

Six potentially life-threatening complications requiring acceleration of the planned resective surgery occurred during invasive monitoring. Following resective surgery, 12 transient sequelae (8 motor deficits, three language deficits, and one transient dyscalculia) and 10 permanent sequelae (5 mild memory disturbances, four visual field cuts, and one contralateral dysesthesia) occurred. In addition, 7 patients experienced transient motor complications. Four permanent postoperative neurological complications (4.8%) occurred: motor deficits in three patients and a partial peripheral facial palsy in one. Finally, five patients developed de novo psychiatric disturbances (transient in four and permanent in one).

CONCLUSIONS

This is the first study to classify complications of epilepsy surgery according to the E-pilepsy consortium protocol. Our findings demonstrate that epilepsy surgery following invasive monitoring is safe and associated with low morbidity when performed in specialized centers. Monitoring these complications according to a unified definition and using a multidimensional protocol will allow for a direct comparison across epilepsy surgery centers, will provide the epileptologists and surgeons with objective percentages to share with their patients and will help in identifying risk factors and improving the safety of epilepsy surgery.

Neurosurgical Experience of Beirut Blast in the Era of Coronavirus Disease 2019 (COVID-19) from a Tertiary Referral Center

Background

In this paper, we shed the light on Beirut’s blast that took place in the coronavirus disease 2019 (COVID-19) era. An explosion that ripped the heart of Beirut, it produced a destructive shock wave that left thousands of casualties and people homeless. This explosion, which had a mushroom-like cloud appearance similar to that of Hiroshima and Nagasaki, was described as the third-biggest explosion in human history. It was a blast that not only destroyed lives but also fell as a heavy burden on the shoulders of a country that was suffering from unprecedented economic crisis on top of the COVID-19 pandemic. Facing all this, health care providers were the first line of defense in what looked like an impossible mission.

Objective

We seek to share with the medical community our experience and the challenges we faced, as a neurosurgery team, during this event, particularly that we were short of basic medical equipment as well as intensive care unit beds since we were in the middle of an economic crisis and the peak of the COVID-19 pandemic. This prohibited us from delivering proper care, whether in the triage of patients or in the operating room, as well as postoperative care. Now, 1 year after this sad event, we revisit the whole situation and examine all the pitfalls that could have been avoided. Thus, we discuss the importance of initiating a disaster response, in particular the neurosurgical emergency response, to be better prepared to face future potential events.

Conclusions

The rate-limiting step in such disasters is definitely a well-prepared trained team with a prompt and fast response. And, since time is brain, then what saves the brain is proper timing.

Minimally Invasive Resection of an S3 Osteoid Osteoma Using an Intraoperative O-Arm: A Technical Note

Osteoid osteomas are benign primary bone tumors that typically arise in posterior vertebrae of the spine. For patients with severe pain or those poorly controlled with non-steroidal anti-inflammatory drugs, surgical management is the mainstay of treatment. The recommended surgical treatment option is complete open excision, although minimally invasive CT-guided percutaneous excision and CT-guided radiofrequency ablation have been reported. Open resection can result in prolonged hospital stays, activity restrictions, and possible spinal destabilization. We sought to utilize a lateral minimally invasive approach. We highlight the importance of aggressive surgical resection and the utility of using fluoroscopy and O-arm guidance to optimize the extent of resection. We report a pediatric case of a 12-year-old male who presented with an S3 osteoid osteoma. The patient underwent a minimally invasive resection with complete resection and confirmation of the histopathologic diagnosis. Postoperative imaging showed complete resection of the tumor. The patient went home five hours after surgery with return to daily activities; his symptoms resolved completely. However, the patient had symptomatic recurrence and underwent a second more aggressive minimally invasive resection using O-arm guidance. At the current three-month follow-up, the patient is symptom- and tumor-free. The minimally invasive resection of a pediatric sacral osteoid osteoma is a valid alternative to standard open resection and is associated with a decreased blood loss, decreased length of stay in the hospital, and decreased time to full functional recovery. The pitfalls are learning curve and risk of incomplete resection that can be counterbalanced with an intraoperative O-arm to guide resection and confirm complete excision.

Effect of Phase Change Material Cooling Vests on Body Thermoregulation and Thermal Comfort of Patients With Paraplegia: A Human Subject Experimental Study

STUDY DESIGN

Randomized experimental study.

OBJECTIVE

Compared to able-bodied people, patients with paraplegia due to thoracic spinal cord injury (SCI) are at an increased risk of heat illnesses during exercise due to impaired thermoregulatory responses. To overcome this limitation, we investigated the performance of three phase change material (PCM) cooling vests of different melting temperatures (Eijsvogels, #49) and coverage area of the trunk.

METHODS

Sixteen participants were divided into three groups according to their injury level. All were tested for V20 full vest (20°C Tm, 75% coverage). Mid-thoracic and high-thoracic groups were tested for V14 vest (14°C Tm, 75% coverage). The mid-thoracic group was tested for V20 half vest (20°C Tm, 50% coverage). The participants performed a 30-min arm-crank exercise followed by a recovery period inside a controlled hot climatic chamber. The heart rate, segmental skin (Tskin), and core temperature (Tcore) values were recorded, and subjective questionnaires were taken.

RESULTS

Compared to no vest (NV) test, all the vests showed an effective decrease in Tskin values of the trunk. However, the decrease in Tskin was not enough to induce a significant decrease in Tcore in all three groups. Mid-thoracic and low-thoracic groups showed a reduction in the increasing Tcore by the end of the exercise and recovery period. Finally, the level of thermal comfort was enhanced for the three groups.

CONCLUSION

The effectiveness of cooling vests for persons with paraplegia is dependent on injury level and thus the ratio of sensate to insensate skin. Future studies necessitate the investigation of the cooling effects of PCM vests at a lower Tm with a larger sample size.

A Bibliometric Analysis of Neurosurgery Research Productivity in Arab Countries Between 2005 and 2019

BACKGROUND

The Arab world is lagging behind in the world of publications and research, especially in the biomedical-related field. This is a bibliometric analysis that aims to assess the neurosurgical research productivity across different Arab countries.

METHODS

PubMed was used to quantify the number of neurosurgery-related articles published by each Arab country, by several journals, investigating specific topics between 2005 and 2019. Numbers were normalized with respect to each country's average population and average gross domestic product (GDP).

RESULTS

Arab countries contributed 0.53% of total neurosurgery publications. Egypt had the highest number of neurosurgery-related publications (362), ahead of Saudi Arabia (238) and Lebanon (133). In terms of publications per million persons, Lebanon was first with 21.6 publications per million persons. In terms of GDP, Egypt ranked first with 18.85 publications per million $. There was an insignificant correlation between the number of publications on one hand and the average GDP (P = 0.09) on the other hand, whereas the average population explains around 50% of the neurosurgery-related publications (R squared = 0.49, P < 0.01). Neoplasms were the dominating area of research, and the WORLD NEUROSURGERY journal had the highest number of publications.

CONCLUSIONS

The results reached by this study reflect an undoubtable need for more research on neurosurgery by Arab countries. This goes back to the different obstacles facing Arab countries every day, affecting the economic, educational, and health care systems.

Negative pharmacological effect on spine fusion: A narrative review of the literature of evidence-based treatment

Spine fusion surgery is commonly performed for diverse indications, the most frequent one being degenerative spine diseases. Despite the growing importance of this surgery, there is limited evidence concerning the effects of drugs on the process of spine fusion and healing. While asymptomatic sometimes, nonunion of the spine can have tremendous repercussions on the patients' quality of life and the healthcare system rendering it an "expensive complication". This literature review identifies the role of some perioperative drugs in spine fusion and reveals their potential role in pseudarthrosis of the spine. This review also benefits spine surgeons looking for current evidence-based practices. We reviewed the data related to nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, vancomycin, bisphosphonates, proton pump inhibitors (PPIs), pregabalin, and opioids. From the available experimental and clinical studies, we conclude that bisphosphonates might positively influence the process of spine fusion, while steroids and vancomycin have shown variable effects, and the remaining medications likely disturb healing and union of the spine. We recommend spine surgeons be cautious about the drugs they resort to in the critical perioperative period until further clinical studies prove which drugs are safe to be used.

Meningioma genomics: a therapeutic challenge for clinicians

Meningiomas are amongst the most commonly encountered intracranial tumors. The majority of these tumors arise intracranially, and the remaining incidents occur along the spinal cord. Meningiomas tend to grow gradually, with many tumors arising in inaccessible locations. Such sporadic behavior poses a therapeutic challenge to clinicians, causing incomplete tumor resections that often lead to recurrence. Therefore, ongoing research seeks to find alternative systematic treatments for meningiomas, with gene-based therapeutics of high interest. Subsequently, genetic studies characterized frequent somatic mutations in NF2, TRAF7, KLF4, AKT1, SMO, and PIK3CA. These genes are communally exhibited in 80% of sporadic meningiomas. In addition, other genes such as the DUSP family, the NR4 family, CMKOR, and FOSL2, have been identified as key players in spinal meningiomas. In this perspective, we aim to investigate current genetic-based studies, with the ongoing research mainly focused on the above NF2, TRAF7, KLF4, AKT1, SMO, and PIK3CA genes and their involved pathways. In addition, this perspective can serve as a potential cornerstone for future genetic analyses of meningioma cases.

Acute ischemic stroke biomarkers: a new era with diagnostic promise?

Stroke is considered as the first cause of neurological dysfunction and second cause of death worldwide. Recombinant tissue plasminogen activator is the only chemical treatment for ischemic stroke approved by the US Food and Drug Administration. It was the only standard of care for a long time with a very narrow therapeutic window, which usually ranges from 3 to 4.5 h of stroke onset; until 2015, when multiple trials demonstrated the benefit of mechanical thrombectomy during the first 6 h. In addition, recent trials showed that mechanical thrombectomy can be beneficial up to 24 h if the patients meet certain criteria including the presence of magnetic resonance imaging/computed tomography perfusion mismatch, which allows better selectivity and higher recruitment of eligible stroke patients. However, magnetic resonance imaging/computed tomography perfusion is not available in all stroke centers. Hence, physicians need other easy and available diagnostic tools to select stroke patients eligible for mechanical thrombectomy. Moreover, stroke management is still challenging for physicians, particularly those dealing with patients with "wake-up" stroke. The resulting brain tissue damage of ischemic stroke and the subsequent pathological processes are mediated by multiple molecular pathways that are modulated by inflammatory markers and post-transcriptional activity. A considerable number of published works suggest the role of inflammatory and cardiac brain-derived biomarkers (serum matrix metalloproteinase, thioredoxin, neuronal and glial markers, and troponin proteins) as well as different biomarkers including the emerging roles of microRNAs. In this review, we assess the accumulating evidence regarding the current status of acute ischemic stroke diagnostic biomarkers that could guide physicians for better management of stroke patients. Our review could give an insight into the roles of the different emerging markers and microRNAs that can be of high diagnostic value in patients with stroke. In fact, the field of stroke research, similar to the field of traumatic brain injury, is in immense need for novel biomarkers that can stratify diagnosis, prognosis, and therapy.

Clinical utility of degradomics as predictors of complications and clinical outcome in aneurysmal subarachnoid hemorrhage

Most of the debilitating conditions following aneurysmal subarachnoid hemorrhage result from symptomatic cerebral vasospasm and delayed cerebral ischemia. Several scales are being used, but they still lack objectivity and fail to quantify complications considered essential for prognostication routine use of biomarkers to predict complications and outcomes after aneurysmal rupture is still experimental. Degradomics were studied extensively in traumatic brain injury, but there is no discussion of these biomarkers related to aneurysmal subarachnoid hemorrhage. Degradomics involve the activation of proteases that target specific substrates and generate specific protein fragments called degradomes. While the proteolytic activities constitute the pillar of development, growth, and regeneration of tissues, dysregulated proteolysis resulting from pathological conditions like aneurysmal subarachnoid hemorrhage ends up in apoptotic processes and necrosis. To our knowledge, this is the first overview that lists a panel of degradomics with cut-off values in serum and cerebrospinal fluid, where specificity and sensitivity are only found in Kallikrein 6, Ubiquitin C Terminal Hydrolase 1 and Alpha-II-Spectrin.

Can we improve the prediction of complications and outcome in aneurysmal subarachnoid hemorrhage? The clinical implications of serum proteomics

Aneurysmal subarachnoid hemorrhage is a devastating condition, often leading to a debilitating outcome. Delayed ischemic neurological deficits are considered the feared sequelae. Proteomics is a large-scale study of proteins incorporating structural and functional properties in complex biological fluids. Analysis of proteomes has led to identifying relevant complex proteins related to specific pathophysiological processes reflecting the severity and extent of diseases. Proteomics has evolved in the past few years; more biomarkers are deemed clinically relevant to diagnose, monitor, and define prognosis in patients with aneurysmal subarachnoid hemorrhage. Despite the absence of candidate biomarkers in the clinical routine, many have shown promising results. The complexity of proteins implicated in aneurysmal subarachnoid hemorrhage rendered these biomarkers' clinical use paved with various pitfalls and technical difficulties, especially when data about the perfect timing and values are lacking. We review the latest literature concerning serum proteomics and their clinical utility regarding the prediction of cerebral vasospasm and other complications of aneurysmal subarachnoid hemorrhage, as well as the clinical outcome. Future prospective studies will allow changing the disease's course, label patients according to their prognosis to provide earlier and better management and improve outcomes.

Frontal Sinus Morphometry in Relation to Surgically Relevant Landmarks in the Middle East Population: Can We Globalize?

BACKGROUND

The frontal bone is frequently approached during neurosurgical procedures. Feared complications of such surgeries include cerebrospinal fluid leak, among others, and frequently result from a breach of the frontal sinus. For this reason, the sinus should be avoided when possible. The supraorbital notch (SON) is a reliable and easily identifiable surgical landmark and its relation to the frontal sinus has been previously studied. However, the frontal sinus shows significant variability in size and shape between populations.

METHODS

In the present study, we investigate the frontal sinus dimension and its relation to the SON in the Middle Eastern population.

RESULTS

The analysis of a set of computed tomography scans reveals a significant variation in size between genders, and we subsequently provide neurosurgeons in the region with population-targeted, gender-specific risk maps.

CONCLUSIONS

We finally conclude that a 2-cm margin rostral and lateral to the SON is safest.

Successful surgical resection of a rare case of a giant sacral chordoma: a multidisciplinary feat

We, here, report the case of a 72-year-old man who presented with a giant sacral chordoma without aggressive clinical and neurological course and confirmed with a CT guided biopsy. The patient underwent multidisciplinary, two-stage successful complete en bloc sacrectomy along with total gross tumour resection, followed by lumboiliac fusion and instrumentation in the second stage without any neurological deficit nor bladder or bowel-related complications.

Safety of stent-assisted coiling for the treatment of wide-necked ruptured aneurysm: A systematic literature review and meta-analysis of prevalence

BACKGROUND

Stent-assisted coil embolization of ruptured wide-necked aneurysms is a controversial treatment modality due to concerns on the peri-procedural safety of anti-platelet therapy in the setting of acute subarachnoid hemorrhage. Our aim was to systematically review the literature on stent-assisted coil embolization of acutely ruptured wide-neck aneurysms to calculate the pooled prevalence of clinical outcome, thromboembolic and hemorrhagic complication rates and overall mortality.

METHODS

We searched PubMed and Google Scholar for articles published between 2009 and 2019 and stratified selected articles based on risk of publication bias. Data on thromboembolic and hemorrhagic complications, clinical outcomes and mortality rates were analyzed using quality-effects model and double arcsine transformation.

RESULTS

24 articles were included featuring a total of 1582 patients. Thromboembolic and hemorrhagic complication rates were witnessed in 9.1% [95% CI: 6.0% - 12.7%; I² = 72.8%] and 8.7% [95% CI: 5.4 - 12.6%; I² = 77.2%] of patients, respectively. 245 patients received external ventricular drains, of which 33 (13.5%) had EVD-related hemorrhages. Total complication rate was 20.8% [95% CI: 14.2 - 28.1%; I² = 87.0%]. 57% of aneurysms were completely occluded and a favorable clinical outcome was reported in 74.7% [95% CI: 66.4 - 82.2%; I² = 86.0] of patients. Overall mortality rate came at 7.8% [95% CI: 4.8 - 11.6%; I² = 76.9%].

CONCLUSION

Stent-assisted coiling of ruptured intracranial aneurysm is a technically feasible procedure with controlled thromboembolic complication rate but may be associated with higher hemorrhagic and total complication rates compared to coiling alone. While stent-assisted coiling of ruptured wide-necked aneurysm seems to yield a lower rate of favorable clinical outcome, overall mortality is comparable to that of endovascular coiling alone.

Hypothalamic Hamartomas: A Comprehensive Review of Literature - Part 3: Updates on Radiotherapy Management

Hypothalamic hamartomas (HH) are rare, non-neoplastic heterotopic tissues which contains normal neurons and glia including oligodendrocytes and fibrillary astrocytes but in an abnormal distribution. They arise from the floor of the third ventricle, tuber cinereum, or mammillary bodies. Estimated incidence ranges from 1 in 50,000 to 1 in 1,000,000. Hypothalamic hamartomas are associated with different clinical presentations including various types of seizures, most characteristically; the gelastic seizures, precocious puberty, cognitive impairment and behavioral changes. In this review, the authors discuss the recent advancements in different modalities of radiotherapy and their application in hypothalamic hamartomas management.

Hypothalamic hamartomas: A comprehensive review of the literature - Part 1: Neurobiological features, clinical presentations and advancements in diagnostic tools

Hypothalamic hamartomas (HH) are rare, non-neoplastic heterotopic tissues which contains normal neurons and glia including oligodendrocytes and fibrillary astrocytes but in an abnormal distribution. They arise from the floor of the third ventricle, tuber cinereum, or mammillary bodies. Estimated incidence ranges from 1 in 50,000-1 in 1,000,000. Hypothalamic hamartomas are associated with different clinical presentations including various types of seizures, most characteristically; the gelastic seizures, precocious puberty, cognitive impairment, and behavioral changes. In this review, the authors discuss advancements in different diagnostic elements of hypothalamic hamartoma; including clinical features, EEG findings, and neuroimaging techniques. Moreover, different classifications described in the literature will be discussed.

The acetabular labrum

The acetabular labrum is a soft-tissue structure which lines the acetabular rim of the hip joint. Its role in hip joint biomechanics and joint health has been of particular interest over the past decade. In normal hip joint biomechanics, the labrum is crucial in retaining a layer of pressurised intra-articular fluid for joint lubrication and load support/distribution. Its seal around the femoral head is further regarded as a contributing to hip stability through its suction effect. The labrum itself is also important in increasing contact area thereby reducing contact stress. Given the labrum’s role in normal hip joint biomechanics, surgical techniques for managing labral damage are continuously evolving as our understanding of its anatomy and function continue to progress. The current paper aims to review the anatomy and biomechanical function of the labrum and how they are affected by differing surgical techniques.

Take home message: The acetabular labrum plays a critical role in hip function and maintaining and restoring its function during surgical intervention remain an essential goal.

Cite this article: Bone Joint J 2016;98-B:730–5.