Diagnostic Yield of Stereotactic Brain Biopsy in a Sub-Saharan Tertiary Center: A Comprehensive 10-Year Retrospective Analysis.

BACKGROUND: Stereotactic brain biopsy is a crucial minimally invasive surgical technique leveraged to obtain tissue specimens from deep-seated intracranial lesions, offering a safer alternative to open craniotomy for patients who cannot tolerate the latter. Despite its effectiveness, the diagnostic yield varies across different centers and has not been widely studied in Sub-Saharan Africa. METHODS: A single-center retrospective analysis was conducted on 67 consecutive stereotactic brain biopsy procedures carried out by experienced neurosurgeons between January 2012 and December 2022 at a tertiary center in Sub-Saharan Africa. Preoperative clinical status, biopsy type, postoperative complication rate, and histological diagnosis were meticulously analyzed. Factors associated with negative biopsy results were identified using IBM Statistical Package for the Social Sciences SPSS version for Mac, with Fisher exact test employed to detect differences in patient characteristics. Statistical significance was pegged at P < 0.05. RESULTS: The overall diagnostic yield rate was 67%. Major contributors to negative biopsy outcomes were superficial location of the lesion, lesion size less than 10 cc, and the use of the Cape Town Stereotactic System. Enhanced yield rates of up to 93% were realized through the application of magnetic resonance imaging-based images, Stealth Station 7, and frozen section analysis. No correlation was observed between the number of cores obtained and the yield rate. Procedure complications were negligible, and no procedure-related mortality was recorded. CONCLUSIONS: The diagnostic yield rate from our study was somewhat lower than previously reported in contemporary literature, primarily attributed to the differing definitions of diagnostic yield, the dominant use of the older framed Cape Town Stereotactic System, computed tomography-based imaging, and the absence of intraoperative frozen section. Nevertheless, biopsies conducted using the frameless system were comparable with studies from other global regions. Our findings reaffirm that stereotactic brain biopsy when complemented with magnetic resonance imaging-based imaging, frameless stereotactic systems and intraoperative frozen section is a safe, effective, and reliable method for obtaining histological diagnosis.

The NED foundation experience: A model of global neurosurgery.

Introduction: The Neurosurgery Education and Development (NED) Foundation (NEDF) started the development of local neurosurgical practice in Zanzibar (Tanzania) in 2008. More than a decade later, multiple actions with humanitarian purposes have significantly improved neurosurgical practice and education for physicians and nurses. Research question: To what extent could comprehensive interventions (beyond treating patients) be effective in developing global neurosurgery from the outset in low and middle-income countries? Material and method: A retrospective review of a 14- year period (2008-2022) of NEDF activities highlighting landmarks, projects, and evolving collaborations in Zanzibar was carried out. We propose a particular model, the NEDF model, with interventions in the field of health cooperation that have simultaneously aimed to equip, treat, and educate in a stepwise manner. Results: 138 neurosurgical missions with 248 NED volunteers have been reported. In the NED Institute, between Nov 2014-Nov 2022, 29635 patients were seen in the outpatient clinics and 1985 surgical procedures were performed. During the course of NEDF's projects, we have identified three different levels of complexity (1, 2 and 3) that include the areas of equipment ("equip"), healthcare ("treat") and training ("educate"), facilitating an increase of autonomy throughout the process. Discussion and Conclusion: In the NEDF's model, the interventions required in each action area (ETE) are coherent for each level of development (1, 2 and 3). When applied simultaneously, they have a greater impact. We believe the model can be equally useful for the development of other medical and/or surgical specialties in other low-resource healthcare settings.

GPU accelerated Cartesian GRAPPA reconstruction using CUDA.

BACKGROUND AND OBJECTIVE: GRAPPA (Generalized Auto-calibrating Partially Parallel Acquisition) is an advanced parallel MRI reconstruction method (pMRI) that enables under-sampled data acquisition with multiple receiver coils to reduce the MRI scan time and reconstructs artifact free image from the acquired under-sampled data. However, the reduction in MRI scan time comes at the expense of long reconstruction time. It is because the GRAPPA reconstruction time shows exponential growth with increasing number of receiver coils. Consequently, the conventional CPU platforms may not adhere to the requirements of fast data processing for MR image reconstruction. METHODS: Graphics Processing Units (GPUs) have recently emerged as a viable commodity hardware to reduce the reconstruction time of pMRI methods. This paper presents a novel GPU based implementation of GRAPPA using custom built CUDA kernels, to meet the rising demands of fast MRI processing. The proposed framework exploits intrinsic parallelism in the calibration and synthesis phases of GRAPPA reconstruction process, aiming to achieve high speed MR image reconstruction for various GRAPPA configuration settings using different number of receiver coils, auto-calibration signals (ACS), sizes of GRAPPA kernel and acceleration factors. In-vivo experiments (using 8, 12 and 30 receiver coils) are performed to compare the performance of the proposed GPU accelerated GRAPPA with the CPU based GRAPPA extensions and GPU counterpart. RESULTS: The results indicate that the proposed method achieves up to ≈47.8× , ≈17× and ≈3.8× speed up gains over multicore CPU (single thread), multicore CPU (8 thread) and Gadgetron (GPU based GRAPPA) respectively, without compromising the reconstruction accuracy. CONCLUSIONS: The proposed method reduces the GRAPPA reconstruction time by employing the calibration phase (GRAPPA weights estimation) and synthesis phase (interpolation) on GPU. Our study shows that the proposed GPU based parallel framework for GRAPPA reconstruction provides a solution for high-speed image reconstruction while maintaining the quality of the reconstructed images.

Needs of Young African Neurosurgeons and Residents: A Cross-Sectional Study.

Introduction: Africa has many untreated neurosurgical cases due to limited access to safe, affordable, and timely care. In this study, we surveyed young African neurosurgeons and trainees to identify challenges to training and practice. Methods: African trainees and residents were surveyed online by the Young Neurosurgeons Forum from April 25th to November 30th, 2018. The survey link was distributed via social media platforms and through professional society mailing lists. Univariate and bivariate data analyses were run and a P-value < 0.05 was considered to be statistically significant. Results: 112 respondents from 20 countries participated in this study. 98 (87.5%) were male, 63 (56.3%) were from sub-Saharan Africa, and 52 (46.4%) were residents. 39 (34.8%) had regular journal club sessions at their hospital, 100 (89.3%) did not have access to cadaver dissection labs, and 62 (55.4%) had never attended a WFNS-endorsed conference. 67.0% of respondents reported limited research opportunities and 58.9% reported limited education opportunities. Lack of mentorship (P = 0.023, Phi = 0.26), lack of access to journals (P = 0.002, Phi = 0.332), and limited access to conferences (P = 0.019, Phi = 0.369) were associated with the country income category. Conclusion: This survey identified barriers to education, research, and practice among African trainees and young neurosurgeons. The findings of this study should inform future initiatives aimed at reducing the barriers faced by this group.

Transfer learning in deep neural network-based receiver coil sensitivity map estimation.

INTRODUCTION: The success of parallel Magnetic Resonance Imaging algorithms like SENSitivity Encoding (SENSE) depends on an accurate estimation of the receiver coil sensitivity maps. Deep learning-based receiver coil sensitivity map estimation depends upon the size of training dataset and generalization capabilities of the trained neural network. When there is a mismatch between the training and testing datasets, retraining of the neural networks is required from a scratch which is costly and time consuming. MATERIALS AND METHODS: A transfer learning approach, i.e., end-to-end fine-tuning is proposed to address the data scarcity and generalization problems of deep learning-based receiver coil sensitivity map estimation. First, generalization capabilities of a pre-trained U-Net (initially trained on 1.5T receiver coil sensitivity maps) are thoroughly assessed for 3T receiver coil sensitivity map estimation. Later, end-to-end fine-tuning is performed on the pre-trained U-Net to estimate the 3T receiver coil sensitivity maps. RESULT AND CONCLUSION: Peak Signal-to-Noise Ratio, Root Mean Square Error and central line profiles (of the SENSE reconstructed images) show a successful SENSE reconstruction by utilizing the receiver coil sensitivity maps estimated by the proposed method.

The Impact of COVID-19 on Neurosurgical Services in Africa.

INTRODUCTION: COVID-19 has affected the global provision of neurosurgical services. We sought to review the impact of COVID-19 on the neurosurgical services in Africa. METHODS: A cross-sectional survey was distributed to African neurosurgeons seeking to review demographics, national and neurosurgical preparedness, and change in clinical services in April 2020. RESULTS: A total of 316 responses from 42 countries were received. Of these, 81.6% of respondents were male and 79.11% were under the age of 45 years. In our sample, 123 (38.92%) respondents were in training. Most (94.3%) respondents stated they had COVID-19 cases reported in their country as of April 2020. Only 31 (41.50%) had received training on managing COVID-19. A total of 173 (54.70%) respondents were not performing elective surgery. There was a deficit in the provision of personal protective equipment (PPE): surgical masks (90.80%), gloves (84.80%), N95 masks (50.80%), and shoe covers (49.10%). Health ministry (80.40%), World Health Organization (74.50%), and journal papers (41.40%) were the most common sources of information on COVID-19. A total of 43.60% had a neurosurgeon in the COVID-19 preparedness team; 59.8% were concerned they may contract COVID-19 at work with a further 25.90% worried they may infect their family. Mental stress as a result of COVID-19 was reported by 14.20% of respondents. As of April 2020, 73.40% had no change in their income. CONCLUSIONS: Most African countries have a national COVID-19 policy response plan that is not always fully suited to the local neurosurgery services. There is an ongoing need for PPE and training for COVID-19 preparedness. There has been a reduction in clinical activities both in clinic and surgeries undertaken.

Transfer learning in deep neural network based under-sampled MR image reconstruction.

In Magnetic Resonance Imaging (MRI), the success of deep learning-based under-sampled MR image reconstruction depends on: (i) size of the training dataset, (ii) generalization capabilities of the trained neural network. Whenever there is a mismatch between the training and testing data, there is a need to retrain the neural network from scratch with thousands of MR images obtained using the same protocol. This may not be possible in MRI as it is costly and time consuming to acquire data. In this research, a transfer learning approach i.e. end-to-end fine tuning is proposed for U-Net to address the data scarcity and generalization problems of deep learning-based MR image reconstruction. First the generalization capabilities of a pre-trained U-Net (initially trained on the human brain images of 1.5 T scanner) are assessed for: (a) MR images acquired from MRI scanners of different magnetic field strengths, (b) MR images of different anatomies and (c) MR images under-sampled by different acceleration factors. Later, end-to-end fine tuning of the pre-trained U-Net is proposed for the reconstruction of the above-mentioned MR images (i.e. (a), (b) and (c)). The results show successful reconstructions obtained from the proposed method as reflected by the Structural SIMilarity index, Root Mean Square Error, Peak Signal-to-Noise Ratio and central line profile of the reconstructed images.

A Continental Survey on the Impact of COVID-19 on Neurosurgical Training in Africa.

BACKGROUND: Containment measures for COVID-19 have affected surgical training globally. We sought to assess how neurosurgical training has been affected across Africa in April 2020. METHODS: A cross-sectional survey was distributed to African Neurosurgical trainees seeking to review demographics and effects of COVID on training. RESULTS: A total of 123 neurosurgery trainees responded from 23 African countries and a further 6 were abroad. A total of 91.80% were men, and 96.70% were training in public institutions. Only 41% had received training in COVID-19 with 61.79% worried that they would contract COVID-19 while performing their clinical duties. There was a marked reduction in clinical activities including a median reduction of elective surgery (-80%), clinics (-83%), and emergency surgery (-38.50%). A total of 23.58% of residents did not receive a formal salary, with 50% on less than $1000 USD gross per month. CONCLUSIONS: This is the first continental survey of neurosurgery trainees in Africa. COVID-19 has significantly affected clinical and learning opportunities. There are concerns of the long-term effects on their training activities for an uncertain period of time during this pandemic. Although there has been a global increase in e-learning, there is need to evaluate if this is accessible to all trainees.

FPGA-based hardware accelerator for SENSE (a parallel MR image reconstruction method).

SENSE (Sensitivity Encoding) is a parallel MRI (pMRI) technique that allows accelerated data acquisition using multiple receiver coils and reconstructs the artifact-free images from the acquired under-sampled data. However, an increasing number of receiver coils has raised the computational demands of pMRI techniques to an extent where the reconstruction time on general purpose computers becomes impractically long for real-time MRI. Field Programmable Gate Arrays (FPGAs) have recently emerged as a viable hardware platform for accelerating pMRI algorithms (e.g. SENSE). However, recent efforts to accelerate SENSE using FPGAs have been focused on a fixed number of receiver coils (L=8) and acceleration factor (Af=2). This paper presents a novel 32-bit floating-point FPGA-based hardware accelerator for SENSE (HW-ACC-SENSE); having an ability to work in coordination with an on-chip ARM processor performing reconstructions for different values of L and Af. Moreover, the proposed design provides flexibility to integrate multiple units of HW-ACC-SENSE with an on-chip ARM processor, for low-latency image reconstruction. The VIVADO High-Level-Synthesis (HLS) tool has been used to design and implement the HW-ACC-SENSE on the Xilinx FPGA development board (ZCU102). A series of experiments has been performed on in-vivo datasets acquired using 8, 12 and 30 receiver coil elements. The performance of the proposed architecture is compared with the single thread and multi-thread CPU-based implementations of SENSE. The results show that the proposed design withstands the reconstruction quality of the SENSE algorithm while demonstrating a maximum speed-gain up to 298× over the CPU counterparts in our experiments.

The College of Surgeons of East, Central, and Southern Africa: Successes and Challenges in Standardizing Neurosurgical Training.

BACKGROUND: The College of Surgeons of East, Central, and Southern Africa (COSECSA) is a regional accrediting body for general and specialty surgical training programs that has recently expanded to include neurosurgery. As neurosurgical services expand in sub-Saharan Africa, the structure of training and accreditation has become a vital issue. METHODS: We review the founding and current structures of COSECSA neurosurgical training, identifying accomplishments and challenges facing the expansion of neurosurgical training in this region. RESULTS: The COSECSA model has succeeded in several countries to graduate qualified neurosurgeons, but challenges remain. Programs must balance the long duration of training required to promote surgical excellence against an overwhelming clinical need that seeks immediate solutions. CONCLUSION: Harnessing global collaboration, rapidly expanding local infrastructure, and a robust multinational training curriculum, COSECSA has emerged as a leader in the effort to train neurosurgeons and is anticipated to dramatically improve on the markedly unmet need for neurosurgical care in sub-Saharan Africa.

Global incidence of brain and spinal tumors by geographic region and income level based on cancer registry data.

While obtaining accurate estimates of tumor incidence volume is a difficult technical problem because it requires collating and analyzing data from dozens of world-wide sources curated under different conditions, our study aims to determine the global incidence of brain and spinal tumors. We analyzed 207 tumor registries on five continents, and calculated age-standardized rates to compare tumor incidence between geographic regions and income levels. Based on data available in current cancer registries, the apparent global incidence of malignant brain tumors was 4.25 cases per 100,000 person-years (95% CI [4.21-4.29]), and varied by region from 6.76 [6.71-6.80] in Europe to 2.81 [2.64-2.99] in Africa. Incidence also varied by World Bank income group, ranging from 6.29 [6.26-6.32] cases per 100,000 in high income countries (HICs), to 4.81 [4.77-4.86] in low and middle-income countries (LMICs). Malignant spinal tumors were much less frequent globally (0.098 [0.093-0.104]) and varied similarly by region and income group. The incidence of brain and spinal tumors varies by region and income group, although case ascertainment bias driven by limited resources in low income regions likely plays a role in variance. The burden of neurosurgical disease in LMICs is large, and similar in scale to HICs.

Experience in the Early Surgical Management of Myelomeningocele in Zanzibar.

BACKGROUND: Neural tube defects are a large health burden for East African countries. Health strategies in the prevention of this disease include nutritional prophylaxis, prenatal diagnosis, and availability of early neonatal neurosurgery. The main objective of this study is to describe our experience in the early surgical management of neural tube defects in the Zanzibar archipelago. METHODS: From December 2016 to December 2017, we prospectively collected data on all patients admitted with the diagnosis of myelomeningocele. We collected variables regarding demographics, maternal health, preoperative imaging, surgical procedures, and complications at follow-up. RESULTS: We collected data on 19 patients. Mean age was 9.8 ± 18.7 days. Of these patients, 52.6% were male and 47.3% were female; 47.3% patients were from Unguja, 42.0% from Pemba, and 5.2% from mainland Tanzania; 68.4% of all mothers were found to have undergone prenatal ultrasonography and 89.5% of all patients received surgery. Surgical wound infection was present in 29.4% of all surgical patients and 52.9% developed secondary hydrocephalus. CONCLUSIONS: Neural tube defects are a prevailing condition in East Africa. We believe that more health initiatives should address its prevention, mainly through maternal nutrition. On the basis of our findings, we consider early neonatal neurosurgery as the most important factor in reducing immediate morbidity and mortality.

The challenges and opportunities of global neurosurgery in East Africa: the Neurosurgery Education and Development model.

OBJECTIVE: The objective of this study was to describe the experience of a volunteering neurosurgeon during an 18-week stay at the Neurosurgery Education and Development (NED) Institute and to report the general situation regarding the development of neurosurgery in Zanzibar, identifying the challenges and opportunities and explaining the NED Foundation's model for safe practice and sustainability. METHODS: The NED Foundation deployed the volunteer neurosurgeon coordinator (NC) for an 18-week stay at the NED Institute at the Mnazi Mmoja Hospital, Stonetown, Zanzibar. The main roles of the NC were as follows: management of patients, reinforcement of weekly academic activities, coordination of international surgical camps, and identification of opportunities for improvement. The improvement opportunities were categorized as clinical, administrative, and sociocultural and were based on observations made by the NC as well as on interviews with local doctors, administrators, and government officials. RESULTS: During the 18-week period, the NC visited 460 patients and performed 85 surgical procedures. Four surgical camps were coordinated on-site. Academic activities were conducted weekly. The most significant challenges encountered were an intense workload, deficient infrastructure, lack of self-confidence among local physicians, deficiencies in technical support and repairs of broken equipment, and lack of guidelines. Through a series of interviews, the sociocultural factors influencing the NED Foundation's intervention were determined. Factors identified for success were the activity of neurosurgical societies in East Africa; structured pan-African neurosurgical training; the support of the Foundation for International Education in Neurological Surgery (FIENS) and the College of Surgeons of East, Central and Southern Africa (COSECSA); motivated personnel; and the Revolutionary Government of Zanzibar's willingness to collaborate with the NED Foundation. CONCLUSIONS: International collaboration programs should balance local challenges and opportunities in order to effectively promote the development of neurosurgery in East Africa. Support and endorsement should be sought to harness shared resources and experience. Determining the caregiving and educational objectives within the logistic, administrative, social, and cultural framework of the target hospital is paramount to success.

Treating Pediatric Hydrocephalus at the Neurosurgery Education and Development Institute: The Reality in the Zanzibar Archipelago, Tanzania.

BACKGROUND: Pediatric hydrocephalus is a health burden for East African countries, with an estimated incidence of 6000 new cases per year. The objective of this study is to describe the epidemiology and surgical outcomes of patients treated for pediatric hydrocephalus in the single neurosurgical center of Zanzibar. METHODS: From December 2016 to December 2017, we prospectively collected data on all patients admitted with the diagnosis of hydrocephalus. Information was gathered regarding demographics, maternal health, preoperative imaging, surgical procedures, and postsurgical complications. RESULTS: We collected data on 63 patients. Average age was 203 days, and gender was 49.2% female and 50.8% male. All mothers of patients attended an antenatal clinic for routine screening during pregnancy. Folic acid prophylaxis was used by 9.5% of the mothers during pregnancy. At the first visit, 46.0% of patients presented with signs of infection, 20.6% with congenital abnormalities, and 20.6% with seizures. Regarding etiology of hydrocephalus, 22.2% of all cases were uncertain; 20.6% were associated with neural tube defects; 39.7% were postinfectious hydrocephalus; 3.2% were aqueduct stenosis; 4.8% were associated with brain tumor; and 9.6% were malformative. We performed 7 endoscopic third ventriculostomies and placed 40 ventriculoperitoneal shunts. The complication rate at follow-up was 12.5%. CONCLUSIONS: It seems that hydrocephalus in Zanzibar has similar causes, progression, and complication rates to previous reports from other African hospitals. Further studies of postinfectious hydrocephalus need to be conducted because recent findings suggest that it is a potentially preventable cause of the disease.

Neurosurgery in East Africa: Foundations.

This article is the first in a series of 3 articles that seek to provide readers with an understanding of the development of neurosurgery in East Africa (Foundations), the challenges that arise in providing neurosurgical care in developing countries (Challenges), and an overview of traditional and novel approaches to overcoming these challenges to improve healthcare in the region (Innovations). We review the history and evolution of neurosurgery as a clinical specialty in East Africa. We also review Kenya, Uganda, and Tanzania in some detail and highlight contributions of individuals and local and regional organizations that helped to develop and shape neurosurgical care in East Africa. Neurosurgery has developed steadily as advanced techniques have been adopted by local surgeons who trained abroad, and foreign surgeons who have dedicated part of their careers in local hospitals. New medical schools and surgical training programs have been established through regional and international partnerships, and the era of regional specialty surgical training has just begun. As more surgical specialists complete training, a comprehensive estimation of disease burden facing the neurosurgical field is important. We present an overview with specific reference to neurotrauma and neural tube defects, both of which are of epidemiologic importance as they gain not only greater recognition, but increased diagnoses and demands for treatment. Neurosurgery in East Africa is poised to blossom as it seeks to address the growing needs of a growing subspecialty.

Neurosurgery in East Africa: Innovations.

In the last 10 years, considerable work has been done to promote and improve neurosurgical care in East Africa with the development of national training programs, expansion of hospitals and creation of new institutions, and the foundation of epidemiologic and cost-effectiveness research. Many of the results have been accomplished through collaboration with partners from abroad. This article is the third in a series of articles that seek to provide readers with an understanding of the development of neurosurgery in East Africa (Foundations), the challenges that arise in providing neurosurgical care in developing countries (Challenges), and an overview of traditional and novel approaches to overcoming these challenges to improve healthcare in the region (Innovations). In this article, we describe the ongoing programs active in East Africa and their current priorities, and we outline lessons learned and what is required to create self-sustained neurosurgical service.