Flexible circumferential bioelectronics to enable 360-degree recording and stimulation of the spinal cord.

The spinal cord is crucial for transmitting motor and sensory information between the brain and peripheral systems. Spinal cord injuries can lead to severe consequences, including paralysis and autonomic dysfunction. We introduce thin-film, flexible electronics for circumferential interfacing with the spinal cord. This method enables simultaneous recording and stimulation of dorsal, lateral, and ventral tracts with a single device. Our findings include successful motor and sensory signal capture and elicitation in anesthetized rats, a proof-of-concept closed-loop system for bridging complete spinal cord injuries, and device safety verification in freely moving rodents. Moreover, we demonstrate potential for human application through a cadaver model. This method sees a clear route to the clinic by using materials and surgical practices that mitigate risk during implantation and preserve cord integrity.

Consensus-Based Development of a Global Registry for Traumatic Brain Injury: Establishment, Protocol, and Implementation.

BACKGROUND AND OBJECTIVES: Global disparity exists in the demographics, pathology, management, and outcomes of surgically treated traumatic brain injury (TBI). However, the factors underlying these differences, including intervention effectiveness, remain unclear. Establishing a more accurate global picture of the burden of TBI represents a challenging task requiring systematic and ongoing data collection of patients with TBI across all management modalities. The objective of this study was to establish a global registry that would enable local service benchmarking against a global standard, identification of unmet need in TBI management, and its evidence-based prioritization in policymaking. METHODS: The registry was developed in an iterative consensus-based manner by a panel of neurotrauma professionals. Proposed registry objectives, structure, and data points were established in 2 international multidisciplinary neurotrauma meetings, after which a survey consisting of the same data points was circulated within the global neurotrauma community. The survey results were disseminated in a final meeting to reach a consensus on the most pertinent registry variables. RESULTS: A total of 156 professionals from 53 countries, including both high-income countries and low- and middle-income countries, responded to the survey. The final consensus-based registry includes patients with TBI who required neurosurgical admission, a neurosurgical procedure, or a critical care admission. The data set comprised clinically pertinent information on demographics, injury characteristics, imaging, treatments, and short-term outcomes. Based on the consensus, the Global Epidemiology and Outcomes following Traumatic Brain Injury (GEO-TBI) registry was established. CONCLUSION: The GEO-TBI registry will enable high-quality data collection, clinical auditing, and research activity, and it is supported by the World Federation of Neurosurgical Societies and the National Institute of Health Research Global Health Program. The GEO-TBI registry ( https://geotbi.org ) is now open for participant site recruitment. Any center involved in TBI management is welcome to join the collaboration to access the registry.

Results of Surgical Treatment of Aneurysmal Subarachnoid Hemorrhage in a Single Institution Over 12 Years.

OBJECTIVE: For patients with aneurysmal subarachnoid hemorrhage (aSAH) in whom endovascular treatment is not the optimal treatment strategy, microsurgical clipping remains a viable option. We examined changes in morbidity and outcome over time in patients treated surgically and in relation to surgeon volume and experience. METHODS: All patients who underwent microsurgery for aSAH from 2007 to 2019 at our institution were included. We compared technical complication rates and surgical outcomes between experienced (≥50 independent cases) and inexperienced (<50 independent cases) surgeons and between high-volume (≥20 cases/year) and low-volume (<20 cases/year) surgeons. RESULTS: Most of the 1,003 aneurysms (970 patients, median age 56 years) were in the middle cerebral (41.4%), anterior communicating (27.6%), and posterior communicating (17.5%) arteries; 46.5% were <7 mm. The technical complication rate was 7%, resulting in postoperative infarct in 4.9% of patients. Nineteen patients (2%) died within 30 days of admission. There were no significant changes in rates of technical complication, postoperative infarct, or mortality over the study period. There were no differences in postoperative infarction and technical complication rates between experienced and inexperienced surgeons (P = 0.28 and P = 0.05, respectively), but there were differences when comparing high-volume and low-volume surgeons (P = 0.03 and P < 0.001, respectively). The independent predictors of postoperative infarctions were aneurysm size (P = 0.001), intraoperative large-vessel injury (P < 0.001), and low surgeon volume (P = 0.03). CONCLUSIONS: We present real-world data on surgical morbidity and outcomes after aSAH. We demonstrated a relationship between surgeon volume and outcome for surgical treatment of aSAH, which supports the benefit of subspecialization in cerebrovascular surgery.

Targeting patient recovery priorities in degenerative cervical myelopathy: design and rationale for the RECEDE-Myelopathy trial-study protocol.

INTRODUCTION: Degenerative cervical myelopathy (DCM) is a common and disabling condition of symptomatic cervical spinal cord compression secondary to degenerative changes in spinal structures leading to a mechanical stress injury of the spinal cord. RECEDE-Myelopathy aims to test the disease-modulating activity of the phosphodiesterase 3/phosphodiesterase 4 inhibitor Ibudilast as an adjuvant to surgical decompression in DCM. METHODS AND ANALYSIS: RECEDE-Myelopathy is a multicentre, double-blind, randomised, placebo-controlled trial. Participants will be randomised to receive either 60-100 mg Ibudilast or placebo starting within 10 weeks prior to surgery and continuing for 24 weeks after surgery for a maximum of 34 weeks. Adults with DCM, who have a modified Japanese Orthopaedic Association (mJOA) score 8-14 inclusive and are scheduled for their first decompressive surgery are eligible for inclusion. The coprimary endpoints are pain measured on a visual analogue scale and physical function measured by the mJOA score at 6 months after surgery. Clinical assessments will be undertaken preoperatively, postoperatively and 3, 6 and 12 months after surgery. We hypothesise that adjuvant therapy with Ibudilast leads to a meaningful and additional improvement in either pain or function, as compared with standard routine care. STUDY DESIGN: Clinical trial protocol V.2.2 October 2020. ETHICS AND DISSEMINATION: Ethical approval has been obtained from HRA-Wales.The results will be presented at an international and national scientific conferences and in a peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN Number: ISRCTN16682024.

Comparison of health-related quality of life in patients with traumatic brain injury, subarachnoid haemorrhage and cervical spine disease.

PURPOSE: The degree of disability that is acceptable to patients following traumatic brain injury (TBI) continues to be debated. While the dichotomization of outcome on the Glasgow Outcome Score (GOSE) into 'favourable' and 'unfavourable' continues to guide clinical decisions, this may not reflect an individual's subjective experience. The aim of this study is to assess how patients' self-reported quality of life (QoL) relates to objective outcome assessments and how it compares to other debilitating neurosurgical pathologies, including subarachnoid haemorrhage (SAH) and cervical myelopathy. METHOD: A retrospective analysis of over 1300 patients seen in Addenbrooke's Hospital, Cambridge, UK with TBI, SAH and patients pre- and post- cervical surgery was performed. QoL was assessed using the SF-36 questionnaire. Kruskal-Wallis test was used to analyse the difference in SF-36 domain scores between the four unpaired patient groups. To determine how the point of dichotomization of GOSE into 'favourable' and 'unfavourable' outcome affected QOL, SF-36 scores were compared between GOSE and mRS. RESULTS: There was a statistically significant difference in the median Physical Component Score (PCS) and Mental Component Score (MCS) of SF-36 between the three neurosurgical pathologies. Patients with TBI and SAH scored higher on most SF-36 domains when compared with cervical myelopathy patients in the severe category. While patients with Upper Severe Disability on GOSE showed significantly higher PC and MC scores compared to GOSE 3, there was a significant degree of variability in individual responses across the groups. CONCLUSION: A significant number of patients following TBI and SAH have better self-reported QOL than cervical spine patients and patients' subjective perception and expectations following injury do not always correspond to objective disability. These results can guide discussion of treatment and outcomes with patients and families.

Far Lateral Approaches: C1 Meningioma With Vertebral Artery Involvement: 3-Dimensional Operative Video.

Tumors around the cervicomedullary junction are rare and constitute 5% of spinal tumors and 1% of cranial tumors. The approach to these lesions is difficult because of the close proximity of the medulla and cervical spinal cord, lower cranial nerves, and vertebral artery (VA) as well as the complex articulation between occipital condyle, C1 and C2. Cervicomedullary junction meningiomas are commonly classified based on their origin in relation to the dentate ligament, but the relationship to the VA typically plays an important role in deciding the surgical approach. For lesions located dorsal to the dentate ligament and not involving the VA, a midline approach is typically sufficient. However, when the VA is involved a far lateral approach is preferred as it offers better access to the V4 segment. We describe a case of a 55-yr-old man who presented with accessory nerve palsy and mild upper motor neuron signs and was found to have a C1 meningioma encasing and narrowing the VA at the V3/V4 segment. Informed consent was obtained. The patient was treated with a right far lateral approach with limited condylectomy to gain access to the V4 segment. We described the steps used for safe resection of the tumor around the VA from distal to proximal. We demonstrate the relationship of the tumor to the VA and the need to completely skeletonize the VA to achieve a gross total resection. We supplement the discussion with a 3D surgical video.

Far Lateral Approaches: Far Lateral Approach With Minimal Condylectomy for C2 Schwannoma: 3-Dimensional Operative Video.

Upper cervical schwannomas are rare lesions and together with meningiomas constitute around 5% of spinal tumors. The approach to these lesions is difficult because of the close proximity of the medulla and cervical spinal cord, lower cranial nerves, and the vertebral artery. Schwannomas in the upper cervical area typically arise from the dorsal roots and are located posterior to the dentate ligament. Nevertheless, a far lateral approach is often required for these lesions because of their lateral extent through the neural foramen and the proximity of both the V3 and V4 segments of the vertebral artery. With these lesions, an extensive condylectomy is rarely required. We present a case of a 40-yr-old woman who presented with an 8-mo history of deteriorating mobility and feeling of heaviness in the lower limbs with a further acute deterioration 1 wk before admission. She had a dissociated sensory loss and myelopathy in keeping with a partial hemicord syndrome. Imaging revealed a right-sided C2 intradural lesion extending through the C2 foramen in keeping with a C2 schwannoma. The patient was counseled on the treatment options, and informed consent for surgery was obtained. We describe a right-sided far lateral approach with minimal condylectomy for gross total resection of this lesion. We demonstrate the relationship of the tumor with the C2 nerve root, the spinal accessory nerve, and the cervical cord. We supplement the discussion with a 3D surgical video.

Far Lateral Approaches: Dural Arteriovenous Fistulae at the Hypoglossal Canal: 3-Dimensional Operative Video.

Cognard type V dural arteriovenous fistulae (dAVF) are typically located at the foramen magnum. Their presentation often mimics that of cervical myelopathy, and they can be easily misdiagnosed even if spinal vascular imaging is undertaken. Treatment typically involves endovascular embolization or surgery when embolization is not possible. We describe a case of a 67-yr-old man who presented with progressive symptoms of cervical myelopathy with a significant reduced ambulation and upper motor neuron signs. Imaging disclosed upper cervical cord edema, and angiography confirmed a Cognard type V dAVF with drainage into the perimedullary and spinal venous system. The dAVF was supplied by the hypoglossal division of the ascending pharyngeal artery. Endovascular treatment was believed to pose a risk of ischemic injury to the hypoglossal nerve, and therefore, surgery was offered. Informed consent was obtained. A far lateral approach was used to access the fistulous point. We describe the relevant vascular anatomy and the benefits of the far lateral approach for this lesion. We also demonstrate a tailored inferior condylectomy to gain access to the intracranial part of the hypoglossal canal, where the draining vein is expected to be found. We supplement the discussion with a 3D surgical video.

Surgical Resection of an Arteriovenous Malformation of the Orbital Surface of the Frontal Lobe with Olfactory Tract Preservation: 2-Dimensional Operative Video.

Medial orbitofrontal area arteriovenous malformations (AVMs) are located in the noneloquent cortex and typically drain superficially into Sylvian veins or the superior sagittal sinus, making them favorable for surgical treatment. However, while typically supplied by pial/cortical branches of the anterior cerebral artery (ACA), they can incorporate the recurrent artery of Heubner and other ACA perforators on their way to the anterior perforated substance located just posterior. We present a case of a 30-year-old female admitted with sudden collapse and intraventricular hemorrhage from a ruptured medial orbitofrontal area AVM. She was admitted to the intensive care unit and an external ventricular drain was placed to treat acute hydrocephalus. Catheter angiography demonstrated an AVM located just anteromedial to the termination of the internal carotid artery with a compact nidus and an associated intranidal flow aneurysm. Arterial supply originated from the orbitofrontal artery off the ACA, with medial lenticulostriates seen coursing past the nidus. Additional supply from the recurrent artery of Heubner could not be excluded. However, a hypodensity in the inferior frontal lobe seen on the presentation computed tomography scan was suggestive of a prior orbitofrontal infarct and thus cortical, rather than perforator, supply. In our practice, treatment of ruptured AVMs is dictated by the patients' clinical recovery and associated high-risk features (e.g., flow aneurysms). In this case, despite the presence of a flow aneurysm, treatment was delayed 18 days due to slow neurologic recovery and family preference. The patient remained in the intensive care unit under close neurologic observation. She was extubated on day 10, and the external ventricular drain was removed on day 12 after confirming resolution of intraventricular hemorrhage. Preoperatively the patient recovered to a Glasgow Coma Scale score of 15. Risks of treatment were discussed, and informed consent was obtained. The patient was treated using a standard pterional craniotomy. We describe the anatomic location of the lesion in the medial orbitofrontal area, the relationship to the olfactory tract and olfactory stria. We demonstrate olfactory tract dissection from its arachnoid cistern between the orbitofrontal lobe and gyrus rectus in order to access the lesion. Indocyanine green angiography is used to help surgical dissection and for quality control at the end of the procedure. We do not perform intraoperative angiography routinely; however, it can be a useful adjunct in deep and/or eloquent locations, which are difficult to image using videoangiography. Nevertheless, in the absence of intraoperative angiography close dissection directly over the nidus on the eloquent side ensures preservation of functional brain. We describe the microsurgical techniques of surgical treatment of AVMs, in particular the "cone" dissection technique of the AVM in order to allow identification of all feeding vessels and tracing "en passant" vessels from proximal to distal, as well as the use of intraoperative videoangiography to elucidate the nidus morphology and immediate postoperative quality control (Video 1, available at https://drive.google.com/file/d/1IXuLg84MwyMek1_Z1f1n7qssLThimvdx/view?usp=sharing).

Longitudinal Changes in Size of Conservatively Managed Flow-Related Aneurysms Associated with Brain Arteriovenous Malformations.

BACKGROUND: Flow aneurysms (FAs) associated with brain arteriovenous malformations (AVMs) are thought to arise from increased hemodynamic stress due to high-flow shunting. This study aims to describe the changes in conservatively managed FAs after successful AVM treatment. METHODS: Patients with symptomatic AVMs and associated FAs who underwent successful treatment of the AVM between 2008 and 2017 were included. FA dimensions were measured on surveillance angiography to assess longitudinal changes. RESULTS: Thirty-two patients were identified with 48 FAs. Sixteen (33%) FAs were treated endovascularly; 18 (38%) FAs were treated surgically; and 14 (29%) FAs (11 patients) were monitored. FAs demonstrated a decrease in size from 5.0 mm to 3.8 mm (24%; P = 0.016) and 4.9 mm to 3.6 mm (27%; P = 0.013) in height and width, respectively, over a median 35 months. However, on subgroup analysis, only class IIb aneurysms demonstrated a significant decrease in size (51% reduction in largest diameter, P = 0.046) and only 3 FAs (21%) resolved. There were no hemorrhages observed during follow-up. CONCLUSIONS: While conservatively managed FAs demonstrated a reduction in size after the culprit AVM was treated, this was only significant in FAs located close to an AVM nidus (class IIb). There were no hemorrhages during the median 35 months' follow-up; however, long-term data are lacking. Our data support close observation of all conservatively managed aneurysms and a tailored approach based on the proximity to the nidus and observed changes in size.

Neurosurgical Randomized Trials in Low- and Middle-Income Countries.

BACKGROUND: The setting of a randomized trial can determine whether its findings are generalizable and can therefore apply to different settings. The contribution of low- and middle-income countries (LMICs) to neurosurgical randomized trials has not been systematically described before. OBJECTIVE: To perform a systematic analysis of design characteristics and methodology, funding source, and interventions studied between trials led by and/or conducted in high-income countries (HICs) vs LMICs. METHODS: From January 2003 to July 2016, English-language trials with >5 patients assessing any one neurosurgical procedure against another procedure, nonsurgical treatment, or no treatment were retrieved from MEDLINE, Scopus, and Cochrane Library. Income classification for each country was assessed using the World Bank Atlas method. RESULTS: A total of 73.3% of the 397 studies that met inclusion criteria were led by HICs, whereas 26.7% were led by LMICs. Of the 106 LMIC-led studies, 71 were led by China. If China is excluded, only 8.8% were led by LMICs. HIC-led trials enrolled a median of 92 patients vs a median of 65 patients in LMIC-led trials. HIC-led trials enrolled from 7.6 sites vs 1.8 sites in LMIC-led studies. Over half of LMIC-led trials were institutionally funded (54.7%). The majority of both HIC- and LMIC-led trials evaluated spinal neurosurgery, 68% and 71.7%, respectively. CONCLUSION: We have established that there is a substantial disparity between HICs and LMICs in the number of published neurosurgical trials. A concerted effort to invest in research capacity building in LMICs is an essential step towards ensuring context- and resource-specific high-quality evidence is generated.

Infratentorial Supracerebellar Approach for Resection of Midbrain Cavernous Malformation: 3-Dimensional Operative Video.

Cavernous malformations (cavernomas) of the brain stem with recurrent hemorrhage may be amenable to microsurgical resection if they are present close to the surface. The risks of surgery need to be balanced with the natural history of the lesion and the accumulation of neurological deficits and risk to life with multiple hemorrhages. In this 3D operative video, we illustrate the technique for the resection of a dorsally located midbrain cavernous malformation. Informed consent was obtained for this procedure. The cavernoma is accessed with the use of a supracerebellar infratentorial approach. The infratentorial craniotomy and coagulation of the superior vermian veins is shown. A description is provided of the use of hemosiderin staining and the intercollicular relative "safe zone"1 as landmarks for the neurotomy. The technique of cavernoma dissection from the surrounding gliotic plane is shown and described. In this case, the patient required prolonged rehabilitation but fully recovered without residual deficit 1 yr following surgery.

Awake Craniotomy for Resection of Left Temporal Cavernoma: 3-Dimensional Operative Video.

Cavernomas presenting with seizures refractory to medical treatment may require surgical excision for seizure control. If superficial, they can be surgically accessible but can pose additional risks when located in or near eloquent cortex. In this 3D operative video we illustrate the technique for the resection of a left temporal cavernoma located near eloquent cortex for speech with awake surgery and cortical mapping to avoid a speech deficit postoperatively. Informed consent was obtained for this procedure. Navigation is used to localize the cavernoma following which a large craniotomy is performed exposing the temporal lobe, frontal lobe, and sylvian vein. Bipolar stimulation is used to localize speech with the patient awake until speech arrest occurs. The cavernoma is situated immediately inferior to the sulcus over which speech arrest occurs. The sulcus immediately above the cavernoma is opened and adjacent arteries are carefully preserved. The glial plane around the cavernoma is used to dissect the cavernoma from the surrounding cortex. Care is taken to remove the haemosiderin as this can act as a precipitant for ongoing seizures. In this case the patient had no neurological deficits following surgery and was seizure free.

Anterolateral Approach for Central Thoracic Disc Prolapse-Surgical Strategies Used to Tackle Differing Operative Findings: 3-Dimensional Operative Video.

Thoracic disc prolapses causing cord compression can be challenging. For compressive central disc protrusions, a posterior approach is not suitable due to an unacceptable level of cord manipulation. An anterolateral transthoracic approach provides direct access to the disc prolapse allowing for decompression without disturbing the spinal cord. In this video, we describe 2 cases of thoracic myelopathy from a compressive central thoracic disc prolapse. In both cases, informed consent was obtained. Despite similar radiological appearances of heavy calcification, intraoperatively significant differences can be encountered. We demonstrate different surgical strategies depending on the consistency of the disc and the adherence to the thecal sac. With adequate exposure and detachment from adjacent vertebral bodies, soft discs can be, in most instances, separated from the theca with minimal cord manipulation. On the other hand, largely calcified discs often present a significantly greater challenge and require thinning the disc capsule before removal. In cases with significant adherence to dura, in order to prevent cord injury or cerebrospinal fluid leak a thinned shell can be left, providing total detachment from adjacent vertebrae can be achieved. Postoperatively, the first patient, with a significantly calcified disc, developed a transient left leg weakness which recovered by 3-month follow-up. This video outlines the anatomical considerations and operative steps for a transthoracic approach to a central disc prolapse, whilst demonstrating that computed tomography appearances are not always indicative of potential operative difficulties.

Supraclavicular Brachial Plexus Approach for Excision of C8 Nerve Root Schwannoma: 3-Dimensional Operative Video.

Brachial plexus tumors are uncommon lesions in young adults. The majority of these are benign peripheral sheath tumors. In this 3-dimensional video, we present a case of a 19-yr-old female who presented to the neurosurgical outpatients with an anterior neck lump. It has been present for months, causing occasional numbness and paraesthesia in the distribution of the left ring finger. There was no objective weakness in finger flexion with normal long flexors reflexes. The cervical spine and supraclavicular brachial plexus were investigated with a magnetic resonance imaging (Gadolinium) scan (Figure 1). It demonstrated 30 × 20 × 20 mm lesion adjacent to the C8 nerve arising from the neural foramen, however, mostly occupying the space lateral to it. The patient was consented for resection of the tumor. This was done via the supraclavicular brachial plexus approach. The brachial plexus nerves were macroscopically demonstrated lateral to the anterior scalene muscle. The intraoperative electrophysiology was used to directly stimulate the nerves, which aided in accurate tracking during the dissection. The tumor was exposed after tracing the C8 nerve deep and medial to the anterior scalene muscle. It was resected down to the foramen, reaching the level of the epidural venous plexus, while C8 was spared. The patient recovered with no neurological deficit. The histopathology confirmed grade 1 schwannoma. Subsequently, there was no radiological follow-up performed. This case demonstrates the surgical dissection of supraclavicular brachial plexus in 3-dimensions while describing the unusual dissection medial to scalenus anterior muscle.

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.

Simultaneous navigated cervico-thoracic and thoraco-lumbar fixation.

STUDY DESIGN: Case report. OBJECTIVE: To investigate the feasibility of using two independent image guidance systems to simultaneously fix multiple segment spine fractures. Image guidance is increasingly used to aid spinal fixation. We describe the first use of multiple navigation systems during a single procedure allowing for multi-segment spinal fixations to be performed simultaneously and capitalizing the advantages of navigation. METHOD: Two Medtronic Stealth Station S7™ systems with O-arm image capture were used to guide fixation of C6 and T12, unstable, AO A4, three-column fractures, in a patient with ankylosing spondylitis. RESULTS: Two surgical teams were able to perform cervico-thoracic and thoraco-lumbar fixations simultaneously. Operative time was 2.5 h. Post-operative imaging showed accurate instrumentation placement. The patient recovered without any neurological sequelae. CONCLUSIONS: Optical independence of the Medtronic Stealth Station™ system allowed for simultaneous navigation guided fixation of multiple segment fractures without compromising accuracy. This may result in shortened operative time and morbidity associated with prolonged prone positioning of polytrauma patients, as well as reducing radiation exposure for theatre staff.