Florian Roser

• MD PhD
• Chair at Cleveland Clinic Abu Dhabi

Background: The cranial nerve (CN) V and adjacent neurovascular structures are crucial landmarks in microvascular decompression (MVD). MVD of CN V is the most effective treatment for patients with drug-resistant trigeminal neuralgia (TN) diagnosis. The endoscope-assisted retrosigmoid approach (RSA) provides better exposure and less cerebellar retra...

Projected trends in population aging have forecasted a massive increase in the number of people with dementia, in particular in sub‐Saharan Africa and the Middle East and North Africa (MENA) region. Cognitive decline is a significant marker for dementia, typically assessed with standardized neuropsychological tools that have been validated in some...

Background: This study aimed to investigate the occurrence of delayed response following microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and identify potential contributing factors. Additionally, we present two cases with delayed relief observed at our institution. Method: Two TN patients with delayed response and cl...

Background: Vestibular schwannoma surgery remains a neurosurgical challenge, with known risks, dependent on a number of factors, from patient selection to surgical experience of the team. The semi-sitting position has gained popularity as an alternative to the traditional supine position for vestibular schwannoma resection due to potential advanta...

Background: In an ample armamentarium in neurosurgery, the semi-sitting position has produced debate regarding its benefits and risks. Although the position is apparently intuitive, many have abandoned its use since its initial inception, because of reported complexity and potential complications, leading to impracticality. However, through standa...

Objectives: Trigeminal schwannoma is an uncommon tumor in the pediatric population. Several surgical approaches have been described in the literature. The objective of this study is to present the case of an 11 year-old male with a giant dumbbell-shaped trigeminal schwannoma removed through a two-stage approach, and review the literature on trigem...

Purpose of Review Although external ventricular drains (EVDs) are widely used, there is a lot of variability in how they are managed. This review will provide an update on the management of EVDs, based on the current evidence. Recent Findings Bundles of care focused on aseptic techniques for EVD insertion, maintenance, and care are likely to preve...

Objective In this systematic review and meta-analysis, we review the literature regarding Cushing's disease (CD) patients with negative or inconclusive MRI. Methods A quantitative systematic review was performed. Article selection was performed by searching MEDLINE (using PubMed), EMBASE, and Cochrane electronic bibliographic databases. Results 2...

Background: Lumbar compartment syndrome is a recognized clinical phenomenon, despite receiving less attention as a clinical entity. Given its rarity, the definitive presentation, diagnosis, and management strategies are not completely agreed upon. Materials and methods: A literature search on PubMed of all case reports of lumbar paraspinal compa...

The present surgical video demonstrates safe opening of the internal auditory canal (IAC) during vestibular schwannoma surgery via a retrosigmoid approach in the sitting position. Resection of the intrameatal portion of a tumor is important for progression-free survival. Preoperative thin-sliced CT revealed a high-riding jugular bulb obscuring the...

Albeit the semi-sitting position in neurosurgery has been in use for several decades, its application remains controversial in the neurosurgical and neuro-anaesthesia communities. The imminent and most feared risk of the sitting position is air entry into the vascular system due to the negative intravascular pressure leading to potentially life-thr...

The objective of this study was to calculate the risk of postsurgical hearing deterioration as a function of changes in the amplitude and latency of the most stable components (waves III and V) of the auditory evoked potential (AEP) during petroclival meningioma resection surgery. We retrospectively analyzed intraoperative AEP monitoring results an...

Background Safety, efficacy and efficiency of neurosurgical robots are defined by their design (i.e., framed and non-framed) and procedural workflow (from image to surgery). The present study describes the quality indicators of three different robots in brain and spine surgery. Methods This single-center study enrolled 252 patients over a ten-year...

Objective This study was aimed to demonstrate the resection of anterior foramen magnum meningiomas through an endoscopic-assisted posterior midline suboccipital subtonsillar approach. Design This study was designed with illustration of the surgical steps and safety of this approach. Setting Evidence of cerebrospinal fluid (CSF) cleft between the tu...

With new technological advancements in spine surgery, come accompanying expectations regarding the association between the incremental improvements of the surgical technique and its ability to provide superior patient outcomes and more efficient surgical workflows at lower cost. In many surgical fields, robots are still being tested on an experimen...

Objective: To review teaching and mentoring techniques of experienced skull base surgeons and educators STUDY DESIGN:: Expert commentary. Setting: 8th Quadrennial International Conference on vestibular schwannoma and other CPA tumors, panel on teaching, and mentoring. Main outcome measures: Experiences and opinions of experienced skull base su...

Objective: To compare ischemic and hemorrhagic stroke patients with COVID-19 to non-COVID-19 controls, and to describe changes in stroke admission patterns during the pandemic. Methods: This is a single center, retrospective, observational study. All consecutive patients admitted with primary diagnosis of ischemic/ hemorrhagic stroke between March...

Expanded endonasal endoscopic approaches provide access to the entire central skull base and craiocervical junction. The authors present a case of an 81-year-old man who presented with progressive spastic quadriparesis to the point of being wheel-chair bound. Cervical spine computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated...

SUMMARY: The mechanisms and phenotype of ischemic stroke associated with coronavirus disease 2019 (COVID-19) remain uncertain. A retrospective study was conducted in patients with COVID-19 presenting with ischemic stroke from March 1 to May 25, 2020, and cases with large-vessel occlusion were identified. To provide baseline institutional stroke dat...

Up to 60% of patients with Chiari type 1 malformation harbor a cervical syringomyelia and a centromedullary syndrome with dissociated pain and thermal sensory impairment, followed by segmental weakness, atrophy, upper motor neuron syndrome, and autonomic dysfunctions due to distension of descending pathways. Comprehensive electrophysiological diagn...

Endoscopy allows neurosurgeons to reach regions in the brain and spine through minimally invasive approaches. Such areas were previously accessible only by extensive and invasive approaches that limited the ability to see the areas of interest. Physicians are increasingly caring for patients who have undergone these procedures (eg, for pituitary tu...

Background: Ventriculoperitoneal shunt is among the most frequent neurosurgical procedures, complicated by infection and obstruction. The first is influenced by number of skin incisions, catheter exposure and manipulation, and the latter by catheter position. Method: Presenting our neuronavigated laparoscopic-assisted minimal exposure shunt tech...

Procedures on cavernous malformations of the brainstem are challenging due to their eloquent location. This accounts especially for recurrent cavernomas as surgical scars, adhesions, and functional shift might have occurred since primary surgery. We report on a 38-year-old female patient with a large recurrent brainstem cavernoma, who underwent pre...

Stereotactic radiosurgery (SRS) has been used as the primary treatment for vestibular schwannoma (VS) over the last two decades. While literature is available on tumor response following SRS, very long-term follow-ups are not yet available. Malignant transformation of benign VS is very rare. There are only a few cases described in the literature, m...

Background: Resection of large falcine meningiomas can be challenging as overlaying cortical brain is endangered during the surgical approach. Method: We describe the endoscope-assisted contralateral paramedian approach to large left-falcine meningiomas to avoid retraction of the ipsilateral thin layer of eloquent brain cortex. Conclusions: Th...

Background: Lesions lateral to the lower brainstem in an area extending from the foraminae of Luschka to the foramen magnum are rare and include different pathologies. There is no consensus on an ideal surgical approach. Method: To gain access to this area, we use the midline suboccipital subtonsillar approach (STA). This midline approach with u...

Objective: Well-defined risk factors for the identification of meningioma patients who might benefit from preoperative or early postoperative seizure prophylaxis are unknown. We investigated and quantified risk factors to determine individual risks of seizure occurrence in meningioma patients. Methods: A total of 634 adult meningioma patients we...

Object: Suboccipital decompression and duraplasty is considered the treatment of choice for Chiari-I-malformation. Several studies have shown improvement of neurophysiological parameters during decompressive surgery in pediatric patients. However, there is no evidence of the beneficial role of intraoperative neuromonitoring in adults. Methods: A...

Background The clinical relevance of emissary veins (EVs) is often neglected. However, for posterior fossa approaches, especially in semisitting positions, these transosseous connections become potentially life threatening. Therefore, knowledge of the presence and configuration of EVs is essential in preoperative planning. We report on the use of p...

Background: We present two exceptional cases of possible tumor seeding in benign vestibular schwannoma (VS) patients occurring years after initial microsurgical resection. Case description: We retrospectively analyzed the surgical management, histology and documented the growth of new tumor occurrence in close vicinity of the original schwannoma...

Expectations regarding new technological advancement in spine surgery are related to improvements of surgical technique. While in other fields, surgical robots are still tested on an experimental level; spinal surgeons have begun to adopt available systems in their daily workflow. Yet, despite the majority of clinical results showing equally high o...

Unlabelled: Xiao and colleagues in China reported successful restoration of bladder control in patients with spinal cord injury (SCI) by establishing a somatic-autonomic reflex pathway through lumbar-to-sacral ventral root nerve rerouting. We evaluated long-term results in eight patients who underwent this procedure at a German university clinic b...

There are several methods to detect apoptosis using cleaved caspase-3 and each harbors its own advantages and disadvantages. When primary cell cultures are used, the disadvantages of the standard methods can make apoptosis detection difficult due to their slow growth rate and replicative senescence, thereby limiting the available cell number and ex...

Objective: Vestibular schwannoma surgery requires a profound knowledge of anatomy and long-standing experience of surgical skull base techniques as patients nowadays requests high quality results from any surgeon from the beginning. This educes a dilemma for the young neurosurgeon as she/he is at the beginning of a learning curve. The presented ser...

Objective: Lesions of the cerebellomedullary cistern lateral to the lower brainstem in an area extending from the foraminae of Luschka to the foramen magnum are rare and can be caused by various sources. There is no consensus on an ideal surgical approach. We describe the anatomical features and the surgical technique of the midline suboccipital s...

Introduction. The endoscope became a highly valued visualization tool in neurosurgery. However, technical limitations caused by the rigidity of current standard endoscopes significantly decrease ergonomy in transcranial neurosurgery. Further technological developments will aid enlarging the surgical applicability. Objective. To evaluate the intraop...

There is ongoing discussion whether radiotherapy might be beneficial in the treatment of intracranial cavernomas, however long-term sequelae due to brainstem irradiation may exist. The case of a 72-year-old female is reported who received radiotherapy in the pre-MRI era due to a suspected intra-axial pontine lesion. Later on she developed severe tr...

Background: The maneuver of transmeatal drilling carries the risk of injuring inner ear structures, which may cause immediate or delayed hearing loss. Objective: To describe the changes in petrous bone anatomy caused by the tumor and to analyze both the incidence and the risk pattern for violation of the endolymphatic system in a surgical series...

Purpose Lateral mass (LM) fixation has become a standard in cervical spine instability treatment; however, maximal biomechanical stability combined with low morbidity remains a challenge. We evaluated our own patient cohort for bicortical screw placement and complication rates and investigated optimal screw trajectories with preoperative multiplana...

Contemporary robotics integrates sensory and advanced navigational hardware to provide advanced degrees of repeatability, accessibility, and speed. The virtues of robotics have been leveraged toward revolutionizing medical applications, including major surgical techniques. Robotic guidance platforms are often characterized by advanced dexterity and...

Although generally considered benign, the biological behaviour of meningiomas varies considerably. The microscopic histopathological classification of the World Health Organization (WHO) cannot entirely predict the clinical behaviour of these tumours. Between 7 and 32 % of benign meningiomas recur after total resection, and between 19 and 50 % (or...

The term syringomyelia designates a disorder that is characterised by the formation of cavities in the spinal cord or the brainstem (syringobulbia). Typically, syringomyelia is associated with an underlying pathological condition that is marked by a disturbance in the circulation of cerebrospinal fl uid. Spinal tumours, trauma, congenital malformat...

Meningiomas are presumed to account for 15 % of brain tumours and are the most common tumours of the sphenoid wing. They are considered to be benign tumours arising from cap cells located in clusters around the arachnoid granulations that exist in relation to neural structures and their foramen. Anatomically they are divided in meningiomas of the l...

Aims of modern vestibular schwannoma surgery are complete tumor resection with functional facial nerve and hearing preservation, if possible. Here we present our technique of bimanual dissection for vestibular schwannoma resection through the retrosigmoid approach. A slightly curved surgical incision is planned two fingers behind the ear extending...

Objective: CD133 is a five transmembrane domain glycoprotein, which is widely used for selection of brain tumor stem cells, although the biological function of CD133 is not well understood. CD133 expression in brain tumor tissue is correlated with poor prognosis. Furthermore, the higher expression of CD133 mRNA indicates the presence of CD133 prote...

Holocord intramedullary low-grade astrocytomas in children and adolescents - involving most or all of the cervical and thoracic spinal cord - are a rare finding. Most of the tumors seem to be pilocytic astrocytomas. Surgical management strategies might not be as clear as in small and circumscribed intramedullary tumors. On the basis of 20 previousl...

Apoptosis can be detected reliably by assaying for cleaved caspase-3, for which active caspase-3 antibodies are used in several methods, such as immunocytochemistry, enzyme-linked immunosorbent assay, and western blot. In this study, we used TaqMan protein assay (TPA), a novel method for protein detection and quantification that detects proteins by...

Even though robotic technology holds great potential for performing spinal surgery and advancing neurosurgical techniques, it is of utmost importance to establish its practicality and to demonstrate better clinical outcomes compared with traditional techniques, especially in the current cost-effective era. Several systems have proved to be safe and...

Background: Training courses in neurosurgery are essential educational elements of residency. Teaching methods vary due to cultural differences, monetary restrictions and infrastructure conditions. Anatomical dissection courses combined with annotated live surgeries performed by senior surgeons have proved to be best accepted by students. Objecti...

Hypericin (HYP) is a naturally occurring photosensitizer. Cellular uptake and photodynamic inactivation after incubation with this photosensitizer have neither been examined in medulloblastoma cells in vitro, nor compared with 5-aminolevulinic acid-derived protoporphyrin IX (5-ALA-derived PpIX). In 3 medulloblastoma cell lines (D283 Med, Daoy, and...

Background: Vascular endothelial growth factor (VEGF)-mediated angiogenesis mediates tumour growth and metastasis. Meningiomas are primarily benign, slow-growing, highly vascularised tumours. Aside from VEGF, there is little data on the function of major angiogenic proteins in meningiomas. Methods: The VEGFA, platelet-derived growth factor B (PDGF...

Background: Glossopharyngeal nerve neuralgia (GPN) is an exceptionally rare skull-based disorder. It is treated similar to other neurovascular conflicts. The approach, however, is debatable, as the caudal cranial nerves and especially the exit zones at the brainstem are barely visible via the retrosigmoid approach. Clinical presentation: We demo...

This article gives an overview of meningiomas, pituitary tumors, and intracranial nerve sheath tumors as regards epidemiology, diagnosis, and treatment. Discussion includes the definition of these tumors and their symptomatology, diagnostic procedures, treatment options, surgical techniques, and outcomes.

The endolymphatic sac tumor (ELST) is a low-grade carcinoma originating in the ear. These extremely rare tumors are capable of invading the cerebellopontine angle and might be mistaken for choroid plexus tumors (CPTs) in this region. Currently, these tumors are distinguished by conventional morphologic and immunohistochemical studies for S-100, cyt...

Due to the European Working Time Directive (EWTD) and a new collective agreement for doctors working at University hospitals in 2006 new shift models had to be designed in the Department of Neurosurgery of the University Hospital Tübingen, Germany. The aim of the study was to show the fit of the models regarding the average weekly working time limi...

Objective: To report about endoscope-assisted surgery of large skull base epidermoid cysts, focusing on the application of neuroendoscopy and the clinical outcome in cases of epidermoid cysts. Methods: Twenty-seven consecutively operated on patients (2005–2011) with an epidermoid cyst of the skull base were retrospectively analyzed. Among them, 13...