Development and first results of a national databank on care and treatment outcome after traumatic brain injury.

PURPOSE: In absence of comprehensive data collection on traumatic brain injury (TBI), the German Society for Neurosurgery (DGNC) and the German Society for Trauma Surgery (DGU) developed a TBI databank for German-speaking countries. METHODS: From 2016 to 2020, the TBI databank DGNC/DGU was implemented as a module of the TraumaRegister (TR) DGU and tested in a 15-month pilot phase. Since its official launch in 2021, patients from the TR-DGU (intermediate or intensive care unit admission via shock room) with TBI (AIS head ≥ 1) can be enrolled. A data set of > 300 clinical, imaging, and laboratory variables, harmonized with other international TBI data collection structures is documented, and the treatment outcome is evaluated after 6- and 12 months. RESULTS: For this analysis, 318 patients in the TBI databank could be included (median age 58 years; 71% men). Falls were the most common cause of injury (55%), and antithrombotic medication was frequent (28%). Severe or moderate TBI were only present in 55% of patients, while 45% suffered a mild injury. Nevertheless, intracranial pathologies were present in 95% of brain imaging with traumatic subarachnoid hemorrhages (76%) being the most common. Intracranial surgeries were performed in 42% of cases. In-hospital mortality after TBI was 21% and surviving patients could be discharged after a median hospital stay of 11 days. At the 6-and 12 months follow-up, a favorable outcome was achieved by 70% and 90% of the participating TBI patients, respectively. Compared to a European cohort of 2138 TBI patients treated in the ICU between 2014 and 2017, patients in the TBI databank were already older, frailer, fell more commonly at home. CONCLUSION: Within five years, the TBI databank DGNC/DGU of the TR-DGU could be established and is since then prospectively enrolling TBI patients in German-speaking countries. With its large and harmonized data set and a 12-month follow-up, the TBI databank is a unique project in Europe, already allowing comparisons to other data collection structures and indicating a demographic change towards older and frailer TBI patients in Germany.

Effect of transcutaneous auricular vagal nerve stimulation on the fatigue syndrome in patients with gastrointestinal cancers - FATIVA: a randomized, placebo-controlled pilot study protocol.

BACKGROUND: Cancer-related fatigue (CRF) is defined as a "distressing, persistent, subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning." CRF is frequently observed in cancer patients even before the initiation of tumor therapy. Its cause is not clear, but in addition to primary effects of therapy, a tumor-induced elevated level of inflammatory cytokines may play a role. Transcutaneous auricular vagal nerve stimulation (taVNS) is a noninvasive way to activate central nervous pathways and modulate pain perception and the immune system. It has positive effects on autoimmune conditions and can also improve fatigue associated with Sjogren's syndrome. It is the main purpose of this feasibility study to investigate the feasibility of daily taVNS against CRF. Therefore, the stimulation protocol of the newly introduced smartphone app of the manufacturer is evaluated. Additionally, the effect taVNS on CRF and quality of life (QoL) shall be evaluated. METHODS: Thirty adult patients with gastrointestinal tumors during or after treatment, relevant CRF (Hornheide questionnaire) and life expectancy > 1 year, are enrolled. Patients are randomized to treatment or sham arm and be informed that they will either feel the stimulation or not. Treatment group will receive left-sided tragus above-threshold stimulation with 25 Hz, 250 µs pulse width, and 28-s/32-s on/off paradigm for 4 h throughout the day for 4 weeks. Sham group will receive no stimulation via a nonfunctional electrode. A daily stimulation protocol with time and average intensity is automatically created by a smartphone app connected to the stimulator via Bluetooth®. Multidimensional Fatigue Inventory-20, Short-Form 36 and Beck Depression Inventory questionnaires will be filled out before and after 4 weeks of stimulation. DISCUSSION: Primarily, the patients' daily stimulation time and intensity will be evaluated through the electronic protocol after 4 weeks. Secondarily, the effect of taVNS on cancer-related fatigue and QoL will be measured through the questionnaires. As taVNS seems to modulate inflammatory cytokines, this noninvasive method may - if accepted by the patients - be a promising adjunct in the treatment of cancer-related fatigue. TRIAL REGISTRATION: The study was approved by local ethics committee (21-7395) and registered at the DRKS database (DRKS00027481).

Shunt Dependence after Intraventricular Hemorrhage and Intraventricular Fibrinolysis with uPA versus rt-PA.

BACKGROUND: We compare the effect of urokinase (urokinase-type plasminogen activator [uPA]) versus alteplase (recombinant tissue plasminogen activator [rt-PA]) for intraventricular fibrinolysis (IVF) in patients with intraventricular hemorrhage (IVH) on ventriculoperitoneal shunt (VPS) dependence, functional outcome, and complications in the management of IVH. METHODS: We retrospectively reviewed the patients admitted with IVH or intracerebral hemorrhage (ICH) with IVH within 7 years in three different departments and found 102 patients who met the inclusion criteria. The primary end points were VPS dependence and Glasgow outcome score (GOS) at 3 months. Secondary end points were rate of rebleeding under IVF and incidence of treatment-related complications. Patients were divided into three groups: group I comprised patients treated with external ventricular drain (EVD) and IVF with uPA; group II comprised patients treated with EVD and IVF with rt-PA; and group III comprised patients treated with EVD alone. RESULTS: In all, 9.8% patients needed VPS: 12.2% in group I and 15.0% in group II, with no statistically significant difference. VPS patients had higher values of the modified Graeb score (mGS), IVH score, and IVH volume. We saw a trend for a better outcome in group II, with six patients achieving a GOS of 4 or 5 after 3 months. The mortality rate was higher in groups I and III. We found no statistical difference in the complication rate between groups I and II. Logistic regression analysis revealed that higher mGS and age predicted worse prognosis concerning mortality. The risk for death rose by 7.8% for each year of age. Any additional mGS point increased the chances of death by 9.7%. CONCLUSION: Our data suggest that both uPA and rt-PA are safe and comparable regarding incidence of communicating hydrocephalus, and age and mGS are predictive for mortality.

Pre- and postoperative self-reported and objectively assessed neurocognitive functioning in lower grade glioma patients.

Due to the tumor itself or its therapy glioma patients may complain on cognitive impairment, while validated neuropsychological testing (NPT) capturing specific neuropsychological domains does not indicate "objective" dysfunction. Little is known on the relevance of this disturbance for patients' everyday life. We aimed to address whether glioma patients treated with state-of-the-art neurosurgical techniques complain on neuropsychological impairment and whether these subjective complaints are disclosed in formal NPT. We assessed both, "objective" and "subjective" neurocognitive functioning in 13 patients with newly diagnosed WHO grade 2 and 3 gliomas, operated between 06/2018 and 12/2020. All underwent both, preoperative and follow-up NPT as well as a semi-structured interview on subjective complaints and specific questionnaires (post-therapeutic) on attention, memory and executive functioning. On group level, no significant changes between preoperative and post-therapeutic NPT occurred. On the individual level, in 3/13 patients new post-therapeutic deficits in objective NPT were detected in specific domains (verbal memory, non-verbal memory, verbal fluency). By contrast, 8/13 patients reported on "subjective" memory impairments post-therapeutically. Furthermore, on specific questionnaires cognitive and emotional executive dysfunction and increased fatigue occurred in patients relative to normative data. Although the findings have to be replicated in larger populations, a discrepancy between "subjective" and "objective" measures was evident. While subjective neurocognitive impairment may simply not represent a true dysfunction, an alternative explanation might be that established standardized NPT is not suitable to detect subtle dysfunction in this population. "Subjective" and "objective" neurocognitive functioning might represent distinct constructs, which should complement each other in patient-centered Neuro-Oncology.

Brainatomy-Demystifying the Temporal Bone, Rule of 3-2-1.

BACKGROUND: The temporal bone is difficult to comprehend in three-dimensional (3D) space. We provide a novel 3D mental model of the temporal bone which helps clinicians and surgeons dealing with it in teaching, diagnosing, conservative managements, and preoperative and intraoperative orientation. This study is part of the scientific project Brainatomy. OBJECTIVE: To analyze and simplify the temporal bone anatomy to enhance its comprehension and long-term retention. METHODS: The study was conducted at the Neurosurgical Department of the University Hospital of Bochum, Germany. We retrospectively analyzed data sets of 221 adult patients who underwent computed tomography (CT) of the skull (n = 167) and magnetic resonance imaging (MRI) of the brain (n = 54). A total of 142 patients with their respective imaging scans remained in our pool of interest after excluding 79 scans. The raw digital imaging and communications in medicine scans were transformed into 3D objects. Spatial analyses were then conducted, and all collected data were used to create our own 3D model of the temporal bone. RESULTS: We define the temporal bone as a prism-shaped model and divide it into 6 compartments: apex, neurovascular, mastoid, blank, tympanic, and temporomandibular compartments. The division into compartments has been achieved with the "Rule of 3-2-1." Finally, the 3D model has been used to record a video (Video), using a novel and "easy-to-follow" didactic approach. CONCLUSION: This simplified 3D model along with the corresponding video (Video) potentially enhances the efficiency of studying temporal none anatomy with a novel "easy-to-follow" approach.

[Surgical treatment and radiation therapy of brain metastases]. / Chirurgische Behandlung und Strahlentherapie von Hirnmetastasen.

The aim of this work is to outline the principles of interdisciplinary treatment of brain metastases. Interdisciplinary treatment is determined by the clinical situation, anatomical conditions and tumor entity and has the goal of reducing toxicity. Magnetic resonance imaging, computed tomography (CT) and positron emission tomography-CT are used to diagnose brain metastases. Neurosurgery is used for accessible, symptomatic metastases. For localized metastases, including multiple metastases, that are surgically inaccessible, radiosurgery is used. If possible, partial brain irradiation is preferred to whole-brain irradiation. Protection of the hippocampus during whole-brain radiotherapy reduces therapy toxicity. In emergency situations, steroids provide effective support and a neurosurgical intervention may be life-saving. The options for systemic drug therapy are increasing.

Applying machine learning to optical coherence tomography images for automated tissue classification in brain metastases.

PURPOSE: A precise resection of the entire tumor tissue during surgery for brain metastases is essential to reduce local recurrence. Conventional intraoperative imaging techniques all have limitations in detecting tumor remnants. Therefore, there is a need for innovative new imaging methods such as optical coherence tomography (OCT). The purpose of this study is to discriminate brain metastases from healthy brain tissue in an ex vivo setting by applying texture analysis and machine learning algorithms for tissue classification to OCT images. METHODS: Tumor and healthy tissue samples were collected during resection of brain metastases. Samples were imaged using OCT. Texture features were extracted from B-scans. Then, a machine learning algorithm using principal component analysis (PCA) and support vector machines (SVM) was applied to the OCT scans for classification. As a gold standard, an experienced pathologist examined the tissue samples histologically and determined the percentage of vital tumor, necrosis and healthy tissue of each sample. A total of 14.336 B-scans from 14 tissue samples were included in the classification analysis. RESULTS: We were able to discriminate vital tumor from healthy brain tissue with an accuracy of 95.75%. By comparing necrotic tissue and healthy tissue, a classification accuracy of 99.10% was obtained. A generalized classification between brain metastases (vital tumor and necrosis) and healthy tissue was achieved with an accuracy of 96.83%. CONCLUSIONS: An automated classification of brain metastases and healthy brain tissue is feasible using OCT imaging, extracted texture features and machine learning with PCA and SVM. The established approach can prospectively provide the surgeon with additional information about the tissue, thus optimizing the extent of tumor resection and minimizing the risk of local recurrences.

Complications of intracerebroventricular chemotherapy via subgaleal reservoir in primary central nervous system lymphoma: A single-institution experience on 1247 installations in 94 consecutive patients.

The implantation of a subgaleal reservoir intracerebroventricular (ICV port) in order to apply ICV chemotherapy in patients with leptomeningeal cancer may be complicated by misplacement of the device, pericatheter leucencephalopathy, hemorrhage and iatrogenic ventriculitis/meningitis. Here we analyzed the occurrence of such complications in patients with primary central nervous system lymphoma (PCNSL) treated with systemic and ICV methotrexate- and cytarabine-based chemotherapy. We retrospectively reviewed the medical records of 94 consecutive patients (1247 installations), who had received an ICV port for intraventricular chemotherapy for treatment of histologically confirmed PCNSL at our institution between September 2005 and October 2018. Infectious and noninfectious complications were systematically recorded including clinical, laboratory, and imaging data. In 9/94 patients (9.6%), a misplacement of the ICV port seen on the postoperative computed tomography scan was corrected immediately and chemotherapy was then continued as planned. In 5/94 patients (5.3%), symptomatic noninfectious complications were observed (four patients with symptomatic pericatheter leucencephalopathy and one patient with surgical scar dehiscence with CSF leak). In 8/94 patients (8.5%), asymptomatic white matter lesions around the catheter were visible on cerebral magnetic resonance imaging after completion of therapy. The rate of infectious complications was 6/94 patients (6.4%). No complication was lethal or required intensive care monitoring. This retrospective study shows that complications of ICV treatment have to be expected in a fraction of patients, however, in this series these complications were manageable and did not result in long-term deficits.

Posterolateral myelotomy for intramedullary spinal cord tumors: the other way to do it?

BACKGROUND AND PURPOSE: To evaluate posterolateral myelotomy (PLM) as a surgical method for all cases of intramedullary spinal cord tumors (IMSCT) by assessing the surgical and functional outcomes of patients treated in our clinic. MATERIALS AND METHODS: Patients with IMSCT who underwent surgery using PLM from 2013 to 2018 were reviewed retrospectively. Objective and quantitative assessment of the preoperative, postoperative, and follow-up neurological status was performed by using the modified McCormick functional schema and sensory pain scale. RESULTS: A total of 33 operations were performed on 27 patients who met the inclusion criteria. The mean grade on the McCormick functional schema increased insignificantly from 2.0 preoperatively to 2.3 immediately postoperatively and decreased back to 2.1 at the follow-up examination. Just one patient exhibited a transient proprioception deficit. Significant pain relief was observed as expressed in an improvement of mean grade on the sensory pain scale. Only in two cases was late neuropathic pain reported. A gross total resection/subtotal resection (GTR/STR) was achieved in all cases of hemangioblastoma and cavernoma, while for the majority of astrocytomas, only partial removal was accomplished. For ependymoma, which represents the most common IMSCT, a GTR/STR was realized in 12 cases (86%). A statistically significant difference (p = 0.027) was found when comparing the extent of tumor resection (EOR) between the two most common IMSCT, i.e., ependymoma and astrocytoma. CONCLUSION: PLM may be considered a reliable surgical method for IMSCT, as it combines a satisfactory EOR with reduced risk of tissue damage and excellent pain relief.

Open-Label Phase II Evaluation of Imatinib in Primary Inoperable or Incompletely Resected and Recurrent Glioblastoma.

PURPOSE: Preclinical studies indicated that imatinib may have single-agent activity in glioblastoma through inhibition of tyrosine kinase activity and also that it might enhance the efficacy of radiotherapy. We therefore sought to investigate clinical efficacy in patients with newly diagnosed and recurrent glioblastoma in combination with radiotherapy. METHODS: We conducted a nonrandomized, 2-arm, open-label phase II trial including patients aged 18 years or older with an ECOG performance status of 0-2 that were either newly diagnosed (arm A) with a measurable tumor (i.e., after incomplete resection or biopsy) or that were diagnosed with progression of a glioblastoma after initial therapy (arm B). Patients in arm A received 600 mg/day imatinib in combination with hypofractionated radiotherapy (2.5 Gy per fraction, 22 fractions). Patients in arm B received 600 mg/day imatinib alone or in combination with re-irradiation at various doses. In case tumor progression occurred, CCNU was added (2 cycles, 100 mg/m2) to imatinib. The primary end point was progression-free survival (PFS). The secondary end point was safety, defined as per Common Terminology Criteria for Adverse Events (version 2.0). Overall survival (OS) was analyzed as an exploratory end point. RESULTS: Fifty-one patients were enrolled, of which 19 were included in arm A and 32 in arm B. The median follow-up was 4 (0.5-30) months in arm A and 6.5 (0.3-51.5) months in arm B. The median PFS was 2.8 months (95% CI 0-8.7) in arm A and 2.1 months (95% CI 0-11.8) in arm B. The median OS was 5.0 (0.8-30) months (95% CI 0-24.1) in arm A and 6.5 (0.3-51.5) months (95% CI 0-32.5) in arm B. The major grade 3 events were seizure (present in 17 patients), pneumonia (11 patients), and vigilance decrease (7 patients). CONCLUSIONS: Imatinib showed no measurable activity in patients with newly diagnosed or recurrent glioblastoma.

Brainatomy: A Novel Way of Teaching Sphenoid Bone Anatomy With a Simplified 3-Dimensional Model.

BACKGROUND: The diagnosis and treatment of diseases at and around the sphenoid bone demands throughout understanding of its anatomy in 3-dimensional (3-D) space. However, despite the complex anatomic nature of the sphenoid bone, the current educational resources for its 3-D anatomy are insufficient for fast and long-term retention of the anatomic relationships. OBJECTIVE: To provide a simplified 3-D model of the sphenoid bone that anyone can easily learn and recall as an internal mental model. METHODS: Various studies on the anatomy of the sphenoid bone were analyzed. The collected data included the shape, foramina, canals, fissures, and minute details of the sphenoid bone. The gained detailed knowledge was subsequently used to create a 3-D model of the sphenoid bone with the help of 3-D computer software. A live lecture was given with this same software and simultaneously recorded with a microphone and a computer-screen recorder. A novel approach in lecturing, building the sphenoid bone from the scratch in a piecemeal fashion, was utilized. RESULTS: The sphenoid bone was recreated as an horizontally elongated box without a superior and posterior wall. All its foramina, canals, and fissures are visually easy to follow. Understanding its neuroanatomic terminologies based on their anatomic nature and relationships is enhanced. CONCLUSIONS: This simplified 3-D model, along with the video lecture, will enhance the efficiency of studying sphenoid bone anatomy. The educational resources of this study can be obtained by medical students, radiologists, neurologists, neurosurgeons, neuroscientists, or anyone else seeking for fundamental understanding of sphenoid bone anatomy.

Comparison between optical coherence tomography imaging and histological sections of peripheral nerves.

OBJECTIVE: Optical coherence tomography (OCT) is an imaging technique that uses the light-backscattering properties of different tissue types to generate an image. In an earlier feasibility study the authors showed that it can be applied to visualize human peripheral nerves. As a follow-up, this paper focuses on the interpretation of the images obtained. METHODS: Ten different short peripheral nerve specimens were retained following surgery. In a first step they were examined by OCT during, or directly after, surgery. In a second step the nerve specimens were subjected to histological examination. Various steps of image processing were applied to the OCT raw data acquired. The improved OCT images were compared with the sections stained by H & E. The authors assigned the structures in the images to the various nerve components including perineurium, fascicles, and intrafascicular microstructures. RESULTS: The results show that OCT is able to resolve the myelinated axons. A weighted averaging filter helps in identifying the borders of structural features and reduces artifacts at the same time. Tissue-remodeling processes due to injury (perineural fibrosis or neuroma) led to more homogeneous light backscattering. Anterograde axonal degeneration due to sharp injury led to a loss of visible axons and to an increase of light-backscattering tissue as well. However, the depth of light penetration is too small to allow generation of a complete picture of the nerve. CONCLUSIONS: OCT is the first in vivo imaging technique that is able to resolve a nerve's structures down to the level of myelinated axons. It can yield information about focal and segmental pathologies.

Association between Vertebral Artery Hypoplasia and Vertebral Artery Aneurysms: A Case-Control Study.

BACKGROUND: The aim of this retrospective case-control study was to determine the association of vertebral artery hypoplasia (VAH) and other anatomical variants with saccular vertebral artery posterior inferior cerebellar artery (VA-PICA) aneurysms. METHODS: The frequency of VAH, vertebral artery (VA) atresia, VA aplasia, and PICA aplasia was analyzed using computed tomography (CT) angiography in 64 patients with VA-PICA aneurysms (43 ruptured and 21 unruptured) and compared with 128 age- and sex-matched controls. Logistic regression was performed to identify independent risk factors for aneurysm formation. RESULTS: Univariate analysis showed that patients with VA-PICA aneurysms had a significantly higher frequency of VAH (53% versus 17%; odds ratio [OR] 4.8; 95% confidence interval [CI], 2.4-9.4; p < 0.0001) and VA aplasia (14% versus 1%; OR 20.8; 95% CI, 2.5-168.0; p = 0.004) compared with controls. VA-PICA aneurysms are detected significantly more often in the dominant VA, which is contralateral to VAH. Other anatomical variants are not related to aneurysm formation. CONCLUSIONS: VAH and VA aplasia are potential risk factors for VA-PICA aneurysms. Altered hemodynamics caused by VAH may result in intracranial aneurysm formation. Additional research should clarify the pathophysiologic association of VAH, VA aplasia, or vascular occlusion with arteriosclerosis and intracranial aneurysm formation.

The Interdisciplinary Management of Foot Drop.

BACKGROUND: Foot drop can be caused by a variety of diseases and injuries. Although it is a common condition, its overall incidence has not been reported to date. Foot drop markedly restricts the everyday activities of persons suffering from it. There is, therefore, a need for an optimized strategy for its diagnosis and treatment that would be standardized across the medical specialties encountering patients with this problem. METHODS: This article consists of a review on the basis of pertinent publications re- trieved by a search in the Pubmed/MEDLINE and Cochrane databases, as well as a description of the authors' proposed strategy for the diagnosis and treatment of foot drop. RESULTS: Foot drop can be due to a disturbance at any central or peripheral location along the motor neural pathway that terminates in the dorsiflexor muscles of the foot, or at multiple locations in series. Optimal localization of the lesion(s) is a pre- requisite for appropriate treatment and a successful outcome. The most common causes are L5 radiculopathy and peroneal nerve injury. An operation by a neuro- surgeon or spinal surgeon is a reasonable option whenever there is a realistic chance that the nerve will recover. In our opinion, any patient with a subjectively disturbing foot drop and a clinically suspected compressive neuropathy of the peroneal nerve should be informed about the option of surgical decompression of the nerve at the fibular head, which can be performed with little risk. In case of a permanent foot drop, some patients can benefit from muscle-transfer surgery. For spastic foot drop, the option of botulinum toxin injections should be evaluated. CONCLUSION: The care of patients with foot drop could be optimized by interdisciplin- ary foot-drop clinics involving all of the relevant specialists. The goals of treatment should always be improved mobility in everyday life and the prevention of falls, pain, and abnormal postures.

High-resolution in vivo imaging of peripheral nerves using optical coherence tomography: a feasibility study.

OBJECTIVE: Because of their complex topography, long courses, and small diameters, peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include MRI and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical coherence tomography (OCT) is the first imaging technique that is able to depict a nerve's ultrastructure at micrometer resolution. In the current study, the authors present an in vivo assessment of human peripheral nerves using OCT. METHODS: OCT measurement was performed in 34 patients with different peripheral nerve pathologies, i.e., nerve compression syndromes. The nerves were examined during surgery after their exposure. Only the sural nerve was twice examined ex vivo. The Thorlabs OCT systems Callisto and Ganymede were used. For intraoperative use, a hand probe was covered with a sterile foil. Different postprocessing imaging techniques were applied and evaluated. In order to highlight certain structures, five texture parameters based on gray-level co-occurrence matrices were calculated according to Haralick. RESULTS: The intraoperative use of OCT is easy and intuitive. Image artifacts are mainly caused by motion and the sterile foil. If the artifacts are kept at a low level, the hyporeflecting bundles of nerve fascicles and their inner parts can be displayed. In the Haralick evaluation, the second angular moment is most suitable to depict the connective tissue. CONCLUSIONS: OCT is a new imaging technique that has shown promise in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable and have already been demonstrated by other groups. Currently, the method resembles an optical biopsy and can be a supplement to intraoperative sonography, giving high-resolution insight into a suspect area that has been located by sonography in advance.

Experimental investigations of a manually versus an electrically driven skull drill for bedside usage.

BACKGROUND: Manual skull drilling is an old but in modern neurosurgery still established procedure which can be applied quickly and universally in emergency situations. Electrical drilling requires more complex equipment and is usually reserved to the Operating Room (OR). It also seems desirable to apply an electrical drill for bedside usage but a suitable product does not exist so far. METHOD: Our experimental study using a manually and an electrically driven skull drill included a total of 40 holes drilled into synthetic biomechanical sheets. Half of the holes were produced with a prototype electrical drilling machine of the company Kaiser Technology and half of them with a traditional manual drill. Different drilling parameters such as the geometry of the borehole, the drilling forces and the drilling vibrations were captured during all experiments. RESULTS: The electrical drilling needed higher vertical force by the operators and a longer time to penetrate the sheet. A reason was the relatively lower rotational speed provided by this particular drill. When drilling electrically the vibrations were substantially less which in turn led to a more precise shape of the holes (revealed by observation via a microscope). CONCLUSIONS: The electrification of bedside drilling can in principle enable emergency craniostomies to be performed with greater ease and accuracy. The power of the electric drive, however, must be at least equivalent to the power of the traditional manual drill. Otherwise, the vertical forces exerted on the scull by the operator become inhibitive. The challenge is to combine cost-efficiency and re-sterilizability of an electrically driven drilling machine which at the same time is small and simple enough to qualify for emergency applications.

Association between vertebral artery hypoplasia and vertebral artery aneurysms: A case-control study.

BACKGROUND: The aim of this retrospective case-control study is to determine the association of vertebral artery hypoplasia (VAH) and other anatomical variants with saccular vertebral artery posterior inferior cerebellar artery (VA-PICA) aneurysms. METHODS: The prevalence of VAH, vertebral artery (VA) atresia, VA aplasia, and PICA aplasia was analyzed using CT angiography in 64 patients with VA-PICA aneurysms (43 ruptured and 21 unruptured) and compared to 128 age- and sex-matched controls. Logistic regression was performed to identify independent risk factors for aneurysm formation. RESULTS: Univariate analysis showed patients with VA-PICA aneurysms had significantly higher incidence of VAH (53% vs. 17%; odds ratio [OR] 4.8; 95% confidence interval [CI] 2.4-9.4; p < 0.0001) and VA aplasia (14% vs. 1%; OR 20.8; 95% CI 2.5-168.0; p = 0.004) compared with controls. Multivariate analysis identified VAH (odds ratio, 3.6; 95% CI 1.8-7.3; p < 0.0001) as an independent strong risk factor for VA-PICA aneurysm formation. VA-PICA aneurysms are detected significantly more often in the dominant VA, which is contralateral to VAH. Other anatomical variants are not related to aneurysm formation. CONCLUSIONS: VAH and VA aplasia are potential risk factors for VA-PICA aneurysms. Altered hemodynamics caused VAH may result in intracranial aneurysm formation. Additional research should clarify the pathophysiological association of VAH, VA aplasia, or vascular occlusion with arteriosclerosis and intracranial aneurysm formation.

Rare finding in peripheral nerve surgery: an unicentric Castleman disease presenting as median nerve tumour.

A 51 year old man presented with progressive swelling in the upper arm. MRI revealed a solitary mass extending from the median nerve. Intraoperative finding was a tumour extending within the nerve in its proximal fibres. The histological result showed a Castleman disease.