Delayed facial nerve palsy after vestibular schwannoma resection: risk factors, extent and prognosis.

INTRODUCTION: Facial nerve palsies may develop during the postoperative period of microsurgical removal of vestibular schwannomas (VSs), even after normal facial function for days or weeks after surgery. The aim of this study was to identify the pathomechanism and predictive factors of delayed palsy. MATERIAL AND METHOD: The clinical data of 193 patients who underwent vestibular schwannoma surgery between 2012 and 2021 were retrospectively analyzed. A total of 134 patients were included. The patients showed intact facial nerve function up to 24 h after surgery. All patients (n = 20) with palsy from postoperative day 4 were included and collectively referred to as delayed facial nerve palsy (DFNP). Various factors were checked using a binomial regression analysis. RESULTS: The mean age of patients with DFNP was 57.8 years (55% female, 45% male). 70% had VS with KOOS ≥ 3, and 60% underwent surgery via a translabyrinthine approach Among the 16 patients with DFNP-related neurotropic pathogens, 25% were seropositive for herpes simplex virus. Most patients (n = 9/20) experienced onset of palsy between postoperative days 6 and 10. Of the four variables included in the significance test, three were significant: KOOS ≥ 3 (p < .04), ipsilateral vestibular organ failure (p < .05), and age group (p < .03). After therapy, 100% of patients recovered almost complete facial nerve function. The parameters mentioned above (KOOS classification and ipsilateral vestibular dysfunction) could be proven risk factors for the occurrence of DFNP.

[Odynophagia as the first symptom of monkeypox infection]. / Odynophagie als erstes Symptom bei Affenpocken-Infektion.

A 50-year-old patient with confirmed monkeypox infection presented with odynophagia and nocturnal dyspnea. Clinically, there was a lesion on the tongue without any skin lesions and fibrinous plaques on the right tonsil with asymmetry of the palatoglossal arch. Due to a suggested abscess in the CT scan, a tonsillectomy à chaud was performed. By pan-orthopox-specific polymerase chain reaction (PCR) the monkeypox infection was also confirmed in the tonsil tissue. Isolated oral findings may represent a monkeypox infection and should be considered as a currently important differential diagnosis, especially for patients at risks.

Odynophagia as the first symptom of monkeypox infection.

A 50-year-old patient with confirmed monkeypox infection presented with odynophagia and nocturnal dyspnea. Clinically, there was a lesion on the tongue without any skin lesions and fibrinous plaques on the right tonsil with asymmetry of the palatoglossal arch. Due to a suggested abscess in the CT scan, a tonsillectomy à chaud was performed. By pan-orthopox-specific polymerase chain reaction (PCR) the monkeypox infection was also confirmed in the tonsil tissue. Isolated oral findings may represent a monkeypox infection and should be considered as a currently important differential diagnosis, especially for patients at risks.

[Traumatology of the lateral skull base]. / Traumatologie der Laterobasis.

The most common cause of lateral skull base fractures are still road traffic accidents, followed by falls. The radiologic classification into otic capsule-sparing or otic capsule-violating fractures correlates well with an increased risk of injury to the sensitive structures of the middle ear with otic capsule-violating fractures. In case of immediate onset complete facial nerve paralysis, decompression surgery is generally recommended if bony impingement can be demonstrated on high-resolution CT of the temporal bone. For many other facials nerve complications, recent publications have achieved good to excellent facial nerve recovery rates with watchful waiting under conservative treatment with prednisolone administration.

[Optic nerve decompression-state of the art]. / Optikusdekompressionen ­ Stand der Technik.

Rarely, but often with serious consequences for the patient, the optic nerve is affected during the course of head injuries. Traumatic optic nerve compression is always an emergency situation, which is why time is of the essence for both diagnosis and treatment. Precise knowledge of this accident sequelae but also of the resulting conditions, especially in terms of traumatic optic neuropathy, is indispensable for adequate patient care. The aim of this paper is to provide an overview of this clinical picture, particularly with regard to etiology, diagnosis, and treatment options, and to discuss this in the context of the current literature.

Biallelic mutation of human SLC6A6 encoding the taurine transporter TAUT is linked to early retinal degeneration.

We previously reported that inactivation of the transmembrane taurine transporter (TauT or solute carrier 6a6) causes early retinal degeneration in mice. Compatible with taurine's indispensability for cell volume homeostasis, protein stabilization, cytoprotection, antioxidation, and immuno- and neuromodulation, mice develop multisystemic dysfunctions (hearing loss; liver fibrosis; and behavioral, heart, and skeletal muscle abnormalities) later on. Here, by genetic, cell biologic, in vivo1H-magnetic resonance spectroscopy and molecular dynamics simulation studies, we conducted in-depth characterization of a novel disorder: human TAUT deficiency. Loss of TAUT function due to a homozygous missense mutation caused panretinal degeneration in 2 brothers. TAUTp.A78E still localized in the plasma membrane but is predicted to impact structural stabilization. 3H-taurine uptake by peripheral blood mononuclear cells was reduced by 95%, and taurine levels were severely reduced in plasma, skeletal muscle, and brain. Extraocular dysfunctions were not yet detected, but significantly increased urinary excretion of 8-oxo-7,8-dihydroguanosine indicated generally enhanced (yet clinically unapparent) oxidative stress and RNA oxidation, warranting continuous broad surveillance.-Preising, M. N., Görg, B., Friedburg, C., Qvartskhava, N., Budde, B. S., Bonus, M., Toliat, M. R., Pfleger, C., Altmüller, J., Herebian, D., Beyer, M., Zöllner, H. J., Wittsack, H.-J., Schaper, J., Klee, D., Zechner, U., Nürnberg, P., Schipper, J., Schnitzler, A., Gohlke, H., Lorenz, B., Häussinger, D., Bolz, H. J. Biallelic mutation of human SLC6A6 encoding the taurine transporter TAUT is linked to early retinal degeneration.

Influence of patient-specific anatomy on medical computed tomography and risk evaluation of minimally invasive surgery at the otobasis.

PURPOSE: With the increasing use of new minimally invasive approaches in temporal bone surgery, the need arises for evaluation of the risk of injury to sensitive anatomical structures. The factors that influence the measurement uncertainty (variation in representation of position and shape of anatomical structures) of imaging are of relevance. We investigate the effect of patients' anatomy on the measurement uncertainty of medical CT. METHODS: Six formalin-fixed temporal bones were used, fiducial markers were bone-implanted, and 20 CT scans of each temporal bone were generated. Surgically threatened anatomical structures of importance were defined. Manual segmentation was performed to create 3D surface models, and different Gaussian filters were applied. Analysis points were established along the border of the superior semicircular canal to determine the deviation between the 3D images of the labyrinth. The standard uncertainty was calculated, and one-way analysis of variance was performed (significance level = 5%) to evaluate the effect of certain factors (patient, side, Gaussian filter) on the measurement uncertainty. RESULTS: The influence of patient-specific anatomy on the measurement uncertainty of medical CT (p = 0.049) was demonstrated for the first time. The applied Gaussian filter (p = 0.622) and the patient's side (p = 0.341) showed no significant effect. CONCLUSION: The applied method and the results of the statistical analysis suggest that the patient's individual anatomical conditions affect the measurement uncertainty of medical CT. Thus, the patient's anatomy must be considered as an important influencing factor during risk evaluation concerning minimally invasive and image-guided surgery.

Patient quality of life after vestibular schwannoma removal: possibilities and limits to measuring different domains of patients' wellbeing.

PURPOSE: Since the 1980s, health-related quality of life (HRQOL) has been recognized in the assessment of medical treatment. To determine the health-related quality of life (HRQOL) of vestibular schwannoma (VS) patients, a specific questionnaire that has been validated in different languages is essential. METHODS: The Short Form-36 Health Survey (SF-36) and PANQOL questionnaires in German were evaluated in patients after removal of a VS via the translabyrinthine approach. Descriptive statistics of a comparison of the SF-36 results to those of a normal sample are illustrated. Criterion validity was investigated using Spearman's rank test to correlate the PANQOL domains with the SF-36 domains. A confirmatory factor analysis of the PANQOL was performed to determine the stability of the factor structure of the PANQOL questionnaire for our cohort. RESULTS: The criterion validity of the German PANQOL questionnaire is comparable to that of the original English version. The SF-36 domains values ranged from 49.31/100 (role physical) to 66.46/100 (physical functioning). Compared to the normal population, patients who underwent surgical removal of a VS showed a significantly reduced quality of life, mainly in domains such as physical and social functioning, as well as psychological wellbeing. CONCLUSION: The German PANQOL has been validated and is now available. Post-surgical treatment should be focused not only on physiological rehabilitation but also on improving the quality of life, especially aspects of psychological and social wellbeing.

AluY-mediated germline deletion, duplication and somatic stem cell reversion in UBE2T defines a new subtype of Fanconi anemia.

Fanconi anemia (FA) is a rare inherited disorder clinically characterized by congenital malformations, progressive bone marrow failure and cancer susceptibility. At the cellular level, FA is associated with hypersensitivity to DNA-crosslinking genotoxins. Eight of 17 known FA genes assemble the FA E3 ligase complex, which catalyzes monoubiquitination of FANCD2 and is essential for replicative DNA crosslink repair. Here, we identify the first FA patient with biallelic germline mutations in the ubiquitin E2 conjugase UBE2T. Both mutations were aluY-mediated: a paternal deletion and maternal duplication of exons 2-6. These loss-of-function mutations in UBE2T induced a cellular phenotype similar to biallelic defects in early FA genes with the absence of FANCD2 monoubiquitination. The maternal duplication produced a mutant mRNA that could encode a functional protein but was degraded by nonsense-mediated mRNA decay. In the patient's hematopoietic stem cells, the maternal allele with the duplication of exons 2-6 spontaneously reverted to a wild-type allele by monoallelic recombination at the duplicated aluY repeat, thereby preventing bone marrow failure. Analysis of germline DNA of 814 normal individuals and 850 breast cancer patients for deletion or duplication of UBE2T exons 2-6 identified the deletion in only two controls, suggesting aluY-mediated recombinations within the UBE2T locus are rare and not associated with an increased breast cancer risk. Finally, a loss-of-function germline mutation in UBE2T was detected in a high-risk breast cancer patient with wild-type BRCA1/2. Cumulatively, we identified UBE2T as a bona fide FA gene (FANCT) that also may be a rare cancer susceptibility gene.

Wnt/ß-catenin signalling induces MLL to create epigenetic changes in salivary gland tumours.

We show that activation of Wnt/ß-catenin and attenuation of Bmp signals, by combined gain- and loss-of-function mutations of ß-catenin and Bmpr1a, respectively, results in rapidly growing, aggressive squamous cell carcinomas (SCC) in the salivary glands of mice. Tumours contain transplantable and hyperproliferative tumour propagating cells, which can be enriched by fluorescence activated cell sorting (FACS). Single mutations stimulate stem cells, but tumours are not formed. We show that ß-catenin, CBP and Mll promote self-renewal and H3K4 tri-methylation in tumour propagating cells. Blocking ß-catenin-CBP interaction with the small molecule ICG-001 and small-interfering RNAs against ß-catenin, CBP or Mll abrogate hyperproliferation and H3K4 tri-methylation, and induce differentiation of cultured tumour propagating cells into acini-like structures. ICG-001 decreases H3K4me3 at promoters of stem cell-associated genes in vitro and reduces tumour growth in vivo. Remarkably, high Wnt/ß-catenin and low Bmp signalling also characterize human salivary gland SCC and head and neck SCC in general. Our work defines mechanisms by which ß-catenin signals remodel chromatin and control induction and maintenance of tumour propagating cells. Further, it supports new strategies for the therapy of solid tumours.

Multistep translation and cultural adaptation of the Penn acoustic neuroma quality-of-life scale for German-speaking patients.

BACKGROUND: Monitoring the health-related quality of life (HRQOL) for patients with vestibular schwannoma (VS) has garnered increasing interest. In German-speaking countries, there is no disease-specific questionnaire available similar to the "Penn Acoustic Neuroma Quality-of-life Scale" (PANQOL). METHOD: We translated the PANQOL for German-speaking patients based on a multistep protocol that included not only a forward-backward translation but also linguistic and sociocultural adaptations. The process consists of translation, synthesis, back translation, review by an expert committee, administration of the prefinal version to our patients, submission and appraisal of all written documents by our research team. The required multidisciplinary team for translation comprised head and neck surgeons, language professionals (German and English), a professional translator, and bilingual participants. A total of 123 patients with VS underwent microsurgical procedures via different approaches at our clinic between January 2007 and January 2017. Among these, 72 patients who underwent the translabyrinthine approach participated in the testing of the German-translated PANQOL. RESULT: The first German version of the PANQOL questionnaire was created by a multistep translation process. The responses indicate that the questionnaire is simple to administer and applicable to our patients. CONCLUSION: The use of a multistep process to translate quality-of-life questionnaires is complex and time-consuming. However, this process was performed properly and resulted in a version of the PANQOL for assessing the quality of life of German-speaking patients with VS.

[Hearing rehabilitation with the cochlea implant following translabyrinthine CPA tumor removal ?] / Hörrehabilitation durch Cochlea-Implantation nach Vestibularisschwannom-Entfernung?

We present a quality analysis of 10 patients with an individual treatment trial for a simultaneous or consecutive cochlea implantation after translabyrinthine removal of a neurinoma at the cerebellopontine angle. The results show that most of the patients benefit from the cochlea implantation after unilateral deafness. Through a careful surgical preparation technique at the inner ear canal and its surroundings the morphological and functional integrity of the neurovascular structures can be guaranteed.

Cochlear obliteration after translabyrinthine vestibular schwannoma surgery.

The objective of the study was to determine the temporal occurrence of cochlear obliteration following translabyrinthine vestibular schwannoma resection. A retrospective chart review, cross-sectional study, and sequential analysis of the time series were performed. The retrospective study included patients undergoing translabyrinthine resection for stage T1-T2 vestibular schwannoma from 2007 to 2010 without prior therapy and postoperative follow-up including MRI of the brain and the cerebellopontine angle. Already 3 months after surgery a radiographic labyrinthine change was observed in 66.7 %, a partial obstruction in 50 %, and an obstruction limited to the saccule in 16.7 %. Only 33.3 % of the patients showed an unchanged inner ear. In consideration of early cochlear obstruction after translabyrinthine vestibular schwannoma resection, temporary follow-up is necessary. Since the indications for cochlear implantation (CI) have been extended, especially concerning patients with single-side deafness, a simultaneous or early second-stage CI after tumour removal should be discussed.

Vascularised local and free flaps in anterior skull base reconstruction.

Lesions of the anterior skull base often require sufficient closure in order to prevent cerebrospinal fluid (CSF) leak, ascending infection and/or brain tissue prolapse. The transfer of devitalized autologous, allogenic or xenogeneic material is not always sufficient particularly not in larger defects or in the recurrent situation. Here the transfer of vascularised tissue seems to be more appropriate. The anterior skull base with various complex defects of 41 patients was reconstructed in an interdisciplinary setting by vascularised, autologous tissue transfer. Minor defects (<2.5 cm in max. diameter), generally occurring after extended endoscopic skull base approaches (n = 26, among those meningiomas, recurrent CSF fistulas, chordoma, chondroblastoma, metastasis, nasal fistula), were reconstructed by a local, vascularized pedicled mucosal flap of the lower turbinate (n = 3) or septum (n = 23). Patients with major defects (>2.5 cm in max. diameter, n = 15), comprising those with malignoma, meningoencephalocele, aneurysmatic bone cyst and trauma, were repaired by a "sandwich technique" with a combination of calvarian split and galea periosteum flap in 10 patients, in one case with a temporalis muscle flap, while in 4 further patients free vascularised radial forearm flaps were used for revision after multiple unsuccessful operations elsewhere. After a mean follow-up time of 30.5 months 38 of the 41 cases were successfully repaired with respect to prevention and treatment of CSF leakage or brain tissue prolapse, only 3 cases needed surgical revision. The reconstruction of the anterior skull base bearing complex lesions is feasible using vascularised, autologous local and also distal tissue transfer in a close interdisciplinary cooperation.

Initial experiences with the Amplatzer Vascular Plug 4 for permanent occlusion of the internal carotid artery in the skull base in patients with head and neck tumors.

INTRODUCTION: As the first report in the literature, we present our initial experiences with the latest generation's Amplatzer Vascular Plug 4 (AVP4) as a device for permanent occlusion of the internal carotid artery in its course in the skull base. METHODS: Permanent occlusion of the internal carotid artery in the skull base was performed in four patients after administration of an intravenous heparin bolus (three patients preoperatively to facilitate radical surgery of head and neck tumors, one patient with a palliative intent to reduce tumor arrosion bleeding risk). RESULTS: In all patients, the deployment of the AVP4 in the artery's course in the skull base was feasible. In two patients, placement was possible in the cavernous segment of the internal carotid artery, and in the other two patients, more proximal in the artery's foramen lacerum and petrous segment, respectively. Occlusion was accomplished in one patient with one AVP4 (occlusion time 25 min), in two patients with two AVP4 (occlusion time 20 min in each case), and in one patient with one AVP4, three additional fibered coils and two Gelfoam pledgets (occlusion time more than 2 h). Complications did not occur in any of the four patients. CONCLUSION: The AVP4 may be a promising device for permanent occlusion of the internal carotid artery, allowing in its latest generation, navigability as distal as the cavernous segment in some, but not in all cases. Difficulties may still occur in very tortuous vessel anatomy.

New software for three-dimensional visualization and calculation of volume of living cells.

We investigated the physical properties of head and neck cancer cells to develop new cell-selective treatment strategies for squamous cell carcinoma. For better characterization and subsequent differentiation of cancerous and healthy cells, we developed MATLAB-based software to analyze image stacks obtained using a confocal laser-scanning microscope. A confocal laser-scanning microscope was used for three-dimensional (3-D) imaging of a cell line from the head and neck area. The volume of cell organelles of interest was calculated using our newly developed software. Our software enables 3-D visualization and volume calculation as well as data analysis associated with cell morphology. Using filter and semi-automatic segmentation algorithms, our software recognizes individual cell organelles in each slice of an image stack. It matches the corresponding cell cross section areas to produce a 3-D image and to determine the volume of the imaged organelles. We calculated the volume of the nucleus, actin filaments and microtubules in relation to total cell volume. Our software enables 3-D visualization and calculation of organelle volume, which improves cell characterization and comparison of healthy and cancerous cell lines. Differences between cell lines can be observed in detail and used to develop new cancer treatment strategies.

The checkpointkinase 2 (CHK2) 1100delC germ line mutation is not associated with the development of squamous cell carcinoma of the head and neck (SCCHN).

BACKGROUND: The checkpointkinase 2 (CHK2) is part of the highly conserved ATM-CHK2 signaling pathway, which is activated in response to DNA damage, in particular after double strand breaks which can be caused by carcinogens like smoking. After induction of downstream targets, e.g. the tumor suppressor p53, its activation leads to cell cycle arrest and apoptosis. Recently, the presence of CHK2 germ line mutations, primarily the 1100delC variant, has been reported to be involved in carcinogenesis. The CHK2 1100delC variant results in a truncated protein which is instable and inactive. Carriers of this variant have been shown to have an increased risk to develop breast cancer and probably also other tumors. Our purpose was to investigate the role of CHK2 germ line mutations in patients with squamous cell carcinoma of the head and neck (SCCHN). MATERIALS AND METHODS: We investigated 91 patients suffering from SCCHN including all tumor sites (oropharynx, hypopharynx, larynx) for the presence of the germ line mutation 1100delC by direct sequence analysis. Patients were characterized by their tumor localization, tumor stage, age, the presence of additional malignant tumors and predisposing carcinogens (smoking, alcohol abuse). RESULTS: None of the patients, independently of the tumor site, age, the abuse of predisposing carcinogens, or the presence of other kinds of tumors, carried the CHK2 1100delC variant. CONCLUSIONS: The germ line CHK2 1100delC variant does not seem to have a major impact on the development of SCCHN.

Materials and techniques for osseous skull reconstruction.

This review paper gives an overview and summarizes the different methods of cranioplasty for reconstruction of the bony skull. There are various origins of cranial defects including trauma, tumours, congenital deformities or postoperative defects due to the surgical procedure itself. The overall goal of skull reconstruction is, on the one hand, appropriate closure, and on the other hand, the perfect cosmetic result. The cranioplasty should be safe, fast and easy to handle. Cost-effectiveness of the procedure represents a further important point. To solve these complex and multimodal problems, different techniques and also various materials for the reconstruction are available. This report details the usual procedures for skull reconstruction, as well as the advantages and limitations of the different materials and operative strategies.

Retrospective in silico evaluation of optimized preoperative planning for temporal bone surgery.

PURPOSE: Robot-assisted surgery at the temporal bone utilizing a flexible drilling unit would allow safer access to clinical targets such as the cochlea or the internal auditory canal by navigating along nonlinear trajectories. One key sub-step for clinical realization of such a procedure is automated preoperative surgical planning that incorporates both segmentation of risk structures and optimized trajectory planning. METHODS: We automatically segment risk structures using 3D U-Nets with probabilistic active shape models. For nonlinear trajectory planning, we adapt bidirectional rapidly exploring random trees on Bézier Splines followed by sequential convex optimization. Functional evaluation, assessing segmentation quality based on the subsequent trajectory planning step, shows the suitability of our novel segmentation approach for this two-step preoperative pipeline. RESULTS: Based on 24 data sets of the temporal bone, we perform a functional evaluation of preoperative surgical planning. Our experiments show that the automated segmentation provides safe and coherent surface models that can be used in collision detection during motion planning. The source code of the algorithms will be made publicly available. CONCLUSION: Optimized trajectory planning based on shape regularized segmentation leads to safe access canals for temporal bone surgery. Functional evaluation shows the promising results for both 3D U-Net and Bézier Spline trajectories.

i3PosNet: instrument pose estimation from X-ray in temporal bone surgery.

PURPOSE: Accurate estimation of the position and orientation (pose) of surgical instruments is crucial for delicate minimally invasive temporal bone surgery. Current techniques lack in accuracy and/or line-of-sight constraints (conventional tracking systems) or expose the patient to prohibitive ionizing radiation (intra-operative CT). A possible solution is to capture the instrument with a c-arm at irregular intervals and recover the pose from the image. METHODS: i3PosNet infers the position and orientation of instruments from images using a pose estimation network. Said framework considers localized patches and outputs pseudo-landmarks. The pose is reconstructed from pseudo-landmarks by geometric considerations. RESULTS: We show i3PosNet reaches errors [Formula: see text] mm. It outperforms conventional image registration-based approaches reducing average and maximum errors by at least two thirds. i3PosNet trained on synthetic images generalizes to real X-rays without any further adaptation. CONCLUSION: The translation of deep learning-based methods to surgical applications is difficult, because large representative datasets for training and testing are not available. This work empirically shows sub-millimeter pose estimation trained solely based on synthetic training data.