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OBJECTIVES: The inter-phase gap (IPG) offset effect is defined as the dB offset between the linear parts of electrically evoked compound action potential (ECAP) amplitude growth functions for two stimuli differing only in IPG. The method was recently suggested to represent neural health in cochlear implant (CI) users while being unaffected by CI electrode impedances. Hereby, a larger IPG offset effect should reflect better neural health. The aims of the present study were to (1) examine whether the IPG offset effect negatively correlates with the ECAP threshold and the preoperative pure-tone average (PTA) in CI recipients with residual acoustic hearing and (2) investigate the dependency of the IPG offset effect on hair cell survival and intracochlear electrode impedances. DESIGN: Seventeen adult study participants with residual acoustic hearing at 500 Hz undergoing CI surgery at the University Hospital of Zurich were prospectively enrolled. ECAP thresholds, IPG offset effects, electrocochleography (ECochG) responses to 500 Hz tone bursts, and monopolar electrical impedances were obtained at an apical, middle, and basal electrode set during and between 4 and 12 weeks after CI surgery. Pure-tone audiometry was conducted within 3 weeks before surgery and approximately 6 weeks after surgery. Linear mixed regression analyses and t tests were performed to assess relationships between (changes in) ECAP threshold, IPG offset, impedance, PTA, and ECochG amplitude. RESULTS: The IPG offset effect positively correlated with the ECAP threshold in intraoperative recordings (p < 0.001) and did not significantly correlate with the preoperative PTA (p = 0.999). The IPG offset showed a postoperative decrease for electrode sets that showed an ECochG amplitude drop. This IPG offset decrease was significantly larger than for electrode sets that showed no ECochG amplitude decrease, t(17) = 2.76, p = 0.014. Linear mixed regression analysis showed no systematic effect of electrode impedance changes on the IPG offset effect (p = 0.263) but suggested a participant-dependent effect of electrode impedance on IPG offset. CONCLUSIONS: The present study results did not reveal the expected relationships between the IPG offset effect and ECAP threshold values or between the IPG offset effect and preoperative acoustic hearing. Changes in electrode impedance did not exhibit a direct impact on the IPG offset effect, although this impact might be individualized among CI recipients. Overall, our findings suggest that the interpretation and application of the IPG offset effect in clinical settings should be approached with caution considering its complex relationships with other cochlear and neural health metrics.
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BACKGROUND: To investigate the association between erectile dysfunction (ED) as well as epistaxis (ES) in relation to the extent of iliac atherosclerosis. METHODS: In this retrospective cross-sectional study, all consecutive male patients treated at our institution from 01/2016 to 12/2020 undergoing abdominal CT scan were evaluated. Patients (n = 1272) were invited by mail to participate in the study in returning two questionnaires for the evaluation of ED (IIEF-5) and ES. Patients who returned filled-in questionnaires within a 3-month deadline were included in the study. The extent of atherosclerosis in the common iliac artery (CIA) and the internal iliac artery (IIA) was assessed by calcium scoring on unenhanced CT. Stratification of results was performed according to reported IIEF-5 scores and consequential ED groups. RESULTS: In total, 437 patients (34.4% of contacted) met the inclusion criteria. Forty-two patients did not fulfill predefined age requirements (< 75 years) and 120 patients had to be excluded as calcium scoring on nonenhanced CT was not feasible. Finally, 275 patients were included in the analysis and stratified into groups of "no-mild" (n = 146) and "moderate-severe" (n = 129) ED. The calcium score (r=-0.28, p < 0.001) and the number of atherosclerotic lesions (r=-0.32, p < 0.001) in the CIA + IIA showed a significant negative correlation to the IIEF-5 score, respectively. Patients differed significantly in CIA + IIA calcium score (difference: 167.4, p < 0.001) and number of atherosclerotic lesions (difference: 5.00, p < 0.001) when belonging to the "no-mild" vs. "moderate-severe" ED group, respectively. A multivariable regression model, after adjusting for relevant baseline characteristics, showed that the number of atherosclerotic CIA + IIA lesions was an independent predictor of ED (OR = 1.05, p = 0.036), whereas CIA + IIA calcium score was not (OR = 1.00031, p = 0.20). No relevant correlation was found between ES episodes and IIEF-5 scores (r=-0.069, p = 0.25), CIA + IIA calcium score (r=-0.10, p = 0.87) or number of atherosclerotic CIA + IIA lesions (r=-0.032, p = 0.60), respectively. CONCLUSIONS: The number of atherosclerotic lesions in the iliac arteries on nonenhanced abdominal CT scans is associated with the severity of ED. This may be used to identify subclinical cardiovascular disease and to quantify the risk for cardiovascular hazards in the future. TRIAL REGISTRATION: BASEC-Nr. 2020 - 01637.
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Aterosclerose , Disfunção Erétil , Humanos , Masculino , Idoso , Disfunção Erétil/diagnóstico por imagem , Disfunção Erétil/complicações , Artéria Ilíaca/diagnóstico por imagem , Estudos Retrospectivos , Cálcio , Estudos Transversais , Epistaxe/complicações , Aterosclerose/complicações , Aterosclerose/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Diffusion MRI (dMRI) tractography has been successfully used to study the trigeminal nerves (TGNs) in many clinical and research applications. Currently, identification of the TGN in tractography data requires expert nerve selection using manually drawn regions of interest (ROIs), which is prone to inter-observer variability, time-consuming and carries high clinical and labor costs. To overcome these issues, we propose to create a novel anatomically curated TGN tractography atlas that enables automated identification of the TGN from dMRI tractography. In this paper, we first illustrate the creation of a trigeminal tractography atlas. Leveraging a well-established computational pipeline and expert neuroanatomical knowledge, we generate a data-driven TGN fiber clustering atlas using tractography data from 50 subjects from the Human Connectome Project. Then, we demonstrate the application of the proposed atlas for automated TGN identification in new subjects, without relying on expert ROI placement. Quantitative and visual experiments are performed with comparison to expert TGN identification using dMRI data from two different acquisition sites. We show highly comparable results between the automatically and manually identified TGNs in terms of spatial overlap and visualization, while our proposed method has several advantages. First, our method performs automated TGN identification, and thus it provides an efficient tool to reduce expert labor costs and inter-operator bias relative to expert manual selection. Second, our method is robust to potential imaging artifacts and/or noise that can prevent successful manual ROI placement for TGN selection and hence yields a higher successful TGN identification rate.
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Conectoma/métodos , Imagem de Tensor de Difusão/métodos , Nervo Trigêmeo/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Bases de Dados Factuais , HumanosRESUMO
OBJECTIVES: To translate and validate the Zurich Chronic Middle Ear Inventory (ZCMEI-21) for the English language in order to provide an English instrument to assess health-related quality of life in chronic otitis media (COM). DESIGN: Pilot translation study including cognitive debriefings, prospective multicentre cross-sectional psychometric validation study. SETTING: Four tertiary referral centres in three different English-speaking countries (UK, USA and Australia). PARTICIPANTS: Adult patients suffering from COM. MAIN OUTCOME MEASURES: The English translation of the ZCMEI-21 (ZCMEI-21-E) and the five-level version of the EQ-5D questionnaire. The EQ-5D, which constitutes a generic measure of health-related quality of life, consists of a descriptive system score and a visual analogue scale. Statistical outcomes included single-item descriptive statistics, internal consistency (Cronbach's α) as an indicator of reliability, as well as construct validity. RESULTS: A total of 124 patients suffering from COM were included. The mean age was 50.1 years (SD 16.9 years), and 72 (58.1%) were males. The Cronbach's α of the ZCMEI-21-E was 0.91, suggesting an excellent internal consistency. The Spearman's correlation coefficient of the ZCMEI-21-E total score was 0.55 (P < 0.0001) for convergent construct validity with EQ-5D descriptive system score and 0.57 (P < 0.0001) with the EQ-5D visual analogue scale. CONCLUSIONS: The ZCMEI-21-E is a new validated questionnaire that provides clinicians with a short, comprehensive and reliable instrument to quantify health-related quality of life in patients suffering from COM. The ZCMEI-21-E may be of use in clinical routine as well as in outcome research and monitoring.
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Idioma , Otite Média/psicologia , Psicometria/métodos , Qualidade de Vida , Traduções , Doença Crônica , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
Cerebrospinal fluid (CSF) biomarkers might be useful in predicting outcome after aneurysmal subarachnoid hemorrhage (aSAH). It was the aim to determine whether tau and amyloid beta CSF concentrations predict functional, health-related quality of life (hrQoL), and neuropsychological outcomes after aSAH. Ventricular CSF was obtained from n = 24 aSAH patients at admission (D0), day 2 (D2), and day 6 (D6). CSF total (t)Tau, phosphorylated (p)Tau(181P), and amyloid beta(1-40 and 1-42) (Aß40/Aß42) levels were compared between patients with favorable and unfavorable functional (modified Rankin Scale (mRS)), hrQoL (Euro-Qol (EQ-5D)), and neuropsychological outcomes at 3 (3 m) and 12 months (12 m). Patients with unfavorable functional (mRS 4-6) and hrQoL outcome (EQ-5D z-score ≤ - 1.0) at 3 and 12 m had higher CSF tTau/pTau and lower Aß40/Aß42 at D0, D2, and D6 with varying degrees of statistical significance. In terms of predicting neuropsychological outcome, CSF pTau showed a statistically significant correlation with the z-scores of executive function (r = - 0.7486, p = 0.008), verbal memory (r = - 0.8101, p = 0.002), attention (r = - 0.6498, p = 0.030), and visuospatial functioning (r = - 0.6944, p = 0.017) at 3 m. At 12 m, CSF pTau had statistically significant correlations with the z-scores of verbal memory (r = - 0.7473, p = 0.008) and visuospatial functioning (r = - 0.6678, p = 0.024). In conclusion, higher tTau/pTau and lower Aß40/Aß42 CSF levels predict unfavorable long-term functional and hrQoL outcomes. Neuropsychological deficits correlate with increased CSF tTau and pTau concentrations.
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Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Qualidade de Vida , Hemorragia Subaracnóidea/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos , Valor Preditivo dos Testes , Recuperação de Função Fisiológica , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/psicologia , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: A large number of reports have not been able to clarify the pathophysiology of Terson syndrome (TS) in aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Prospective single-center study on aSAH patients. Fundoscopic and radiological signs of TS were assessed. The opening intracranial pressure (ICP) in patients who required a ventriculostomy was recorded with a manometer. RESULTS: Six out of 36 included patients had TS (16.7 %), which was associated with unfavorable admission scores. Twenty-nine patients (80.5 %) required ventriculostomy; TS was associated with higher ICP (median, 40 vs. 15 cm cmH2O, p = .003); all patients with TS had pathological ICP values of >20 cmH2O. Patients with a ruptured aneurysm of the anterior cerebral artery complex were ten times as likely to suffer from TS (OR 10.0, 95 % CI 1.03-97.50). Detection of TS on CT had a sensitivity of 50 %, a specificity of 98.4 %, a positive predictive value of 83.3 %, and a negative predictive value of 92.4 %. Mortality was 45 times as high in patients with TS (OR 45.0, 95 % CI 3.86-524.7) and neurologic morbidity up until 3 months post-aSAH was significantly higher in patients with TS (mRS 4-6; 100 vs. 17 %; p = .001). CONCLUSIONS: Our findings demonstrate an association between raised ICP and the incidence of TS. TS should be ruled out in aSAH patients presenting comatose or with raised ICP to ensure upfront ophthalmological follow-up. In alert patients without visual complaints and a TS-negative CT scan, the likelihood for the presence of TS is very low.
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Pressão Intracraniana , Hemorragia Subaracnóidea/complicações , Hemorragia Vítrea/etiologia , Adulto , Idoso , Aneurisma Roto/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hemorragia Subaracnóidea/diagnóstico , Hemorragia Vítrea/diagnóstico , Hemorragia Vítrea/epidemiologiaRESUMO
OBJECTIVES: Predicting the course of cranial nerve (CN) VII in the cerebellopontine angle (CPA) on preoperative imaging for vestibular schwannoma (VS) may help guide surgical resection and reduce complications. Diffusion MRI based tractography has been used to identify cranial nerve trajectory, but intraoperative validation of this novel approach is challenging. Currently, validation is based on operative report descriptions of the course of cranial nerves, but yields a simplified picture of the three-dimensional (3D) course of CN VII. In this study, we investigate the accuracy of tractography with detailed patient-specific 3D-printed VS tumors. DESIGN: Retrospective case review. SETTING: Tertiary referral center. PARTICIPANTS: Twenty adult VS surgical candidates. MAIN OUTCOME MEASURES: We compared tractography with intraoperative 3D course of CN VII. The surgeons were blinded to tractography and drew the intraoperative course of the CN VII on a patient specific 3D-printed tumor model for detailed comparison with tractography. RESULTS: Of 20 patients, one was excluded due to subtotal removal and inability to assess CN VII course. In the remaining 19 patients, 84% (16/19) tractography was successful. In 94% of tumors with tractography (15/16), the intraoperative description of CN VII course matched the tractography finding. The maximum distance, however, between tractography and intraoperative course of CN VII was 3.7âmmâ±â4.2âmm. CONCLUSION: This study presents a novel approach to CN VII tractography validation in VS. Although descriptions of CN VII intraoperatively match tractography, caution is warranted as quantitative measures suggest a clinically significant distance between tractography and CN VII course.
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Neuroma Acústico , Adulto , Nervos Cranianos , Imagem de Tensor de Difusão , Nervo Facial/diagnóstico por imagem , Nervo Facial/cirurgia , Humanos , Neuroma Acústico/diagnóstico por imagem , Neuroma Acústico/cirurgia , Estudos RetrospectivosRESUMO
Objective The auditory brain stem implant (ABI) is a neuroprosthesis placed on the surface of the cochlear nucleus (CN) to provide hearing sensations in children and adults who are not candidates for cochlear implantation. Contemporary ABI arrays are stiff and do not conform to the curved brain stem surface. Recent advancements in microfabrication techniques have enabled the development of flexible surface arrays, but these have only been applied in animal models. Herein, we measure the surface curvature of the human CN and adjoining regions to assist in the design and placement of next-generation conformable clinical ABI arrays. Three-dimensional (3D) reconstructions from ultrahigh T1-weighted brain magnetic resonance imaging (MRI) sequences and histologic reconstructions based on postmortem adult human brain stem specimens were used. Design This is a retrospective review of radiologic data and postmortem histologic axial sections. Setting This is set at the tertiary referral center. Participants Data were acquired from healthy adults. Main Outcome Measures The main outcome measures are principal curvature values (Kmin and Kmax) and global radius of curvature. Results The CN was successfully extracted and rendered as a 3D surface in all cases. Significant curvatures of the CN in both histologic and radiographic reconstructions were found with global radius of curvature ranging from 2.08 to 8.5 mm. In addition, local curvature analysis revealed that the surface is highly complex. Conclusion Detailed rendering of the human CN is feasible using histology and 3D MRI reconstruction and highlights complex surface topography that is not recapitulated by contemporary stiff ABI arrays.
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OBJECTIVE: The cochlear nucleus (CN) is the target of the auditory brainstem implant (ABI). Most ABI candidates have Neurofibromatosis Type 2 (NF2) and distorted brainstem anatomy from bilateral vestibular schwannomas. The CN is difficult to characterize as routine structural MRI does not resolve detailed anatomy. We hypothesize that diffusion tensor imaging (DTI) enables both in vivo localization and quantitative measurements of CN morphology. STUDY DESIGN: We analyzed 7 Tesla (T) DTI images of 100 subjects (200 CN) and relevant anatomic structures using an MRI brainstem atlas with submillimetric (50âµm) resolution. SETTING: Tertiary referral center. PATIENTS: Young healthy normal hearing adults. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Diffusion scalar measures such as fractional anisotropy (FA), mean diffusivity (MD), mode of anisotropy (Mode), principal eigenvectors of the CN, and the adjacent inferior cerebellar peduncle (ICP). RESULTS: The CN had a lamellar structure and ventral-dorsal fiber orientation and could be localized lateral to the inferior cerebellar peduncle (ICP). This fiber orientation was orthogonal to tracts of the adjacent ICP where the fibers run mainly caudal-rostrally. The CN had lower FA compared to the medial aspect of the ICP (0.44â±â0.09 vs. 0.64â±â0.08, pâ<â0.001). CONCLUSIONS: 7T DTI enables characterization of human CN morphology and neuronal substructure. An ABI array insertion vector directed more caudally would better correspond to the main fiber axis of CN. State-of-the-art DTI has implications for ABI preoperative planning and future image guidance-assisted placement of the electrode array.
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Implantes Auditivos de Tronco Encefálico , Núcleo Coclear , Substância Branca , Adulto , Anisotropia , Imagem de Tensor de Difusão , HumanosRESUMO
BACKGROUND: The trigeminal nerve (TGN) is the largest cranial nerve and can be involved in multiple inflammatory, compressive, ischemic or other pathologies. Currently, imaging-based approaches to identify the TGN mostly rely on T2-weighted magnetic resonance imaging (MRI), which provides localization of the cisternal portion of the TGN where the contrast between nerve and cerebrospinal fluid (CSF) is high enough to allow differentiation. The course of the TGN within the brainstem as well as anterior to the cisternal portion, however, is more difficult to display on traditional imaging sequences. An advanced imaging technique, diffusion MRI (dMRI), enables tracking of the trajectory of TGN fibers and has the potential to visualize anatomical regions of the TGN not seen on T2-weighted imaging. This may allow a more comprehensive assessment of the nerve in the context of pathology. To date, most work in TGN tracking has used clinical dMRI acquisitions with a b-value of 1000 s/mm2 and conventional diffusion tensor MRI (DTI) tractography methods. Though higher b-value acquisitions and multi-tensor tractography methods are known to be beneficial for tracking brain white matter fiber tracts, there have been no studies conducted to evaluate the performance of these advanced approaches on nerve tracking of the TGN, in particular on tracking different anatomical regions of the TGN. OBJECTIVE: We compare TGN tracking performance using dMRI data with different b-values, in combination with both single- and multi-tensor tractography methods. Our goal is to assess the advantages and limitations of these different strategies for identifying the anatomical regions of the TGN. METHODS: We proposed seven anatomical rating criteria including true and false positive structures, and we performed an expert rating study of over 1000 TGN visualizations, as follows. We tracked the TGN using high-quality dMRI data from 100 healthy adult subjects from the Human Connectome Project (HCP). TGN tracking performance was compared across dMRI acquisitions with b = 1000 s/mm2, b = 2000 s/mm2 and b = 3000 s/mm2, using single-tensor (1T) and two-tensor (2T) unscented Kalman filter (UKF) tractography. This resulted in a total of six tracking strategies. The TGN was identified using an anatomical region-of-interest (ROI) selection approach. First, in a subset of the dataset we identified ROIs that provided good TGN tracking performance across all tracking strategies. Using these ROIs, the TGN was then tracked in all subjects using the six tracking strategies. An expert rater (GX) visually assessed and scored each TGN based on seven anatomical judgment criteria. These criteria included the presence of multiple expected anatomical segments of the TGN (true positive structures), specifically branch-like structures, cisternal portion, mesencephalic trigeminal tract, and spinal cord tract of the TGN. False positive criteria included the presence of any fibers entering the temporal lobe, the inferior cerebellar peduncle, or the middle cerebellar peduncle. Expert rating scores were analyzed to compare TGN tracking performance across the six tracking strategies. Intra- and inter-rater validation was performed to assess the reliability of the expert TGN rating result. RESULTS: The TGN was selected using two anatomical ROIs (Meckel's Cave and cisternal portion of the TGN). The two-tensor tractography method had significantly better performance on identifying true positive structures, while generating more false positive streamlines in comparison to the single-tensor tractography method. TGN tracking performance was significantly different across the three b-values for almost all structures studied. Tracking performance was reported in terms of the percentage of subjects achieving each anatomical rating criterion. Tracking of the cisternal portion and branching structure of the TGN was generally successful, with the highest performance of over 98% using two-tensor tractography and b = 1000 or b = 2000. However, tracking the smaller mesencephalic and spinal cord tracts of the TGN was quite challenging (highest performance of 37.5% and 57.07%, using two-tensor tractography with b = 1000 and b = 2000, respectively). False positive connections to the temporal lobe (over 38% of subjects for all strategies) and cerebellar peduncles (100% of subjects for all strategies) were prevalent. High joint probability of agreement was obtained in the inter-rater (on average 83%) and intra-rater validation (on average 90%), showing a highly reliable expert rating result. CONCLUSIONS: Overall, the results of the study suggest that researchers and clinicians may benefit from tailoring their acquisition and tracking methodology to the specific anatomical portion of the TGN that is of the greatest interest. For example, tracking of branching structures and TGN-T2 overlap can be best achieved with a two-tensor model and an acquisition using b = 1000 or b = 2000. In general, b = 1000 and b = 2000 acquisitions provided the best-rated tracking results. Further research is needed to improve both sensitivity and specificity of the depiction of the TGN anatomy using dMRI.
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Encéfalo/anatomia & histologia , Imagem de Tensor de Difusão/métodos , Interpretação de Imagem Assistida por Computador/métodos , Nervo Trigêmeo/anatomia & histologia , Adulto , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão/normas , Humanos , Interpretação de Imagem Assistida por Computador/normas , Nervo Trigêmeo/diagnóstico por imagemRESUMO
OBJECTIVE: The etiology of symptoms following primary repair of superior canal dehiscence (SCD) may be due to a persistent third window. However, the extent of surgery cannot be seen on postoperative computed tomography (CT) since most repair materials are not radiopaque. We hypothesize that the extent of superior semicircular canal (SSC) occlusion following primary repair can be quantified based on postoperative magnetic resonance imaging (MRI) data. STUDY DESIGN: Retrospective series. SETTING: Tertiary care center. PATIENTS: Adult patients with a history of SCD syndrome who 1) report persistent symptoms following primary SCD repair and 2) underwent heavily T2-weighted MRI postoperatively. INTERVENTIONS: Analysis of SSC using 3D-reconstruction of CT co-registered with MRI data. MAIN OUTCOME MEASURES: Arc length of fluid void on MRI and quantification of persistent SCD based on CT/MRI co-registration. RESULTS: We identified 9 revision cases from a cohort of 145 SCD repairs at our institution (2002-2017) with CT/MRI data. A fluid void on postoperative MRI (indicating occlusion of the SSC) was observed in all cases (anterior limb: 50.1 degrees [±21.8 SD] and posterior limb 48.1 degrees [±28.5 SD]). Co-registration of CT/MRI revealed a residual defect that was most commonly found along the posterior limb in most patients with persistent symptoms. CONCLUSIONS: The extent of SCD repair can be determined using reformatted or direct T2-weighted MRI sequences in the plane of Pöschl. Co-registration of CT/MRI may be useful to determine the location of a residual superior canal defect and when present was found most commonly along the posterior limb.
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Doenças do Labirinto/diagnóstico por imagem , Canais Semicirculares/diagnóstico por imagem , Feminino , Humanos , Doenças do Labirinto/patologia , Doenças do Labirinto/cirurgia , Imageamento por Ressonância Magnética , Masculino , Período Pós-Operatório , Estudos Retrospectivos , Canais Semicirculares/patologia , Canais Semicirculares/cirurgia , Tomografia Computadorizada por Raios X , Falha de TratamentoRESUMO
Objectives Predicting the course of cranial nerves (CNs) VII and VIII in the cerebellopontine angle on preoperative imaging for vestibular schwannoma (VS) may help guide surgical resection and reduce complications. Diffusion magnetic resonance imaging dMRI is commonly used for this purpose, but is limited by its resolution. We investigate the use of super-resolution reconstruction (SRR), where several different dMRIs are combined into one dataset. We hypothesize that SRR improves the visualization of the CN VII and VIII. Design Retrospective case review. Setting Tertiary referral center. SRR was performed on the basis of axial and parasagittal single-shot epiplanar diffusion tensor imaging on a 3.0-tesla MRI scanner. Participants Seventeen adult patients with suspected neoplasms of the lateral skull base. Main Outcome Measures We assessed separability of the two distinct nerves on fractional anisotropy (FA) maps, the tractography of the nerves through the cerebrospinal fluid (CSF), and FA in the CSF as a measure of noise. Results SRR increases separability of the CN VII and VIII (16/17 vs. 0/17, p = 0.008). Mean FA of CSF surrounding the nerves is significantly lower in SRRs (0.07 ± 0.02 vs. 0.13 ± 0.03 [axial images]/0.14 ± 0.05 [parasagittal images], p = 0.00003/ p = 0.00005). Combined scanning times (parasagittal and axial) used for SRR were shorter (8 minute 25 seconds) than a comparable high-resolution scan (15 minute 17 seconds). Conclusion SRR improves the resolution of CN VII and VIII. The technique can be readily applied in the clinical setting, improving surgical counseling and planning in patients with VS.
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Auditory brainstem implants (ABIs) provide sound awareness to deaf individuals who are not candidates for the cochlear implant. The ABI electrode array rests on the surface of the cochlear nucleus (CN) in the brainstem and delivers multichannel electrical stimulation. The complex anatomy and physiology of the CN, together with poor spatial selectivity of electrical stimulation and inherent stiffness of contemporary multichannel arrays, leads to only modest auditory outcomes among ABI users. Here, we hypothesized that a soft ABI could enhance biomechanical compatibility with the curved CN surface. We developed implantable ABIs that are compatible with surgical handling, conform to the curvature of the CN after placement, and deliver efficient electrical stimulation. The soft ABI array design relies on precise microstructuring of plastic-metal-plastic multilayers to enable mechanical compliance, patterning, and electrical function. We fabricated soft ABIs to the scale of mouse and human CN and validated them in vitro. Experiments in mice demonstrated that these implants reliably evoked auditory neural activity over 1 month in vivo. Evaluation in human cadaveric models confirmed compatibility after insertion using an endoscopic-assisted craniotomy surgery, ease of array positioning, and robustness and reliability of the soft electrodes. This neurotechnology offers an opportunity to treat deafness in patients who are not candidates for the cochlear implant, and the design and manufacturing principles are broadly applicable to implantable soft bioelectronics throughout the central and peripheral nervous system.
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Implantes Auditivos de Tronco Encefálico , Animais , Implantes Cocleares , Núcleo Coclear , Surdez/terapia , Estimulação Elétrica , Humanos , CamundongosRESUMO
Objective We compare the open and transnasal approaches for the excision of juvenile nasopharyngeal angiofibromas regarding the rate of morbidity, and residual tumor and its symptomatic recurrence over time. In addition, we present volumetric measurements of juvenile nasopharyngeal angiofibromas over time. Methods All surgically treated patients of our institution were reviewed back to 1969 for type of surgery, residual tumor by magnetic resonance imaging (MRI)-based volumetry, recurrence, and morbidity. We performed a prospective clinical and radiological follow-up on reachable patients. Results In total, 40 patients were retrievable from our records. We were able to follow up on 13 patients after a mean of 15.7 years since surgery (range: 1-47 years). Patients operated by the open approach had a higher rate of postoperative complications and thus a higher morbidity than endoscopic patients (4/4 vs 3/9; p = 0.007), although tumor sizes were equal among groups ( p = 0.12). Persisting tumor was noted in 3/4 and 4/9 ( p = 0.56) patients, respectively. The corresponding mean volumes of residual tumors were 16.2 ± 14.4 cm 3 and 10.8 ± 6.6 cm 3 ( p = 0.27). No progression could be noted in endoscopically treated patients ( p = 0.24, mean time between scans 2 years). Conclusions Our analysis shows that the endoscopic approach results in less morbidity. The open approach does not guarantee freedom from persisting tumor tissue. Age seems to be a most important risk factor for the conversion of an asymptomatic persistence into a symptomatic recurrence.
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OBJECTIVE: To assess the consequences of aneurysmal subarachnoid hemorrhage (aSAH) on sexual pleasure in patients with an otherwise favorable neurologic outcome. METHODS: Anonymous, standardized questionnaires concerning sexual function, including the International Index of Erectile Function (IIEF), Female Sexual Function Index (FSFI), and a statement on subjective change in sexual pleasure after aSAH, were completed by 33 patients treated at the Cantonal Hospital St Gallen between 2005 and 2013. All had favorable neurologic outcomes (Glasgow Outcome Scale score 4 or 5). RESULTS: Ten patients (31.3%) reported a subjective worsening of sexual pleasure after aSAH. Sexual dysfunction according to FSFI criteria affected 9 of the 19 female patients (47.4%). All 19 women had a hypoactive sexual desire disorder. Erectile dysfunction was present in 7 of the 14 male patients (50%). Patients with World Federation of Neurosurgical Societies (WFNS) grade 2 aSAH were significantly more likely to report a subjective worsening of sexual experience after hemorrhage than those with WFNS grade 1. CONCLUSIONS: This is the first known evaluation of sexual health following aSAH with otherwise favorable neurologic outcomes, and confirms that sexual dysfunction is common in this population. Sexual health should be explored during follow-up with these patients.
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Disfunções Sexuais Fisiológicas/epidemiologia , Disfunções Sexuais Fisiológicas/etiologia , Hemorragia Subaracnóidea/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Septal perforation closure is still often invasive and complex, with relatively low closure rates. OBJECTIVES: We aimed to provide the first results of a case series of 20 patients with nasal septal perforations who underwent septal perforation repair by both an open and a minimally invasive technique by using a graft that consisted of temporoparietal fascia and a polydioxanone (PDS) plate without mucosal flaps. Between 2014 and 2016, we tested, for the first time, the feasibility of the insertion of this graft via a hemitransfixion incision at our institution. The rationale for the closed approach was to avoid any visible nasal scars. We reported our results of both approaches. METHODS: The septal perforations were closed by insertion of a graft, which consisted of a 0.25-mm PDS flexible plate enveloped by temporoparietal fascia, into the perforation. The insertion of the graft was performed either via a columellar incision (open approach) or via a cosmetically advantageous hemitransfixion incision (closed approach) in an underlay technique. No attempts were made to close the perforation by mucosal flap rotation and/or advancement. Protective silastic sheeting to both sides of the perforation provided fixation to the graft while natural mucosal healing occurred over the perforation in the course of 3 to 8 weeks. RESULTS: Eighteen of 20 perforations were closed by mucosa at the last follow-up. The mean follow-up was 8.7 months. Thirteen patients had surgery via the closed approach. CONCLUSION: We showed, for the first time, that the insertion of a graft that consisted of a PDS flexible plate enveloped in temporoparietal fascia via a hemitransfixion incision was feasible and resulted in complete mucosal closure of nasal septal perforations in most patients. By performing the hemitransfixion incision, we avoided any visible nasal scars.