Cochlear implantation in single-sided deafness: a single-center experience of 138 cases

OBJECTIVES

Assess the outcomes in patients who underwent cochlear implant (CI) for single-sided deafness (SSD).

METHODS

All patients affected by SSD who underwent CI at Gruppo Otologico, Piacenza, from October 2012 to May 2022 with at least 6 months of follow-up were selected in the study group. The analysis included subjective and objective measures performed pre-operative and up to 24 months after surgery. Hearing threshold on both sides was evaluated with a weighted four-frequency average (PTA [0.5 kHz + 1 kHz + 2 kHz + 4 kHz]/4) on pure tone audiometry and speech audiometry (Speech Discrimination Score, SDS). The Speech Spatial and Qualities of Hearing scale (SSQ Questionnaire) for binaural hearing benefits and sound localization, the Tinnitus Handicap Inventory Questionnaire (THI) and Dizziness Handicap Inventory Questionnaire (DHI) were used for subjective assessment.

RESULTS

Data from 138 patients, 69 males and 69 females, (mean age 49 years, range 17-77 years) underwent CI for SSD were examined. Single-sided hearing deprivation average before undergoing CI surgery was 2.5 years (range 3 months-35 years). There was a significant reduction of THI and DHI scores compared to pre-operative scores alongside a referred improvement in social, physical, and emotional well-being through the SSQ questionnaire.

CONCLUSIONS

To the best of our knowledge, this paper descried the largest cohort of SSD who underwent CI in a single institution. According to our findings CI in patients affected by SSD represents a valuable tool for an overall improvement of tinnitus and dizziness but also quality of life, after at least 6 months of follow-up. Further studies are desirable to improve rehabilitation pathways and possibly set new standards of care of this condition.

Genome-wide association meta-analyses combining multiple risk phenotypes provide insights into the genetic architecture of cutaneous melanoma susceptibility

Most genetic susceptibility to cutaneous melanoma remains to be discovered. Meta-analysis genome-wide association study (GWAS) of 36,760 cases of melanoma (67% newly genotyped) and 375,188 controls identified 54 significant (P < 5 × 10-8) loci with 68 independent single nucleotide polymorphisms. Analysis of risk estimates across geographical regions and host factors suggests the acral melanoma subtype is uniquely unrelated to pigmentation. Combining this meta-analysis with GWAS of nevus count and hair color, and transcriptome association approaches, uncovered 31 potential secondary loci for a total of 85 cutaneous melanoma susceptibility loci. These findings provide insights into cutaneous melanoma genetic architecture, reinforcing the importance of nevogenesis, pigmentation and telomere maintenance, together with identifying potential new pathways for cutaneous melanoma pathogenesis.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Filament identification in wide-angle high speed imaging of the mega amp spherical tokamak

A new tomographic inversion technique is presented for the identification of plasma filaments in wide-angle visible camera data. The technique works on the assumption that background subtracted images of filaments can be represented as a superposition of uniformly emitting magnetic equilibrium field lines. A large collection of equilibrium magnetic field lines is traced and projected onto the camera field of view and combined to form a geometry matrix describing the coordinate transformation from magnetic field aligned coordinates to image pixel coordinates. Inverting this matrix enables the reprojection of the emission in the camera images onto a field aligned basis, from which filaments are readily identifiable. The inversion is a poorly conditioned problem which is overcome using a least-squares approach with Laplacian regularization. Blobs are identified using the "watershed" algorithm and 2D Gaussians are fitted to get the positions, widths, and amplitudes of the filaments. A synthetic camera diagnostic generating images containing experimentally representative filaments is utilized to rigorously benchmark the accuracy and reliability of the technique. 74% of synthetic filaments above the detection amplitude threshold are successfully detected, with 98.8% of detected filaments being true positives. The accuracy with which filament properties and their probability density functions are recovered is discussed, along with sources of error and methods to minimize them.

Body site-specific genetic effects influence naevus count distribution in women

Body site is highly relevant for melanoma: it affects prognosis and varies according to the patient's sex. The distribution of naevi, a major risk factor for melanoma, at different body sites also varies according to sex in childhood. Using naevus counts at different body sites in 492 unrelated adults from both sexes, we observed that women have an increased number of naevi on the lower limbs compared to men (p = 8.5 × 10^-5 ), showing that a high naevus count on this site persists from childhood throughout life. Then, using data from 3,232 twins, we observed, in women, the lowest naevus count heritability on the trunk (26%), and the highest on the lower limbs (69%). Finally, we showed that, in 2,864 women, six genomic loci previously associated with both naevus count and melanoma risk (IRF4, DOCK8, MTAP, 9q31.2, KITLG and PLA2G6) have an effect on naevus count that is body site-specific, but whose effect sizes are predominantly stronger on the lower limbs. Sex-specific genetic influence on naevus count at different sites may explain differences in site-specific melanoma incidence as well as prognosis between sexes.

Publisher Correction: Novel pleiotropic risk loci for melanoma and nevus density implicate multiple biological pathways

The original version of this Article contained errors in the spelling of the authors Fan Liu and M. Arfan Ikram, which were incorrectly given as Fan Lui and Arfan M. Ikram. In addition, the original version of this Article also contained errors in the author affiliations which are detailed in the associated Publisher Correction.

Novel pleiotropic risk loci for melanoma and nevus density implicate multiple biological pathways

The total number of acquired melanocytic nevi on the skin is strongly correlated with melanoma risk. Here we report a meta-analysis of 11 nevus GWAS from Australia, Netherlands, UK, and USA comprising 52,506 individuals. We confirm known loci including MTAP, PLA2G6, and IRF4, and detect novel SNPs in KITLG and a region of 9q32. In a bivariate analysis combining the nevus results with a recent melanoma GWAS meta-analysis (12,874 cases, 23,203 controls), SNPs near GPRC5A, CYP1B1, PPARGC1B, HDAC4, FAM208B, DOCK8, and SYNE2 reached global significance, and other loci, including MIR146A and OBFC1, reached a suggestive level. Overall, we conclude that most nevus genes affect melanoma risk (KITLG an exception), while many melanoma risk loci do not alter nevus count. For example, variants in TERC and OBFC1 affect both traits, but other telomere length maintenance genes seem to affect melanoma risk only. Our findings implicate multiple pathways in nevogenesis.

Genome-wide association study in 176,678 Europeans reveals genetic loci for tanning response to sun exposure

The skin’s tendency to sunburn rather than tan is a major risk factor for skin cancer. Here we report a large genome-wide association study of ease of skin tanning in 176,678 subjects of European ancestry. We identify significant association with tanning ability at 20 loci. We confirm previously identified associations at six of these loci, and report 14 novel loci, of which ten have never been associated with pigmentation-related phenotypes. Our results also suggest that variants at the AHR/AGR3 locus, previously associated with cutaneous malignant melanoma the underlying mechanism of which is poorly understood, might act on disease risk through modulation of tanning ability.

The skin’s tanning response to sun exposure shows great interindividual variability. Here, Visconti et al. perform a genome-wide association study for ease of skin tanning and identify 20 genetic loci, ten of which had not previously been associated with pigmentation-related traits.

New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P<5 × 10(-8)), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk.

Long term surgical and hearing outcomes in the management of tympanomastoid paragangliomas

OBJECTIVE

To analyze the long term outcomes after surgery in tympanomastoid paragangliomas.

STUDY DESIGN

Retrospective study.

METHODS

The charts of 145 patients with tympanomastoid paragangliomas managed between 1988 and 2013 were reviewed. The clinical features, audiological data, pre- and postoperative notes were noted. The tumors were staged according to the modified Fish and Mattox classification. The surgical approaches for all patients were formulated according to the surgical algorithm developed at our center.

RESULTS

34 (23.5%), 46 (31.7%), 22 (15.2%), 18 (12.4%) and 25 (17.2%) patients were diagnosed to have TMP class A1, A2, B1, B2 and B3 tumors respectively. Gross tumor resection was achieved in 141 (97.2%) patients. The facial nerve was uncovered in four patients and infiltrated in three. The cochlea was found eroded in seven cases. The mean follow-up was 48.4 months. Recurrence was seen in one patient (0.7%). In the cases where the facial nerve was preserved (n=143), the nerve function was graded as HB grade 1 in 138 patients (97%). Postoperatively, the mean AC showed an improvement in all categories except in class B2 and B3, which corresponds to the classes that include patients who underwent subtotal petrosectomy.

CONCLUSION

We report the long term surgical outcomes in tympanomastoid paragangliomas in the largest series published till date. It is possible to completely eradicate all types of tympanomastoid paragangliomas with minimum sequelae by choosing the correct surgical approach to achieve adequate exposure for individual tumor classes as described in our classification and algorithm.

LEVEL OF EVIDENCE

IIb.

Impact of cholesterol lowering treatment on plasma kynurenine and tryptophan concentrations in chronic kidney disease: relationship with oxidative stress improvement

BACKGROUND AND AIM

Tryptophan (Trp) degradation via indoleamine (2,3)-dioxygenase (IDO), with consequent increased in kynurenine (Kyn) concentrations, has been proposed as marker of immune system activation. Oxidative stress (OS) might contribute to the pro-inflammatory state in chronic kidney disease (CKD) through the activation of NF-kB, with consequent activation and recruitment of immune cells.

METHODS AND RESULTS

Serum concentrations of Trp and Kyn, oxidative stress indices malondialdehyde (MDA) and allantoin/uric acid (All/UA) ratio and anti-oxidant amino acid taurine were measured in 30 CKD patients randomized to 40 mg/day simvastatin (group 1), ezetimibe/simvastatin 10/20 mg/day (group 2) or ezetimibe/simvastatin 10/40 mg/day (group 3) and treated for 12 months. Baseline Kyn and Kyn/Trp ratio were higher in CKD patients vs. healthy controls (1.67 ± 0.62 μmol/L vs 1.25 ± 0.40 μmol/L, p < 0.01 and 0.036 ± 0.016 vs 0.023 ± 0.010, p < 0.001 respectively). Both Kyn and Kyn/Trp ratio significantly decreased after cholesterol lowering treatment, to values comparable with healthy controls after one year treatment (1.67 ± 0.62 μmol/L vs 1.31 ± 0.51 μmol/L, p < 0.0001 and 0.036 ± 0.016 vs 0.028 ± 0.012 p < 0.0001, respectively). This was paralleled by a significant decrease in MDA (218 ± 143 nmol/L vs 176 ± 123 nmol/L, p < 0.01) and All/UA ratio (1.47 ± 0.72 vs 1.19 ± 0.51, p < 0.01) in CKD patients.

CONCLUSIONS

Amelioration of both oxidative and inflammation status after cholesterol lowering treatment in CKD might be mediated by restoration of antioxidant taurine concentrations during therapy (from 51.1 ± 13.3 μmol/L at baseline to 63.1 ± 16.4 μmol/L, p < 0.001 by ANOVA), suggesting that improvement of both oxidative and inflammation status in CKD patients could be explained, at least partly, by the cholesterol lowering effects.

Petrous bone cholesteatoma

Petrous bone cholesteatoma is a rare pathologic entity and may be a difficult surgical challenge because of potential involvement of the facial nerve, carotid artery, dura mater, otic capsule, and risk of cerebrospinal fluid leak. The objective of this article is to present a personal classification of petrous bone cholesteatomas, a survey of recent surgical attitudes, and our present surgical strategy based on our experience with 54 operations between 1978 and 1990. Radical petromastoid exenteration with marsupialization and the middle cranial fossa approach were used only for small pure infra- or supralabyrinthine cholesteatomas, respectively. The enlarged transcochlear approach with closure of the external auditory canal was used for infralabyrinthine, infralabyrinthine-apical, and massive petrous bone cholesteatomas. Five cases with petrous bone cholesteatomas in different locations are described in detail to present the signs and symptoms together with the management.

An easy, cost-effective and time-conserving method of studying the vascular anatomy of the base of the skull

In this work we present a simple, rapid, cost-effective and time-conserving method of studying the vascular anatomy of the base of the skull. This method is based on the injection of the arteries and veins with an appropriate coloring solution that possesses the property of rapid solidification. This technique of preparation of the coloring solution and the method of injection is described in detail. The advantages and disadvantages of this technique are also discussed.

The system of the modified transcochlear approaches to the petroclival area and the prepontine cistern

Between June 1986 and June 1993 46 different tumors (27 extradural and 19 intradural) located in the petroclival area and/or prepontine cistern have been operated on at The Gruppo Otologico Piacenza and the ENT Department of Bergamo, Italy using a modification of the transcochlear approach. Total tumor removal was obtained in all cases. Complications occurred in eight patients. One patient died due to infarction of the brain stem. The system of modified transcochlear approaches conceived for the removal of various intradural and extradural tumors is presented. This approach, together with its modifications, is the major operative access to the central skull base and clivus among a series of lateral approaches described in the literature. The basilar surgical technique (type A) and its modifications (types B, C, D) are described in detail, and five different, illustrative cases are presented. Indications, limits, results, and complications related to the approach are discussed.

Intratemporal hemangiomas involving the facial nerve: diagnosis and management

Intratemporal vascular tumors involving the facial nerve are rare benign lesions. Because of their variable clinical features, they are often misdiagnosed preoperatively. This study presents a series of 21 patients with such lesions managed from 1977 to 1994. Facial nerve dysfunction was the most common complaint, present in 60% of the cases, followed by hearing loss, present in 40% of cases. High-resolution computed tomography, magnetic resonance imaging with gadolinium, and a high index of clinical suspicion is required for preoperative diagnosis of these lesions. Early surgical resection of these tumors permits acceptable return of facial nerve function in many patients.

Surgical anatomy of the extended middle cranial fossa approach

The extended middle cranial fossa approach includes removal of the petrous bone from its subtemporal surface in order to expose widely the internal auditory canal and the posterior fossa dura around its porus while preserving all the important and closely related anatomical structures. We have dissected 25 temporal bones and five fresh cadavers in order to define the limits of this approach. Measurements were obtained between the different structures to find reliable angles and distances that could guide working in this area. A new method of identification of the internal auditory canal is discussed based on the measurements taken.The results of the present work showed wide variations in the different structures. The arcuate eminence was coincident with the superior semicircular canal in only 48% of bones. Dehiscence of the geniculate ganglion and of the internal carotid artery was noted in 16% and 20% of specimens, respectively. The angles measured between the different structures showed great variations. However, the angle between the internal auditory canal and superior petrosal sinus was constant. Though the extended middle cranial fossa is a versatile approach, it affords a limited access to the cerebellopontine angle. A thorough understanding of the complex and variable anatomy of this area is necessary should this approach be utilized.

Posterior fossa meningioma: surgical strategy

Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far.

Meningiomas intrinsic to the geniculate ganglion

Geniculate ganglion meningiomas are extremely rare lesions-only 14 cases have been reported in the literature. Two new cases of these tumors are described. On computed tomography and magnetic resonance imaging, both lesions appeared centered on the area of the geniculate ganglion, extending to the tympanic cleft and eroding the middle cranial fossa floor. The first case was treated through a middle cranial fossa approach. Because the tumor was so large in the second case, a subtotal petrosectomy was used. The authors review the literature to clarify the clinical and radiological characteristics of these tumors and their surgical treatment.

Decision making in acoustic neuroma management: the only hearing ear

Patients with acoustic neuroma in their only hearing ear are not frequently seen in clinical practice. Managing this group of patients is a challenge to both patient and surgeon. In this study we report on five cases of acoustic neuroma in an only hearing ear. Our decision for nonsurgical management of those patients with regular follow-up using auditory brainstem responses and magnetic resonance imaging is discussed. Other management options currently available are considered as well.

Fast-growing vestibular schwannoma

A case of a Jehovah's witness affected by an intracanalicular vestibular schwannoma with an extremely fast growth rate is presented. Nine months after presentation, the tumor reached 23 mm in the cerebellopontine angle. A partial removal through a retrosigmoid approach was planned. Because of the presence of a dominant high jugular bulb masquering the internal auditory canal, the intracanalicular portion of the tumor was left in place. The residual tumor grew 12 mm in 2 months. Even after a gross total removal through a middle cranial fossa approach, the tumor recurred, reaching the size of 30 mm in 17 months. A modified transcochlear approach was then performed, and the patient was free of disease at the last radiologic follow-up, 8 months after the surgery. We illustrate our strategy in treating this aggressive benign lesion with unusual behavior.

A posterolateral approach to the skull base: the petro-occipital transsigmoid approach

This posterolateral approach is directed to the petro-occipital skull base and is a combination of a suboccipital craniotomy, with an inferoposterior petrosectomy. The areas exposed are the jugular foramen, occipital condyle, lower clivus to the midline, petrous apex, tympanic cavity, the vertical portion of the intrapetrous carotid artery below the level of the eustachian tube, cerebellopontine angle, the jugulocarotid space in the upper neck. We evaluated 45 cases as follows: 13 chemodectomas, 14 lower cranial nerve schwannomas, 10 meningiomas, and 8 other lesions. The approach is indicated for extra-, intra-, and transdural lesions of the jugular foramen area. The transdural lesions could be extirpated in a single procedure without cerebrospinal fluid leak. This, in addition to preservation of the facial nerve, middle and inner ear functions, constituted the main advantages of this approach. Lower cranial nerve deficit formed the major morbidity in the present series and is still an unsolved problem in such cases.

Intermediate nerve schwannoma: a rare tumour

The intermediate nerve (IN), also called the nerve of Wrisberg, is a relatively small nerve with a variable anatomical course. Currently, this nerve is not addressed well in the pertinent literature. Pre-operative diagnosis of IN tumours is clinically challenging due to the lack of related symptoms. Symptoms are typically caused by the functional deterioration of neighbouring anatomical structures. In this report, we describe a patient with a schwannoma that arose at the porus acusticus of the internal auditory canal; during surgery, this proved to originate from the IN. We discuss our findings in the context of previously reported cases of IN schwannomas and analyse the vague characteristics and symptoms of this rare tumour.

[Emotional aspects and quality of life of patients after acoustic neuroma surgery]

Acoustic neuromas are rare lesions arising in the internal auditory canal (IAC) and extending in the posterior cranial fossa. Surgical removal is the treatment of choice; peri and postoperative complications are directly related to the size of the tumour. Some Authors think the surgical treatment and related temporary or permanent neurological deficits could change the QoL and the psychological status.

PURPOSE

The aim of this analysis is to ascertain if the surgical procedure could significantly worsen the QoL of this population 12 months after the discharge from surgical department.

METHODS

By using a questionnaires of Quality of Life aims to evaluate the impact that the disease and the surgical procedure have on this population.

SUBJECTS

We have evaluated a sample of 150 subjects one year after the surgical removal of a acoustic neuroma. Data have been collected through questionnaires the Whoqol-Brief, the BDI, the STAI Y1 and Y2 and specific item to assess effects of postoperative dysfunctions.

RESULTS

Data reveal a negative effect on QoL, 94% of the subjects show lower score at Whoquol-Brief and in anxiety with scores higher than normative score sample (state-anxiety (t = 5.602 p = .000; trait-anxiety: t = 4.354 p = .000). Higher incidence of depressive disorders have not been found.

CONCLUSION

Psychological support to subjects after discharge from acoustic neuroma surgical removal should be tailored to improve quality of life and for a better management of anxiety.

Technique to prevent post-operative CSF leak in the translabyrinthine excision of vestibular schwannoma

Cerebrospinal fluid (CSF) leak following VS removal is a challenging complication. With experience, it can be seen that anatomical factors such as the extent of pneumatization of the petrous temporal bone and posterior wall of the internal auditory canal play animportant role in contributing to CSF leak. Nevertheless, the risk of post-operative CSF leak remains a major concern for both the surgeon and patient. This paper describes a technique, which we have used since 1994, and which has helped us to achieve the lowest reported rate of post-operative CSF leak in translabyrinthine excision of vestibular schwannoma in the world literature.

Canalplasty for severe external auditory meatus exostoses

Exostoses of the external auditory meatus is a well known condition which infrequently requires surgical correction. However, the stenosis caused by severe exostosis can affect quality of life considerably and may require surgical intervention. Canalplasty, in such a situation, is a valid and effective management option. In our series the commonest indication for surgery was recurrent otitis externa. The detailed surgical technique is described and a retrospective analysis of 65 such procedures is presented. There were only two significant complications, both post-operative stenosis, requiring further corrective surgery. In conclusion, canalplasty for the exostosis of the external auditory meatus is a safe surgical option.