Cochlear Implants: An Excursus into the Technologies and Clinical Applications

Hearing loss causes severe alterations in social function and daily communications. Cochlear device implantation (CDI) is the only beneficiary method for auditory rehabilitation in patients with severe to profound sensorineural hearing loss (SNHL). Regarding a report in 2014, over 300,000 people had received cochlear implants throughout the world since December 2012 among which about 60,000 were adults and 40,000 were children in the United States. In this chapter, we discuss the history, origin, mechanism of action, and type of cochlear implants, as well as method of surgery and complications

Predictors of Thyroid Gland Invasion in Laryngeal Squamous Cell Carcinoma

Introduction: Laryngeal squamous cell carcinoma (SCC) can invade the thyroid gland leading to unnecessary thyroidectomies with subsequent hypothyroidism and hyperparathyroidism. Thus, clinicopathological variables should be defined in order to predict thyroid gland invasion preoperatively.   Materials and Methods: We performed a retrospective analysis of 1,465 patients with laryngeal SCC referred to our center between March 2009 and January 2016. Among these patients, 60 individuals underwent total laryngectomy and either thyroid lobectomy and isthmectomy or total thyroidectomy.   Results: Thyroid gland invasion was observed in 20% of samples. The following variables were associated with thyroid gland invasion: transglottic spread of the tumor (odds ratio [OR]: 2.04, 95% confidence interval [CI]: 1.15–5.81, P=0.004), thyroid cartilage involvement (OR: 1.53, 95% CI: 0.94–2.50, P=0.02), and anterior commissure involvement (OR: 5.75, 95% CI: 0.86–38.42, P=0.01). In addition, the largest dimension of the tumor was significantly associated with thyroid gland involvement (r=0.36, 95% CI 0.05–0.67, P=0.004). Multivariate linear regression analysis confirmed these findings.   Conclusion: The rate of thyroidectomies performed in cases of laryngeal SCC is much higher than the actual rate of thyroid gland invasion. Thus, preoperative evaluation to find transglottic spread of the tumor, thyroid cartilage, and anterior commissure involvement should be considered

Pure Red Cell Aplasia as a Presenting Feature in Systemic Lupus Erythematosus and Association with Thymoma, Hypothyroidism and Hypoparathyroidism: a Case Report and Literature Review

This paper presents a 54-year-old female with lupus whom severe anaemia due to pure red cell aplasia (PRCA) was the first manifestation. There was seven years interval between PRCA onset and diagnosis of lupus. Thymectomy due to thymoma had been carried out six years before but anaemia sustained. Hypothyroidism and hypoparathyroidism were other associated diseases. Severe anaemia and the need for monthly blood infusions were resolved following treatment with Prednisolone, Hydroxychloroquine and Levothyroxine

Determination of the radioanatomical factors related to the position of facial nerve in accessing jugular foramen and carotid artery in temporal bone

Introduction: Preservation of the facial nerve is of great importance in temporal bone surgeries. We intend to investigate the measurements of the radioanatomical factors related to the position of the facial nerve in accessing jugular foramen and internal carotid artery (ICA) in temporal bone of patients who were candidates for temporal high resolution computed tomography (HRCT) scan. Methods: In this correlation cross-sectional study, samples were selected from patients referred to Amir Alam Hospital who were previously candidates for temporal HRCT. Radioanatomic factors were evaluated in three axial, coronal and sagittal views. Analyzes were performed using descriptive statistics, correlation analysis and factor analysis. Results: A total of 173 samples were investigated. The most reliable radioanatomical factor based on coefficient of variation (CV) was the distance of the 7th nerve to the temporomandibular joint (TMJ) in the inferior to the cochlea in the sagittal view (variable name S2) (CV = 8.1%) and then the distance from the 7th nerve to the TMJ in the inferior section of the cochlea in the axial view (variable name AI3) (CV = 8.4%). Based on correlation analysis and then confirmatory factor analysis, three common latent factors were identified (overall R2 = 0.999). Conclusion: The results of this study can be used for two purposes. First, the direct use of the estimated measures in surgical operations, and the second is more advanced modeling to choose the approach in the surgical operation and how to implement that approach. For the first aim, the two factors AI3 and S2 were the most reliable radioanatomical factors in different people. For the second aim, the three-dimensional understanding of the obtained measurements and the further identification of the anatomical nature of the latent factors can help in choosing the approach in surgery

Central Vestibular Dysfunction in Head Injury

<jats:sec><jats:title>Objectives</jats:title><jats:p> This study aims to provide an overview of dizziness post head injury in those with prominent features for central vestibular dysfunction (CVD) in comparison to those with a post-traumatic peripheral vestibular etiology. </jats:p></jats:sec><jats:sec><jats:title>Study design</jats:title><jats:p> Retrospective. </jats:p></jats:sec><jats:sec><jats:title>Setting</jats:title><jats:p> University Health Network (UHN) Workplace Safety and Insurance Board (WSIB) database from 1988 to 2018 were evaluated for post-traumatic dizziness. </jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p> The UHN WSIB neurotology database (n = 4291) between 1998 and 2018 was retrospectively studied for head-injured workers presenting with features for CVD associated with trauma. All patients had a detailed neurotological history and examination, audiovestibular testing that included video nystagmography (VNG) and cervical vestibular-evoked myogenic potentials (cVEMPs). Imaging studies including routine brain and high-resolution temporal bone computed tomography (CT) scans and/or intracranial magnetic resonance imaging (MRI) were available for the majority of injured workers. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> Among 4291 head-injured workers with dizziness, 23 were diagnosed with features/findings denoting CVD. Complaints of imbalance were significantly more common in those with CVD compared to vertigo and headache in those with peripheral vestibular dysfunction. Atypical positional nystagmus, oculomotor abnormalities and facial paralysis were more common in those with CVD. </jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p> Symptomatic post-traumatic central vestibular injury is uncommon. It occurred primarily following high-impact trauma and was reflective for a more severe head injury where shearing effects on the brain often resulted in diffuse axonal injury. Complaints of persistent imbalance and ataxia were more common than complaints of vertigo. Eye movement abnormalities were highly indicative for central nervous system injury even in those with minimal change on CT/MRI. </jats:p></jats:sec&gt

The Follow-Up Role of the Vestibular Evoked Myogenic Potential Test in Meniere’s Disease

Despite some proposed roles for the diagnostic impact of the cervical vestibular evoked myogenic potential test in the patients with Meniere’s disease, the role of this test as an objective instrument in following up the patients with Meniere’s disease who underwent. Intratympanic steroid injection is not cleared. In a prospective study, thirty-one adult patients with definite one-sided Meniere's disease with vertigo as main complaint refractory to medical treatments for three months, were selected. Patients underwent three times of intratympanic dexamethasone injection with one-week intervals. We performed cervical vestibular evoked myogenic potential test at first and four weeks after the last injection for all participants. We followed the patients for one year. The study results were analyzed with the chi-square test. Cervical vestibular evoked myogenic potential test could not be recorded in 26 patients (83.9%), and the test results were abnormal in the remaining 5 patients. The results were abnormal in the healthy ear of 32.3% of the patients. Despite the clinical improvement of the symptoms after intratympanic injection, the test results were not changed. Cervical vestibular evoked myogenic potential test could not be recorded in the majority of the patients with Meniere's disease; while it is usually recorded in normal ears. On the other hand, results of the cervical vestibular evoked myogenic potential test do not change during the early phase after treatment and could not be a good option for follow up and evaluating the response in this situation

Analysis of Saccular Function With Vestibular Evoked Myogenic Potential Test in Meniere's Disease

Meniere’s disease is the disorder of inner ear characterized by vertigo, tinnitus and sensorineural hearing loss. The vestibular evoked myogenic potential (VEMP) test could be useful in the analysis of saccular function, and diagnosis of Meniere’s disease. In this study, we’ve analyzed the saccular function, using VEMP test in different groups of Meniere’s disease. Patients were categorized as possible, probable or definite Meniere’s disease groups according to the guideline of American Academy of Otolaryngology-Head and Neck Surgery. The exclusion criteria were neuromuscular system diseases, diseases of central nervous system, inner ear disorders, conductive hearing loss, a history of ototoxic drug consumption, being a drug abuser and a positive history of inner ear surgery or manipulations. The VEMP test is the recording of positive and negative waves from sternocleidomastoid muscle that is made by an auditory click to the ear. From the total of 100 patients, the waves of VEMP test was seen in 59 patients which 19 patients had abnormal amplitude, and latency and 40 patients were with normally recorded waves. There was a significant relationship between the severity of hearing loss and a VEMP test without any recorded waves. Most of the cases with ‘no wave recorded’ VEMP test, were patients with severe hearing loss. However, there wasn’t any relation between the pattern of hearing loss and ‘no wave recorded’ VEMP test. VEMP test could be a valuable diagnostic clue especially in patients with definite Meniere’s disease

HLA-Cw Allele Frequency in Definite Meniere’s Disease Compared to Probable Meniere’s Disease and Healthy Controls in an Iranian Sample

Introduction Several lines of evidence support the contribution of autoimmune mechanisms in the pathogenesis of Meniere’s disease. The aim of this study was determining the association between HLA-Cw Alleles in patients with definite Meniere’s disease and patients with probable Meniere’s disease and a control group.  Materials and Methods: HLA-Cw genotyping was performed in 23 patients with definite Meniere’s disease, 24 with probable Meniere’s disease, and 91 healthy normal subjects, using sequence specific primers polymerase chain reaction technique. The statistical analysis was performed using stata 8 software.  Results: There was a significant association between HLA-Cw*04 and HLA-Cw*16 in both definite and probable Meniere’s disease compared to normal healthy controls. We observed a significant difference in HLA-Cw*12 frequencies between patients with definite Meniere’s disease compared to patients with probable Meniere’s disease (P=0.04). The frequency of HLA-Cw*18 is significantly higher in healthy controls (P=0.002).  Conclusion: Our findings support the rule of HLA-Cw Alleles in both definite and probable Meniere’s disease. In addition, differences in HLA-Cw*12 frequency in definite and probable Meniere’s disease in our study’s population might indicate distinct immune and inflammatory mechanisms involved in each condition

Intratympanic Injection of Dexamethasone and Electrocochleographic Data in Cases of Definite One Sided Refractory Meniere’s Disease

Introduction: Meniere’s disease (MD) is a disease of the inner ear that presents itself with repeated episodes of vertigo (96.2%), tinnitus (91.1%), and sensorineural hearing loss (87.7 %). In this article we sought to assess the effects of intratympanic (IT) injections of dexamethasone on definite cases of MD using electrocochleography (ECOG). Materials and Methods: In this hospital-based case series in 36 patients, we measured audiometric values and ECOG in all patients before, 1 month and 6 months after 4-mg/mL IT injections of dexamethasone. Results: Four patients (11%) had improved hearing following the intervention. No difference in pure tone audiometry (PTA) was observed following IT injections (P=0.492), while speech discrimination score (SDS) was significantly improved (P=0.008). There was a significant improvement in vertigo 1 month after IT injections (