Retrosternal goiter masquerading as type II respiratory failure. A case report.

INTRODUCTION AND IMPORTANCE: Retrosternal Goiter (RG) represents a challenging clinical entity for surgeons. Although the vast majority of cases are successfully operated via a cervical access, there still remains a small minority that require an extra-cervical approach, even in experienced hands. Factors that shift the odds towards an extra-cervical approach are mainly related to the anatomic characteristics of the retrosternal mass. CASE PRESENTATION: We herein report a case of RG presenting as type 2 respiratory failure without a palpable neck mass, in an 81-year-old female. Despite her history of subtotal thyroidectomy for Graves' disease, the patient's chest x-ray showed a central mediastinal mass shifting the trachea to the left. The retrosternal mass extended below the aortic arch, and carina on computed tomography. It also extended into the posterior mediastinum. All these anatomical features of the RG along with the patient's previous neck surgery were in favor of an extra-cervical approach. Nevertheless, a cervical approach was attempted, and was concluded successfully. CONCLUSION: CT plays a key role in determining the likelihood of requiring an extra-cervical approach in RG. Even if the odds seem to be in favor of an extra-cervical approach, an attempt to remove the goiter through a cervical incision should always be made by an experienced surgeon, using all available techniques, and taking all required precautions, on account of less risk of surgical and aesthetic damage obtained with this approach.

SLC26A4 Phenotypic Variability Influences Intra- and Inter-Familial Diagnosis and Management.

SLC26A4 is one of the most common genes causing autosomal recessive non-syndromic sensorineural hearing loss (SNHL). It has been reported to cause Pendred Syndrome (PDS) and DFNB4 which is deafness with enlarged vestibular aqueduct (EVA). However, mutated SLC26A4 is not conclusive for having either DFNB4 or PDS. Three unrelated Jordanian families consisting of eight affected individuals with congenital bilateral hearing loss (HL) participated in this study. Whole-exome and Sanger sequencing were performed to investigate the underlying molecular etiology of HL. Further clinical investigations, including laboratory blood workup for the thyroid gland, CT scan for the temporal bone, and thyroid ultrasound were performed. Three disease-causing variants were identified in SLC26A4 in the three families, two of which were novel. Two families had a novel pathogenic homozygous splice-site accepter variant (c.165-1G>C), while the third family had compound heterozygous pathogenic variants (c.1446G>A; p.Trp482* and c.304G>A; p.Gly102Arg). Our approach helped in redirecting the diagnosis of several affected members of three different families from non-syndromic HL to syndromic HL. Two of the affected individuals had typical PDS, one had DFNB4, while the rest had atypical PDS. Our work emphasized the intra- and inter-familial variability of SLC26A4-related phenotypes. In addition, we highlighted the variable phenotypic impact of SLC26A4 on tailoring a personalized healthcare management.

The Quantum Tunneling of Ions Model Can Explain the Pathophysiology of Tinnitus.

Tinnitus is a well-known pathological entity in clinical practice. However, the pathophysiological mechanisms behind tinnitus seem to be elusive and cannot provide a comprehensive understanding of its pathogenesis and clinical manifestations. Hence, in the present study, we explore the mathematical model of ions' quantum tunneling to propose an original pathophysiological mechanism for the sensation of tinnitus. The present model focuses on two major aspects: The first aspect is the ability of ions, including sodium, potassium, and calcium, to depolarize the membrane potential of inner hair cells and the neurons of the auditory pathway. This membrane depolarization is induced via the quantum tunneling of ions through closed voltage-gated channels. The state of membrane depolarization can be a state of hyper-excitability or hypo-excitability, depending on the degree of depolarization. Both of these states aid in understanding the pathophysiology of tinnitus. The second aspect is the quantum tunneling signals between the demyelinated neurons of the auditory pathway. These signals are mediated via the quantum tunneling of potassium ions, which exit to the extracellular fluid during an action potential event. These quantum signals can be viewed as a "quantum synapse" between neurons. The formation of quantum synapses results in hyper-excitability among the demyelinated neurons of the auditory pathway. Both of these aspects augment and amplify the electrical signals in the auditory pathway and result in a loss of the spatiotemporal fidelity of sound signals going to the brain centers. The brain interprets this hyper-excitability and loss of spatiotemporal fidelity as tinnitus. Herein, we show mathematically that the quantum tunneling of ions can depolarize the membrane potential of the inner hair cells and neurons of the auditory pathway. Moreover, we calculate the probability of action potential induction in the neurons of the auditory pathway generated by the quantum tunneling signals of potassium ions.

Minimizing the Number of Aeroallergen Extracts in Skin Prick Test in IgE-Mediated Allergic Disorders in Both Adults and Children in Jordan.

BACKGROUND: Skin prick test (SPT) is the most common diagnostic procedure that is performed considering the history of aeroallergen sensitivity among patients. Moreover, it is important to identify the diagnostic and therapeutic benefits of allergen's number in skin prick testing in both adults and children. OBJECTIVE: The present study aims to detect the minimum number of allergens used in SPT to identify 95% of sensitized patients in both pediatric and adult age groups in Jordan. PATIENTS AND METHODS: Retrospective analysis of a 20 allergen extracts SPT results for 2253 patients (aged 8 and above) was conducted to assess the minimum number of allergen extracts needed to identify 95% of the sensitized patients in both adults and children. RESULTS: The results showed that 50.9% of the pediatric group was sensitized to at least one aeroallergen extract in comparison to 48.3% of the adult group. Only 8 allergen extracts were necessary to identify 95% of the sensitized patients which are olive pollen, Dermatophagoides pteronyssinus, Salsola kali, 4 cereals, Wall pellitory, Dermatophagoides farinae, Cypress and mugwort. Same number was needed in children but with the replacement of mugwort with alternaria to achieve a similar result. CONCLUSION: The study concluded that only 8 allergen extracts were needed for detecting 95% of sensitized patients (both pediatrics and adults) in SPT. The authors proposed a two-stage screening: stage 1 includes the minimum number of allergen extracts to detect 95% of sensitized patients and stage 2 for the patients who tested negative in stage 1 which will include a broader allergen extracts panel excluding those which were already tested in stage 1.

Extending the spectrum of CLRN1- and ABCA4-associated inherited retinal dystrophies caused by novel and recurrent variants using exome sequencing.

BACKGROUND: Inherited retinal dystrophies (IRDs) are characterized by extreme genetic and clinical heterogeneity. There are many genes that are known to cause IRD which makes the identification of the underlying genetic causes quite challenging. And in view of the emergence of therapeutic options, it is essential to combine molecular and clinical data to correctly diagnose IRD patients. In this study, we aimed to identify the disease-causing variants (DCVs) in four consanguineous Jordanian families with IRDs and describe genotype-phenotype correlations. METHODS: Exome sequencing (ES) was employed on the proband patients of each family, followed by segregation analysis of candidate variants in affected and unaffected family members by Sanger sequencing. Simulation analysis was done on one novel CLRN1 variant to characterize its effect on mRNA processing. Clinical evaluation included history, slit-lamp biomicroscopy, and indirect ophthalmoscopy. RESULTS: We identified two novel variants in CLRN1 [(c.433+1G>A) and (c.323T>C, p.Leu108Pro)], and two recurrent variants in ABCA4 [(c.1648G>A, p.Gly550Arg) and (c.5460+1G>A)]. Two families with the same DCV were found to have different phenotypes and another family was shown to have sector RP. Moreover, simulation analysis for the CLRN1 splice donor variant (c.433+1G>A) showed that the variant might affect mRNA processing resulting in the formation of an abnormal receptor. Also, a family that was previously diagnosed with nonsyndromic RP was found to have Usher syndrome based on their genetic assessment and audiometry. CONCLUSION: Our findings extend the spectrum of CLRN1- and ABCA4-associated IRDs and describe new phenotypes for these genes. We also highlighted the importance of combining molecular and clinical data to correctly diagnose IRDs and the utility of simulation analysis to predict the effect of splice donor variants on protein formation and function.

Evaluation of dizziness at Jordan University Hospital.

OBJECTIVE: This study was performed prospectively to evaluate the dizzy patients in the Neurotology Outpatient clinic at Jordan University Hospital, Amman, Jordan during the period 1993-2000 and to discuss the prevalence and etiology of dizziness. METHODS: Data were collected from 108 patients (52 males and 56 females) with a mean age of 45.6-years. Diagnosis was made on the basis of history, physical, otolaryngological and neurological examination and confirmed by relevant investigation including laboratory, radiological and audio vestibular tests. RESULTS: Secure diagnosis were made in 98% of patients (14% had one cause alone and 84% had multiple causes). Cardiovascular disorders accounted for 31.5% of primary and 49% of secondary causes, peripheral vestibular disorders, 25% of primary and 3% of secondary causes, central vestibular disorders 17% of primary and 9% of secondary causes, metabolic endocrine 13% of primary and 38% of secondary causes, cervical osteoarthritis 5.5% of primary and 28% of secondary causes and psychogenic 4.6% of primary and 6.5% of secondary causes. CONCLUSION: Our findings demonstrate that vertigo is the most common subtype of dizziness (50%). Multiple causes are more prevalent in older age and the single cause is more prevalent in younger age. Cardiovascular was the most common cause of dizziness followed by vestibular disorders, metabolic and cervical osteoarthritis. Vestibular disorders are primary causes and non vestibular are predominantly secondary causes of dizziness. Hyperlipidemia, diabetes and cervical causes are major secondary contributors to dizziness. We recommend a multi disciplinary setting and application of a comprehensive diagnostic and treatment approach without unnecessary protracted investigative scheme and installment of rehabilitation facilities.

Pediatric Endoscopic DCR: The Outcome in 50 Patients.

Congenital nasolacrimal duct obstruction is a very common condition affecting 20 % of infants. Pediatric DCR is indicated when there is no response to previous therapy like probing, or is associated with recurrent dacryocystitis. This is a retrospective case series study of 50 pediatric patients who underwent endoscopic DCR in two centers, Jordan University Hospital/Jordan, and Mosul teaching and private hospitals/Iraq. The age ranged from 3 to 12 years with a mean of 6.2 years. The overall success rate of endoscopic DCR was 90 %, and failed cases were mainly due to presaccal obstruction. No major complications were reported, but minor complications occurred in about 60 % of cases. As a conclusion, endoscopic DCR is a safe and effective procedure in pediatric age group.