scholarly journals Viral and Bacterial Causes of Labyrinthitis

2021 ◽  
pp. 412-417
Author(s):  
Suzan Sulaiman Alzaidi ◽  
Abdullah Ali Alali ◽  
Zainab Radhi Alebrahim ◽  
Hawraa Abdulwahab Mayouf ◽  
Raghad Fahad Alomairy ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Bacterial Infections ◽  
Nausea And Vomiting ◽  
Current Evidence ◽  
Congenital Hearing Loss ◽  
Membranous Structure ◽  
Common Pathogen

Labyrinthitis is a known inflammation of the membranous structure of the inner ear. Affected patients usually present with nausea and vomiting, vertigo, hearing loss/impairment, and tinnitus. Many etiologies have been proposed to lead to the development of labyrinthitis, including bacterial, viral, systemic, and iatrogenic causes and the most commonly reported causes include viral and bacterial infections. Not many investigations have elaborated on the viral and bacterial etiologies, and the evidence seems to be scattered across the different studies. In the present study, we have reviewed the literature to discuss the current evidence regarding the viral and bacterial causes of labyrinthitis. Many viruses and bacteria were reported in the literature to cause the condition. However, the most common pathogen includes cytomegalovirus and maternal rubella infections, leading to congenital hearing loss. Other viruses as measles and mumps might also lead to developing post-natal labyrinthitis. Studies also indicates that COVID-19 can be a recent cause of the disease. However, evidence regarding this information, similar to the case with other viral and bacterial etiologies, still needs further validation and reporting before making solid conclusions. Accordingly, we encourage researchers to furtherly report about similar cases and conduct epidemiological investigations to better understand the etiology of the disease.

scholarly journals Cochlear Nerve Canal Stenosis: Association With MYH14 and MYH9 Genes

2021 ◽  
pp. 014556132199683
Author(s):  
Wenqi Liang ◽  
Line Wang ◽  
Xinyu Song ◽  
Fenqi Gao ◽  
Pan Liu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Next Generation Sequencing ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Transverse Diameter ◽  
Congenital Hearing Loss ◽  
Canal Stenosis ◽  
Ear Anomalies ◽  
Generation Sequencing

The bony cochlear nerve canal transmits the cochlear nerve as it passes from the fundus of the internal auditory canal to the cochlea. Stenosis of the cochlear nerve canal, defined as a diameter less than 1.0 mm in transverse diameter, is associated with inner ear anomalies and severe to profound congenital hearing loss. We describe an 11-month-old infant with nonsyndromic congenital sensorineural hearing loss with cochlear nerve canal stenosis. Next-generation sequencing revealed heterozygous mutations in MYH9 and MYH14, encoding for the inner ear proteins myosin heavy chain IIA and IIC. The patient’s hearing was rehabilitated with bilateral cochlear implantation.

scholarly journals Genetics of Nonsyndromic Congenital Hearing Loss

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Oguz Kadir Egilmez ◽  
M. Tayyar Kalcioglu
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Hair Cells ◽  
Neurotransmitter Release ◽  
Intracellular Transport ◽  
Autosomal Recessive ◽  
Treatment Options ◽  
The Body ◽  
Congenital Hearing Loss ◽  
Congenital Hearing Impairment

Congenital hearing impairment affects nearly 1 in every 1000 live births and is the most frequent birth defect in developed societies. Hereditary types of hearing loss account for more than 50% of all congenital sensorineural hearing loss cases and are caused by genetic mutations. HL can be either nonsyndromic, which is restricted to the inner ear, or syndromic, a part of multiple anomalies affecting the body. Nonsyndromic HL can be categorised by mode of inheritance, such as autosomal dominant (called DFNA), autosomal recessive (DFNB), mitochondrial, and X-linked (DFN). To date, 125 deafness loci have been reported in the literature: 58 DFNA loci, 63 DFNB loci, and 4 X-linked loci. Mutations in genes that control the adhesion of hair cells, intracellular transport, neurotransmitter release, ionic hemeostasis, and cytoskeleton of hair cells can lead to malfunctions of the cochlea and inner ear. In recent years, with the increase in studies about genes involved in congenital hearing loss, genetic counselling and treatment options have emerged and increased in availability. This paper presents an overview of the currently known genes associated with nonsyndromic congenital hearing loss and mutations in the inner ear.

Drug Delivery to the Inner Ear: Strategies and Their Therapeutic Implications for Sensorineural Hearing Loss

2012 ◽  
Vol 9 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Teresa Rivera ◽  
Lorena Sanz ◽  
Guadalupe Camarero ◽  
Isabel Varela-Nieto
Keyword(s):  
Drug Delivery ◽  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Inner Ear ◽  
Sensorineural Hearing ◽  
Therapeutic Implications

scholarly journals A novel case of concurrent occurrence of demyelinating-polyneuropathy-causing PMP22 duplication and SOX10 gene mutation producing severe hypertrophic neuropathy

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nozomu Matsuda ◽  
Koushi Ootsuki ◽  
Shunsuke Kobayashi ◽  
Ayaka Nemoto ◽  
Hitoshi Kubo ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Neuromuscular Disorders ◽  
Whole Body ◽  
Congenital Hearing Loss ◽  
Severe Phenotype ◽  
Demyelinating Neuropathy ◽  
Magnetic Resonance Neurography ◽  
Peripheral Myelin Protein 22 ◽  
Hypertrophic Neuropathy

Abstract Background Hereditary motor and sensory neuropathy, also referred to as Charcot–Marie–Tooth disease (CMT), is most often caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. This duplication causes CMT type 1A (CMT1A). CMT1A rarely occurs in combination with other hereditary neuromuscular disorders. However, such rare genetic coincidences produce a severe phenotype and have been reported in terms of “double trouble” overlapping syndrome. Waardenburg syndrome (WS) is the most common form of a hereditary syndromic deafness. It is primarily characterized by pigmentation anomalies and classified into four major phenotypes. A mutation in the SRY sex determining region Y-box 10 (SOX10) gene causes WS type 2 or 4 and peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, WS, and Hirschsprung disease. We describe a 11-year-old boy with extreme hypertrophic neuropathy because of a combination of CMT1A and WS type 2. This is the first published case on the co-occurrence of CMT1A and WS type 2. Case presentation The 11-year-old boy presented with motor developmental delay and a deterioration in unstable walking at 6 years of age. In addition, he had congenital hearing loss and heterochromia iridis. The neurological examination revealed weakness in the distal limbs with pes cavus. He was diagnosed with CMT1A by the fluorescence in situ hybridization method. His paternal pedigree had a history of CMT1A. However, no family member had congenital hearing loss. His clinical manifestation was apparently severe than those of his relatives with CMT1A. In addition, a whole-body magnetic resonance neurography revealed an extreme enlargement of his systemic cranial and spinal nerves. Subsequently, a genetic analysis revealed a heterozygous frameshift mutation c.876delT (p.F292Lfs*19) in the SOX10 gene. He was eventually diagnosed with WS type 2. Conclusions We described a patient with a genetically confirmed overlapping diagnoses of CMT1A and WS type 2. The double trouble with the genes created a significant impact on the peripheral nerves system. Severe phenotype in the proband can be attributed to the cumulative effect of mutations in both PMP22 and SOX10 genes, responsible for demyelinating neuropathy.

Evaluation of DNA damages in congenital hearing loss patients

2021 ◽  
Vol 822 ◽  
pp. 111744
Author(s):  
Özge Çağlar ◽  
Hayal Çobanoğlu ◽  
Atilla Uslu ◽  
Akın Çayır
Keyword(s):  
Hearing Loss ◽  
Congenital Hearing Loss ◽  
Dna Damages

scholarly journals Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos

2021 ◽  
Vol 22 (12) ◽  
pp. 6497
Author(s):  
Anna Ghilardi ◽  
Alberto Diana ◽  
Renato Bacchetta ◽  
Nadia Santo ◽  
Miriam Ascagni ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Hair Cells ◽  
Muscle Fibers ◽  
Underlying Mechanism ◽  
Loss Of Function ◽  
Zebrafish Model ◽  
Developmental Defects ◽  
Inner Ear Development ◽  
Syndromic Hearing Loss

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.

scholarly journals Ultrasound Microbubbles Enhance the Efficacy of Insulin-Like Growth Factor-1 Therapy for the Treatment of Noise-Induced Hearing Loss

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3626
Author(s):  
Yi-Chun Lin ◽  
Yuan-Yung Lin ◽  
Hsin-Chien Chen ◽  
Chao-Yin Kuo ◽  
Ai-Ho Liao ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Growth Factor ◽  
Inner Ear ◽  
Outer Hair Cells ◽  
Round Window Membrane ◽  
Insulin Like Growth Factor ◽  
Noise Induced Hearing Loss ◽  
Ear Diseases ◽  
Brainstem Response ◽  
Ultrasound Microbubbles

The application of insulin-like growth factor 1 (IGF-1) to the round window membrane (RWM) is an emerging treatment for inner ear diseases. RWM permeability is the key factor for efficient IGF-1 delivery. Ultrasound microbubbles (USMBs) can increase drug permeation through the RWM. In the present study, the enhancing effect of USMBs on the efficacy of IGF-1 application and the treatment effect of USMB-mediated IGF-1 delivery for noise-induced hearing loss (NIHL) were investigated. Forty-seven guinea pigs were assigned to three groups: the USM group, which received local application of recombinant human IGF-1 (rhIGF-1, 10 µg/µL) following application of USMBs to the RWM; the RWS group, which received IGF-1 application alone; and the saline-treated group. The perilymphatic concentration of rhIGF-1 in the USM group was 1.95- and 1.67- fold of that in the RWS group, 2 and 24 h after treatment, respectively. After 5 h of 118 dB SPL noise exposure, the USM group had the lowest threshold shift in auditory brainstem response, least loss of cochlear outer hair cells, and least reduction in the number of synaptic ribbons on postexposure day 28 among the three groups. The combination of USMB and IGF-1 led to a better therapeutic response to NIHL. Two hours after treatment, the USM group had significantly higher levels of Akt1 and Mapk3 gene expression than the other two groups. The most intense immunostaining for phosphor-AKT and phospho-ERK1/2 was detected in the cochlea in the USM group. These results suggested that USMB can be applied to enhance the efficacy of IGF-1 therapy in the treatment of inner ear diseases.

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