Structural connectivity changes in unilateral hearing loss.

Network connectivity, as mapped by the whole brain connectome, plays a crucial role in regulating auditory function. Auditory deprivation such as unilateral hearing loss might alter structural network connectivity; however, these potential alterations are poorly understood. Thirty-seven acoustic neuroma patients with unilateral hearing loss (19 left-sided and 18 right-sided) and 19 healthy controls underwent diffusion-weighted and T1-weighted imaging to assess edge strength, node strength, and global efficiency of the structural connectome. Edge strength was estimated by pair-wise normalized streamline density from tractography and connectomics. Node strength and global efficiency were calculated through graph theory analysis of the connectome. Pure-tone audiometry and word recognition scores were used to correlate the degree and duration of unilateral hearing loss with node strength and global efficiency. We demonstrate significantly stronger edge strength and node strength through the visual network, weaker edge strength and node strength in the somatomotor network, and stronger global efficiency in the unilateral hearing loss patients. No discernible correlations were observed between the degree and duration of unilateral hearing loss and the measures of node strength or global efficiency. These findings contribute to our understanding of the role of structural connectivity in hearing by facilitating visual network upregulation and somatomotor network downregulation after unilateral hearing loss.

Post headshake nystagmus: further correlation with other vestibular test results.

BACKGROUND: It is generally accepted that headshake nystagmus (HSN) is generated from an asymmetrical peripheral vestibular input and a correlation exists between HSN and canal paresis. There have been limited reports, however, how HSN correlates with the more recently introduced tests of vestibular function. AIMS/OBJECTIVES: To evaluate the correlation between HSN and unilateral weakness on caloric testing, high-frequency vestibulo-ocular reflex (VOR) function on video head impulse testing (VHIT) and otolith function determined by vestibular evoked myogenic potentials (VEMPs). METHODS: A retrospective study of all patients who underwent complete vestibular function testing at our tertiary referral center from 2016 to 2019 was performed. Demographic data, clinical diagnosis (where available), the results of video-nystagmography, vHIT, and VEMPs were evaluated. RESULTS: Of the 1499 patients in the study period, 101 (6.7%) had HSN. Vestibular test abnormalities were more common in patients with HSN. The sensitivity of HSN for underlying pathology was low in comparison with vestibular testing. However, HSN demonstrated a high specificity. CONCLUSIONS AND SIGNIFICANCE: HSN generation is likely more complex than caloric-induced nystagmus, probably due to additional variables within the vestibular system. HSN may provide clinicians with additional information concerning high-frequency VOR function involving lateral semicircular and otolith dysfunction.

Post-lingual non-syndromic hearing loss phenotype: a polygenic case with 2 biallelic mutations in MYO15A and MITF.

BACKGROUND: Hearing loss (HL) represents the most common congenital sensory impairment with an incidence of 1-5 per 1000 live births. Non-syndromic hearing loss (NSHL) is an isolated finding that is not part of any other disorder accounting for 70% of all genetic hearing loss cases. METHODS: In the current study, we reported a polygenic mode of inheritance in an NSHL consanguineous family using exome sequencing technology and we evaluated the possible effect of the detected single nucleotide variants (SNVs) using in silico methods. RESULTS: Two bi-allelic SNVs were detected in the affected patients; a MYO15A (. p.V485A) variant, and a novel MITF (p.P338L) variant. Along with these homozygous mutations, we detected two heterozygous variants in well described hearing loss genes (MYO7A and MYH14). The novel MITF p. Pro338Leu missense mutation was predicted to change the protein structure and function. CONCLUSION: A novel MITF mutation along with a previously described MYO15A mutation segregate with an autosomal recessive non-syndromic HL case with a post-lingual onset. The findings highlight the importance of carrying whole exome sequencing for a comprehensive assessment of HL genetic heterogeneity.

Loop underlay tympanoplasty for anterior, subtotal and total tympanic membrane perforations: a retrospective review.

BACKGROUND: The study aims at reporting our experience with loop underlay tympanoplasty, a modification of the underlay technique previously reported, for the reconstruction of anterior, subtotal or total tympanic membrane perforations. METHODS: A retrospective review of charts of patients who have undergone loop underlay tympanoplasty from January 2002 to January 2012 was performed. One thousand one hundred patients were included. Hearing test results preoperatively and postoperatively were reported. On follow up visits, the closure of the tympanic membrane perforation and the improvement of hearing compared to preoperative measurements with absence of complications were considered as successful outcomes of the surgery. RESULTS: At the three-month follow-up visit, the perforation closure rate was found to be 99.3% and Air-Bone Gap closure rate to less than 10 dB was 99.5%. The complication rate, including post-operative infection, was 0.72%. CONCLUSION: The loop underlay technique combines advantages of both underlay and overlay techniques with excellent postoperative outcomes.

The OTOGL p.Arg925* Variant is Associated with Moderate Hearing Loss in a Syrian Nonconsanguineous Family.

AIM: To screen for the genetic basis of congenital hearing loss in a Syrian family. METHODS: A Syrian patient living in Lebanon presented with moderate congenital hearing loss. The patient's large nonconsanguineous family was recruited. DNA was extracted from blood samples and sent for whole-exome sequencing. A detailed clinical examination along with audiograms was obtained for all subjects. RESULTS: Hearing loss was noted to be mild to moderate in the low and mid frequencies, sloping to moderate to severe in the high frequencies for all affected members. Results of DNA analysis showed the presence of a previously described p.Arg925* mutation in the OTOGL gene on both alleles in affected family members, whereas nonaffected members either had the wild type or one copy of the mutated allele. DISCUSSION: Mutations affecting the OTOGL gene have been recently connected with nonsyndromic sensorineural hearing loss. Seven such mutations have already been described. The p.Arg925* reported in this study has been found once in a French family. The current report is the first to describe this mutation in a Middle Eastern family.

Adaptation of the Arabic Version of the Tinnitus Handicap Inventory.

OBJECTIVE: To translate the Tinnitus Handicap Inventory (THI) into literary Arabic to come up with a unified Arabic version and to determine its validity and reliability in assessing the quality of life of Arabic-speaking patients with tinnitus. STUDY DESIGN: Clinical measurement study. SETTING: Tertiary care center. SUBJECTS AND METHODS: The original English THI was translated into literary Arabic by a forward- and back-translation process according to the published guidelines for cross-cultural adaptation of health-related quality-of-life measures and applied to 100 patients with chronic tinnitus. Internal consistency reliability was then assessed by calculating Cronbach's alpha coefficient. Pearson correlation coefficients were also calculated for the different scales and the different baseline characteristics. RESULTS: Results showed high internal consistency and reliability coefficients (total THI: 0.93, functional subscale: 0.86, emotional subscale: 0.86, catastrophic subscale: 0.66) comparable to those of the original English THI. CONCLUSION: The Arabic version of the THI is a valid and reliable tool for the assessment of the impact of tinnitus on the quality of life of Arabic-speaking patients with the complaint of chronic tinnitus.