Performance of Deaf Participants in an Abstract Visual Grammar Learning Task at Multiple Formal Levels: Evaluating the Auditory Scaffolding Hypothesis

Previous research has hypothesized that human sequential processing may be dependent upon hearing experience (the "auditory scaffolding hypothesis"), predicting that sequential rule learning abilities should be hindered by congenital deafness. To test this hypothesis, we compared deaf signer and hearing individuals' ability to acquire rules of different computational complexity in a visual artificial grammar learning task using sequential stimuli. As a group, deaf participants succeeded at all levels of the task; Bayesian analysis indicates that they successfully acquired each of several target grammars at ascending levels of the formal language hierarchy. Overall, these results do not support the auditory scaffolding hypothesis. However, age- and education-matched hearing participants did outperform deaf participants in two out of three tested grammars. We suggest that this difference may be related to verbal recoding strategies in the two groups. Any verbal recoding strategies used by the deaf signers would be less effective because they would have to use the same visual channel required for the experimental task.

Reorganization of large-scale brain networks in deaf signing adults: The role of auditory cortex in functional reorganization following deafness

If the brain is deprived of input from one or more senses during development, functional and structural reorganization of the deprived regions takes place. However, little is known about how sensory deprivation affects large-scale brain networks. In the present study, we use data-driven independent component analysis (ICA) to characterize large-scale brain networks in 15 deaf early signers and 24 hearing non-signers based on resting-state functional MRI data. We found differences between the groups in independent components representing the left lateralized control network, the default network, the ventral somatomotor network, and the attention network. In addition, we showed stronger functional connectivity for deaf compared to hearing individuals from the middle and superior temporal cortices to the cingulate cortex, insular cortex, cuneus and precuneus, supramarginal gyrus, supplementary motor area, and cerebellum crus 1, and stronger connectivity for hearing non-signers to hippocampus, middle and superior frontal gyri, pre- and postcentral gyri, and cerebellum crus 8. These results show that deafness induces large-scale network reorganization, with the middle/superior temporal cortex as a central node of plasticity. Cross-modal reorganization may be associated with behavioral adaptations to the environment, including superior ability in some visual functions such as visual working memory and visual attention, in deaf signers.

Doors Syndrome: Case Report

DOORS syndrome is an autosomal recessive genetic neurometabolic disorder. It occurs equally in men and women. Major causes include TBC1D 24 mutations and genetic factors. Here, we discuss a 23-year-old male patient who applied to our clinic with anonychia of the toes and was diagnosed with DOORS syndrome with other accompanying clinical symptoms.

Cross-modal integration and plasticity in the superior temporal cortex

In congenitally deaf people, temporal regions typically believed to be primarily auditory enhance their response to nonauditory information. The neural mechanisms and functional principles underlying this phenomenon, as well as its impact on auditory recovery after sensory restoration, yet remain debated. In this chapter, we demonstrate that the cross-modal recruitment of temporal regions by visual inputs in congenitally deaf people follows organizational principles known to be present in the hearing brain. We propose that the functional and structural mechanisms allowing optimal convergence of multisensory information in the temporal cortex of hearing people also provide the neural scaffolding for feeding visual or tactile information into the deafened temporal areas. Innate in their nature, such anatomo-functional links between the auditory and other sensory systems would represent the common substrate of both early multisensory integration and expression of selective cross-modal plasticity in the superior temporal cortex.

Neuroplasticity following cochlear implants

The auditory cortex of people with sensorineural hearing loss can be re-afferented using a cochlear implant (CI): a neural prosthesis that bypasses the damaged cells in the cochlea to directly stimulate the auditory nerve. Although CIs are the most successful neural prosthesis to date, some CI users still do not achieve satisfactory outcomes using these devices. To explain variability in outcomes, clinicians and researchers have increasingly focused their attention on neuroscientific investigations that examined how the auditory cortices respond to the electric signals that originate from the CI. This chapter provides an overview of the literature that examined how the auditory cortex changes its functional properties in response to inputs from the CI, in animal models and in humans. We focus first on the basic responses to sounds delivered through electrical hearing and, next, we examine the integrity of two fundamental aspects of the auditory system: tonotopy and processing of binaural cues. When addressing the effects of CIs in humans, we also consider speech-evoked responses. We conclude by discussing to what extent this neuroscientific literature can contribute to clinical practices and help to overcome variability in outcomes.

The role of the endoscope in cochlear implantation. A systematic review

OBJECTIVE

To review the role of the endoscope in cochlear implantation (CI).

METHODS

MEDLINE, ScienceDirect, Google Scholar and the Cochrane Library databases as well as other sources were searched by two independent reviewers. Studies including patients undergoing either exclusively endoscopic or endoscopic ally assisted CI were eligible for inclusion. Endoscopic CI approaches and postoperative complications were the primary outcomes. Secondary endpoints included the degree of round window (RW) microscopic visualization according to St Thomas' Hospital classification as well as type of cochleostomy for electrode insertion in the scala tympani (ST).

RESULTS

Fourteen studies met the inclusion criteria comprising 191 endoscopic or endoscopically assisted CI cases. The endoscope was used for better visualization of the RW across all included studies, facilitated the insertion of the electrode in the ST and spared a mastoidectomy in a number of cases. No facial nerve palsy was reported in any of the studies. The most common complication was external auditory canal/ tympanic membrane tear followed by chorda tympani injury.

CONCLUSION

The microscopic CI approach is still the gold standard. The endoscope facilitates the recognition of the RW area and leads to successful and safe implantation particularly in difficult anatomical scenarios, ear malformations and advanced otosclerosis. Endoscopically assisted CI procedures offer the opportunity to avoid a posterior tympanotomy and reduce the risk of facial nerve injury. To date, the lack of long term data does not permit the widespread adoption of completely endoscopic CI procedures without a mastoidectomy.

Adverse event of Sinovac Coronavirus vaccine: Deafness

COVID-19 has spread worldwide and is one of the most threatening infectious diseases in the world. Vaccination is known as an effective method to protect susceptible populations against such diseases. The Coronavirus vaccine developed by Sinovac has been shown to have a high protective effect, but it also has potential adverse events. For example, our department saw two patients with reported cases of deafness that occurred after inoculation with the Sinovac Coronavirus vaccine. While deafness is only a rare adverse event from the Coronavirus vaccine, whether other vaccination centers, hospitals, and centers for disease control (CDCs) have encountered similar cases still needs to be investigated, reported, and analyzed.

The potential effect of the updated national criteria on adult cochlear implantation in England and Wales

OBJECTIVES

Following an update of 'old' TA166 guidance (March 2019), the National Institute for Health and Care Excellence (NICE) predicted a 70% increase in cochlear implantation (CI). We investigated the effect of the 'new' TA566 criteria on adult CI at our regional centre.

METHODS

Adult CI assessments between 1st January 2015 and 31st December 2018 (before new criteria) and between 7th March 2019 and 31st August 2019 (after new criteria) were retrospectively examined. Calculated eligibility and uptake rates predicted change in annual implantation under the new guidance.

RESULTS

552 patients were identified in the first study period, with a median of 148 assessments per year. Of 533 with complete assessments, 58% were eligible, of whom 74% were implanted. Retrospective application of the new criteria was possible for 277 patients; eligibility and uptake were 67% and 80%, respectively. In the second study period (n = 60), new criteria eligibility was 62% and uptake was 78%. Increased eligibility under the new criteria predicts an increase of between 13 and 23% in annual adult implantation.

CONCLUSIONS

We demonstrate increased implant eligibility under the latest NICE guidance. Assuming consistent referral patterns, our predicted increase in adult implantation is considerably less than that predicted elsewhere.

The outcomes of bilateral bone conduction hearing devices (BCHD) implantation in the treatment of hearing loss: A systematic review

OBJECTIVES

Bone Conduction Hearing Devices (BCHDs) are a means of improving hearing ability in those that do not receive full benefit from conventional hearing aids. In 2016, the NHS started commissioning bilateral BCHDs. This review aims to evaluate the current literature and identify areas for further research.

METHODS

This review was conducted in line with the PRISMA guidelines and registered on the PROSPERO database (registration CRD42020191956). MEDLINE, CINAHL and The Cochrane Library were systematically searched. The full text of relevant titles and abstracts was then reviewed before data extraction was undertaken. Risk of bias was assessed using the ROBINS-1 tool.

RESULTS

Searches identified 125 studies. After removing duplicates, 28 full texts were screened. 14 studies were included in the final review. Amongst the audiological outcomes, greater improvements for bilateral compared to unilateral BCHDs were seen in hearing thresholds, understanding speech in quiet, localization, and restoration of binaural hearing. Thus, supporting the addition of a second implant. For speech in noise however, bilateral BCHDs were less effective when the noise was presented from one side. Increases in measures of Quality of Life, including the Glasgow Benefit Index, were seen across all included studies. No studies included complication rates.

CONCLUSION

Overall, bilateral BCHDs offer benefits to the recipient's audiological capabilities and QoL. However, more research is required on the complications and the cost of bilateral BCHDs. Further to this, future research should aim to use uniform tests to measure outcomes.

Neonatal Screening for Congenital Hearing Loss in the North of Jordan; Findings and Implications

BACKGROUND

Congenital hearing loss is one of the important illnesses that affect newborns. Early diagnosis and treatment are a challenge for medical authorities in developing countries to improve children's functional, intellectual, emotional, and social abilities. We aimed to study the prevalence of congenital hearing loss in northern Jordan community and identify factors that could affect hearing screening protocol.

METHODS

Prospective cross-sectional study of 1595 infants born in our hospital underwent hearing screening tests. Totally, 104 were tested in NICU and the rest examined in the nursery room using Otoacoustic emission (OAE) test as a primary testing tool. The patients were followed in the three hearing screening phases. Factors affecting screening results were studied and analyzed.

RESULTS

The total number of newborns who didn't pass the first OAE test in one or both ears were 90 (5.6%); 69 from the nursery group and 21 from the NICU group. In the 2^nd screening phase 21 (23.3%) didn't attend the appointment. Sixty-four passed the second screening OAE test. Five newborns (5.6%) had a second refer result in one or both ears and referred for a diagnostic ABR test. Three infants passed the test and two found to have bilateral hearing loss.

CONCLUSIONS

Hearing screening test is conducted via a 3-phases-protocol. OAE is used in the first two phases and ABR in the third phase. Hearing results is significantly affected for infants admitted to NICU. The following factors increase OAE fail response: mechanical ventilation for more than 5 days, Hyperbilirubinemia, associated congenital anomalies. Mode of delivery doesn't have statistical significance on hearing screening results.

Disability in a medieval village community: A unique case of facial dysmorphism

OBJECTIVE

To identify the pathology causing the severe facial dysmorphia of a medieval individual from the site of Rigny (Indre-et-Loire, France) and to evaluate its functional repercussions on the subject's hearing and social life.

MATERIALS

An individual from Rigny for the osteological study, 69 individuals from the region for the Ct-Scan study and 48 individuals from the site for the isotopic analysis.

METHODS

Macroscopic analysis was performed using standard osteological methods. Consequences of pathology on hearing were assessed by CT-scan. Dietary behaviour was analysed by stable carbon and nitrogen isotope analysis of bone collagen.

RESULTS

The individual is a woman who was over 50 years of age at the time of her death with a severe form of Treacher-Collins syndrome that resulted in deafness. No osteological signs of maltreatment were observed and there is no evidence that this individual's diet was different from that of the rest of the community.

CONCLUSIONS

All information testifies to the integration of this individual into the village population.

SIGNIFICANCE

This study is the first archaeological description of Treacher Collins syndrome. It shows the ability of the paleopathological approach to help identify the attitudes of societies for which written sources are most often lacking.

LIMITATIONS

In the absence of palaeogenomic analysis it is not possible to identify the origin of this case.

SUGGESTIONS FOR FURTHER RESEARCH

Increase the paleopathological semiology by CT-scan in order to specify the consequences of pathologies and integrate isotopic analyses to enrich discussion about perceptions of disease.

Reduced flash lag illusion in early deaf individuals

When a brief flash is quickly presented aligned with a moving target, the flash typically appears to lag behind the moving stimulus. This effect is widely known in the literature as a flash-lag illusion (FLI). The flash-lag is an example of a motion-induced position shift. Since auditory deprivation leads to both enhanced visual skills and impaired temporal abilities, both crucial for the perception of the flash-lag effect, here we hypothesized that lack of audition could influence the FLI. 13 early deaf and 18 hearing individuals were tested in a visual FLI paradigm to investigate this hypothesis. As expected, results demonstrated a reduction of the flash-lag effect following early deafness, both in the central and peripheral visual fields. Moreover, only for deaf individuals, there is a positive correlation between the flash-lag effect in the peripheral and central visual field, suggesting that the mechanisms underlying the effect in the center of the visual field expand to the periphery following deafness. Overall, these findings reveal that lack of audition early in life profoundly impacts early visual processing underlying the flash-lag effect.

Cochlear implantation in patients with Pendred syndrome

OBJECTIVE

To examine the outcomes of cochlear implantation in children with Pendred Syndrome.

MATERIAL AND METHODS

A retrospective case series of nine pediatric patients with Pendred syndrome undergoing cochlear implantation at a tertiary academic medical center from 2003 to 2017.

RESULTS

All patients were diagnosed with bilateral mild-to-profound to severe-to-profound sensorineural hearing loss and used hearing aids prior to implantation. Preoperative imaging results revealed that all patients exhibited bilateral enlarged vestibular aqueducts and 8 of 9 had cochlear dysplasia equivalent to Incomplete Partition II. Despite inner ear malformations, all electrodes were successfully implanted with minimal complications and favorable post-operative audiological outcomes.

CONCLUSIONS

Cochlear implantation is an effective and successful treatment for severe-to-profound hearing loss in children with Pendred syndrome and for whom traditional amplification aids provide limited benefit. With early intervention, cochlear implantation allows speech and cognitive development in Pendred children comparable to that of normal hearing individuals, allowing patients to learn in a mainstream educational setting.

The Importance of Intact Senses in Mating and Social Assessments Made by Deaf Individuals

Social perception is a multimodal process involving vision and audition as central input sources for human social cognitive processes. However, it remains unclear how profoundly deaf people assess others in the context of mating and social interaction. The current study explored the relative importance of different sensory modalities (vision, smell, and touch) in assessments of opposite- and same-sex strangers. We focused on potential sensory compensation processes in mate selection (i.e., increased importance of the intact senses in forming impressions of an opposite-sex stranger as a potential partner). A total of 74 deaf individuals and 100 normally hearing controls were included in the study sample. We found diminished importance of vision and smell in deaf participants compared with controls for opposite- and same-sex strangers, and increased importance of touch for the assessment of same-sex strangers. The results suggested that deaf people rely less on visual and olfactory cues in mating and social assessments, highlighting a possible role of sign language in shaping interpersonal tactile experience in non-romantic relationships.

Deaf adults at higher risk for severe illness: COVID-19 information preference and perceived health consequences

OBJECTIVES

This study explores deaf and hard of hearing (DHH) individuals' preferred sources of information for COVID-19 and their perceptions of developing severe illness from COVID-19 given underlying medical conditions.

METHODS

A national online bilingual American Sign Language/English survey was conducted from April 17 to May 1, 2020. Weighted sample of 474 DHH adults living in the United States. Multivariate logistic regression analyses were conducted to examine independent associations of sociodemographic variables and health indicators with perceived COVID-19 health consequences.

RESULTS

About 44% of the medical condition sample used the Internet (English-based text) first for COVID-19 information, followed by TV (24%). Only 1% selected healthcare provider as the go-to source; the remainder got information from family or friends. Perceived health consequences increased with age (adjusted OR = 1.04; CI 95% = 1.02, 1.06). At-risk respondents who self-identified as persons of color were nearly three times more likely to believe that their health will be severely affected by COVID-19 compared to respondents who self-identified as white (adjusted OR = 2.94; CI 95% = 1.20, 7.18).

CONCLUSIONS

Perception of COVID-19 health consequences vary among DHH adults at higher risk for severe illness.

PRACTICE IMPLICATIONS

Information delivery methods must be flexible and comprehensive to meet the diverse community's needs, especially during the COVID-19 pandemic.

Deaf women's experiences of maternity and primary care: An integrative review

BACKGROUND

An estimated 24,000 people in the UK report using British Sign Language (BSL) as their first language. Misconceptions about deaf culture and language mean that deaf people have less access to health information and their health literacy is lower. Deaf people's health needs go under the radar in primary care with ensuing poorer health outcomes. Deaf women's experiences of maternity care are poorly understood.

METHODS

Using Whittemore and Knafl's method for an integrative review, the following databases were searched: EMBASE, MedLine, CINAHL and Maternity and Infant Care. After reviewing 430 journal article titles and abstracts against the inclusion/exclusion criteria, 11 articles were included for final review. Selected studies were conducted internationally and were available in English. 10 were qualitative studies, 1 used survey design. They were reviewed using the Caldwell Framework.

FINDINGS

These show that deaf women avoid seeking care, have a lack of access to health information and healthcare providers, including midwives, have a lack of deaf awareness. For deaf women, during pregnancy, birth and postnatal periods, this can mean having longer hospital stays and more complex postnatal care needs in both the hospital and community setting.

CONCLUSIONS

Current care provisions do not always meet the needs of the deaf BSL using women who use maternity services. Midwives should be aware of deafness as a culture and how to best meet the needs of the community to improve health outcomes for women and their babies.

Essential Role of Sptan1 in Cochlear Hair Cell Morphology and Function Via Focal Adhesion Signaling

Hearing loss is the most common human sensory deficit. Hearing relies on stereocilia, inserted into the cuticular plate of hair cells (HCs), where they play an important role in the perception of sound and its transmission. Although numerous genes have been associated with hearing loss, the function of many hair cell genes has yet to be elucidated. Herein, we focused on nonerythroid spectrin αII (SPTAN1), abundant in the cuticular plate, surrounding the rootlets of stereocilia and along the plasma membrane. Interestingly, mice with HC-specific Sptan1 knockout exhibited rapid deafness, abnormal formation of stereocilia and cuticular plates, and loss of HCs from middle and apical turns of the cochlea during early postnatal stages. Additionally, Sptan1 deficiency led to the decreased spreading of House Ear Institute-Organ of Corti 1 cells, and induced abnormal formation of focal adhesions and integrin signaling in mouse HCs. Altogether, our findings highlight SPTAN1 as a critical molecule for HC stereocilia morphology and auditory function via regulation of focal adhesion signaling.

The impact of visual cues during visual word recognition in deaf readers: An ERP study

Although evidence is still scarce, recent research suggests key differences in how deaf and hearing readers use visual information during visual word recognition. Here we compared the time course of lexical access in deaf and hearing readers of similar reading ability. We also investigated whether one visual property of words, the outline-shape, modulates visual word recognition differently in both groups. We recorded the EEG signal of twenty deaf and twenty hearing readers while they performed a lexical decision task. In addition to the effect of lexicality, we assessed the impact of outline-shape by contrasting responses to pseudowords with an outline-shape that was consistent (e.g., mofor) or inconsistent (e.g., mosor) with their baseword (motor). Despite hearing readers having higher phonological abilities, results showed a remarkably similar time course of the lexicality effect in deaf and hearing readers. We also found that only for deaf readers, inconsistent-shape pseudowords (e.g., mosor) elicited larger amplitude ERPs than consistent-shape pseudowords (e.g., mofor) from 150 ms after stimulus onset and extending into the N400 time window. This latter finding supports the view that deaf readers rely more on visual characteristics than typical hearing readers during visual word recognition. Altogether, our results suggest different mechanisms underlying effective word recognition in deaf and hearing readers.

A scoping review of global aminoglycoside antibiotic overuse: A potential opportunity for primary ototoxicity prevention

BACKGROUND

Aminoglycosides are widely used, broad-spectrum antibiotics with significant potential for ototoxicity. Global efforts to prevent ototoxicity must account for aminoglycoside overuse and non-prescription use.

OBJECTIVES

The goals of this study were to a) estimate the prevalence of aminoglycoside overuse by synthesizing evidence on self-medication, over the counter (OTC) availability, and household antibiotic storage for later use, and to report the specific aminoglycosides used and the predictors of overuse, and b) leverage this information to comment on potential risk of ototoxicity.

METHODS

Two systematic search strings were conducted to extract peer-reviewed articles published from 2005 to 2020. The first focused on overuse of aminoglycoside antibiotics. The second focused on potentially ototoxic effects of aminoglycosides related to drug overuse.

RESULTS

A total of 26 articles were included (first search string: n = 21; second search string: n = 5). The prevalence of aminoglycoside self-medication was high and household storage and OTC availability of aminoglycosides was common. Gentamicin was the most commonly overused aminoglycoside. No studies provided information on antibiotic dosing or resultant toxicities, including ototoxicity.

CONCLUSIONS

The limited available evidence indicates that antibiotic overuse (self-medication, home storage, and non-prescription availability) is relatively common, especially in low resource settings, and that aminoglycoside antibiotics comprise a variable, but concerning, proportion of non-prescribed antibiotics. Additional evidence is needed to evaluate the relationship between these dispensing patterns and ototoxicity.

Deafness in an auditory specialist, the big brown bat (Eptesicus fuscus)

Bats are long-lived animals that show presumed resistance to noise-induced and age-related hearing loss, which has been attributed to their dependence on sound processing for survival. Echolocation and basic auditory functions have been studied extensively in the big brown bat (Eptesicus fuscus), an insectivorous microchiropteran species. We conducted hearing tests and analysis of cochlear sensory cells in a group of big brown bats that exhibited anomalies in behavioral sonar tracking experiments and/or lacked neural responses to acoustic stimulation in subcortical auditory nuclei. We show for the first time the presence of profound deafness and extensive cochlear damage in an echolocating bat species. Auditory brainstem responses were abnormal or absent in these bats, and histological analyses of their cochleae revealed extensive loss of hair cells, supporting cells, and spiral ganglion neurons. The underlying cause of deafness is unknown.

Brain plasticity and hearing disorders

Permanently changed sensory stimulation can modify functional connectivity patterns in the healthy brain and in pathology. In the pathology case, these adaptive modifications of the brain are referred to as compensation, and the subsequent configurations of functional connectivity are called compensatory plasticity. The variability and extent of auditory deficits due to the impairments in the hearing system determine the related brain reorganization and rehabilitation. In this review, we consider cross-modal and intra-modal brain plasticity related to bilateral and unilateral hearing loss and their restoration using cochlear implantation. Cross-modal brain plasticity may have both beneficial and detrimental effects on hearing disorders. It has a beneficial effect when it serves to improve a patient's adaptation to the visuo-auditory environment. However, the occupation of the auditory cortex by visual functions may be a negative factor for the restoration of hearing with cochlear implants. In what concerns intra-modal plasticity, the loss of interhemispheric asymmetry in asymmetric hearing loss is deleterious for the auditory spatial localization. Research on brain plasticity in hearing disorders can advance our understanding of brain plasticity and improve the rehabilitation of the patients using prognostic, evidence-based approaches from cognitive neuroscience combined with post-rehabilitation objective biomarkers of this plasticity utilizing neuroimaging.

The benefits of underwater vibrostimulation in the rehabilitation of children with impaired hearing

INTRODUCTION

Early intervention is crucial for the optimal speech and language development of children with impaired hearing. Underwater vibrostimulation could help develop behavioural reactions to low-frequency stimuli immediately after diagnosis and facilitate aural rehabilitation after hearing aid (HA) or cochlear implant (CI) activation.

GOALS

To determine the limits of underwater vibrotactile stimuli perception and to measure the effect of vibrostimulation training on the aural rehabilitation of young children.

METHODS

Two adults and three children with congenital hearing loss participated in the first part of the study. Pure tones between 100 and 4000 Hz and natural broadband sounds were delivered under water while the participants were sitting in a pool. The lower thresholds of perception and the maximum comfortable levels were measured and the subjective sensations were recorded. In the second part of the study, 15 children <3 years old were presented with the same stimuli until they developed stable conditioned reactions to the stimuli. The time until the development of "hearing behaviour" and the number of fitting sessions after HA or CI activation were compared between the vibrostimulation group and a control group who did not receive such training.

RESULTS

In the first part of the study, participants were most sensitive to 100-400 Hz stimuli, while the stimuli >1000 Hz did not evoke any sensations. The vibrations were felt across all body parts and produced hearing-like sensations in the ear. In the second part of the study, children in the vibrostimulation group required fewer fitting sessions and developed "hearing behaviour" sooner than the control group.

CONCLUSIONS

Underwater vibrostimulation is a promising new method of early aural rehabilitation that could be recommended for implementation in paediatric audiology centres.

Shift of musical hallucinations to visual hallucinations after correction of the hearing deficit in a patient with Lewy body dementia: a case report

Background

Musical hallucinations are a particular type of auditory hallucination in which the patient perceives instrumental music, musical sounds, or songs. Musical hallucinations are associated with acquired hearing loss, particularly within the elderly. Under conditions of reduced auditory sensory input, perception-bearing circuits are disinhibited and perceptual traces released, implying an interaction between peripheral sensory deficits and central factors related to brain dysfunction.

Case presentation

A 71-year-old Caucasian man with hearing loss complained of memory difficulties and resting tremor of the right upper limb in the previous 2 years. He already had difficulties in instrumental activities of daily life. Neurological examination showed Parkinsonian signs and hypoacusia. Neuropsychological examination identified deficits in executive functions and memory tests. Brain computerized tomography and nuclear magnetic resonance scans showed mild cortical and subcortical atrophy. The clinical diagnosis of possible dementia with Lewy bodies was established. Five years later, the patient began complaining of musical hallucinations. There had been no previous change in medication. An otorhinolaryngologist diagnosed age-related hearing loss and prescribed bilateral hearing aids. After using the hearing aids, the patient did not hear the songs any longer, only some tinnitus, described as a whistle. However, at the same time, the patient started experiencing visual hallucinations he never had before.

Discussion

To our knowledge, the immediate shift of hallucinations from one sensory modality to another sensory modality when perception is improved has not been previously described. This report emphasizes the interaction between brain pathology and sensory deficits for the genesis of hallucinations, and reinforces the theory that attention and control networks must couple properly to the default mode network, as well as integrate and select adequately peripheral signals to the somatosensory cortices, in order to keep a clear state of mind.

Conclusion

The clinician should bear in mind and let the patient know that improving one sensory modality to ameliorate hallucinations may sometimes paradoxically lead to hallucinations in a different sensory modality.

Identification of a Novel Stop Loss Mutation in P2RX2 Gene in an Iranian Family with Autosomal Nonsyndromic Hearing Loss

Background:

Hearing loss, a congenital genetic disorder in human, is difficult to diagnose. WES is a powerful approach for ethiological disgnosis of such disorders.

Methods:

One Iranian family with two patients were attented in the study. Sequencing of known NSHL genes was carried out to recognize the genetic causes of HL.

Results:

Molecular analyses identified a novel stop loss mutation, c.1048T>G (p.Term350Glu), whitin the P2RX2 gene, causing a termination-site modification.This event would lead to continued translation into the 3' UTR of the gene, which in turn may result in a longer protein product. The mutation was segregating with the disease phenotype and predicted to be pathogenic by bioinformatic tools.

Conclusion:

This study is the first Iranian case report of a diagnosis of ADNSHL caused by P2RX2 mutation. The recognition of other causative mutations in P2RX2 gene more supports the probable function of this gene in causing ADNSHL.