Sudden bilateral deafness from hyperleukocytosis in chronic myeloid leukemia

Sudden-onset bilateral deafness as a clinical manifestation of hyperleukocytosis in chronic myeloid leukemia (CML) is a rare occurrence. We found only 27 clinical descriptions in 16 published papers. In this work, the authors present a review on deafness in CML and describe a new case with prominent hyperleukocytosis, where the neurological findings suggest slowing of the circulation through small blood vessels in the brainstem as the cause of deafness. The evolution was good after treatment. To our knowledge, this is the second case documented with electrical auditory brainstem-evoked potentials and the first with magnetic resonance imaging. Copyright (C) 2000 S. Karger AG, Basel.

Perfil audiológico e genético de pacientes com perda auditiva sensorioneural não sindrônica atendidos no Hospital das Clínicas da Faculdade de Medicina de Botucatu-Universidade Estadual Paulista

Pós-graduação em Bases Gerais da Cirurgia - FMB

Análise de mutações no gene GJB2 em indivíduos com deficiência auditiva neurossensorial não sindrômica

A surdez é o defeito sensorial mais frequente nos seres humanos, podendo ter diferentes causas ambientais ou hereditárias. Em países desenvolvidos, estimativas sugerem que em cada 1000 nascidos dois manifestam algum tipo de surdez e mais de 60% desses casos são de origem genética. No Brasil, muito pouco ainda é conhecido sobre surdez hereditária, acreditasse que quatro em cada mil recém-nascidos manifestem algum tipo de deficiência auditiva e que a frequência da surdez causada por fatores genéticos seja da ordem de 16%, enquanto os 84% restantes dos casos sejam causado por fatores ambientais e de etiologia desconhecida. As várias formas de surdez hereditária já identificada são muito raras, com exceção de uma causada por mutações no gene GJB2 que codifica a conexina 26. As conexinas representam uma classe de família de proteínas responsáveis pela formação de canais de comunicação entre células adjacentes (Gap Junctions), esta comunicação entre células adjacentes é fundamental para o crescimento e para a diferenciação de tecidos. Até o presente foram descritas 102 mutações do GJB2 que estão associadas com surdez hereditária. Três mutações se destacam por apresentarem frequência elevada em grupos populacionais específicos: 35delG entre europeus e brasileiros; 167delT entre Judeus askenazitas; e 235delG entre asiáticos. Neste trabalho, foi realizada a análise molecular de toda a sequência codificadora do gene GJB2 (Conexina 26) em uma amostra populacional constituída de 30 indivíduos não aparentados com surdez esporádica pré-lingual não sindrômica provenientes da população de Belém do Pará. O DNA foi obtido através de amostras de sangue periférico e analisado por meio da técnica convencional de PCR seguida do sequenciamento automático. Mutações no gene da Conexina 26 foram observadas em 20% da amostra (6/30). As mutações 35delG e R143W foram observadas em um único paciente (1/30), as duas no estado heterozigoto e relacionadas com a surdez do paciente. Duas outras mutações foram observadas em diferentes indivíduos: G160S em 1 paciente correspondendo a 3,3% (1/30); e V27I foi observado em 4 indivíduos com frequência alélica de 0.08; contudo as mutações G160S e V27I não estão relacionadas com a surdez. Neste trabalho as frequências observadas de mutações são equivalentes a frequências observadas em outras populações anteriormente estudadas. Esses resultados indicam que mutações no gene GJB2 são importantes causas de surdez em nossa região e não se pode excluir que a possibilidade da surdez apresentada por alguns indivíduos possa ser decorrente, principalmente, por fatores ambientais como processos infecciosos ocorridos durante a gestação, ou nos primeiros meses de vida.

Aberrant transcript produced by a splice donor site deletion in the TECTA gene is associated with autosomal dominant deafness in a Brazilian family

We ascertained a Brazilian family with nine individuals affected by autosomal dominant nonsyndromic sensorineural hearing loss. The bilateral hearing loss affected mainly mid-high frequencies, was apparently stable with an early onset. Microsatellites close to the DFNA8/DFNA12 locus, which harbors the TECTA gene, showed significant multipoint lod scores (32) close to marker D11S4107. Sequencing of the exons and exon-intron boundaries of the TECTA gene in one affected subject revealed the deletion c.5383 + 5delGTGA in the 5' end of intron 16, that includes the last two bases of the donor splice site consensus sequence. This mutation segregates with deafness within the family. To date, 33 different TECTA mutations associated with autossomal dominant hearing loss have been described. Among them is the mutation reported herein, first described by Hildebrand et al. (2011) in a UK family. The audioprofiles from the UK and Brazilian families were similar. In order to investigate the transcripts produced by the mutated allele, we performed cDNA analysis of a lymphoblastoid cell line from an affected heterozygote with the c.5383 + 5delGTGA and a noncarrier from the same family. The analysis allowed us to identify an aberrant transcript with skipping of exon 16, without affecting the reading frame. One of the dominant TECTA mutations already described, a synonymous substitution in exon 16 (c.5331 G<A), was also shown to affect splicing resulting in an aberrant transcript lacking exon 16. Despite the difference in the DNA level, both the synonymous substitution in exon 16 (c.5331 G<A) and the mutation described herein affect splicing of exon 16, leading to its skipping. At the protein level they would have the same effect, an in-frame deletion of 37 amino-acids (p.S1758Y/G1759_N1795del) probably leading to an impaired function of the ZP domain. Thus, like the TECTA missense mutations associated with dominant hearing loss, the c5383 + 5delGTGA mutation does not have an inactivating effect on the protein. (C) 2012 Elsevier B.V. All rights reserved.

Surgical complications in 550 consecutive cochlear implantation

Cochlear implantation is a safe and reliable method for auditory restoration in patients with severe to profound hearing loss. Objective: To describe the surgical complications of cochlear implantation. Materials and Methods: Information from 591 consecutive multichannel cochlear implant surgeries were retrospectively analyzed. All patients were followed-up for at least one year. Forty-one patients were excluded because of missing data, follow-up loss or middle fossa approach. Results: Of 550 cochlear implantation analyzed, 341 were performed in children or adolescents, and 209 in adults. The mean hearing loss time was 6.3 +/- 6.7 years for prelingual loss and 12.1 +/- 11.6 years for postlingual. Mean follow-up was 3.9 +/- 2.8 years. Major complications occurred in 8.9% and minor in 7.8%. Problems during electrode insertion (3.8%) were the most frequent major complication followed by flap dehiscence (1.4%). Temporary facial palsy (2.2%), canal-wall lesion (2.2%) and tympanic membrane lesion (1.8%) were the more frequent minor complications. No death occurred. Conclusion: There was a low rate of surgical complications, most of them been successfully managed. These results confirm that cochlear implant is a safe surgery and most surgical complications can be managed with conservative measures or minimal intervention.

Speech perception and cortical auditory evoked potentials in cochlear implant users with auditory neuropathy spectrum disorders

Objective: To characterize the PI component of long latency auditory evoked potentials (LLAEPs) in cochlear implant users with auditory neuropathy spectrum disorder (ANSD) and determine firstly whether they correlate with speech perception performance and secondly whether they correlate with other variables related to cochlear implant use. Methods: This study was conducted at the Center for Audiological Research at the University of Sao Paulo. The sample included 14 pediatric (4-11 years of age) cochlear implant users with ANSD, of both sexes, with profound prelingual hearing loss. Patients with hypoplasia or agenesis of the auditory nerve were excluded from the study. LLAEPs produced in response to speech stimuli were recorded using a Smart EP USB Jr. system. The subjects' speech perception was evaluated using tests 5 and 6 of the Glendonald Auditory Screening Procedure (GASP). Results: The P-1 component was detected in 12/14 (85.7%) children with ANSD. Latency of the P-1 component correlated with duration of sensorial hearing deprivation (*p = 0.007, r = 0.7278), but not with duration of cochlear implant use. An analysis of groups assigned according to GASP performance (k-means clustering) revealed that aspects of prior central auditory system development reflected in the P-1 component are related to behavioral auditory skills. Conclusions: In children with ANSD using cochlear implants, the P-1 component can serve as a marker of central auditory cortical development and a predictor of the implanted child's speech perception performance. (c) 2012 Elsevier Ireland Ltd. All rights reserved.

Factors influencing the decision for Baha in unilateral deafness: the Bern benefit in single-sided deafness questionnaire

The data of 46 adults with single-sided sensorineural deafness who were candidates for bone-anchored hearing aids (Baha) CROS (contralateral routing of signals) were analyzed. All candidates tested a Baha with a headband in their normal environment. Subsequently, 29 of the candidates chose a permanent Baha CROS fitting, and 17 declined, thus forming the two study groups. No significant difference regarding age, sex or duration of deafness was found between the two groups. Similarly, the transcranial attenuation was not significantly different between those who accepted and declined a Baha. Subjects with some residual hearing in their poorer ear tended to decline a Baha, but the effect was not statistically significant. For a subset of 28 subjects, the Bern Benefit in Single-Sided Deafness questionnaire was administered. The questionnaire consists of 10 visual analogue scales rating the subjectively perceived benefit of the Baha or any other CROS device in different situations. Scores were found to be significantly higher for speech understanding at some distance (p = 0.026), for speech understanding in noise (p = 0.037), for group conversations (p < 0.01), and for the overall benefit (p < 0.01) for those candidates who chose to use a Baha as a CROS device permanently.

Benefits of low-frequency attenuation of baha® in single-sided sensorineural deafness

To investigate the effect of low-frequency attenuation of Bone-Anchored Hearing Aids (Bahas) in users with single-sided sensorineural deafness (SSD). The underlying notion is that low-frequency sounds up to approximately 1500 Hz reach the contralateral ear without significant attenuation and that Bahas tend to show more distortion at lower frequencies. Furthermore, to transmit low frequencies, higher moving masses are needed when compared with high frequencies.

Assessment of speech perception and communication skills in adolescents with cochlear implants for pre- and peri-lingual deafness

This study aimed to assess speech perception and communication skills in adolescents between ages 8 and 18 that received cochlear implants for pre- and peri-lingual deafness.

Does a pleiotropic gene explain deafness and blue irises in white cats?

The prevalence of deafness is high in cat populations in which the dominant white gene is segregating. The objective of this study was to investigate whether there is a gene that is responsible for deafness as well as for blue eyes and to establish a plausible mode of inheritance. For this purpose, data from an experimental colony with deaf cats were analyzed. The hearing status was determined by acoustically evoked brain stem responses (BAER). Complex segregation analyses were conducted to find out the most probable mode of inheritance using maximum likelihood procedures. The prevalence of deafness and partial hearing in the experimental colony was 67% and 29%, respectively. The results of the bivariate segregation analysis support the hypothesis of a pleiotropic major gene segregating for deafness and blue iris colour. The high heritability coefficients for both traits, 0.55 and 0.75 respectively, indicate that beside the major gene there is an important influence of polygenic effects.

Influence of directionality and maximal power output on speech understanding with bone anchored hearing implants in single sided deafness

Bone-anchored hearing implants (BAHI) are routinely used to alleviate the effects of the acoustic head shadow in single-sided sensorineural deafness (SSD). In this study, the influence of the directional microphone setting and the maximum power output of the BAHI sound processor on speech understanding in noise in a laboratory setting were investigated. Eight adult BAHI users with SSD participated in this pilot study. Speech understanding in noise was measured using a new Slovak speech-in-noise test in two different spatial settings, either with noise coming from the front and noise from the side of the BAHI (S90N0) or vice versa (S0N90). In both spatial settings, speech understanding was measured without a BAHI, with a Baha BP100 in omnidirectional mode, with a BP100 in directional mode, with a BP110 power in omnidirectional and with a BP110 power in directional mode. In spatial setting S90N0, speech understanding in noise with either sound processor and in either directional mode was improved by 2.2-2.8 dB (p = 0.004-0.016). In spatial setting S0N90, speech understanding in noise was reduced by either BAHI, but was significantly better by 1.0-1.8 dB, if the directional microphone system was activated (p = 0.046), when compared to the omnidirectional setting. With the limited number of subjects in this study, no statistically significant differences were found between the two sound processors.

Neurotologic and functional MRI findings in a patient with bilateral profound deafness having Brown-Vialetto-Van Leare syndrome

INTRODUCTION We report the first findings of functional magnetic resonance imaging of the auditory cortex in a young woman with a bilateral cochleovestibular deficit as first manifestation of Brown-Vialetto-Van Leare syndrome. The patient had no open speech discrimination, even with hearing aids, and is depending on lip reading for communication. METHODS To evaluate the possible efficiency of a cochlear implantation, we investigated hemodynamic responses within the central auditory pathways using an auditory functional magnetic resonance imaging paradigm. RESULTS Blood oxygen level-dependent correlates were detected bilaterally along the auditory pathways after exposure to intermittent clicking tone stimulation at 2 kHz. CONCLUSION These results suggest integrity of the central auditory pathways and represent a positive argument to propose a cochlear implantation with the aim to restore hearing.

A novel mutation in BCS1L associated with deafness, tubulopathy, growth retardation and microcephaly

We report a novel homozygous missense mutation in the ubiquinol-cytochrome c reductase synthesis-like (BCS1L) gene in two consanguineous Turkish families associated with deafness, Fanconi syndrome (tubulopathy), microcephaly, mental and growth retardation. All three patients presented with transitory metabolic acidosis in the neonatal period and development of persistent renal de Toni-Debré-Fanconi-type tubulopathy, with subsequent rachitis, short stature, microcephaly, sensorineural hearing impairment, mild mental retardation and liver dysfunction. The novel missense mutation c.142A>G (p.M48V) in BCS1L is located at a highly conserved region associated with sorting to the mitochondria. Biochemical analysis revealed an isolated complex III deficiency in skeletal muscle not detected in fibroblasts. Native polyacrylamide gel electrophoresis (PAGE) revealed normal super complex formation, but a shift in mobility of complex III most likely caused by the absence of the BCS1L-mediated insertion of Rieske Fe/S protein into complex III. These findings expand the phenotypic spectrum of BCS1L mutations, highlight the importance of biochemical analysis of different primary affected tissue and underline that neonatal lactic acidosis with multi-organ involvement may resolve after the newborn period with a relatively spared neurological outcome and survival into adulthood. CONCLUSION Mutation screening for BCS1L should be considered in the differential diagnosis of severe (proximal) tubulopathy in the newborn period. What is Known: • Mutations in BCS1L cause mitochondrial complex III deficiencies. • Phenotypic presentations of defective BCS1L range from Bjornstad to neonatal GRACILE syndrome. What is New: • Description of a novel homozygous mutation in BCS1L with transient neonatal acidosis and persistent de Toni-Debré-Fanconi-type tubulopathy. • The long survival of patients with phenotypic presentation of severe complex III deficiency is uncommon.