Hearing impairment (HI) affects 1 in 650 newborns, which makes it the most common congenital sensory impairment. Despite extraordinary genetic heterogeneity, mutations in one gene, GJB2, which encodes the connexin 26 protein and is involved in inner ear homeostasis, are found in up to 50% of patients with autosomal recessive nonsyndromic hearing loss. Because of the high frequency of GJB2 mutations, mutation analysis of this gene is widely available as a diagnostic test. In this study, we assessed the association between genotype and degree of hearing loss in persons with HI and biallelic GJB2 mutations. We performed cross-sectional analyses of GJB2 genotype and audiometric data from 1,531 persons, from 16 different countries, with autosomal recessive, mildto-profound nonsyndromic HI. The median age of all participants was 8 years; 90% of persons were within the age range of 0-26 years. Of the 83 different mutations identified, 47 were classified as nontruncating, and 36 as truncating. A total of 153 different genotypes were found, of which 56 were homozygous truncating (T/T), 30 were homozygous nontruncating (NT/NT), and 67 were compound heterozygous truncating/nontruncating (T/ NT). The degree of HI associated with biallelic truncating mutations was significantly more severe than the HI associated with biallelic nontruncating mutations (). The HI of 48 different genotypes was less severe P ! .0001 than that of 35delG homozygotes. Several common mutations (M34T, V37I, and L90P) were associated with mildto-moderate HI (median 25-40 dB). Two genotypes-35delG/R143W (median 105 dB) and 35delG/dela(GJB6-D13S1830) (median 108 dB)-had significantly more-severe HI than that of 35delG homozygotes.

The review of electrode insertion studies into human temporal bones, as well as a post-mortem anatomical study of implanted temporal bones, showed an increased risk of scala vestibuli insertions and insertion-induced damage to intracochlear structures when the cochleostomy was performed more anterior to the round window. These results were endorsed by studies detailing the anatomy of the hook region of the cochlea.

Mastoid obliteration with autogenous cranial bone is a safe and extremely effective option for treatment of problematic canal wall-down mastoid cavities. Surgical techniques that include sterile harvest of the cranial bone graft mixed with antibiotic, revision of the cavity to expose viable native bone, inclusion of the epitympanic spaces in the obliteration, and complete coverage of the pAte with autogenous fascia have proven critical to successful outcome.

Higher stimulation rates do not necessarily result in improved performance.

Catecholamine-secreting paragangliomas (CSPs) present challenges for the managing team of surgeons and anesthesiologists. Without proper preoperative management and planning, the patient is at high risk for complications and significant morbidity. A review of the literature looking at all aspects of the care of patients with CSP was performed to provide a consensus on the comprehensive care of these difficult patients. A case study is also provided to illustrate the management algorithm. Specific recommendations are made with regards to preoperative workup, including serum and urine testing, tumor localization, angiography, and embolization. Preoperative and intraoperative management techniques by the surgical and anesthesiology teams are discussed, including pharmaceutical interventions and fluid management. Aspects of postoperative care are also discussed. Management of patients with CSP requires significant attention to detail by a multidisciplinary team of surgeons and anesthesiologists. By following the recommendations included within this article, the morbidity associated with removal of these tumors can be significantly reduced or eliminated.

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