Speech recognition and communication outcomes with cochlear implantation in Usher syndrome type 3.

BACKGROUND: Usher syndrome Type 3 (USH3) is an autosomal recessive disorder characterized by variable type and degree of progressive sensorineural hearing loss and retinitis pigmentosa. Cochlear implants are widely used among these patients. OBJECTIVES: To evaluate the results and benefits of cochlear implantation in patients with USH3. STUDY DESIGN: A nationwide multicenter retrospective review. MATERIALS AND METHODS: During the years 1995-2005, in 5 Finnish university hospitals, 19 patients with USH3 received a cochlear implant. Saliva samples were collected to verify the USH3 genotype. Patients answered to 3 questionnaires: Glasgow Benefit Inventory, Glasgow Health Status Inventory, and a self-made questionnaire. Audiological data were collected from patient records. RESULTS: All the patients with USH3 in the study were homozygous for the Finnish major mutation (p.Y176X). Either they had severe sensorineural hearing loss or they were profoundly deaf. The mean preoperative hearing level (pure-tone average, 0.5-4 kHz) was 110 ± 8 dB hearing loss (HL) and the mean aided hearing level was 58 ± 11 dB HL. The postoperative hearing level (34 ± 9 dB HL) and word recognition scores were significantly better than before surgery. According to the Glasgow Benefit Inventory scores and Glasgow Health Status Inventory data related to hearing, the cochlear implantation was beneficial to patients with USH3. CONCLUSION: Cochlear implantation is beneficial to patients with USH3, and patients learn to use the implant without assistance.

HOX-GFP and WOX-GFP lentivirus vectors for inner ear gene transfer.

CONCLUSION: GFP transgene was expressed in the lining cells of the perilymphatic space. Lentivirus vectors are safe and cause only minimal inflammatory reaction. Transgene products can be delivered into the perilymph by utilizing lentivirus vectors. OBJECTIVES: To analyze the efficiency and safety of lentiviral vectors HOX-GFP and WOX-GFP in intracochlear gene transfer. MATERIALS AND METHODS: Lentivirus vectors were tested for their transduction efficiency in vivo in CD-1 mice. Half of the animals were pretreated with kanamycin. Lentivirus vector or saline (1 microl) was injected into the inner ear. All the animals were sacrificed 14 days after the surgery and the cochleae and selected organs were analyzed immunohistochemically. RESULTS: HOX-GFP and WOX-GFP expression was restricted to the lining cells of the scala tympani and scala vestibuli. No GFP expression was seen in the organ of Corti or the spiral ganglion. Aminoglycoside treatment had no effect on the expression of these vectors. The distant spread of lentivirus vectors was minimal; only the liver of one animal showed some GFP expression. Inflammatory reaction caused by these vectors was mild. Few inflammatory cells were found in the perilymphatic space of the cochlea and in the vestibular organ.

Biocompatibility of polylactides in the middle ear: an experimental animal study.

OBJECTIVE: To study the suitability of resorbable polylactides for reconstruction in middle ear surgery. EXPERIMENTAL ANIMALS: Twenty-four chinchillas. INTERVENTIONS: Twenty chinchillas were operated on using 2 types of polylactides inserted into the middle ear and outer ear canal, 10 animals in each group. At 6 months, the animals were killed, and their temporal bones were removed for sectioning. Degree of inflammation, fibrosis, degradation of polylactide material, and new bone formation were assessed histologically. MAIN OUTCOME MEASURES: Polylactide implants caused only a mild local inflammation, with no difference between the 2 materials tested. CONCLUSION: Polylactide acid-based middle ear implants were successfully used in the reconstructive middle ear surgery. Resorption occurred without complications.