Cochlear implants (CIs) provide auditory perception to individuals with severe hearing impairment. However, their ability to encode complex auditory stimuli is limited due, in part, to poor spatial resolution caused by electrical current spread in the inner ear. Directing nerve cell processes towards target electrodes may reduce the problematic current spread and improve stimulatory specificity. In this work, photopolymerization was used to fabricate micro- and nano-patterned methacrylate polymers to probe the extent of spiral ganglion neuron (SGN) neurite and Schwann cell (SGSC) contact guidance based on variations in substrate topographical cues. Micropatterned substrates are formed in a rapid, single-step reaction by selectively blocking light with photomasks which have parallel line-space gratings with periodicities of 10 – 100 μm. Channel amplitudes of 250 nm – 10 μm are generated by modulating UV exposure time, light intensity, and photoinitiator concentration. Gradual transitions are observed between ridges and grooves using scanning electron and atomic force microscopy. The transitions stand in contrast to vertical features generated via etching lithographic techniques. Alignment of neural elements increases significantly with increasing feature amplitude and constant periodicity, as well as with decreasing periodicity and constant amplitude. SGN neurite alignment strongly correlates (r = 0.93) with maximum feature slope. Multiple neuronal and glial types orient to the patterns with varying degrees of alignment. This work presents a method to fabricate gradually-sloping micropatterns for cellular contact guidance studies and demonstrates spatial control of inner ear neural elements in response to micro- and nano-scale surface topography.

The national rate of craniotomy for spontaneous CSF leak repair is rising. This condition is yet another public health problem related to the rising obesity epidemic. All patients with spontaneous CSF leaks should be evaluated for OSA.

Objective Compare pre and postoperative performance in patients undergoing cochlear implantation (CI) for unilateral severe-to-profound sensorineural hearing loss (single-sided deafness, SSD). Study design IRB-approved, prospective Setting Tertiary center Patients Twenty-nine patients have undergone CI for SSD. SSD was due to Ménière's disease (MD) in 10 subjects; these also suffered from recalcitrant vertigo spells and in these 10 patients along with 2 others the CI was placed simultaneous with a labyrinthectomy. Intervention(s) CI with or without labyrinthectomy. Main outcome measure(s) CNC word and AzBio sentences in quiet were administered to the implanted ear. A multiple-loudspeaker sound localization test was administered in the bilateral listening condition. All data were collected pre-operatively and 3, 6, 12-months post-operatively with post-operative data available for 19 subjects. Additionally, a tinnitus handicap questionnaire is administered pre- and 12-months post-operatively. Results CNC word and AzBio sentence scores showed improvement in the implanted ear. Sound localization appeared to improve in an experience dependent fashion in some patients. Most patients reported diminished tinnitus following cochlear implantation. All patients undergoing labyrinthectomy experienced resolution of vertigo attacks. Conclusions CI restores auditory function to the deafened ear. Additionally, the binaural input appears to improve sound localization for most patients. In patients with severe hearing loss and recalcitrant vertigo attacks due to MD, simultaneous labyrinthectomy and CI effectively relieves vertigo attacks and improves auditory function.