IntroductionCoronavirus disease 2019 (COVID‐19) has rapidly become a global pandemic, but little is known about its potential impact on patients with myasthenia gravis (MG).MethodsWe studied the clinical course of COVID‐19 in five hospitalized patients with autoimmune MG (four with acetylcholine receptor antibodies, one with muscle‐specific tyrosine kinase antibodies) between April 1, 2020‐April 30‐2020.ResultsTwo patients required intubation for hypoxemic respiratory failure, whereas one required significant supplemental oxygen. One patient with previously stable MG had myasthenic exacerbation. One patient treated with tocilizumab for COVID‐19 was successfully extubated. Two patients were treated for MG with intravenous immunoglobulin without thromboembolic complications.DiscussionOur findings suggest that the clinical course and outcomes in patients with MG and COVID‐19 are highly variable. Further large studies are needed to define best practices and determinants of outcomes in this unique population.

In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported “optophonic” effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach.

An important step to describe the effects of inner-ear impedance and pathologies on middle-and inner-ear mechanics is to quantify middle-and inner-ear function in the normal ear. We present middle-ear pressure gain G MEP and trans-cochlear-partition differential sound pressure ΔP CP in chinchilla from 100 Hz to 30 kHz derived from measurements of intracochlear sound pressures in scala vestibuli P SV and scala tympani P ST and ear-canal sound pressure near the tympanic membrane P TM . These measurements span the chinchilla's auditory range. G MEP had constant magnitude of about 20 dB between 300 Hz and 20 kHz and phase that implies a 40-μs delay, values with some similarities to previous measurements in chinchilla and other species. ΔP CP was similar to G MEP below about 10 kHz and lower in magnitude at higher frequencies, decreasing to 0 dB at 20 kHz. The high-frequency rolloff correlates with the audiogram and supports the idea that middle-ear transmission limits high-frequency hearing, providing a stronger link between inner-ear macromechanics and hearing. We estimate the cochlear partition impedance Z CP from these and previous data. The chinchilla may be a useful animal model for exploring the effects of nonacoustic inner-ear stimulation such as "bone conduction" on cochlear mechanics.