We report on a family with maternally inherited sensorineural hearing loss, in which no history of aminoglycoside injection and no other specific etiology could be identified in any member. A 1555 A-to-G mutation of mitochondrial DNA was found in all members demonstrating hearing loss. The hearing in the propositus and his sister was severely impaired at a younger age than that in the mother. This case suggests that the 1555 point mutation of mitochondrial DNA has potential to promote inherited nonsyndromic hearing loss without any known etiology.

Facial nerve stimulation by an activated cochlear implant was noted in a 56-year-old patient who had undergone cochlear implant with a Nucleus 22 implant 2 years previously as treatment for total sensorineural hearing loss following meningitis at age 54. Past history was complicated by total renal failure for which hemodialysis had been required during the past 13 years. Facial spasm occurred 5 months postoperatively with activation of the basal electrodes (channels 13 and 15 of the implant). The facial stimulation was eliminated by deprogramming these electrodes. High-resolusion computed tomography (CT) scanning was unable to demonstrate lucency of the otic capsule and cochlear ossification, but basal electrodes of the implant could be identified near the labyrinthine segment of the facial nerve. To further evaluate bone changes in the patient, the total and regional bone mineral density (BMD) of the head and radius was measured by dual energy X-ray absorptiometry. All BMD values of the patient were markedly low when compared to those of 62 other hemodialysis patient. These findings demonstrate that facial nerve stimulation can occur in the presence of low impedance due to cortical bone changes induced by long-term hemodialysis.

We have established a new model for investigating the relationship between cochlear lateral wall damage and sensory cell degeneration in guinea pigs by using a photochemical reaction between the systemic injection of Rose Bengal (RB) and controlled green light irradiation to the cochlea. The photochemical reaction produced a reactive oxygen species, which then damaged the endothelium. This triggered platelet adhesion and aggregation at the site of endothelial injury to produce thrombi and affect microcirculation in the lateral wall at the site of irradiation. Changes were studied under a scanning electron microscope (SEM), and compound action potentials (CAP) were measured. SEM observations after tangential illumination of the cochlear wall revealed degeneration of the stria vascularis (SV). Specific morphological findings at 24 h included delayed degeneration of the outer hair cells concurrent with a significant increase in the CAP. Based on these findings, we suggest that degeneration of the SV was a direct result of the photochemical reaction, but CAP changes and sensory hair cell damage were secondarily caused by SV degeneration.

Cervical lymphadenopathy with packet formation as the sole presentation of tuberculosis is very rarely seen in modern Japan.

This study describes the effect of speech rate (fast, 11 syllables per second; medium, 9 syllables per second; slow, 6 syllables per second) on speech perception in 10 cochlear implant users. The speech perception performance was evaluated on the basis of the percentage score of syllables that were correctly recalled in sentences composed of 4 to 6 words. The percentage scores at the fast, medium, and slow speech rates were 15.7%, 39.0%, and 56.0%, respectively. The effect of speech rate slowing was significant (p < .0001). Variations in the effect of speech rate slowing were observed in the cochlear implant users. The improvement of speech perception by speech rate slowing was significantly (p < .005) related to the word test score and the score at the fast speech rate. The results reveal that the rate of speech is an important factor in improving the speech perception of cochlear implant users.