Clinical features and prognostic factors of pediatric idiopathic sudden hearing loss from moderate to profound degree.

BACKGROUND: The pediatric idiopathic sudden sensorineural hearing loss (PISSNHL) is not rare in the clinics, however, the prognostic factors of PISSNHL are still unclear. OBJECTIVES: To investigate the clinical and audiologic characteristics associated with prognosis in PISSNHL. MATERIAL AND METHODS: Clinical and audiological characteristics and possible prognostic factors were retrospectively evaluated in 76 PISSNHL patients aged less than 19 years. RESULTS: Hearing loss was moderate in nine patients, severe in 21 patients, profound in 46 patients. Among five types of audiogram, 3.9% were classified as ascending, 11.8% as descending, 25.0% as flat, 55.3% as profound, and 3.9% as concave. The recovery rate according to Siegel's criteria was 55.3%. There was no significant difference between the recovery group and the poor recovery group in terms of age, sex, laterality of hearing loss, the onset of treatment, and accompanying symptoms (p > 0.05). The initial hearing levels and the audiogram type were significantly different in the two groups (p < 0.001) according to univariate analysis, while only the initial hearing level was significantly different (p = 0.046) according to multivariate analysis. CONCLUSIONS AND SIGNIFICANCE: Prognosis of PISSNHL was mainly related to initial hearing at onset. An initial hearing level greater than 80 dB was a poor prognostic factor.

Reanimation of paralyzed laryngeal muscles by electrical stimulation synchronized with inspiration.

OBJECTIVE: To determine the effects of electrical stimulation on denervated cat posterior cricoarytenoid (PCA) muscle. STUDY DESIGN AND SETTING: This study was conducted on six cats with PCA muscle denervation. All animals were sacrificed 12 weeks after surgery and the glottal area in the live animals and the fiber diameters of PCA muscle were obtained. RESULTS: Signals synchronized with inspiration were recorded and transmitted to stimulate PCA muscle. The abduction of the paralyzed vocal cord during inspiration was observed; this allows enough flow of air through the larynx to maintain the respiration. The stimulated fiber diameters of PCA muscle were different from that of nonstimulated (P < 0.01). Although all denervated muscles were degenerated, electrical stimulation was used to prevent muscular atrophy. CONCLUSIONS: This study indicates that electrical stimulation of the PCA muscle synchronized with inspiration could restore the abduction of a paralyzed vocal cord and prevent the denervated muscles from atrophying. SIGNIFICANCE: Electrical stimulation synchronized with inspiration may lead to reanimation of paralyzed laryngeal muscles.