Antonio Quaranta

We present a case of squamous spindle cell carcinoma of the external auditory meatus in a 38-year-old man. The tumour was extended to the inner ear, the temporal bone, the middle cranial fossa and the meningo-cerebral tissue. The surgical intervention of temporo-occipital craniotomy removed most of the neoplasia. At pathologic examination, the tumour showed an undifferentiated spindle cell pattern. Immunohistochemistry with a large antibody panel found a weak positivity only to EMA. The diagnosis was made when the electron microscopy showed rare junctional structures and tonofilaments.

Conclusions The results show that, in humans, activation of the contralateral EAR makes the PTC narrower at 1 kHz but wider at 4 kHz. These data are consistent with those reported previously in animals and demonstrate that, during medial efferent stimulation in humans, frequency resolution is improved at low frequencies but impaired at high frequencies. Objective To evaluate, in humans, the effect of activation of the contralateral efferent acoustic reflex (EAR) on the psychoacoustical tuning curves (PTCs) recorded for 1- and 4-kHz probe tones. Material and methods Ten young (20–30 years) volunteers served as subjects. They had normal hearing (thresholds10 and Q₂₀ were calculated as the ratio between the test frequency and the bandwidth of the PTC at 10 and 20 dB above the tip of the curve, respectively. The EAR was activated with a 40-dB SL contralateral narrow-band noise centered on the characteristic frequency of the PTC (1 or 4 kHz). Q₁₀ and Q₂₀ were measured in the presence and absence of the contralateral noise. Results Activation of the EAR led to a significant increase (p10 at 1 kHz and a significant decrease (p20 were not significant.

The aim of this study was to evaluate, in 20 young volunteer subjects, the effects of supra-physiological vitamin B12 administration on noise-induced temporary threshold shift (TTS). All subjects had hearing thresholds within 15dBHL and type A tympanograms. The subjects were randomly assigned to two different groups. Experimental group subjects received cyanocobalamin, 1 mg daily for 7 days, and 5 mg on the eighth day. Control group subjects received a placebo injection daily for 8 days. The vitamin B12 concentration, hearing thresholds and TTS2 (10 min of exposure, narrowband noise centred at 3 kHz, bandwidth of 775 Hz, 112 dB SPL) were measured before and 8 days after treatment. At the end of treatment, the serum vitamin B12 concentration was significantly increased in the experimental group. After 8 days of treatment, the control group showed the same hearing thresholds and TTS2 degrees. Statistical analysis showed that TTS2 decreased significantly at 3 and 4 kHz when cobalamin was used to increase the serum concentration of vitamin B12 to >2350 pg/ml. In addition, a protective effect at 3 kHz in the experimental group was evident when compared with the placebo group. These results suggest that elevated plasma cyanocobalamin levels may reduce the risk of hearing dysfunction resulting from noise exposure in healthy, young subjects. El propósito de este estudio fue evaluar, en 20 sujetos voluntarios jóvenes, los efectos de la administración supra-fisiológica de vitamina B12 sobre el cambio temporal de los umbrales auditivos inducido por ruido (TTS). Todos los sujetos tenían umbrales auditivos alrededor de 15 dB HL y timpanogramas tipo “A”, y fueron distribuidos al azar en dos grupos diferentes. Los sujetos del grupo experimental recibieron 1 mg diario de cianocobalamina por 7 días, y 5 mg en el octavo día. Los sujetos del grupo control recibieron una inyección diaria de placebo por 8 días. La concentración de vitamina B12, el umbral auditivo y el TTS2 (10 minutos de exposición, ruido de banda estrecha centrado en 3 kHz, ancho de banda de 775 Hz, 112 dB SPL) se midieron antes del tratamiento y 8 días después del mismo. Al final del tratamiento, la concentración sérica de vitamina B12 estaba significativamente elevada en el grupo experimental. Luego de 8 días de tratamiento, el grupo control mostró los mismos umbrales auditivos y grados de TTS2. El análisis estadístico mostró que el TTS2 disminuyó significativamente en 3 y 4 kHz, cuando se utilizó la cianocobalamina para aumentar las concentraciones séricas de vitamina B12 hasta>2350pg/ml. Además, fue evidente un efecto protector en 3 kHz en el grupo experimental cuando se comparó con el grupo placebo. Estos resultados sugieren que los niveles plasmáticos elevados de cianocobalamina pueden reducir el riesgo de disfunción auditiva como resultado de la exposición al ruido, en sujetos jóvenes sanos.

Objective – To evaluate the effect of ipsilateral and contralateral low-frequency (250 Hz) narrow-band noise (NBN) on the temporary threshold shift (TTS) induced by a 2 kHz tone in young normally hearing subjects with a functioning auditory efferent system. Material and Methods – Sixteen young volunteers served as subjects. All the subjects were young (20–30 years), disease-free and had a medical history negative for otological disease, noise exposure and use of ototoxic drugs. They had normal hearing [thresholds of 125–8000 Hz below 20 dB hearing level (HL)], transient-evoked otoacoustic emissions and contralateral suppression. The subjects were randomly assigned to one of three different groups. Subjects in Group A (n=5) were exposed to a 90 dB HL 2 kHz pure tone for 10 min. Subjects in Group B (n=6) were exposed to a 90 dB HL 2 kHz pure tone and an ipsilateral 45 dB HL 250 Hz NBN for 10 min. Subjects in Group C (n=5) were exposed to a 90 dB HL 2 kHz pure tone and a contralateral 45 dB HL 250 Hz NBN for 10 min. The right ear served as the test ear. The TTS 2 min after the end of the exposure (TTS₂) was measured in all subjects at 2, 3 and 4 kHz. Results – TTS₂ in Group A was significantly higher at 3 kHz (p=0.011) and at 4 kHz (p=0.003) than TTS₂ in Group B. At 4 kHz, TTS₂ in Group C was significantly higher (p=0.013) than TTS₂ in Group B. Although TTS₂ in Group C was lower than TTS₂ in Group A, this difference was not significant. The presence of an ipsilateral low-frequency NBN significantly reduced TTS₂ induced by a 90 dB HL 2 kHz tone. A contralateral low-frequency NBN reduced TTS₂ in this group of subjects; however, the reduction was not significant. Conclusion – The results of this study show that an ipsilateral low-intensity, low-frequency (250 Hz) NBN can give protection from a TTS induced by a 2 kHz tone. Contralateral low-frequency NBN did not induce any protective effect.

The aim of the present study was to evaluate the performance of ears with inner ear disorder, responsive to immunosuppressive drugs, in advanced tests designed to assess primary cochlear functions (temporal integration, frequency selectivity, cochlear mechanics). The results of this study suggest that immunomediated inner ear disease results, in the acute clinical stage, in the development of endolymphatic hydrops, which increases the stiffness of the vibrating structures within the inner ear and causes dysfunctions of the outer hair cells. Our patients presented with upsloping or flat sensorineural hearing loss, absence of evoked otoacoustic emissions and distortion-product otoacoustic evoked emissions and abnormal temporal integration, frequency selectivity and cochlear mechanics. Following immunosuppressive treatment, hydrops recovered, hearing subsequently returned to normal, the audiometric curve became flat at low-to-middle frequencies and primary cochlear function tended to normalize. This study seems to support the usefulness of testing primary cochlear functions in order to monitor the clinical course of immunomediated inner ear disorders.