The Effects of Riluzole on Cisplatin-induced Ototoxicity

Abstract Introduction Riluzole (2-amino-6-trifluoromethoxy benzothiazole) is known as a neuroprotective, antioxidant, antiapoptotic agent. It may have beneficial effects on neuronal cell death due to cisplatin-induced ototoxicity. Objective To evaluate the effect of riluzole on cisplatin-induced ototoxicity in guinea pigs. Methods Twenty-four guinea pigs, studied in three groups, underwent auditory brainstem response evaluation using click and 8 kHz tone burst stimuli. Subsequently, 5 mg/kg of cisplatin were administered to all animals for 3 days intraperitoneally (i.p.) to induce ototoxicity. Half an hour prior to cisplatin, groups 1, 2 and 3 received 2 ml of saline i.p., 6 mg/kg of riluzole hydrochloride i.p., and 8 mg/kg of riluzole hydrochloride i.p., respectively, for 3 days. The auditory brainstem responses were repeated 24 hours after the last drug administration. The cochleae were analyzed by transmission electron microscopy (TEM). Results After drug administiration, for 8,000 Hz stimulus, group 1 had significantly higher threshold shifts when compared with groups 2 (p < 0.05) and 3 (p < 0.05), and there was no significant difference in threshold shifts between groups 2 and 3 (p > 0.05). Transmission electron microscopy findings demonstrated the protective effect of riluzole on the hair cells and the stria vascularis, especially in the group treated with 8 mg/kg of riluzole hydrochloride. Conclusion We can say that riluzolemay have a protective effect on cisplatin- induced ototoxicity. However, additional studies are needed to confirm these results and the mechanisms of action of riluzole.

Emissões otoacústicas transientes como método complemantar no topodiagnóstico das perdas auditivas neurossensoriais / Passing otoacustic emissions as a complementar method in the topodiagnosis of the neurosensories hearing loss

Introdução: Não faz parte da rotina clínica avaliar as emissões otoacústicas (EOAETs) em pacientes com perda auditiva neurossensorial. Entretanto obter-se-ia informações valiosas em relação ao topodiagnóstico. Objetivo: Identificar sinais de alteração retrococlear em indivíduos com diagnóstico de disacusia neurossensorial. Método: Estudo prospectivo, quantitativo, observacional e transversal. Foram analisados 34 prontuários de usuários do Serviço de Atendimento Fonoaudiológico. Foram incluídos no estudo indivíduos com perda auditiva neurossensorial de grau moderado a profundo. Realizou-se avaliação de Emissões Otoacústicas Transientes (EOAETs) em todos os indivíduos da amostra. Os que não apresentaram EOAETs tiveram a condição das orelhas média e externa avaliadas por meio de meatoscopia e timpanometria para eliminar orelhas com sinais de alteração condutiva. Resultados: Após aplicados os critérios de exclusão, restaram 13 indivíduos, totalizando 26 orelhas: quatro com perda auditiva de grau moderado (15%), quatro com grau moderadamente severo (15%), duas com grau severo (8%), 15 com grau profundo (58%) e uma com anacusia (4%). As curvas timpanométricas encontradas foram 22 (85%) Tipo A e quatro (15%) Tipo C. Verificou-se presença de EOAETs em apenas duas orelhas (8%) de um mesmo sujeito. Conclusão: Verificou-se predomínio de ausência de EOAETs em sujeitos com perda auditiva neurossensorial de grau moderado a profundo. Em um único caso as EOAETs foram registradas, o que sugere alteração retrococlear. Levantando a suspeita de alterações retrococleares.

Introduction: To evaluate the otoacustic emissions (EOAETs) in patients with neurosensory hearing loss do not belong to the clinical routine. However it would obtain valuables information concerning the topodiagnosis. Objective: To identify signs of retro cochlear alteration in individuals with neurosensory dysacusis diagnosis. Method: A transversal, observational, quantitative and, prospective study. Were analyzed 34 patients' records of users of the Speech Therapy Attendance Service. In the study were included individuals with neurosensory hearing loss of moderate to deep degree. An evaluation of Passing Otoacustic Emissions (EOAETs) was performed in all the individuals of the sample. Those that do not presented EOAETs had the external and middle ear' condition evaluates through meatoscopy and tympanometry to eliminate ears with sings of conductive alteration. Results: Before that the exclusion criteria were applied, they have remained 13 individuals, totalizing 26 ears: four with hearing loss of moderate degree (15%), four with moderately severe degree (15%), two with severe degree (8%), 15 with deep degree (58%) and, one with deafness (4%). The tympanometric curves found were 22 (85%) Type A and, four (15%) Type C. It was verified the presence of EOAETs in only two ears (8%) of a same individual. Conclusion: It was verified the predominance of the EOAETs absence in individuals with neurosensory hearing loss of moderate to deep degree. In one case the EOAETs were registered, that suggest retrocochlear alteration. Raising suspicion of retrocochlear alterations.

Resonancia Nuclear Magnética del hueso temporal / MNR of the temporal bone

La evolución por Resonancia Magnética del hueso temporal y del ángulo cerebelopontino, es de rutina en el paciente con hipoacusia neurosensorial y acúfenos a fin de descartar un neurinoma del octavo par. Sin embargo existen otras patologías poco frecuentes que asientan en esta región. En un período de cuatro años se estudiaron 5 pacientes que presentaron neuritis del nervio facial, 5 con laberintitis osificante, 1 caso de trombosis carotídea en su trayecto intrapetroso por fractura del peñasco, un encefalocele temporal por dehiscencia del tegmen timpani, 4 neurinomas del facial y 1 paciente con fístula dural. El propósito de este trabajo es demostrar la utilidad de la RM como método no invasivo en el diagnóstico de estas patologías

Manifestaciones vestibulares en las enfermedades metabolicas / Vestibular manifestations in metabolic diseases

Se sugiere un estudio minucioso en todos los pacientes con sintomatología vestibular vertiginosa haciendo, notar la importancia de la evaluación otoneurologíca en relación a los pacientes con alteraciones metabólicas mas comunes como las disglicemias, hiperuricemia, hipercolesterolemia.

Preservaçäo da audiçäo na cirurgia do neurinoma do acústico / Hearing preservation in surgery of acoustic neurinoma

Os autores descrevem sua experiência com a preservaçäo do nervo coclear e da audiçäo na cirurgia do neurinoma do acústico. Dos sete casos com audiçäo pré-operatória, operados nos últimos quatro anos, a audiçäo foi mantida no nível pré-operatório em seis deles. Justificam a preferência pelo acesso suboccipital, retosigmoideo transmeatal para a cirurgia de qualquer neurioma do acústico e apontam os detalhes técnicos que devem ser observados para atingir os objetivos da cirurgia

SISI modificado: sua aplicaçäo em indivíduos normais e em pacientes com perdas neuro-sensoriais / Modified SISI: its applications in normal subjects and in patients with neuro-sensorial loss

The SISI-modified test was applied in 242 ears: 72 normal ones, 130 with cochlear sensorineural hearing loss and 12 with acoustic neurinoma. The results were presented and its validity as a meaningfull test in the diagnostic audiologic battery was discussed