In Vivo Real-time Remote Cochlear Implant Capacitive Impedance Measurements: A Glimpse Into the Implanted Inner Ear.

OBJECTIVES: To propose a remote, real-time, safe, and easy systematic method to determine electrode electric impedance components: access resistance, polarization capacitance, and polarization resistance. PATIENTS: Patients who received a cochlear implant and had normal cochlear anatomy and complete array insertion were recruited. A total of four adult patients were included and separated in two groups according to implantation time. INTERVENTION: Cochlear implant electrical impedance and its components were measured in all patients by using a novel diagnostic tool: a custom made software running in the patient's computer. Data is transmitted in real time to the investigator. Various stimulation and measuring strategies were used to obtain specific information in each cochlear region. MAIN OUTCOME MEASURES: Access resistance, polarization capacitance, and resistance of each patient were measured. Measurement success rate and required time for the patient were recorded. RESULTS: Access resistance, polarization capacitance, and resistance were obtained in different modes, thus in every specific region of the cochlea. All measurements were successful. Each measurement took approximately 7 minutes and was transmitted in real time to the investigators. CONCLUSION: Routine use of this tool may allow constant assessment of cochlear health and could be eventually used to monitor the effect of drugs in the inner ear. This methodology provides an in vivo "electrical view" of the inside of the implanted cochlea.

Real-Time Intracochlear Electrocochleography Obtained Directly Through a Cochlear Implant.

HYPOTHESIS: Utilizing the cochlear implant to record electrophysiologic responses during device placement is a feasible and efficacious technique for monitoring near real-time cochlear physiology during and following electrode insertion. BACKGROUND: Minimizing intracochlear trauma during cochlear implantation has emerged as a highly researched area to help improve patient performance. Currently, conventional cochlear implant technology allows for the recording of electrically evoked compound action potentials (eCAPs). Acoustically evoked potentials may be more sensitive in detecting physiologic changes occurring as a result of electrode insertion. Electrocochleography obtained from within the cochlea allows hair cell and neural response monitoring along the cochlear spiral at locations where changes most likely would occur. METHODS: Intracochlear electrocochleography (ECochG) was recorded from the cochlear implant during surgery in 14 subjects. A long acquisition time (54.5 ms), capable of measuring potentials from the low frequency-serving apical region of the cochlea (125 and 500 Hz) was employed. Two distinct intracochlear processing methods were used and compared in obtaining electrophysiologic data. RESULTS: Measureable intracochlear ECochG responses were obtained from all 14 participants. The 1st harmonic distortions (cochlear microphonic and auditory nerve neurophonic) generally increased steadily with electrode insertion. Electrode and frequency scan following insertion revealed that response amplitude varied based on location of recording electrode and frequency of stimulation. Exquisite sensitivity to manipulation during round window muscle packing was demonstrated. CONCLUSION: Intracochlear ECochG recorded from the electrode array of the cochlear implant is a highly feasible technique that sheds light on cochlear micromechanics during cochlear implant electrode placement.

Serie parasitosis en dermatología. Miasis: diferentes formas de presentación clínica / Parasitic series in dermatology. Myiasis: different forms of clinical presentation

La miasis es una infestación por larvas en desarrollo de una gran variedad de moscas del orden Díptera. Según el sitio de invasión, se clasifica en miasis cavitarias, que pueden deberse a invasión de cavidades naturales o de heridas, y miasis forunculoide, cuando atraviesa piel indemne. Esta infestación presenta una distribución mundial, con variaciones estacionales en relación con la latitud geográfica y el ciclo de vida de distintas especies de moscas. Presentamos una serie de tres casos de pacientes con distintas formas clínicas de manifestación de miasis. (AU)

Myiasis is the tissue infestation by a variety of Diptera order larvae flies. According to the invasion site, they are classified in myiasis of cavities, which can be because of an invasion of natural cavities or wounds, and furuncular myiasis, when they invade through intact skin. This infestation has a worldwide distribution, with seasonal variations in relation to the geographic latitude and the life cycle of different species of flies. We present three cases of patients with different clinical forms of presentation of myiasis. (AU)

Carcinoma espinocelular del oído externo con extensión parotídea: a propósito de un caso / Squamous cell carcinoma of the external ear with parotid extension: case report

El pabellón auricular y el conducto auditivo externo constituyen una región anatómica que puede ser asiento de múltiples patologías, entre ellas procesos inflamatorios, infecciosos y neoplásicos, tanto benignos como malignos. Con respecto a los tumores, los diversos tipos suelen presentarse con síntomas y signos similares y en general es difícil inferir la variedad histológica del tumor a través del examen físico, por lo cual es necesario el estudio histopatológico para determinar el diagnóstico. La mayoría de los tumores del oído externo son carcinomas; entre ellos se destacan el carcinoma basocelular, el más frecuente, y el carcinoma espinocelular. Menos frecuentemente se encuentran otros tipos de tumores como los melanomas, adenocarcinomas, carcinomas de glándulas ceruminosas, carcinomas mucoepidermoides, sarcomas, procesos linfoproliferativos, etc. Suelen ocurrir en la edad media y avanzada (50-70 años) y con mayor periodicidad en el sexo masculino. En el presente trabajo se describe un caso clínico de carcinoma espinocelular del oído externo, tratado exitosamente mediante cirugía y radioterapia, así como también se describen las características clínicas de esta enfermedad, con especial atención al compromiso del oído externo por ella.

The pinna and the ear canal are an anatomical region that can be affected by many diseases, including inflammatory, infectious and benign and malignant neoplastic processes. With regard to tumors, various types usually present with similar symptoms and usually is very difficult to know the histological type through physical examination, so histopathological examination is necessary in order to determine the diagnosis. Most tumors are carcinomas; they can be basal cell carcinoma (more frequently), or squamous carcinoma. Less frequently are other types of tumors such as melanomas, adenocarcinomas, ceruminous glands carcinomas, mucoepidermoid carcinomas, sarcomas, lymphoproliferative disorders, etc. They usually present in middle and advanced age people (50-70 years) and are more frequently in men. In this article we present a case of squamous cell carcinoma of the external ear with extention to parotid gland, successfully treated with surgery and radiotherapy, as well as we describe the clinical characteristics of this disease, with special attention to the compromise of the external ear. (AU)