Exposición a solventes y disfunción auditiva central: revisión de la evidencia científica / Solvent exposure and central auditory dysfunction: a literature review on the scientific evidence

Diversos estudios han demostrado que los solventes orgánicos pueden inducir una disfunción auditiva. Los modelos animales han mostrado que los solventes son capaces de dañar las células ciliadas externas. Estudios de campo en trabajadores expuestos a solventes han encontrado por una parte, una mayor prevalencia de hipoacusia sensorioneural en comparación a grupos controles, y por otra, una dis función auditiva central asociada a la exposición a solventes. El presente trabajo tiene como objetivo revisar y discutir la evidencia científica acerca de la disfunción auditiva central asociada a la exposición a solventes como el tolueno, estireno, xileno, bisulfato de carbono, y mezcla de ellos. Se discuten los resultados de las investigaciones llevadas a cabo en humanos expuestos laboralmente a estos agentes. Se discuten además, los mecanismos de ototoxicidady neurotoxidad de los solventes y sus implicancias en la evaluación de la hipoacusia inducida por solventes.

Different studies have demonstrated that solvents may induce an auditory dysfunction. Animal models have shown that solvents can injure the outer hair cells. Studies conducted in workers exposed to solvents have found on one hand, a higher prevalence of sensorineural hearing loss in comparison to non-exposed control group subjects. On the other hand, these studies have found a central auditory dysfunction associated with solvent exposure. The present manuscript aims at revising and discussing the scientific evidence on central auditory dysfunction associated with exposure to solvents such as toluene, styrene, xylene, carbon disulphate, and mixtures. Results from studies conducted in humans occupationally exposed to solvents are discussed. Also, the oto-and neuro-toxicity induced by solvents and the implications for the assessment of solvent-induced hearing loss are addressed.

Intoxicación por amitraz / Amitraz poisoning

En nuestro medio, la intoxicación por amitraz y su solvente xileno es una patología poco frecuente, pero puede observarse un aumento en zonas rurales, donde se lo emplea como insecticida-ectoparasiticida. Por tal razón, se cuenta con escasa bibliografía que oriente su manejo en niños. Presentamos el caso de un paciente de 2 años de edad, con ingestión accidental de amitraz, internado en nuestra Unidad de Cuidados Intensivos Pediátricos y que requirió ventilación mecánica. Creemos que comunicar este caso puede ser útil para alertar sobre esta intoxicación, poco frecuente en nuestro medio.

Poisoning due to amitraz together with its solvent xilene, is an unusual condition although may be increasing in rural areas where it is used as insecticide-ectoparasiticide. At present, there is scare references to orient physicians concerning its handlingin childhood. We present the case of a 2-year-old boy who suffered an accidental intake of amitraz and was admitted into our Pediatric Intensive Care Unit requiring mechanical ventilation. We consider the usefulness of informing the medical community about this case so as to be aware of this rare kind of poisoning in our community.

Audiological findings in individuals exposed to organic solvents: case studies.

Millions of people around the world are exposed to industrial organic solvents such as toluene and xylene in the manufacturing sectors. Solvents are neurotoxic substances that are detrimental to the functioning of the nervous system, including the central auditory nervous system (CANS). This study investigated hearing and auditory processing in seven individuals with a history of exposure to industrial solvents. A battery of audiological tests was administered to all subjects: pure tone, speech, and impedance audiometry, otoacoustic emissions tests, auditory brainstem responses, middle latency responses, as well as the SCAN-A and R-SPIN tests with low predictability sentence lists. All individuals in this study exhibited findings consistent with retrocochlear and/or central abnormality. Two of the seven subjects in this study had normal pure tone thresholds at all frequencies bilaterally, yet showed abnormal retrocochlear/central results on one or more tests. The auditory test battery approach used in this study appears to be valuable in evaluating the pathological conditions of the CANS in solvent-exposed individuals.

Distúrbios otoneurológicos relacionados aos agentes químicos - revisäo de literatura de 2 caos de intoxicaçäo por mercúrio / Otoneurological disturbances related to chemical agents - literature review and report of 2 cases of mercury intoxication

Os autores fazem uma revisão de literatura sobre alterações do sistema otoneurológico, decorrente da ação de agentes químicos como solventes e metais pesados, na maioria das ocasiões por exposição no trabalho. Relatam dois casos de intoxicação ocupacional por mercúrio, comentando a importância dos exames complementares para o diagnóstico.