Abordagem inicial no atendimento ambulatorial em distúrbios neurotoxicológicos: parte III - solventes orgânicos / Initial approach to outpatient treatment of neurotoxicological disorders: Part III – organic solvents

Introdução: Milhões de pessoas são expostas diariamente aos solventes. Inúmeros solventes podem causar intoxicação aguda. Menos clara é a associação da exposição crônica e em baixas doses poder produzir alteração neurológica. Diversas atividades ocupacionais estão envolvidas com a sua exposição. Condição bastante diferente é o seu uso inadvertido com intuito alucinógeno. Método: Trata-se de revisão atualizada da literatura a partir de pesquisa na base de dados MEDLINE e LILACS. Também utilizou-se livros e documentos publicados em formato eletrônico.Discussão: Distúrbios neuromusculares, distúrbios do movimento, alterações cognitivo-comportamentais e neurofisiológicas têm sido relacionados a inúmeros agentes tóxicos nos últimos anos. A proposta deste artigo é revisar os principais distúrbios neurológicos associados à exposição crônica por solventes orgânicos. A fim de facilitar a abordagem inicial no atendimento ambulatorial aos distúrbios neurotoxicológicos foram confeccionadas tabelas descrevendo os principais agentes tóxicos, as fontes de exposição envolvidas e suas principais manifestações neurológicas. Conclusão: Tolueno, bissulfeto de carbono e n-Hexano são alguns solventes envolvidos nos distúrbios neurotoxicológicos, Contudo, fica evidente nesta revisão que são necessários novos estudos a fim de determinar a real associação destes e outros solventes nos distúrbios crônicos do sistema nervoso central e periférico.

Introduction: Millions of peoples are exposed to solvents every day. Most solvents cause acute intoxication. Less evident is the association of chronic exposure and in low doses in producing neurological disorders. Innumerable occupational activities are involved in the exposure to solvents. Their inadvertent use with hallucinogenous intention is an entirely different condition. Method: The method consists of an updated review of the literature based on research in the MEDLINE and LILACS databases, as well as books and documents published online. Discussion: Neuromuscular disorders, movement disorders, cognitive-behavioral and neurophysiological changes have been attributed to innumerable toxic agents in recent years. This article proposes to review the main neurological disorders associated with chronic exposure to organic solvents. To facilitate the initial approach to treatment of neurotoxicological disorders of outpatient, tables were devised to describe the main toxic agents, the sources of exposure involved and their main neurological manifestations. Conclusions: Toluene, carbon bisulfate and n-hexane are some of the solvents involved in neurotoxicological disorders. However, this review reveals the need for new studies to determine the real association of these and other solvents in chronic disorders of the central and peripheral nervous systems.

[Evaluation of neuropathy in workers predisposed to inhalation of N-hexane]

Workers who are exposed to inhalation N-hexane can gradually develop progressive polyneuropathy, sometimes results in paralysis and even death. Shoe workers, printers, rubber cement workers and every other job which use glue, are at risk of inhalation of N-hexane. The aim of this study was to compare variables related to neuropathy in these workers with healthy controls. We compared the results of nerve conduction study [NCS] on 30 N-hexane-exposed cases and 30 non-exposed healthy controls. All participants were male. Case group included 12 printers and 18 shoemakers. Their mean occupational experiences were 5.2 and 17 years, respectively. Mean of sural sensory nerve action potential [SNAP] and tibial compound muscle action potential [CMAP] amplitudes were significantly lower in exposed group [p value <0/05]. Mean of F-wave distal latencies significantly higher in the exposed individuals [p value<0/50]. Mean of sural SNAP and tibial CMAP-related distal latencies and tibial CMAP-related conduction velocities were not significantly different [P value >0/05]. This study showed peripheral nervous system involvement in glue-exposed workers. It seems that NCS is an effective method for diagnosis of subclinical and clinical neuropathy in N-hexane exposure. We can use this inexpensive and noninvasive method for screening and prevention of polyneuropathy in such persons

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.

Glue sniffing neuropathy

N-hexane induced polyneuropathy is well recognized. Glue Sniffing, the volatile substance abuse or a long tern exposure to an offending solvent at place of work causes a type of sensory-motor neuropathy. A sub-acute pure motor presentation, in a young Bahraini male is reported and relevant literature reviewed