Foot drop - an uncommon presentation of FOLFOX toxicity

A quimioterapia com FOLFOX (oxaliplatina, leucovorina e 5-fluorouracilo) é frequentemente utilizada em doentes com cancro colorretal. Os sais de platina são conhecidos por serem uma classe de quimioterápicos que comumente induzem neurotoxicidade periférica. Na toxicidade induzida pela oxaliplatina, os sintomas sensitivos são os mais frequentes. Neste artigo, apresentamos dois casos clínicos de pacientes com adenocarcinoma de cólon, ambos submetidos à quimioterapia com FOLFOX4, e que desenvolveram neurotoxicidade incomum, apresentando pé pendente após o terceiro ciclo de tratamento. Esta manifestação clínica pode ser explicada por dano axonal nos neurônios motores periféricos do nervo peroneal comum (fibular), que fornece inervação motora aos músculos do pé. A paralisia do nervo fibular causa fraqueza súbita nos músculos do pé, que parece ser temporária. Ambos os doentes recuperaram completamente do evento sem necessidade de ajustes no tratamento, nem introdução de medicamentos diferentes. A apresentação de pé pendente como toxicidade da quimioterapia ainda é pouco compreendida. Os casos relatados mostram o pé pendente como uma manifestação grave e incomum de neuropatia induzida por FOLFOX, que pode ser transitória, e não requer necessariamente intervenção específica.

Chemotherapy based on FOLFOX (oxaliplatin, leucovorin, and 5-fluorouracil) regimen is frequently used in colorectal cancer patients. Oxaliplatin and other platinum agents are known to be a class of chemotherapy drugs that commonly induce peripheral neurotoxicity. The most frequent oxaliplatin related neurotoxicity is sensitive symptoms. Here, we present two cases of patients with colon adenocarcinoma, both undergoing chemotherapy with FOLFOX4, who developed uncommon neurotoxicity, presenting with foot drop after the third treatment cycle. Foot drop may be explained by axonal damage of peripheral motor neurons of the common peroneal (fibular) nerve, which provides motor innervation to the foot muscles. Peroneal nerve palsy causes sudden weakness in the muscles of the foot that seems to be temporary. Both patients completely recovered from the event. There was no need for treatment adjustments, neither introduction of different drugs. Foot drop as chemotherapy toxicity is still poorly understood. The reported cases show foot drop as a severe and uncommon manifestation of FOLFOX-induced neuropathy, that might be transitory, and does not necessarily requires specific intervention.

Developmental neurotoxicity: methylmercury and prenatal exposure protection in the context of the Minamata Convention / Neurotoxicidad durante el desarrollo: metilmercurio y protección frente a la exposición prenatal a este contaminante en el contexto del Convenio de Minamata

Mercury is a global pollutant of public environmental health concern due to its long-range atmospheric distribution, environmental distribution, and neurotoxic effects. Following biological methylation, methylmercury (MeHg) can be un-evenly bioaccumulated within aquatic food chains. Fish consumption can be a significant route of human exposure to MeHg. MeHg exposure in the prenatal stage, at relatively low levels, has recently been established as harmful during neurological development, potentially leading to intellectual disability. The Minamata Convention on Mercury is a global agreement, currently under ratification, to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. The resolution regarding the role of the World Health Organization and ministries of health in the implementation of the Convention includes protection of human health from critical exposures to MeHg. Riverside populations living in areas with artisanal small-scale gold mining, and relying heavily on fish consumption, have been identified as the most vulnerable population in terms of MeHg exposure and developmental neurotoxicity. This article focuses on the proper design and dissemination of fish advisories within the context of implementation of the Convention.

El mercurio es un contaminante global motivo de preocupación en materia de salud pública ambiental como consecuencia de su amplia distribución atmosférica, su distribución ambiental y sus efectos neurotóxicos. Tras su metilación biológica, el metilmercurio (MeHg) se puede bioacumular de manera desigual en las cadenas alimentarias acuáticas. El consumo de pescado puede ser una ruta significativa de exposición humana al MeHg. Recientemente, se ha establecido que la exposición a niveles relativamente bajos de MeHg en la etapa prenatal es perjudicial para el neurodesarrollo, pudiendo ocasionar discapacidad intelectual. El Convenio de Minamata sobre el Mercurio es un acuerdo a escala mundial, actualmente en fase de ratificación, cuyo objeto es proteger la salud humana y el medio ambiente de las emisiones antropogénicas y los vertidos de mercurio y sus compuestos. La resolución referente a la función de la Organización Mundial de la Salud y los ministerios de salud en la aplicación del Convenio incluye la protección de la salud humana de exposiciones importantes al MeHg. Se ha establecido que las poblaciones ribereñas que residen en zonas de extracción artesanal de oro a pequeña escala, y que dependen en gran medida del consumo de pescado, son las más vulnerables en términos de exposición al MeHg y neurotoxicidad durante el desarrollo. Este artículo se centra en el diseño y la difusión adecuados de las recomendaciones relativas al consumo de pescado en el contexto de la aplicación del Convenio.