É apresentado caso de paciente agricultor que, após uso inadequado de inseticida organofosforado (triclorfon), teve sinais e sintomas de intoxicação aguda e, três meses após, desenvolveu quadro de polineuropatia sensitivo-motora. O exame eletroneuromiográfico revelou alterações axonais e desmielinizantes difusas. O estudo do nervo sural, em cortes semi-finos, à ultramicroscopia e à técnica de fibras isoladas revelou degeneração axonal e transformação granular do axoplasma com perda dos neurofilamentos e neurotúbulos.

The authors observed a patient who worked in a farm and suffered an organophosphate intoxication (trichlorphon). The immediate effect was manifested by vomiting and abdominal cramps. Three months later he presented a distal symmetric sensorimotor (predominantly motor) neuropathy with distal muscle atrophy. Electromyography has revealed denervation changes in every muscle studied and the sensory and motor nerve conduction was slowed in arms and legs. The sural nerve biopsy specimen studied by light microscopy with semi-thin section and teased fiber preparation showed axonal degeneration. The ultrastructural studies of the axonal alterations consisted of degeneration of the neurofilaments and the neurotubules with granular appearance of the axoplasm.

A forma familiar da miastenia gravis é condição relativamente rara, ocorrendo em cerca de 3,4% dos pacientes miastênicos. Os autores registram os casos de dois irmãos não-gêmeos, apresentando miastenia gravis com acometimento predominantemente ocular desde o nascimento. Um terceiro irmão faleceu na infância, provavelmente com a mesma afecção. Os pais eram consanguíneos. Estudo da incidência da forma familiar da miastenia e de seus aspectos clínicos, genéticos e terapêuticos complementa os registros.

The familiar form of myasthenia gravis is a relatively rare condition, occurring in about 3.4 per cent of myasthenic patients. Two familial cases with ocular myasthenia gravis are reported. They had a third brother who died probably with the same disease. Their parents are cousins. The authors made a brief approach of genetic, clinical, statistical and therapeutics aspects of the disease.