Definition and diagnosis of small fiber neuropathy: consensus from the Peripheral Neuropathy Scientific Department of the Brazilian Academy of Neurology / Definição e diagnóstico de neuropatia de fibras finas: consenso do Departamento Científico de Neuropatias Periféricas da Academia Brasileira de Neurologia

ABSTRACT The aim of this study was to describe the results of a Brazilian Consensus on Small Fiber Neuropathy (SFN). Fifteen neurologists (members of the Brazilian Academy of Neurology) reviewed a preliminary draft. Eleven panelists got together in the city of Fortaleza to discuss and finish the text for the manuscript submission. Small fiber neuropathy can be defined as a subtype of neuropathy characterized by selective involvement of unmyelinated or thinly myelinated sensory fibers. Its clinical picture includes both negative and positive manifestations: sensory (pain/dysesthesias/pruritus) or combined sensory and autonomic complaints, associated with an almost entirely normal neurological examination. Standard electromyography is normal. A growing list of medical conditions is associated with SFN. The classification of SFN may also serve as a useful terminology to uncover minor discrepancies in the normal values from different neurophysiology laboratories. Several techniques may disclose sensory and/or autonomic impairment. Further studies are necessary to refine these techniques and develop specific therapies.

RESUMO O objetivo deste estudo é descrever os resultados de um Consenso Brasileiro sobre Neuropatia de Fibras Finas (NFF). Quinze neurologistas (membros da Academia Brasileira de Neurologia) revisaram uma versão preliminar do artigo. Onze panelistas se reuniram na cidade de Fortaleza para discutir e terminar o texto para a submissão do manuscrito. NFF pode ser definida como um subtipo de neuropatia caracterizada pelo envolvimento seletivo de fibras sensitivas amielínicas ou pouco mielinizadas. Seu quadro clínico inclui manifestações negativas e positivas: sensitivas (dor/disestesias/prurido) ou queixas sensitivas e autonômicas combinadas, associadas a exame neurológico quase totalmente normal. A eletromiografia convencional é normal. Uma lista crescente de condições médicas causa NFF. NFF também pode servir como uma terminologia útil para referenciar pequenas discrepâncias nos valores normais de diferentes laboratórios de neurofisiologia. Diferentes técnicas podem evidenciar anormalidades sensitivas e/ou autonômicas. São necessários mais estudos para refiná-las e para o desenvolvimento de terapias específicas.

Neuropatía diabética periférica: eficacia clínica de la evaluación semiológica / Diabetic peripheral neuropathy: semiológica clinical efficacy of assessment

El diagnóstico de la Neuropatía Diabética Periférica es tardío. Identificar maniobras semiológicas que permitan el diagnóstico precoz de la neuropatía diabética. Estudio de casos, analítico, transversal y operacional: personas sanas, prediabéticos, diabéticos de reciente diagnóstico y diabéticos de más de 5 años de diagnóstico. Se realizaron 2 evaluaciones: la primera por dos investigadores a ciegas que evaluaron: sensibilidad mecánica, reflejos osteotendinosos y palestesia. También se evaluación de la córnea con Rosa de Bengala y se aplicó el Cuestionario DN4. Segunda Evaluación: von Frey. Biopsia de Piel: será tratada con inmunohistoquímica de campo claro. Muestra de 25 personas. El DN4, obtuvo 14 personas con dolor neuropático. La tinción con Rosa de Bengala obtuvo 7 pacientes con ojo seco y una diabética con más de 5 años de diagnóstico con alteración corneal. En la evaluación con von Frey hubo 3 pacientes con zonas sin respuesta al microfilamento de 10 g. La inmunohistoquímica demostró que el número y densidad de fibras nerviosas tuvo un promedio de 7 fibras/campo en sanos y a partir de los prediabéticos disminuyó desde 4,4 fibras/campo. El ojo seco justifica la evaluación periódica del internista. La evaluación de la sensibilidad con los filamentos de von Frey señala que el monofilamento utilizado individualmente tiene menor eficiencia diagnóstica. La biopsia demostró una capacidad diagnóstica precoz de esta, aún en ausencia de síntomas. La biopsia de piel con cuantificación del número y densidad de fibras, es útil en la identificación temprana de lesión de fibras C y se comporta como método de pesquisa.

The diagnosis of Diabetic Peripheral Neuropathy is made lately. To identify semiological maneuvres that allow early diagnosis of diabetic neuropathy. Case studie, analitic, transversal and operational, without therapeutic intervention in healthy, prediabetic, diabetic and newly diagnosed diabetes over 5 years of diagnosis. The First Assessment was: conducted by two blinded researchers measuring mechanical sensitivity, tendon reflexes, and palesthesia. Von Frey 3) Skin biopsy: the cornea Bengal Rose and DN4 Questionnaire. The second assessment was done with brightfield immunohistochemistry. The sample consisted of 25 persons. The DN4 had 14 people with neuropathic pain. Staining with Rose Bengal scored 7 persons. The second Assessment was done in patients with dry eye and over 5 years of diagnosis of corneal disorder. The evaluation with von Frey 3 patients with no response areas were obtained at 10 g microfilament. Immunohistochemistry showed that the number and density of nerve fibers had an average of 7 fibers in healthy and from prediabetic decreased to 4.4 fibers. The Dry eye justifies the periodic evaluation by the internist. The evaluation of sensitivity with von Frey hairs used indicate that the monofilament has a lower diagnostic efficiency individually. The biopsy revealed an early diagnostic capacity in this condition in the absence of symptoms. Skin biopsy with quantification of the number and density of nerve fibers is useful in early identification of C fiber damage and behaves like screening method.