Bases fisiopatológicas para una clasificación de la neuropatía diabética / A new physiopathological classification of diabetic neuropathy

Nowadays, Diabetic Neuropathy (DN) is considered the most common cause of peripheral neuropathy in clinical practice. It can affect sensitive, motor or autonomic nerve fibers, with symmetric, asymmetric, acute or chronic presentations. Due to this variability, with multiple physiopathologic mechanisms involved, a complex clinical classification has been used until recently. The aim of this review is to present a new classification of diabetic neuropathy, based on its physiopathology. It is divided in metabolic microvascular and hypoxic, autoimmune and inflammatory, compressive, secondary to complications ofdiabetes and related to treatment. It must be understood that DN is notjust a functional disease, but a complication of diabetes with molecular and pathological substrates caused by hyperglycemia. Therefore, normalization of blood glucose is a fundamental step towards the successful prevention and treatment of DN.

Classification of the severity of diabetic neuropathy: a new approach taking uncertainties into account using fuzzy logic

OBJECTIVE: This study proposes a new approach that considers uncertainty in predicting and quantifying the presence and severity of diabetic peripheral neuropathy. METHODS: A rule-based fuzzy expert system was designed by four experts in diabetic neuropathy. The model variables were used to classify neuropathy in diabetic patients, defining it as mild, moderate, or severe. System performance was evaluated by means of the Kappa agreement measure, comparing the results of the model with those generated by the experts in an assessment of 50 patients. Accuracy was evaluated by an ROC curve analysis obtained based on 50 other cases; the results of those clinical assessments were considered to be the gold standard. RESULTS: According to the Kappa analysis, the model was in moderate agreement with expert opinions. The ROC analysis (evaluation of accuracy) determined an area under the curve equal to 0.91, demonstrating very good consistency in classifying patients with diabetic neuropathy. CONCLUSION: The model efficiently classified diabetic patients with different degrees of neuropathy severity. In addition, the model provides a way to quantify diabetic neuropathy severity and allows a more accurate patient condition assessment.

Focal and multifocal diabetic neuropathies

Diabetic neuropathy is the most common neuropathy in industrialized countries, with a remarkable range of clinical manifestations. The vast majority of the patients with clinical diabetic neuropathy have a distal symmetrical form that progress following a fiber-length dependent pattern, with predominant sensory and autonomic manifestations. This pattern of neuropathy is associated with a progressive distal axonopathy. Patients are exposed to trophic changes in the feet, pains and autonomic disturbances. Less often, diabetic patients may develop focal and multifocal neuropathy that includes cranial nerve involvement, limb and truncal neuropathies. This neuropathic pattern tends to occur after 50 years of age, mostly in patients with longstanding diabetes mellitus. The LDDP does not show any trend to improvement and either relentlessly progresses or remain relatively stable over years. Conversely the focal diabetic neuropathies, which are often associated with inflammatory vasculopathy on nerve biopsies, remain self limited, sometimes after a relapsing course.

A neuropatia diabética é a mais predominante das neuropatias nos países industrializados apresentando uma gama variável de manifestações clinicas. A maioria dos pacientes com neuropatia diabética apresenta uma forma simétrica distal que progride para um padrão fibra comprimento dependente com manifestações sensitivas e autonomicas. Este tipo de neuropatia é associado com uma axonopatia distal progressiva. Os pacientes apresentam modificações tróficas nos pés, dores e distúrbios autonômicos. Menos freqüentemente os pacientes diabéticos podem desenvolver neuropatia focal e multifocal que incluem envolvimento de nervos cranianos, tronco e membros inferiores. Este padrão de neuropatia é mais freqüente em pacientes com mais de 50 anos e com longa historia de diabetes. Este tipo de neuropatia fibra-comprimento dependente não apresenta melhora, progride lentamente ou permanece estável por vários anos. As neuropatias focais que são associadas freqüentemente com vasculopatias inflamatórias nas biópsias de nervo, permanecem auto limitadas por vezes com surtos de remissão.

Diabetic retinopathy is a poor predictor of type of nephropathy in proteinuric type 2 diabetic patients.

BACKGROUND: Both diabetic nephropathy (DN) and nondiabetic nephropathy (NDN) are reported to occur in patients with type 2 diabetes mellitus (DM). The precise diagnosis of the type of nephropathy has obvious clinical and prognostic implication. The aim of the study was to evaluate the histologic spectrum of nephropathy in proteinuric type 2 diabetic patients and to find the correlation between type of nephropathy and diabetic retinopathy (DR). METHODS: Twenty eight proteinuric type 2 diabetic patients were included in the study. Five patients (ADPKD 3 and chronic pyelonephritis 2) were excluded from biopsy. Percutaneous renal biopsy was carried in remaining 23 patients. RESULTS: There was a preponderance of male (75%) and majority of the patients were in the age group of 30-78 years. Duration of diabetes ranged between 4 months to 25 years with mean +/- SD of 10.53 +/- 7.62 years. The presenting features were nephrotic syndrome 14 (60.9%), non-nephrotic proteinuria 9 (39.1%) and impaired renal function in 19 (82.6%) patients. Renal biopsy in 23 cases revealed; isolated diabetic nephropathy 13 (56.2%), NDN7 (13.43%) and 3 (13%) patients had NDN superimposed on diabetic nephropathy. Membranous nephropathy (2), focal segmental glomerulosclerosis (2), mesangiocapillary glomerulonephritis (1) were the nondiabetic glomerular disease in our type 2 diabetic patients. Chronic pyelonephritis and ischemic interstial nephropathy was the predominant tubulointerstial lesion in this study. Diabetic retinopathy (DR) observed in 12 (75%) patients with biopsy proven DN and absent in 4 (25%) patients with DN. The distribution of renal lesions in patients with DR (n = 15) showed DN in 9 (60%), NDN 3 (20%) and remaining 3 patients had combined lesions. Renal biopsy in 8 patients without DR showed typical DN in 4 (50%) and NDN in 4 (50%) patients. CONCLUSION: This study demonstrates presence of both glomerular and tubulointerstitial lesions unrelated to diabetes (NDN) in proteinuric type 2 diabetic patients. Further presence or absence of DR was a poor predictor of diabetic nephropathy because DN was noted in 50% of patients without DR and 40% of patients with DR had non-diabetic nephropathy either alone or in combination with DN.

Neuropatía diabética: etiopatogenia y clasificación / Diabetic neuropathy: etiology, pathogenesis and classification

Se hace una revisión, de la etiopatogenia, clasificación, cuadro clínico y tratamiento de esta enfermedad. Desarrollo: Se realiza una revisión bibliográfica de la epidemiología destacando su frecuencia en diabéticos y la etiopatogenia avalada por varias teorías, tanto metabólicas, como vasculares, además de las más modernas de crecimiento neural. Se discute la clasificación actual de las neuropatías periféricas y la sintomatología de las mismas de acuerdo a las fibras que afecta. Conclusiones: Se realiza una revisión de la neuropatía diabética, su epidemiología, su etiopatogenia, clasificación, y cuadro clínico. Se destaca la importancia de esta enfermedad en el desarrollo de las ulceras plantares

Neuropatía diabética periférica: clasificación, diagnóstico diferencial y evaluación / Peripheral diabetic neuropathy: classification, differential diagnosis and evaluation

La neuropatía periférica es la complicación neurológica crónica más frecuente de la diabetes mellitus, encontrándose al diagnóstico, en general, en el 10 por ciento de los diabéticos tipo 2. Su clasificación y evaluación se dificulta por lo silente de los síntomas en las primeras etapas y por la diversidad se manifestaciones que presenta. Este artículo presenta elementos que permiten realizar un enfoque útil al momento de evaluar la neuropatía diabética periférica: analiza la clasificación propuesta por P.K. Thomas del Instituto de Neurología del Royal Free Hospital, que se fundamenta en criterios clínicos; muestra un cuadro de diagnóstico diferencial con otros tipos de neuropatía y, finalmente se centra en detallar protocolos de evaluación clínica de la neuropatía diabética, destacando el método desarrollado por Feldman y cols., de la Universidad de Michigan. Este grupo utilizó como referencia para el diseño de su protocolo, los criterios de Dyck y cols. de la lClínica Mayo, aventajando a estos últimos, en que mejoraron la aplicabilidad clínica del método, manteniendo un nivel aceptable de confiabilidad en el diagnóstico. El protocolo del grupo de la Universidad de Michigan, entrega un sistema de evaluación que todo médico puede aplicar en sus pacientes

Neuropatia diabética: I. Conceito, epidemiologia, classificaçäo, quadro clínico e eletroneuromiográfico: estudo de 210 casos / Diabetic neuropathy: I. Definition, epidemiology, classification, clinical features and electrophysiologic changes: study of 210 patients

Os autores fazem revisäo da neuropatia diabética, seu conceito, sua prevalência e citam as várias classificaçöes existentes. Referem-se aos principais quadros clínicos apresentando 210 pacientes com neuropatia diabética estudados num período de quatro anos (1987-1991). As polineuropatias compreendem 184 casos. A forma sensitiva foi a predominante ocorrendo em 135 enfermos. Seguiram-se com menor número as formas sensitivo-motora, atáxica, motora e autonômica. Os distúrbios autonômicos estiveram presentes 63 vezes, sendo as alteraçöes pupilares as mais freqüentes. Os nervos cranianos foram acometidos 20 vezes, predominando a paralisia do VII e III nervos. O nervo mediano foi acometido em 20 oportunidades e a plexopatia lombar unilateral ocorreu em 10 pacientes. A eletroneuromiografia foi realizada em 63 pacientes, predominando a lesäo axonal sensitivo-motora (43 vezes)

Diabetic peripheral neuropathy.

Diabetic neuropathy, a challenging contemporary problem, has a clinical prevalence of 60% problematic peripheral neuropathy occurs in about 20%. Recent concepts in aetiopathogenesis include the role of sorbitol excess and myoinositol depletion in causing deficient Na+/K+ ATPase activity. Sorbitol excess per se may result in intraneuronal oedema. Besides these metabolic hypotheses, theories on endoneurial microcapillary pathology and hypoxia have gained favour. Furthermore, a unifying concept of sorbitol excess with intraneuronal oedema leading to secondary vascular compromise has been suggested. A new research classification linking clinical and laboratory evaluation has been proposed which may serve to unify research results. Quantitative sensory testing, autonomic function testing and electrodiagnosis have been utilised to detect incipient diabetic neuropathy. The benefit of 'tight' glycaemic control has been objectively documented by using laboratory parameters. Oral myoinositol supplementation and gangliosides have produced marginal improvement. The role of intraneuronal oedema in the pathogenesis of diabetic neuropathy and its reversal by aldose reductase inhibitors holds out fresh promise for their use in prevention and treatment.

Classificaçäo das neuropatias diabéticas / Classification of the diabetic neuropathies

Diversas classificaçöes foram propostas para as neuropatias diabéticas desde a classificaçäo inicial de Leyden em 1893. De modo geral cada classificaçäo, ao longo do tempo, guardou relaçöes com os avanços nos conhecimentos a respeito das referidas neuropatias. Qualquer classificaçäo das neuropatias diabéticas parecia artificial a Pirart tal o polimorfismo das neuropatias diabéticas detectado por aquele autor. As classificaçöes mais recentes levaram em conta os avanços dos métodos de investigaçäo das neuropatias diabéticas . Embora tenhamos demonstrado a reprodutibilidade da classificaçäo de Brow e Asbury, a classificaçäo de Dyck, que leva em conta aspectos topográficos e fisiológicos de maneira menos detalhada do que a daqueles autores, parece ser mais útil na prática clínica

Enfoque dinámico de la neuropatía diabética / Dynamic approach of diabetic neuropathy

Las complicaciones del sistema nervioso producidas por la diabetes mellitus han sido descriptas desde hace unos doscientos años. en todo este tiempo se hja forjado el concepto de la neuropatía diabética a través de sucesivas etapas de inestigación, pasando por un período descriptivo clínico inicial, otro de exploración morfológica posterior y un período actual de abordaje multidisciplinario de la diabetes. Puede afirmarse que los logros obtenidos han dado origen a una disciplina particular: la neurodiabetología. Entre las muchas cuestiones sin resolver dos han acaparado nuestra atención: una es el problema de la clasificación, discutiéndose la inclusión del sistema nervioso central como asiento de lesión; la otra es la noción de "especificidad" de lesión del sistema nervioso central debida a la diabetes. Nuevas orientaciones, basadas en abordajes muldidisciplinarios, intentan un enfoque dinámico de la neuropatía diabética. Este enfoque da una cabida decisiva blanco de lesión diabética, al par que incorpora al "diabético normal" aún a sufrir la agresión de us sistema nervioso y, finalmente, considera la determinación de secuencias patogenéticas definidas con valor teórico y práctico en el establecimiento de indicadores de evolutividad

Autonomic neuropathy in Iraqi diabetics

Tests for autonomic nervous functions based on cardiovascular reflexes were performed on 67 diabetic patients with a mean age of 53.39 year. The mean duration of diabetes is 8.26 year. The patients were categorized into 4 groups; normal [35.28%], early [borderline] parasympathetic damage [5.97%] definite [late] parasympathetic damage [35.82%] and combined sympathetic and parasympathetic damage [22.39%]. 64.18% of the patients have autonomic neuropathy and as these abnormalities can be easily diagnosed with an ordinary electrocardiography, we recommend that they be looked for in all diabetics