Heterogeneidade clínica e coexistência das neuropatias diabéticas: diferenças e semelhanças entre diabetes melito tipos 1 e 2 / Clinical heterogeneity and coexistence of diabetic neuropathies: difference and similarities between types 1 and 2 diabetes mellitus

OBJETIVO: Estudar a heterogeneidade e a coexistência das neuropatias no diabetes melito tipos 1 (DMT1) e 2 (DMT2). MÉTODOS: Foram avaliados 74 DMT2 e 20 DMT1 em relação à idade (anos), tempo de diagnóstico do DM (TDDM, em anos), índice de massa corpórea (IMC, kg/m²), HbA1c e tipo de neuropatia (critérios da American Diabetes Association). RESULTADOS: DMT1 era mais jovem (32,7 ± 11 versus 56,9 ± 10,3; p = 0,0001), com maior TDDM (17,1 ± 9,7 versus 10,4 ± 6,8; p = 0,003) e menor IMC (23,6 ± 3,8 versus 28,4 ± 5,3; p = 0,0005). A neuropatia autonômica cardiovascular (NAC) (60 por cento versus 32,4 por cento; p = 0,02) e a coexistência desta com polineuropatia (PND) (62,5 por cento versus 33,3 por cento; p = 0,03) foram mais prevalentes no DMT1; a PND dolorosa crônica (PNDDC) (60,8 por cento versus 30,0 por cento; p = 0,009) o foi no DMT2. A HbA1c (p = 0,04) foi preditiva de PND em ambos os grupos. O TDDM (p = 0,03) e a PNDDC (p = 0,003) foram preditivos de NAC no DMT1. A idade (p = 0,0004) teve valor preditivo para PNDDC no DMT2. CONCLUSÕES: As neuropatias apresentam distribuição heterogênea no DMT1 e no DMT2. Com exceção do controle glicêmico, os fatores relacionados a essa complicação diferem de acordo com o tipo de diabetes.

OBJECTIVE: To evaluate the heterogeneity and the coexistence of diabetic neuropathy (DNP) in type 1 (T1DM) and 2 (T2DM) diabetes mellitus. METHODS: 74 T2DM and 20 T1DM patients were evaluated according to age (years), time from diagnosis of diabetes (TDD, years), body mass index (BMI, kg/m²), HbA1c and DNP type (American Diabetes Association criteria). RESULTS: T1DM was younger (32.7 ± 11.0 versus 56.9 ± 10.3; p = 0.0001), leaner (BMI: 23.6 ± 3.85 versus 28.4 ± 5.3; p = 0.0005) and they had longer TDD (17.1 ± 9.7 versus 10.4 ± 6.8; p = 0.003). Cardiovascular autonomic neuropathy (CAN) (60 percent versus 32.4 percent; p = 0.02) and its coexistence with polyneuropathy (PN) (62.5 percent versus 33.3 percent; p = 0.03) were more common in T1DM. Chronic painful polyneuropathy (CPP) was more prevalent in T2DM (60.8 percent versus 30.0 percent; p = 0.009). Logistic regression showed HbA1c as an independent variable related to PN (p = 0.04) in both groups. TDD (p = 0.03) and CPP (p = 0.003) were related to CAN in T1DM. Age (p = 0.0004) was related to CPP in T2DM. CONCLUSIONS: The DNP have shown a heterogeneity distribution in type 1 and type 2 diabetes mellitus. The related factors to different phenotypes of this complication, apart from hyperglycemia, may be variable between these two types of diabetes mellitus.

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.

Hepatitis C virus infection, cryoglobulinemia, and peripheral neuropathy: a case report

Hepatitis C virus (HCV) is essentially hepatotropic but its manifestations can extend beyond the liver. It can be associated with autoimmune diseases, such as mixed cryoglobulinemia, membranoproliferative glomerulonephritis, autoimmune thyroiditis, and lymphoproliferative disorders. The mechanisms that trigger these manifestations are not completely understood. We describe a 48-year-old man with chronic HCV infection (circulating HCV RNA and moderate hepatitis as indicated by liver biopsy), cryoglobulinemia, and sensory and motor peripheral neuropathy. The diagnosis of multineuropathy was confirmed by clinical examination and electromyographic tests. A nerve biopsy revealed an inflammatory infiltrate in the perineurial space and signs of demyelination and axonal degeneration. The patient had no improvement of neurological symptoms with the use of analgesics and neuro-modulators. He was then treated with interferon-alpha (3 million units subcutaneously, 3 times per week) and ribavirin (500 mg orally, twice a day) for 48 weeks. Six months after the end of therapy, the patient had sustained viral response (negative HCV RNA) and remission of neurological symptoms, but cryoglobulins remained positive. A review of the literature on the pathogenesis and treatment of neurological manifestations associated with HCV infection is presented. This report underscores the need for a thorough evaluation of HCV-infected patients because of the possibility of extrahepatic manifestations. Antiviral treatment with interferon and ribavirin can be effective and should be considered in patients with neurological complications associated with HCV infection.

Neuropatia cronica desmielinizante inflamatoria: hallazgos en 30 pacientes / Chronic inflammatory demyelinating polyneuropathy. Findings in 30 patients

La neuropatía crónica desmielinizante inflamatoria (NCDI) constituye una entidad reconocida desde hace ya varios años, aunque su patogenia no ha sido aún dilucidada totalmente. Sin embargo, existen suficientes evidencias que sugieren que su producción es inmunomediada. Entre los años 1992 y 1997 hemos podido estudiar 30 pacientes con esta patología y que son el objeto de esta comunicación. En ellos se procedió a su estudio clínico y de laboratorio. Estos últimos comprendieron la electrofisiología de sus nervios, la inmunoelectroforesis de sus proteínas séricas, el estado físico-químico, y cuando posible, inmunológico de sus líquidos cefalorraquídeos (LCR) y la biopsia del nervio safeno externo que se llevó a cabo en algo más de la mitad de los probandos. Los hallazgos clínicos más relevantes fueron debilidad muscular, atrofias musculares, hipo a arreflexia osteotendinosa, parestesias e hipoestesias. La investigación de la capacidad de conducción de sus nervios mostró reducción de esos valores, en el rango de desmielinización, en todos ellos. La inmunoelectroforesis de las proteínas séricas detectó la existencia de gammopatía monoclonal en el 17 por ciento de los pacientes. El examen de LCR descubrió aumento de proteínas en el 79 por ciento de los probandos y la imagen histológica fue de desmielinización en los 17 enfermos que aceptaron el procedimiento. Según nuestro criterio la NCDI constituye una enfermedad con características definidas que puede ser detectada aunando los hallazgos clínicos, electrofisiológicos y de LCR. La biopsia de nervio, si bien es un elemento diagnóstico de apoyo, puede no ser necesaria para el reconocimiento de esta dolencia en la medida en que exista coherencia entre las observaciones clínicas, las de condución nerviosa y las de LCR. Su individualización temprana es de valor, ya que permite una precoz acción terapéutica evitando las eventuales secuelas que pudiera dejar.