Atrofia muscular espinal y bulbar: enfermedad de Kennedy. Aspectos clínicos y genéticos / Spinal and bulbar muscular atrophy (SBMA): Kennedy's disease. Clinical and genetic aspects

La atrofia muscular espinal y bulbar es una enfermedad neurológica caracterizada por degeneración gradual de la motoneurona inferior, que resulta en debilidad muscular, atrofia y fasciculaciones. Es una entidad de etiología genética con mecanismo de herencia ligado al cromosoma X recesivo, por lo que afecta a varones, en la que se produce una expansión del triplete CAGn en el gen del receptor de andrógenos. Se manifiesta por signos de insensibilidad a los andrógenos (ginecomastia e infertilidad). A partir de los 20-30 años, aproximadamente, comienzan los signos de afectación de la motoneurona inferior a nivel espinal con calambres y temblor de acción y posteriormente debilidad muscular. En la evolución se evidencia compromiso bulbar. Se presenta el caso clínico-genealógico de un varón de 32 años con temblores en quien se confirma molecularmente la enfermedad de Kennedy. Este es el primer caso, hasta nuestro conocimiento, reportado en Uruguay. Se destaca la importancia de plantear dicha afección en un paciente joven con "temblores" cuando aún no es ostensible la debilidad muscular. La historia familiar es de capital importancia. La presencia de fasciculaciones en el estudio eléctrico a nivel perioral es muy sugestiva de esta patología. La confirmación molecular es importante para el asesoramiento genético.

Spinal and bulbar muscular atrophy (SBMA) is a neurological disease characterized by the progressive degeneration of the inferior motor neurones, what results in muscle weakness, atrophy and fasciculations. It possesses a genetic etiology with X-linked recessive inheritance mode, and thus affects men. There is an abnormal expansion of the CAG polyglutamine encoding repeat within the androgen receptor gene. It is noticed by signs of androgen insentistivity (gynecomastia and infertility). At 20-30 years old approximately signs of compromise of the lower motor neurones in the spine are seen in cramps and action tremor followed by muscle weakness, evidencing bulbar involvement in the evolution. The study presents the ciínical-genealogical case of a 32 year-old male with tremor, whose Kennedy disease was confirmed with molecules. This is the first case reported in Uruguay as far as we know. The importance of considering this condition is pointed out in a young patient with "tremor" when muscle weakness is not evident yet. Family history is key. The presence of fasciculation in the electrical study strongly suggests this condition. Molecular confirmation is important for genetic advice purposes.

A atrofia muscular bulbo-espinal (BSMA) é uma doença neurológica caracterizada pela degeneração gradual do neurônio motor inferior causando fraqueza muscular, atrofia e fasciculações. É uma entidade de etiologia genética com mecanismo de herança ligada ao cromossoma X recessivo, afetando por isso a indivíduos do sexo masculino, nos quais se observa a expansão do triplete CAGn no gene do Receptor de Andrógenos (RA). Manifesta-se pela ausência de sensibilidade aos andrógenos (ginecomastia e infertilidade); a partir dos 20-30 anos aproximadamente começam a manifestar-se os sinais de afetação do neurônio motor inferior na região espinal com câimbras e tremor de ação e posteriormente debilidade muscular. Em sua evolução observa-se compromisso bulbar. Apresenta-se o caso clínico - genealógico de um indivíduo de sexo masculino de 32 anos com tremores, no qual foi realizado diagnóstico molecular de doença de Kennedy. Este é o primeiro caso informado no Uruguai, que seja de nosso conhecimento. Destaca-se a importância da suspeita desta afecção em um paciente jovem com "tremores" mesmo quando a debilidade muscular ainda não é ostensível. A história familiar é fundamental. A presença de fasciculações no estudo elétrico na região perioral é muito sugestiva desta patologia. A confirmação molecular é importante para o assessoramento genético.

Genotype-phenotype correlations in Charcot-Marie-Tooth disease type 2 caused by mitofusin 2 mutations.

BACKGROUND: Mutations in the gene encoding mitofusin 2 (MFN2) cause Charcot-Marie-Tooth disease type 2 (CMT2), with heterogeneity concerning severity and associated clinical features. OBJECTIVE: To describe MFN2 mutations and associated phenotypes in patients with hereditary motor and sensory neuropathy (HMSN). DESIGN: Direct sequencing of the MFN2 gene and clinical investigations of patients with MFN2 mutations. SETTING: Molecular genetics laboratory of a university hospital and the Limoges National Referral Center for Rare Peripheral Neuropathies. PATIENTS: One hundred fifty index patients with HMSN and a median motor nerve conduction velocity of 25 m/s or greater and without mutations in the genes encoding connexin 32 and myelin protein zero. MAIN OUTCOME MEASURES: Results of genetic analyses and phenotypic observations. RESULTS: Twenty different missense mutations were identified in 20 index patients. Mutation frequency was 19 of 107 (17.8%) in patients with CMT2 and 1 of 43 (2.3%) in patients with a median motor nerve conduction velocity less than 38 m/s. Four patients had proven de novo mutations, 8 families had autosomal dominant inheritance, and 3 had autosomal recessive inheritance. The remaining 5 patients were sporadic cases with heterozygous mutations. Phenotypes varied from mild forms to early-onset severe forms. Additional features were encountered in 8 patients (32%). Six patients underwent sural nerve biopsy: electronic microscopy showed prominent mitochondrial abnormalities on longitudinal sections. CONCLUSIONS: MFN2 mutations are a frequent cause of CMT2, with variable severity and either dominant or recessive inheritance. MFN2 gene testing must be a first-line analysis in axonal HMSN irrespective of the mode of inheritance or the severity of the peripheral neuropathy.

[TNF-alpha, C-reactive protein and serum adiponectin modified in infertile patients with insulin resistance]. / Alteración del factor de necrosis tumoral-alpha, proteína C reactiva y adiponectina séricas en pacientes infértiles con resistencia a la insulina.

BACKGROUND: Women's reproductive potential is closely related to nutritional status. Some of the molecules that participate in ovarian regulation are produced in the adipose tissue, and therefore their production is associated with adiposity. OBJECTIVE: To determine serum leptin, adiponectin, C-reactive protein, interleukin-6, and tumor necrosis factor alpha in infertile women with or without insulin resistance; and to associate these molecules with adiposity. METHODS: Thirty-one infertile women were included. Nutritional status was evaluated through clinical and biochemical parameters. Patients were stratified according with their body mass index and the presence of insulin resistance. For statistics, parametric analyses were conducted. RESULTS: The prevalence of overweight was 67.5%; high adiposity was present in 92.3% and central distribution of fat in 96.2% of studied women. Hypercholesterolemia was found in 32.3% of patients, hypertriglyceridemia in 25.8%, and 61.3% presented hyperinsulinemia. Overweight women presented lower adiponectin, and higher TNF-alpha and C-reactive protein concentrations, than those with normal body mass index (p < 0.05). Overweight women had also a higher probability for insulin resistance (p = 0.04). These women with insulin resistance presented lower adiponectin and higher C-reactive protein concentrations than non insulin resistance women. Body mass index correlated with leptin (r= 0.41), TNF-alpha (r= 0.41), and C-reactive protein (r= 0.33) concentrations. CONCLUSION: The prevalence of overweight, high adiposity, dislipidemias, and IR was high in our population studied. We conclude that adiposity is closely associated with some of the molecules that participate in the reproductive process and that also regulate inflammatory responses.

Eficacia de los antivirales en la parálisis de Bell / Efficacy of antiviral in treatment of Bell’s Palsy

Introducción: la parálisis de Bell es una afección frecuente que presenta en 15% de los casos una recuperación incompleta. En los últimos años se ha acumulado evidencia del posible roldel virus herpes simple tipo 1 en su etiología. Objetivos: comparar la eficacia de valaciclovir y prednisona versus prednisona placebo en laparálisis de Bell. Material y método: se realizó un ensayo prospectivo, randomizado y placebo controlado. Delos 41 pacientes incluidos, 21 fueron tratados con valaciclovir 2 g día durante siete días más prednisona (PV) y 19 con prednisona más placebo (PP) administrados oralmente.Los controles clínicos se realizaron a las 2, 4, 8 y 12 semanas, los pacientes con recuperación incompleta fueron seguidos durante seis meses. La recuperación fue definida comosatisfactoria con un puntaje mayor a 90 usando una escala compuesta de parálisis facial (FGS). Resultados: la evolución de la escala de parálisis facial no mostró diferencias significativasentre ambos grupos. La recuperación a los seis meses fue de 86,4% en el grupo PV y 89,5% en el grupo PP (p=0,86). El tiempo medio de recuperación en días fue 70,2 y 71,1, respectivamente (p=0,88). Conclusiones: nuestros resultados no demuestran un beneficio adicional del valaciclovir en eltratamiento de la parálisis de Bell.De acuerdo con las evidencias actuales, no hay consenso respecto al uso rutinario de antivirales en todos los caso de parálisis de Bell (NCT00561106).

Introduction: Bell’s Palsy is a frequent condition, and 15% of patients affected show incomplete recoveries. Over thepast years, wide evidence has been gathered as to the possible incidence of Herpes simplex virus type 1 in itsetiology. Objectives: to compare the efficacy of valacyclovir and prednisone versus prednisone plus placebo. Of 41 patients included in the study, 21 were treated with valacyclovir, 2g a day for seven days, and prednisone; and 19with prednisone plus placebo, administered orally. Clinical controls were carried out at weeks 2, 4, 8 and12. Patients who had incomplete recoveries were followed studied for six months. Recovery was defined as satisfactory when the score was over 90, using a facial paralysis complex scale (FGS – Facial Grading Scale).Results: no meaningful difference in the evolution of the facial paralysis were found between the two groups. After six months, recovery was 86.4% in the valacyclovir and prednisone group, and 89.5% in the prednisone plus placebo group (p=0,86). Average recovery time was 70.2 and 71.1 days, respectively (p=0,88). Conclusions: our results fail to prove additional benefits of the alacyclovir in the treatment of Bell’s Palsy. According to current evidence available, there is no agreementregarding the antivirals ordinary use in all cases of Bell’s Palsy (NCT00561106).

Introdução: a paralisia de Bell é uma afecção freqüente que em 15% dos casos apresenta recuperação incompleta.Nos últimos anos tem-se observado evidência da participação do vírus herpes simplex tipo 1 em sua etiologia.Objetivos: comparar a eficácia da associação valaciclovir e prednisona versus prednisona placebo na paralisiade Bell. Material e método: foi realizado um estudo prospectivo, randomizado e placebo controlado. Dos 41 pacientesincluídos, 21 foram tratados com valaciclovir 2 g/dia durante sete dias mais prednisona (PV) e 19 com prednisona mais placebo (PP) administrados por via oral. Os controles clínicos foram realizados nas semanas 2,4, 8 e 12; os pacientes com recuperação incompleta foram seguidos durante seis meses. A recuperação foi definida como satisfatória quando apresentavam pontuação superior a 90 usando uma escala composta de paralisia facial(FGS). Resultados: a evolução da escala de paralisia facial não mostrou diferenças significativas entre ambos os grupos. A recuperação aos seis meses foi de 86,4% no grupo PV e 89,5% no grupo PP (p=0,86). O tempo médio derecuperação em dias foi 70,2 e 71,1 ,respectivamente (p=0,88).Conclusões: nossos resultados não mostraram um beneficio adicional do uso do valaciclovir no tratamentoda paralisia de Bell. De acordo com as evidências atuais, não existe consensosobre o uso rotineiro de anti-virais em todos los caso de paralisia de Bell (NCT00561106).

Intranervous immunoglobulin deposits: an underestimated mechanism of neuropathy.

There are several pathogenic mechanisms of peripheral nerve involvement in patients with monoclonal dysglobulinemia. Intranervous proliferation of malignant cells, immunoglobulin, or amyloid deposits in the endoneurial space can only be determined by examination of nerve biopsy specimens. We present clinical, electrophysiological, and histological data from seven patients whose polyneuropathy was induced by immunoglobulin deposits in the endoneurial space. As these lesions cannot be demonstrated on clinical and electrophysiological grounds, the indication for nerve biopsy derives from careful analysis of each patient presenting with a polyneuropathy and a monoclonal dysglobulinemia. To visualize and clearly characterize these deposits, electron microscopic examination is indispensable. Immunocytochemical methods using both light and electron microscopy for ultrastructural analysis are of great value. Demonstration of endoneurial immunoglobulin deposits may have major therapeutic consequences. Indeed, identification of these deposits prompted the use of aggressive treatment, which was quite effective in five of our seven patients.

[Hereditary neuropathies]. / Neuropathies génétiques.

Although there are many human hereditary neuropathies, most of them with the exception of Charcot-Marie-Tooth disease or hereditary sensorimotor neuropathy, are rare. Irrespective of their type, the mode of transmission may be autosomal dominant or recessive, or X-linked. The most difficult to diagnose, however, are the sporadic forms. It is customary to distinguish the cases in which the neuropathy is the sole clinical expression from multisystemic diseases where neuropathy is one component of multi-organ involvement. The complexity and the multiplicity of genes involved and the lack of understanding of their exact functions hinder logical presentation of these hereditary neuropathies. For understandable technical reasons, the stage of specific treatment, namely the repair of the mutated gene, has yet to be attained.