Late-onset familial amyloidosis polyneuropathy associated with c.186G>C in transthyretin.

INTRODUCTION: The most common form of hereditary amyloidosis is associated with variants of transthyretin (TTR). Familial amyloidosis polyneuropathy associated with variants of TTR (FAP-TTR) is an infrequent, multisystemic disease, with predominant involvement of the peripheral nervous system. More than 130 pathogenic variants have been identified so far and most of them are amyloidogenic, being Val30Met the most frequently described. CASE REPORT: A 74 year-old male was evaluated for progressive decreased sensitivity and associated loss of strength in four limbs in the previous two years, needing assistance for walking. Areflexia, bilateral tibialis anterior and gastrocnemius atrophy, bilateral anesthesia and apalesthesia were found in lower limbs. Bilateral hypoesthesia was reported in upper limbs. No painful dysesthesia, hyperalgesia or allodynia were found. DNA sequencing of the TTR gene led to the detection of the variant c.186G>C in heterozygous state. The resulting variant (Glu62Asp), located in the critical functional domain, has not been published before. CONCLUSION: The importance of considering late onset, sporadic FAP-TTR as a differential diagnosis of cryptogenic polyneuropathy is highlighted.

Introducción: La forma más común de amiloidosis hereditaria está asociada con variantes de la transtiretina. La polineuropatía amiloidótica familiar asociada con variantes de la TTR (FAP-TTR) es una enfermedad multisistémica poco frecuente, con afectación predominante del sistema nervioso periférico. Hasta ahora se han identificado más de 130 variantes patogénicas y la mayoría de ellas son amiloidogénicas, siendo Val30Met la más frecuentemente descrita. Caso clínico: Un paciente de 74 años fue evaluado por disminución progresiva de la sensibilidad y pérdida asociada de fuerza en las cuatro extremidades de dos años de evolución, necesitando ayuda para caminar. En las extremidades inferiores se observó arreflexia, atrofia bilateral del tibial anterior y del gastrocnemio, anestesia bilateral y apalestesia. Los miembros superiores presentaban hipoestesia bilateral. No se observaron disestesias dolorosas, hiperalgesia ni alodinia. La secuenciación del ADN del gen TTR permitió detectar la variante c.186G>C en estado heterocigoto. La variante resultante (Glu62Asp), localizada en el dominio funcional crítico de la proteína, no ha sido informada con anterioridad. Conclusión: Se destaca la importancia de considerar la FAP-TTR esporádica de aparición tardía como un diagnóstico diferencial de la polineuropatía criptogénica.

Guía de práctica clínica de tratamiento de la polineuropatía amiloidótica familiar / Practice guideline for the treatment of familial amyloid polyneuropathy

Resumen Esta guía de práctica clínica de tratamiento de la polineuropatía amiloidótica familiar se basa en la mejor evidencia disponible de efectividad clínica. Se generó un listado de preguntas con formato PICO centradas en efectividad y seguridad del tratamiento de polineuropatía amiloidótica familiar. Se realizó la búsqueda en PubMed, Cochrane y Epistemonikos. Los niveles de evidencia y los grados de recomendación se basaron en el sistema GRADE. Las recomendaciones se graduaron según dirección y fuerza y se evaluaron con la herramienta GLIA para su implementación. Resumen de recomendaciones: En pacientes con polineuropatía amiloidótica familiar y neuropatía estadio I y II, se sugiere el tratamiento con inotersen 300 mg subcutáneo semanal o patisirán 0.3 mg/kg endovenoso una vez cada 3 semanas, dado que, probablemente, estabilicen o enlentezcan el avance de la neuropatía y el empeoramiento de la calidad de vida (calidad de la evidencia moderada; fuerza de la recomendación débil). En pacientes con polineruropatía amiloidótica familiar y neuropatía estadio I, se sugiere el tratamiento con tafamidis 20 mg vía oral, una vez por día, ya que podría enlentecer el avance de la neuropatía y el empeoramiento en la calidad de vida (calidad de la evidencia baja; fuerza de la recomendación débil), y aquellos con polineuropatía amiloidótica familiar y neuropatía sintomática y en ausencia de otros tratamientos con eficacia aprobada, se sugiere el tratamiento con diflunisal 250 mg dos veces al día, vía oral, ya que podría evitar la progresión de la neuropatía (calidad de la evidencia baja; fuerza de la recomendación débil).

Abstract. This clinical practice guideline for the treatment of familial amyloid polyneuropathy is based on the best available evi dence of clinical effectiveness. A list of questions was generated with a PICO format focused on the effectiveness and safety of the treatment of familial amyloid polyneuropathy. The search was carried out in PubMed, Cochrane and Epistemonikos. The levels of evidence and grades of recommendation were based on the GRADE system. Recommendations were graded according to their direction and their strength and were evaluated with the GLIA tool for their implementation. In patients with familial amyloid polyneuropathy and stage I and II neuropathy, it is suggested: inotersen 300 mg subcutaneous weekly or patisirán 0.3 mg/kg intravenously once every 3 weeks, since they probably stabilize or slow the progression of neuropathy and worsening quality of life (moderate qual ity of evidence; strength of recommendation weak). In patients with familial amyloid polyneuropathy and stage I neuropathy, treatment with tafamidis 20 mg orally, once a day, is suggested, as it could slow the progression of neuropathy and worsen quality of life (low quality of evidence; strength of recommendation weak). In patients with familial amyloid polyneuropathy and symptomatic neuropathy and in the absence of other treatments with approved efficacy, treatment with oral diflunisal 250 mg twice daily is suggested, as it could prevent the progres sion of neuropathy (quality evidence low; strength of recommendation weak).

[Practice guideline for the treatment of familial amyloid polyneuropathy]. / Guía de práctica clínica de tratamiento de la polineuropatía amiloidótica familiar.

This clinical practice guideline for the treatment of familial amyloid polyneuropathy is based on the best available evidence of clinical effectiveness. A list of questions was generated with a PICO format focused on the effectiveness and safety of the treatment of familial amyloid polyneuropathy. The search was carried out in PubMed, Cochrane and Epistemonikos. The levels of evidence and grades of recommendation were based on the GRADE system. Recommendations were graded according to their direction and their strength and were evaluated with the GLIA tool for their implementation. In patients with familial amyloid polyneuropathy and stage I and II neuropathy, it is suggested: inotersen 300 mg subcutaneous weekly or patisirán 0.3 mg/kg intravenously once every 3 weeks, since they probably stabilize or slow the progression of neuropathy and worsening quality of life (moderate quality of evidence; strength of recommendation weak). In patients with familial amyloid polyneuropathy and stage I neuropathy, treatment with tafamidis 20 mg orally, once a day, is suggested, as it could slow the progression of neuropathy and worsen quality of life (low quality of evidence; strength of recommendation weak). In patients with familial amyloid polyneuropathy and symptomatic neuropathy and in the absence of other treatments with approved efficacy, treatment with oral diflunisal 250 mg twice daily is suggested, as it could prevent the progression of neuropathy (quality evidence low; strength of recommendation weak).

Esta guía de práctica clínica de tratamiento de la polineuropatía amiloidótica familiar se basa en la mejor evidencia disponible de efectividad clínica. Se generó un listado de preguntas con formato PICO centradas en efectividad y seguridad del tratamiento de polineuropatía amiloidótica familiar. Se realizó la búsqueda en PubMed, Cochrane y Epistemonikos. Los niveles de evidencia y los grados de recomendación se basaron en el sistema GRADE. Las recomendaciones se graduaron según dirección y fuerza y se evaluaron con la herramienta GLIA para su implementación. Resumen de recomendaciones: En pacientes con polineuropatía amiloidótica familiar y neuropatía estadio I y II, se sugiere el tratamiento con inotersen 300 mg subcutáneo semanal o patisirán 0.3 mg/kg endovenoso una vez cada 3 semanas, dado que, probablemente, estabilicen o enlentezcan el avance de la neuropatía y el empeoramiento de la calidad de vida (calidad de la evidencia moderada; fuerza de la recomendación débil). En pacientes con polineruropatía amiloidótica familiar y neuropatía estadio I, se sugiere el tratamiento con tafamidis 20 mg vía oral, una vez por día, ya que podría enlentecer el avance de la neuropatía y el empeoramiento en la calidad de vida (calidad de la evidencia baja; fuerza de la recomendación débil), y aquellos con polineuropatía amiloidótica familiar y neuropatía sintomática y en ausencia de otros tratamientos con eficacia aprobada, se sugiere el tratamiento con diflunisal 250 mg dos veces al día, vía oral, ya que podría evitar la progresión de la neuropatía (calidad de la evidencia baja; fuerza de la recomendación débil).

[Argentine consensus on late-onset Pompe's disease]. / Consenso argentino sobre enfermedad de Pompe de inicio tardío.

Pompe's disease (PD) is an infrequent metabolic autosomic recessive disorder produced by the lack or deficiency of the acid alpha-glucosidase lysosomal enzyme in tissues of involved individuals. Delayed-onset PD is considered whenever symptoms onset start after one year of age. We present an update of the recommendations for the management of delayed-onset PD, taking as reference the guidelines from the Argentine Consensus for diagnosis, treatment and follow-up of PD published in 2013. The present consensus gathered several experts in PD in the areas of internal medicine, laboratory diagnosis, neuropathology, pulmonology, nutrition, neurology, metabolic and neuromuscular disorders as well as rehabilitation to perform an update of the literature of delayed-onset PD, with special attention on relevant information published within the last 4 years. The entire working group approved the final version of the consensus. Each participant provided a declaration of conflict of interest. As a result, it is an update of the previous Argentine PD Consensus with focus on the delayed-onset presentation of the disease. Being such infrequent disorder, available data were rather limited and thus, the recommendations represent expert opinions.

Consenso argentino sobre enfermedad de Pompe de inicio tardío / Argentine consensus on late-onset Pompe's disease

La enfermedad de Pompe (EP) es un desorden metabólico autosómico recesivo infrecuente, producido por la ausencia o deficiencia de la enzima lisosomal alfa-glucosidasa ácida en los tejidos de los individuos afectados. Se considera enfermedad de Pompe de inicio tardío (EPIT) en aquellos individuos de más de un año de edad al comienzo de los síntomas. El objetivo del presente consenso es el de actualizar las pautas y recomendaciones para un correcto tratamiento de los pacientes con EPIT, tomando como referencia los lineamientos del Consenso Argentino para el diagnóstico, seguimiento y tratamiento de la enfermedad de Pompe publicado en el año 2013. Se organizó un consenso que reunió profesionales con experiencia en la EP en las áreas de clínica médica, diagnóstico de laboratorio, neuropatología, neumonología, nutrición, neurología, enfermedades metabólicas, enfermedades neuromusculares y rehabilitación. Se realizó una actualización de la bibliografía sobre EPIT, con especial atención en las publicaciones relevantes de los últimos cuatro años. Los términos finales del documento fueron consensuados por todo el grupo de trabajo. Cada participante proporcionó su declaración de conflicto de intereses. El resultado es una actualización del último Consenso Argentino para la EP, con particular enfoque en su forma de comienzo tardío. Tratándose de una afección infrecuente, en la que los datos disponibles son limitados, las presentes recomendaciones deben ser consideradas como opinión de expertos.

Pompe's disease (PD) is an infrequent metabolic autosomic recessive disorder produced by the lack or deficiency of the acid alpha-glucosidase lysosomal enzyme in tissues of involved individuals. Delayed-onset PD is considered whenever symptoms onset start after one year of age. We present an update of the recommendations for the management of delayed-onset PD, taking as reference the guidelines from the Argentine Consensus for diagnosis, treatment and follow-up of PD published in 2013. The present consensus gathered several experts in PD in the areas of internal medicine, laboratory diagnosis, neuropathology, pulmonology, nutrition, neurology, metabolic and neuromuscular disorders as well as rehabilitation to perform an update of the literature of delayed-onset PD, with special attention on relevant information published within the last 4 years. The entire working group approved the final version of the consensus. Each participant provided a declaration of conflict of interest. As a result, it is an update of the previous Argentine PD Consensus with focus on the delayed-onset presentation of the disease. Being such infrequent disorder, available data were rather limited and thus, the recommendations represent expert opinions.

Writing tremor secondary to ischemic stroke: a report on a case with a remarkable response to topiramate.

UNLABELLED: Writing tremor (WT) is a task-specific tremor that occurs only or mostly while writing with the dominant hand. Secondary cases are extremely uncommon. We report on a patient who, after developing a WT after an ischemic stroke, had a remarkable response to topiramate (TPM). CASE: A 65-year-old right-handed man with a history of arterial hypertension, dyslipidemia, and coronary heart disease presented dizziness and headache followed by a loss of consciousness and then a right hemiparesis. He regained his strength on the fifth day. Fourteen days after stroke, he developed a WT as well as other complications with activities such as welding (he is a welder) and using a spoon. He was treated with 50 mg/d of TPM with marked improvement in WT. A few weeks after TPM was discontinued, the WT symptoms reappeared and he was retreated, showing the same beneficial reaction.Electromyographic record showed a 5- to 6-Hz tremor in his right hand, and a magnetic resonance imaging showed bilateral small frontoparietal subcortical infarcts. CONCLUSIONS: Primary WT pathophysiology is not well known, and secondary WT as a result of stroke is even less considered. Although patients with essential tremor benefit with TPM and WT could be a variant of essential tremor, we used TPM with our patient and there was a marked benefit.

Amyotrophic lateral sclerosis-immunoglobulins selectively interact with neuromuscular junctions expressing P/Q-type calcium channels.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by a gradual loss of motoneurons. The majority of ALS cases are associated with a sporadic form whose etiology is unknown. Several pieces of evidence favor autoimmunity as a potential contributor to sporadic ALS pathology. To gain understanding concerning possible antigens interacting with IgGs from sporadic ALS patients (ALS-IgGs), we studied immunoreactivity against neuromuscular junction (NMJ), spinal cord and cerebellum of mice with and without the Ca(V) 2.1 pore-forming subunit of the P/Q-type voltage-gated calcium (Ca(2+)) channel. ALS-IgGs showed a strong reactivity against NMJs of wild-type diaphragms. ALS-IgGs also increased muscle miniature end-plate potential frequency, suggesting a functional role for ALS-IgGs on synaptic signaling. In support, in mice lacking the Ca(V) 2.1 subunit ALS-IgGs showed significantly reduced NMJ immunoreactivity and did not alter spontaneous acetylcholine release. This difference in reactivity was absent when comparing N-type Ca(2+) channel wild-type or null mice. These results are particularly relevant because motoneurons are known to be early pathogenic targets in ALS. Our findings add further evidence supporting autoimmunity as one of the possible mechanisms contributing to ALS pathology. They also suggest that serum autoantibodies in a subset of ALS patients would interact with NMJ proteins down-regulated when P/Q-type channels are absent.