Guillain-Barré Syndrome and COVID-19 Vaccine: A Multicenter Retrospective Study of 46 Cases.

ABSTRACT: In the context of the global vaccination campaign against COVID-19, several cases of postvaccinal Guillain-Barré syndrome (GBS) were reported. Whether a causal relationship exists between these events has yet to be established. We investigated the clinical and electromyographic characteristics of patients who developed GBS after COVID-19 vaccination and compare these with findings in patients with GBS, without a history of recent vaccination. We included 91 cases between March 2020 and March 2022, treated at 10 referral hospitals of Buenos Aires, Argentina. Of these, 46 had received vaccination against COVID-19 within the previous month. Although Medical Research Council sum-scores were similar in both groups (median 52 vs. 50; P = 0.4), cranial nerve involvement was significantly more frequent in the postvaccination group (59% vs. 38%; P = 0.02), as was bilateral facial paralysis (57% vs. 24%; P = 0.002). No differences were found in clinical or neurophysiological phenotypes, although 17 subjects presented the variant of bilateral facial palsy with paresthesias (11 vs. 6; P = 0.1); nor were significant differences observed in length of hospital stay or mortality rates. Future vaccine safety monitoring and epidemiology studies are essential to demonstrate any potential causal relationship between these events.

Exposure to endogenous and exogenous sex hormones and reproductive history influence prognosis in women with ALS.

INTRODUCTION/AIMS: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a higher incidence in men suggesting an influence of sex steroids. Our objective was to investigate past exposure to endogenous and synthetic steroids in female ALS patients and controls. METHODS: We administered a questionnaire to 158 postmenopausal women (75 ALS patients and 83 controls). We calculated reproductive time span (RTS), lifetime endogenous estrogen (LEE) and progesterone exposures (LPE), oral contraceptive pill (OCP) use, and reproductive history. RESULTS: ALS patients showed shorter LEE and LPE, a lower proportion of breast cancer, and 11% showed no history of pregnancies vs. 4% of controls. Odds ratios (ORs) showed that <17 y of LEE and a delayed menarche (>13 y) constitute risk factors for ALS [OR = 2.1 (95% confidence interval {CI}, 1.08-4.2); and OR = 2.4 (95% CI, 1.1-5.1) respectively]. According to Cox survival analysis, for each year the LEE increased over 17 y, it was independently associated with longer survival [hazard ratio (HR) = 0.37 (95% CI, 0.16-0.85)] after adjusting for smoking, age and site of onset. Multivariate regression analysis demonstrated that for each month using OCP for longer than 40 mo increased the risk of ALS [adjusted OR = 4.1 (95% CI, 1.2-13.8)]. DISCUSSION: Thus, longer exposure to endogenous female sex steroids increased survival and reduced ALS susceptibility. In contrast, longer exposure to synthetic sex steroids showed a negative impact by reducing the production of endogenous female sex steroids or due to crossover with other steroid receptors. Given the neuroprotective effects of sex steroids, we suggest that abnormalities of neuroendocrine components may alter motor function in women with ALS.

[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.

Usefulness of diffusion tensor imaging in amyotrophic lateral sclerosis: potential biomarker and association with the cognitive profile.

METHODS: This was a case-control study conducted from December 1, 2012 to December 1, 2014. Clinical and demographic data were recorded. A neuropsychological test battery adapted to ALS patients was used. An MRI with DTI was performed in all patients and fractional anisotropy (FA) was analyzed in the white matter using the tract based spatial statistics program. RESULTS: Twenty-four patients with ALS (15 females, mean age 66.9 + -2.3) and 13 healthy controls (four females, average age 66.9 + - 2) were included. The DTI showed white matter damage in ALS patients vs. healthy controls (p < 0.001). DISCUSSION: In our preliminary study the alterations of white matter in DTI were significantly associated with cognitive impairment in patients with ALS.

Incidence of Autoimmune Myasthenia Gravis in a Health Maintenance Organization in Buenos Aires, Argentina.

BACKGROUND: Different epidemiological studies, especially in Europe, have estimated the incidence density of myasthenia gravis (MG) to range between 1.7 and 21.3/1,000,000/person-year; however, data from regions such as Latin America are scarce. This study is aimed at estimating the incidence and prevalence of acquired MG in Buenos Aires, Argentina. METHODS: The study population comprised of affiliates of the Italian Hospital Medical Care Program, a prepaid health maintenance organization located in Buenos Aires. The evaluation method for case detection included a retrospective search from January 1, 2006, through December 31, 2012. RESULTS: Of the 60 cases identified, 36 (60%) were females. The median age at diagnosis was 69 years (IQR 51.5-79). The mean age at diagnosis was 63.3 years (SD ±20). A total of 28 patients (46.7%) had generalized MG and 32 had ocular MG (53.3%). Thirty five patients (58.3%) had acetylcholine receptor antibodies and 2 (3.3%) had muscle-specific receptor tyrosine kinase antibodies. The crude incidence density (ID) of MG was 61.33 per 1,000,000 person-years (95% CI 47.62-79.99). The adjusted ID for the Argentinean population was 38.8 per 1,000,000 person-years (95% CI 27.09-50.51) and for the Buenos Aires population was 47.49 (95% CI 34.73-60.25). CONCLUSIONS: The results obtained are similar to those published for other geographical areas.

Usefulness of diffusion tensor imaging in amyotrophic lateral sclerosis: potential biomarker and association with the cognitive profile / Utilidad del tensor de difusión en esclerosis lateral amiotrofica: potencial biomarcador y asociación con el perfil cognitivo

ABSTRACT The objective of this preliminary study was to correlate diffusion tensor imaging (DTI) alterations with the cognitive profile of patients with amyotrophic lateral sclerosis (ALS). Methods This was a case-control study conducted from December 1, 2012 to December 1, 2014. Clinical and demographic data were recorded. A neuropsychological test battery adapted to ALS patients was used. An MRI with DTI was performed in all patients and fractional anisotropy (FA) was analyzed in the white matter using the tract based spatial statistics program. Results Twenty-four patients with ALS (15 females, mean age 66.9 + -2.3) and 13 healthy controls (four females, average age 66.9 + - 2) were included. The DTI showed white matter damage in ALS patients vs. healthy controls (p < 0.001). Discussion In our preliminary study the alterations of white matter in DTI were significantly associated with cognitive impairment in patients with ALS.

RESUMEN El objetivo del presente estudio preliminar fue correlacionar alteraciones del Tensor de Difusión (TD) con el perfil cognitivo de pacientes con Esclerosis Lateral Amiotrofica (ELA). Metodos Se realizó estudio casos-controles entre el 1 de Diciembre del 2012 hasta el 1 de Diciembre del 2014. Se registraron datos clínicos y demográficos. Se utilizó batería de tests neuropsicológicos adaptada a ELA. Se realizó RMN de cerebro con TD en todos los pacientes, la Fracción de Anisotropía (FA) se analizó en sustancia blanca, utilizando el programa Tract Based Spatial Statistics. Resultados Se incluyeron 24 pacientes con ELA (15 mujeres, edad media 66.9 + -2.3) y 13 controles sanos (4 mujeres, edad media 66.9 +-2). El TD mostró daño en sustancia blanca en los pacientes con ELA vs controles (p < 0.001). Discusión En nuestro estudio preliminar las alteraciones de sustancia blanca en TD se asociaron significativamente con alteraciones cognitivas en pacientes con ELA.

Immune-mediated rippling muscle disease and myasthenia gravis.

Cases of acquired rippling muscle disease in association with myasthenia gravis have been reported. We present three patients with iRMD (immune-mediated rippling muscle disease) and AChR-antibody positive myasthenia gravis. None of them had thymus pathology. They presented exercise-induced muscle rippling combined with generalized myasthenia gravis. One of them had muscle biopsy showing a myopathic pattern and a patchy immunostaining with caveolin antibodies. They were successfully treated steroids and azathioprine. The immune nature of this association is supported by the response to immunotherapies and the positivity of AChR-antibodies.

[Presentations of transthyretin associated familial amyloid polyneuropathy in Argentina]. / Presentaciones de polineuropatía amiloidótica familiar asociada a transtiretina en la Argentina.

Transthyretin-related familial amyloid polyneuropathy (TTR-FAP) is a hereditary disease with variable geographical distribution. The aim of this study was to present our experience with TTR-FAP patients. We retrospectively analyzed nine cases belonging to different families. Diagnostic criteria were based on the combination of compatible clinical picture, histopathological findings and genetic confirmation. Five cases showed the classic presentation and other 4 the late onset variant. The p.Val30Met mutation in the TTR gene was found in 6 cases and p.Ala36Pro, p.Thr60Ala and p.Tyr114Cys in the remaining 3, respectively. The median age of symptom onset was 35 years (26-60 range). Mean time to diagnosis was 4.2 ± 1.5 years. Our patient series showed the heterogeneity in clinical presentation of TTR-FAP in a non-endemic region of South America.

Presentaciones de polineuropatía amiloidótica familiar asociada a transtiretina en la Argentina / Presentations of transthyretin associated familial amyloid polyneuropathy in Argentina

La polineuropatía amiloidótica familiar asociada a transtiretina (PAF-TTR) es una enfermedad hereditaria con distribución geográfica variable. El objetivo de este trabajo fue presentar nuestra experiencia con pacientes con PAF-TTR. Se evaluaron retrospectivamente 9 casos pertenecientes a diferentes familias. Los criterios diagnósticos utilizados se basaron en la combinación de un cuadro clínico compatible, hallazgos histopatológicos y confirmación genética. Cinco casos mostraron la presentación clásica y 4 la variante de inicio tardío. La mutación p.Val30Met en el gen TTR fue hallada en 6 casos y p.Ala36Pro, p.Thr60Ala y p.Tyr114Cys en los 3 los restantes, respectivamente. La edad media de inicio fue 35 años (rango 26-60). El tiempo medio al diagnóstico fue de 4.2 ± 1.5 años. Siete pacientes recibieron diagnóstico erróneo inicial, 3 de la variante clásica y 4 de la tardía. Nuestra serie de pacientes mostró marcada heterogeneidad en la presentación clínica del grupo de PAF-TTR de inicio tardío, en una región no endémica de Sudamérica.

Transthyretin-related familial amyloid polyneuropathy (TTR-FAP) is a hereditary disease with variable geographical distribution. The aim of this study was to present our experience with TTR-FAP patients. We retrospectively analyzed nine cases belonging to different families. Diagnostic criteria were based on the combination of compatible clinical picture, histopathological findings and genetic confirmation. Five cases showed the classic presentation and other 4 the late onset variant. The p.Val30Met mutation in the TTR gene was found in 6 cases and p.Ala36Pro, p.Thr60Ala and p.Tyr114Cys in the remaining 3, respectively. The median age of symptom onset was 35 years (26-60 range). Mean time to diagnosis was 4.2 ± 1.5 years. Our patient series showed the heterogeneity in clinical presentation of TTR-FAP in a non-endemic region of South America.

Incidence and prevalence of amyotrophic lateral sclerosis in an HMO of Buenos Aires, Argentina.

The incidence of amyotrophic lateral sclerosis (ALS) ranges from 1.7 to 2.3 per 100,000 persons worldwide. Few epidemiological studies have been published in Latin America. The aim of this study was to estimate the incidence and prevalence of ALS in an HMO (Health Maintenance Organization) of Buenos Aires, capital city of Argentina. The population studied was affiliates of the Italian Hospital Medical Care Program, whose distribution across age and gender strata is similar to the population of Buenos Aires. Cases were detected from 1 January 2003 to 31 December 2010. Incidence density (ID) and prevalence for ALS were estimated for the whole period and at 31 December 2010, respectively. During the seven-year study period, the crude ID estimated was 3.17 per 100,000 person-years (95% CI 2.24-4.48) and the age-adjusted ID for the Buenos Aires population was 2.23 per 100,000 person-years (95% CI 1.45-3.01). Point prevalence at 31 December 2010 was 8.86 per 100,000 persons (95% CI 4.05-13.68). Mean age at diagnosis was 72.29 years (SD 8.5). In conclusion, estimated age-adjusted ID and prevalence of ALS were similar to the incidence and prevalence rates found in other geographical areas.

Epidemiology of amyotrophic lateral sclerosis patients in a centre in Buenos Aires / Epidemiología de los pacientes con esclerosis lateral amiotrófica en el centro de Buenos Aires

Sporadic amyotrophic lateral sclerosis (sALS) is considered a multifactorial disease with genetic and environmental factors causing motor neuron degeneration. OBJECTIVE: To describe the epidemiological and occupational characteristics of patients with sALS who attended the Ramos Mejía Hospital at Buenos Aires, Argentina. METHOD: We analyzed the medical records of sALS patients diagnosed between 2001 and 2008. All occupations were coded according to the International Standard Classification of Occupation (ISCO). RESULTS: 187 patients were assessed, 38.5 percent were women and 61.5 percent men. Mean age at diagnosis was 55 years. 16 percent of them came from rural areas; 68 percent of the studied population had no health insurance. 40 percent were employed in elementary occupations, 19 were technicians and 8 handicraftsmen. CONCLUSION: The most represented profession was elementary occupation. A large proportion of patients came from rural areas, which might suggest an increased risk of environmental exposure to an unknown agent in those regions.

La esclerosis lateral amiotrófica esporádica (ELAe) es considerada una enfermedad multifactorial. OBJETIVO: Describir las características epidemiológicas y laborales de un grupo de pacientes con ELAe que fueron evaluados en el Hospital Ramos Mejía de Buenos Aires, Argentina. MÉTODO: Se analizaron los registros médicos de pacientes con ELAe diagnosticados entre 2001 y 2008. Las ocupaciones fueron codificadas de acuerdo a la Clasificación Internacional de Ocupaciones (ISCO). RESULTADOS: 187 pacientes fueron evaluados, 38,5 por ciento mujeres y 61,5 por ciento hombres. Edad media al diagnóstico 55 años. 16 por ciento procedían de zonas rurales, 68 por ciento no tenía seguro de salud. 40 por ciento se encontraba empleado en ocupaciones elementales, 19 por ciento eran técnicos , 8 por ciento artesanos y 7 por ciento operadores de maquinas. CONCLUSIÓN: La profesión más representada fue la de ocupación elemental. Una gran proporción de los pacientes provenían de zonas rurales, lo que podría sugerir un mayor riesgo de exposición ambiental a un agente desconocido en esas regiones.

Sporadic amyotrophic lateral sclerosis: new hypothesis regarding its etiology and pathogenesis suggests that astrocytes might be the primary target hosting a still unknown external agent.

This article briefly describes the already known clinical features and pathogenic mechanisms underlying sporadic amyotrophic lateral sclerosis, namely excitoxicity, oxidative stress, protein damage, inflammation, genetic abnormalities and neuronal death. Thereafter, it puts forward the hypothesis that astrocytes may be the cells which serve as targets for the harmful action of a still unknown environmental agent, while neuronal death may be a secondary event following the initial insult to glial cells. The article also suggests that an emergent virus or a misfolded infectious protein might be potential candidates to accomplish this task.

Sporadic amyotrophic lateral sclerosis: new hypothesis regarding its etiology and pathogenesis suggests that astrocytes might be the primary target hosting a still unknown external agent / Esclerosis lateral amiotrófica esporádica: nueva hipótesis relacionada con su etiología y patogenia que sugiere que los astrocitos podrían ser el blanco primario alojando un agente nocivo aun desconocido

This article briefly describes the already known clinical features and pathogenic mechanisms underlying sporadic amyotrophic lateral sclerosis, namely excitoxicity, oxidative stress, protein damage, inflammation, genetic abnormalities and neuronal death. Thereafter, it puts forward the hypothesis that astrocytes may be the cells which serve as targets for the harmful action of a still unknown environmental agent, while neuronal death may be a secondary event following the initial insult to glial cells. The article also suggests that an emergent virus or a misfolded infectious protein might be potential candidates to accomplish this task.

El artículo presente describe, brevemente, las características clínicas y los mecanismos patogénicos de la esclerosis lateral amiotrófica esporádica, tales como la excitotoxicidad, el stress oxidativo, el daño proteico, la inflamación, las anormalidades genéticas y la muerte neuronal. Luego de ello, sugiere la posibilidad hipotética de que los astrocitos podrían ser el blanco primario de la acción de una agente ambiental, externo, aún desconocido, y que la muerte neuronal aconteciera secundariamente a ese daño astrocitario inicial. El artículo concluye discutiendo la posibilidad de que un virus ambiental o endógeno o una proteína mal plegada, que adquiriera características de infectividad, puedan ser la causa de la enfermedad.

Epidemiology of amyotrophic lateral sclerosis patients in a centre in Buenos Aires.

UNLABELLED: Sporadic amyotrophic lateral sclerosis (sALS) is considered a multifactorial disease with genetic and environmental factors causing motor neuron degeneration. OBJECTIVE: To describe the epidemiological and occupational characteristics of patients with sALS who attended the Ramos Mejía Hospital at Buenos Aires, Argentina. METHOD: We analyzed the medical records of sALS patients diagnosed between 2001 and 2008. All occupations were coded according to the International Standard Classification of Occupation (ISCO). RESULTS: 187 patients were assessed, 38.5% were women and 61.5% men. Mean age at diagnosis was 55 years. 16% of them came from rural areas; 68% of the studied population had no health insurance. 40% were employed in elementary occupations, 19 were technicians and 8 handicraftsmen. CONCLUSION: The most represented profession was elementary occupation. A large proportion of patients came from rural areas, which might suggest an increased risk of environmental exposure to an unknown agent in those regions.