Dysautonomia and related outcomes in Guillain-Barre syndrome.

BACKGROUND: Guillain-Barre syndrome (GBS) presents an annual incidence of 1.2-2.3 per 100,000. Sympathetic and parasympathetic nervous systems' peripheral control of visceral organs is affected by GBS aberrant immune response. Associated cardiovascular, gastrointestinal, sudomotor, pupillary, and other systems disturbances cause significant morbidity and mortality. This study aims to evaluate the dysautonomia spectrum in GBS patients, its relationship with patient outcomes, and compare it with those without autonomic disturbances. METHODS: We performed an ambispective review study of patients with GBS and dysautonomia admitted to the Institute of Neurology from 2017 to 2021. We recorded demographics, comorbidities, nerve conduction studies, clinical course, hospital complications, and functional outcomes. RESULTS: We included 214 patients, mean age 46.44 ± 16.49 years, 51 (31 %) presented dysautonomia, hypertension in most of the patients 39 (84.8 %), hypotension 35 (76.1 %), tachycardia 35 (76.1 %), enteric dysmotility 35 (76.1 %), and need for vasopressor 27 (58.7 %) were common characteristics. Twenty (39.2 %) with a demyelinating form and twenty (39.2 %) with an axonal motor form. The bivariate analysis report factors associated with dysautonomia, were lower cranial nerves (VII, IX, X) involvement (p = 0.002), need for mechanical ventilation (p = 0.0001) and intensive care (p = 0.0001), higher mEGOS (p = 0.05), EGRIS (p = 0.004), GBS disability score (p = 0.004), and delirium presence (p = 0.001). Kaplan-Meier survival analysis showed that dysautonomic patients needed more days for the independent walk (p = 0.004). There was no associated mortality. CONCLUSIONS: Autonomic dysfunction in GBS significantly affects the peripheral nervous system. With consequently worse functional results. Further investigation needs to clarify whether more aggressive treatment is beneficial in this category of GBS.

Deltoid muscle strength and autonomic dysfunction as independent risk factors for invasive mechanical ventilation in patients with Guillain-Barré syndrome.

BACKGROUND: Almost a third of patients with Guillain-Barré Syndrome (GBS) require mechanical ventilation, increasing mortality by 15-30% and proving poor functional outcomes. The Erasmus GBS Respiratory Insufficiency Score (EGRIS) is the most frequently used scale to assess probability of respiratory insufficiency within the first week of admission. We aim to determine other clinical and electrophysiological prognostic factors for invasive mechanical ventilation (IMV) in patients with GBS. MATERIAL AND METHODS: A cross-sectional ambispective cohort study was carried out in a referral center in Mexico City, from January 2015 to December 2019. Baseline demographics, MRC score, Hughes scale, EGRIS, dysautonomia and nerve conduction studies were performed on admission in GBS patients that required IMV. A multivariable analysis for IMV and a survival analysis for independent walk in prolonged-IMV (>14 days) were performed. RESULTS: Forty-nine (32%) out of 153 GBS patients required IMV. Statistically significant prognostic factors in multivariable analysis were deltoid muscle strength ≤2 [OR 7.1 (1.6-31.1)], EGRIS [OR 2.5 (1.3-4.6)] and autonomic dysfunction [OR 6.6 (2.0-22.0)]. Electrodecrement <1 mV in the compound muscle action potential (CMAP) of distal motor median nerve was more prevalent in prolonged-IMV patients (44.8% vs. 21%, p = .049). A significant minor prevalence of prolonged-IMV patients regain independent walk at 6 months using the Kaplan-Meier method (log rank test p < .001). CONCLUSIONS: We provide new specific clinical (deltoid muscle strength and autonomic dysfunction) and electrophysiological variables to discriminate GBS patients that will require IMV.

Predictores de fenómeno de no reflujo en infarto agudo del miocardio con elevación del segmento ST / Predictors in no-reflow phenomenon in acute myocardial infarction with ST-segment elevation

Resumen Antecedentes: El fenómeno de «no reflujo¼ (NR) es una de las complicaciones más temidas tras una intervención coronaria percutánea (ICP) en el tratamiento del infarto de miocardio con elevación del segmento ST (IAMCEST) por su elevada morbimortalidad. Objetivo: Describir los factores predictores para el fenómeno de NR en un grupo de sujetos con IAMCEST tratados con ICP. Método: Se estudiaron 103 casos de IAMCEST a los que se les realizó una ICP. Los sujetos se dividieron de acuerdo con la presencia del fenómeno de NR. Se estudió mediante un análisis multivariante la edad, el sexo, presencia de comorbilidades, el peso y otros parámetros clínicos y de laboratorio como predictores del fenómeno de NR. Resultados: En este estudio, el análisis con regresión logística identificó como factores independientes para el desarrollo de fenómeno de NR el flujo TIMI basal ≤ 2 (razón de momios [OR]6.03; intervalo de confianza del 95% [IC 95%]: 0.9-11.8; p = 0.04), estadio enfermedad renal según KDIGO (Kidney Disease Improving Global Outcomes) ≥ 3 (OR 3.49; IC 95%: 1.2-2.6; p = 0.02) y nivel de glucosa ≥ 180 mg/dl(OR 2.61; IC 95%: 1.0-2.4; p = 0.04). Conclusiones: El fenómeno de NR sigue siendo un reto para la morbimortalidad a corto y a largo plazo en el IAMCEST. Los factores identificados pueden ser utilizados para la estratificación de los casos con IAMCEST y riesgo de fenómeno de NR previo a la ICP.

Abstract Background: No-reflow (NR) phenomenon is one of the most feared complications after percutaneous coronary intervention (PCI) in the treatment of ST-segment elevation myocardial infarction (STEMI) due to its high morbidity and mortality. Objective: To describe the predictive factors for NR phenomenon in a group of subjects with STEMI treated with PCI. Method: One hundred and three cases of STEMI who underwent PCI. The subjects were divided according to the presence of NR phenomenon. In a multivariate analysis age, gender, comorbidities, weight, and other clinical and laboratory parameters were studied as predictors of NR phenomenon were studied. Results: In this study, logistic regression analysis identified as independent factors for the development of NR phenomenon baseline TIMI flow ≤ 2 (OR 6.03; 95% CI, 0.9 to 11.8; p = 0.04), ER KDIGO ≥ 3 (OR OR 2.61; 95% CI, 1.0 to 2.4; p = 0.04). Conclusions: NR phenomenon continues to be a challenge for short and long-term morbidity and mortality in STEMI. The identified factors can be used for the stratification of cases with STEMI and risk of NR phenomenon prior to PCI.

Experiencia con la enfermedad de Creutzfeldt-Jakob de un único centro de referencia en México. Análisis de una serie de casos / Experience with Creutzfeldt-Jakob disease in a single referral center in Mexico. Case series

Resumen Introducción: La enfermedad de Creutzfeldt-Jakob (ECJ) es una enfermedad del sistema nervioso central rápidamente progresiva y mortal causada por priones. Objetivo: Presentar las principales características clínicas y paraclínicas de pacientes con probable ECJ en un centro de referencia de América Latina. Métodos: Estudio retrospectivo de pacientes diagnosticados con demencia rápidamente progresiva entre 2014 y 2019. Se incluyeron características clínicas, demográficas, del electroencefalograma, imágenes por resonancia magnética, proteína 14-3-3 y tomografía por emisión de positrones (PET), cuando estaba disponible. Resultados: Veinticuatro pacientes cumplieron con los criterios de ECJ esporádica (75 % mujeres), la edad media fue de 59.29 ± 11.67 años, la duración de la enfermedad desde el inicio de los síntomas hasta el ingreso hospitalario fue de 7.41 ± 6.54 meses y las primeras manifestaciones más comunes fueron las alteraciones del comportamiento (41.7 %). Los complejos de ondas delta prevalecieron en el electroencefalograma (54.2 %), la hiperintensidad cortical en la resonancia magnética (83.3 %) y el hipometabolismo frontal en la PET (37.5 %). En el análisis del líquido cefalorraquídeo, siete casos mostraron proteína tau total positiva; cinco, proteína 14-3-3 positiva; y tres, proteína tau hiperfosforilada positiva. Conclusiones: Existe importante heterogeneidad clínica en cuanto a los síntomas iniciales. Los hallazgos de las pruebas auxiliares coincidieron con los de otras series.

Abstract Introduction: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and fatal central nervous system disease caused by prions. Objective: To present the main clinical and paraclinical characteristics of patients with probable CJD in a referral center of Latin America. Methods: Retrospective study of patients diagnosed with rapidly progressive dementia between 2014 and 2019. Clinical, demographic, electroencephalogram, magnetic resonance imaging, and 14-3-3 protein characteristics were included, as well as positron-emission tomography (PET) data when available. Results: Twenty-four patients met the criteria for sporadic CJD (75% were women). Mean age was 59.29 ± 11.67 years, while mean disease duration from symptom onset to hospital admission was 7.41 ± 6.54 months. The most common first symptom was behavioral changes (41.7%). Delta wave complexes prevailed (54.2%) on electroencephalogram, cortical hyperintensity (83.3%) on magnetic resonance and frontal hypometabolism (37.5%) on PET. Seven cases showed positive total Tau; five, positive 14-3-3 protein; and three, positive phosphorylated tau on cerebrospinal fluid analysis. Conclusions: There is significant clinical heterogeneity regarding initial symptoms. Auxiliary test findings were consistent with those of other series.

Predictors in no-reflow phenomenon in acute myocardial infarction with ST-segment elevation.

BACKGROUND: No-reflow (NR) phenomenon is one of the most feared complications after percutaneous coronary intervention (PCI) in the treatment of ST-segment elevation myocardial infarction (STEMI) due to its high morbidity and mortality. OBJECTIVE: To describe the predictive factors for NR phenomenon in a group of subjects with STEMI treated with PCI. METHOD: One hundred and three cases of STEMI who underwent PCI. The subjects were divided according to the presence of NR phenomenon. In a multivariate analysis age, gender, comorbidities, weight, and other clinical and laboratory parameters were studied as predictors of NR phenomenon were studied. RESULTS: In this study, logistic regression analysis identified as independent factors for the development of NR phenomenon baseline TIMI flow ≤ 2 (OR 6.03; 95% CI, 0.9 to 11.8; p = 0.04), ER KDIGO ≥ 3 (OR OR 2.61; 95% CI, 1.0 to 2.4; p = 0.04). CONCLUSIONS: NR phenomenon continues to be a challenge for short and long-term morbidity and mortality in STEMI. The identified factors can be used for the stratification of cases with STEMI and risk of NR phenomenon prior to PCI.

ANTECEDENTES: El fenómeno de «no reflujo¼ (NR) es una de las complicaciones más temidas tras una intervención coronaria percutánea (ICP) en el tratamiento del infarto de miocardio con elevación del segmento ST (IAMCEST) por su elevada morbimortalidad. OBJETIVO: Describir los factores predictores para el fenómeno de NR en un grupo de sujetos con IAMCEST tratados con ICP. MÉTODO: Se estudiaron 103 casos de IAMCEST a los que se les realizó una ICP. Los sujetos se dividieron de acuerdo con la presencia del fenómeno de NR. Se estudió mediante un análisis multivariante la edad, el sexo, presencia de comorbilidades, el peso y otros parámetros clínicos y de laboratorio como predictores del fenómeno de NR. RESULTADOS: En este estudio, el análisis con regresión logística identificó como factores independientes para el desarrollo de fenómeno de NR el flujo TIMI basal ≤ 2 (razón de momios [OR]6.03; intervalo de confianza del 95% [IC 95%]: 0.9-11.8; p = 0.04), estadio enfermedad renal según KDIGO (Kidney Disease Improving Global Outcomes) ≥ 3 (OR 3.49; IC 95%: 1.2-2.6; p = 0.02) y nivel de glucosa ≥ 180 mg/dl(OR 2.61; IC 95%: 1.0-2.4; p = 0.04). CONCLUSIONES: El fenómeno de NR sigue siendo un reto para la morbimortalidad a corto y a largo plazo en el IAMCEST. Los factores identificados pueden ser utilizados para la estratificación de los casos con IAMCEST y riesgo de fenómeno de NR previo a la ICP.

FUS as a cause of familial Amyotrophic lateral sclerosis, a case report in a pregnant patient.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease. In 10% the disease is familial and rarely occurs in childbearing age women. A 28-year-old female pregnancy patient presented a two-month history of dropped head syndrome, dysphagia, muscle weakness, atrophy, and lingual wasting. Electromyography supported the diagnosis of ALS. Due to family history and background, we carried out molecular genetic testing. We identified a novel variant of uncertain significance: c. 1566 G > C (p.Arg522Ser) in exon 15 in FUS gene. Our findings provide the first case of ALS onset during pregnancy with a novel mutation in FUS gene reported in Mexico.

Very low peroneal nerve compound muscle action potential amplitude predicts poor outcome in patients with Guillain-Barré syndrome: a prospective cohort.

INTRODUCTION: Twenty percent of patients with Guillain-Barré syndrome (GBS) have poor outcomes despite proper management. The aim of the study was to characterize electrophysiological factors related to poor outcome in patients with GBS. METHODS: We conducted an observational study from a prospective cohort of 91 patients with GBS in a tertiary healthcare center in Mexico, from 2017 to 2019. Demographics and nerve conduction studies were performed on admission, and a 3-month follow-up for GBS disability score was ensued, allocating patients in good (GBS disability score ≤ 2) and poor outcome (GBS disability score ≥ 3) groups. A logistic regression analysis for independent walk at 3 months was performed. Kaplan-Meier estimator curves for independent walk in very low (< 20% LLN) and low-normal ( ≥20% LLN) peroneal nerve CMAPs are presented. RESULTS: From the 91 GBS patients included, 37 (40.6%) did not regain independent walk at 3 months. Axonal variants were more common in the poor outcome group (31.4% vs 59.4%, p = 0.01) as well as AIDP variants with motor conduction block (6.6% vs 42.4%, p = 0.018). Univariable analysis was statistically significant for very low median, ulnar, tibial, and peroneal CMAP amplitudes in poor outcome patients; however, multivariable analysis was only significant for very low peroneal nerve CMAP amplitude (OR 3.6 [1.1-11.5, p = 0.024]). Conversely, a greater proportion of GBS patients with low-normal CMAPs recovered independent walk at 90 days (75% vs 30%, p < 0.001). CONCLUSION: Severe axonal injury of the peroneal nerve, axonal, and AIDP with motor conduction block variants predicts worse functional outcome regarding independent walk at 3 months.

Experience with Creutzfeldt-Jakob disease in a single referral center in Mexico. Case series.

INTRODUCTION: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and fatal central nervous system disease caused by prions. OBJECTIVE: To present the main clinical and paraclinical characteristics of patients with probable CJD in a referral center of Latin America. METHODS: Retrospective study of patients diagnosed with rapidly progressive dementia between 2014 and 2019. Clinical, demographic, electroencephalogram, magnetic resonance imaging, and 14-3-3 protein characteristics were included, as well as positron-emission tomography (PET) data when available. RESULTS: Twenty-four patients met the criteria for sporadic CJD (75% were women). Mean age was 59.29 ± 11.67 years, while mean disease duration from symptom onset to hospital admission was 7.41 ± 6.54 months. The most common first symptom was behavioral changes (41.7%). Delta wave complexes prevailed (54.2%) on electroencephalogram, cortical hyperintensity (83.3%) on magnetic resonance and frontal hypometabolism (37.5%) on PET. Seven cases showed positive total Tau; five, positive 14-3-3 protein; and three, positive phosphorylated tau on cerebrospinal fluid analysis. CONCLUSIONS: There is significant clinical heterogeneity regarding initial symptoms. Auxiliary test findings were consistent with those of other series.

INTRODUCCIÓN: La enfermedad de Creutzfeldt-Jakob (ECJ) es una enfermedad del sistema nervioso central rápidamente progresiva y mortal causada por priones. OBJETIVO: Presentar las principales características clínicas y paraclínicas de pacientes con probable ECJ en un centro de referencia de América Latina. MÉTODOS: Estudio retrospectivo de pacientes diagnosticados con demencia rápidamente progresiva entre 2014 y 2019. Se incluyeron características clínicas, demográficas, del electroencefalograma, imágenes por resonancia magnética, proteína 14-3-3 y tomografía por emisión de positrones (PET), cuando estaba disponible. RESULTADOS: Veinticuatro pacientes cumplieron con los criterios de ECJ esporádica (75 % mujeres), la edad media fue de 59.29 ± 11.67 años, la duración de la enfermedad desde el inicio de los síntomas hasta el ingreso hospitalario fue de 7.41 ± 6.54 meses y las primeras manifestaciones más comunes fueron las alteraciones del comportamiento (41.7 %). Los complejos de ondas delta prevalecieron en el electroencefalograma (54.2 %), la hiperintensidad cortical en la resonancia magnética (83.3 %) y el hipometabolismo frontal en la PET (37.5 %). En el análisis del líquido cefalorraquídeo, siete casos mostraron proteína tau total positiva; cinco, proteína 14-3-3 positiva; y tres, proteína tau hiperfosforilada positiva. CONCLUSIONES: Existe importante heterogeneidad clínica en cuanto a los síntomas iniciales. Los hallazgos de las pruebas auxiliares coincidieron con los de otras series.

Prognostic Factors in Elderly Patients With Guillain-Barré Syndrome: Does Age Matter?

INTRODUCTION: Twenty to 40% of Guillain Barré syndrome (GBS) patients will not be able to walk independently despite effective treatment. Older patients carry additional risks for worse outcomes. METHODS: A single center, ambispective cohort study was performed. Only subjects ≥18 years with a 3-month follow-up were included. Elderly patients were considered as a whole if ≥ 60 years. Demographics, CSF and nerve conduction studies were compared. A binomial logistic regression and Kaplan-Meier analyses were carried out to estimate good prognosis (Hugues ≤2) at 3-month follow-up. RESULTS: From 130 patients recruited, 27.6% were elderly adults. They had a more severe disease, higher mEGOS and more cranial nerve involvement. Age ≥70 years, invasive mechanical ventilation and axonal subtype, portrayed an unfavorable 3-month outcome. Further analysis demonstrated an earlier recovery in independent walk at 3 months for patients <70 years. CONCLUSIONS: Elderly patients with GBS have a more severe disease at admission and encounter worse prognosis at 3-month follow-up, especially those above 70 years.

Classic and overlapping Miller-Fisher syndrome: clinical and electrophysiological features in Mexican adults.

Classic and overlapping Miller-Fisher syndrome (MFS) have divergent clinical courses. Few studies have addressed the electrophysiological evaluation of MFS patients, most of them carried out in Asia. This work describes and compares their clinical and neurophysiological characteristics. From a Guillain-Barré syndrome (GBS) patient cohort, we made a selection of twenty MFS cases. We defined classic and overlapping MFS, as stated by Wakerley et al. (Nat Rev Neurol 10(9):537-544, 2014). We describe and compare clinical, biochemical, and electrodiagnostic parameters between groups. Seventy-five percent were men, mean age was 42.2 ± 13.6 years, and 45% had a Hughes score ≥ 3. MFS/GBS was the most frequent clinical subtype with 50%. Almost one-third had unaltered electrophysiological studies. Comparative analysis between groups showed statistically significant differences in length of stay, dysautonomia presence, and treatment type. Kaplan-Meier survival analysis showed that 100% of the patients had an independent walk at 3 months. This study reports Mexican MFS patient's characteristics and represents the most extensive case series in Latin America. We observed a high proportion of overlapping syndromes, a good recovery profile, and no significant severe complications.

Malnutrition and Associated Motor and Non-motor Factors in People with Parkinson's Disease.

BACKGROUND: People with Parkinson's disease (PwP) are at higher risk of developing malnutrition. Several factors have been suggested to be involved including motor symptoms, non-motor symptoms, and treatment-related complications. OBJECTIVE: The objective of the study was to analyze the combined effect of motor, non-motor, and pharmacological factors in the risk of malnutrition in PwP. METHODS: Eighty-seven consecutive PwP were included in the study. Clinical data and pharmacological treatment were collected. Nutritional status was assessed using the Mini-Nutritional Assessment (MNA) questionnaire. Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-motor Symptoms Scale (NMSS), Hamilton Depression Rating Scale HAM-D, and Montreal Cognitive Assessment were applied. RESULTS: Thirty (34.4%) PwP were at risk of malnutrition and seven had malnutrition (8%). Abnormal nutritional status was associated with lower education, higher MDSUPDRS Parts I, II, and III and total scores, and higher scores in the NMSS domain of sleep disorders and fatigue. MDS-UPDRS motor score remained as a determinant of abnormal nutritional status, defined as MNA < 23.5, with an odds ratio 1.1 (95% confidence interval 1.01-1.10, p = 0.02). CONCLUSION: The main factor associated with nutritional status was severity of the motor symptoms as assessed by the MDS-UPDRS Part III. Non-motor symptoms and treatment-related complications were not associated with malnutrition.

Malnutrition and Associated Motor and Non-motor Factors in People with Parkinson's Disease

Background: People with Parkinson’s disease (PwP) are at higher risk of developing malnutrition. Several factors have been suggested to be involved including motor symptoms, non-motor symptoms, and treatment-related complications. Objective: The objective of the study was to analyze the combined effect of motor, non-motor, and pharmacological factors in the risk of malnutrition in PwP. Methods: Eighty-seven consecutive PwP were included in the study. Clinical data and pharmacological treatment were collected. Nutritional status was assessed using the Mini-Nutritional Assessment (MNA) questionnaire. Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Non-motor Symptoms Scale (NMSS), Hamilton Depression Rating Scale HAM-D, and Montreal Cognitive Assessment were applied. Results: Thirty (34.4%) PwP were at risk of malnutrition and seven had malnutrition (8%). Abnormal nutritional status was associated with lower education, higher MDS-UPDRS Parts I, II, and III and total scores, and higher scores in the NMSS domain of sleep disorders and fatigue. MDS-UPDRS motor score remained as a determinant of abnormal nutritional status, defined as MNA <23.5, with an odds ratio 1.1 (95% confidence interval 1.01-1.10, p = 0.02). Conclusion: The main factor associated with nutritional status was severity of the motor symptoms as assessed by the MDS-UPDRS Part III. Non-motor symptoms and treatment-related complications were not associated with malnutrition. (REV INVEST CLIN. 2020;72(5):293-9)

Electrophysiological subtypes and associated prognosis factors of Mexican adults diagnosed with Guillain-Barré syndrome, a single center experience.

BACKGROUND: The clinical characteristics of electrophysiological subtypes and prognostic factors of Mexican adults diagnosed with Guillain-Barré Syndrome (GBS) have not been described. MATERIALS AND METHODS: A single center, ambispective, cohort study was performed (2015-2019). GBS was defined following the Asbury and Cornblath criteria. Electrodiagnosis was made according to Hadden criteria. Clinical, biochemical and electrodiagnostic parameters were described, compared and analyzed using a multivariate model. Only patients who completed a 3-month follow-up were included. RESULTS: 137 GBS patients (92 males; mean age 46.6 ± 16.6).132 (96.3%) underwent an electrodiagnostic assessment.68 (51.5%) were classified as axonal GBS, with further classified into two groups: acute motor axonal neuropathy (AMAN) 45.4%, and acute motor and sensory axonal neuropathy (AMSAN) 8,6%. The following characteristics were lower in the AMAN group: Medical Research Counsel sumscore (MRC) 30.1 ± 16.3 vs 36.4 ± 14.4, unilateral facial palsy 10% vs 25.9% and albuminocytologic dissociation 41.3% vs. 71.7%.Multivariate analysis found AMAN as an independent predictor of an unfavorable outcome OR: 3.34 (p = 0.03) CONCLUSIONS: AMAN subtype is the most frequent presentation of GBS in Mexican adult patients and an independent predictor of inability to walk independently at 3 months after discharge.

Intravenous cyclophosphamide monthly pulses in refractory myasthenia gravis.

INTRODUCTION: Refractory myasthenia gravis (MG) is defined as a failure to respond adequately to conventional therapies, the inability to reduce immunosuppressive therapy without clinical relapse or the need for ongoing rescue therapy, severe adverse effects from immunosuppressive therapy (treatment intolerant) or frequent myasthenic crisis even on therapy. Cyclophosphamide (CYC) is a DNA alkylating agent that causes important interference in transcription processes and DNA replication, it has been used in refractory MG with controversial results. We aim to determine the efficacy of CYC in refractory MG in the Mexican population. METHODS: In an observational, longitudinal retrospective study, we identified eight refractory MG patients treated with 30-50 mg/kg monthly CYC for at least 6 months. The efficacy was assessed by Osserman scale considering significant improvement a ≥ 1 point reduction and Myasthenia Gravis Composite Scale. The relapse-free and remission-free period were also calculated using the Kaplan-Meier statistic. RESULTS: Clinical improvement was achieved in 75% of the patients. According to the Kaplan-Meier analysis, the median progression-free survival (PFS) was 9 (6.2-11.5) months and the median time to progression (TTP) was 4 (1-8) months. Response was independent of patient's characteristics, except for the MG age of onset (p = 0.0025). CONCLUSIONS: CYC was effective in all patients with refractory MG for a mean of 9 months, with worsening thereafter, which could be associated with low cumulative dose. The symptomatic improvement with CYC was noted within the 1st month. We conclude that CYC is effective as an induction to remission therapy, although our data suggest it is not effective as a long-term therapy.