A Predictive Model for Guillain-Barré Syndrome Based on Ensemble Methods.

Nowadays, Machine Learning methods have proven to be highly effective on the identification of various types of diseases, in the form of predictive models. Guillain-Barré syndrome (GBS) is a potentially fatal autoimmune neurological disorder that has barely been studied with computational techniques and few predictive models have been proposed. In a previous study, single classifiers were successfully used to build a predictive model. We believe that a predictive model is imperative to carry out adequate treatment in patients promptly. We designed three classification experiments: (1) using all four GBS subtypes, (2) One versus All (OVA), and (3) One versus One (OVO). These experiments use a real-world dataset with 129 instances and 16 relevant features. Besides, we compare five state-of-the-art ensemble methods against 15 single classifiers with 30 independent runs. Standard performance measures were used to obtain the best classifier in each experiment. Derived from the experiments, we conclude that Random Forest showed the best results in four GBS subtypes classification, no ensemble method stood out over the rest in OVA classification, and single classifiers outperformed ensemble methods in most cases in OVO classification. This study presents a novel predictive model for classification of four subtypes of Guillain-Barré syndrome. Our model identifies the best method for each classification case. We expect that our model could assist specialized physicians as a support tool and also could serve as a basis to improved models in the future.

Caracterización general de Zika / General characterization of Zika

El Zika es un arbovirosis que causa enfer-medad febril caracterizada por fiebre, rash, artralgias y conjuntivitis no purulenta. En 2015 se registraron casos autóctonos en Brasil, en menos de un año el Zika se exten-dió a más de 30 países y territorios de Améri-ca Central, América del Sur, el Caribe y México, entre estos Honduras. Se ha rela-cionado con aumento de los casos de Gui- llain Barré y microcefalia en zonas donde produce epidemia. En Honduras, entre la semana epidemiológica 1 del 2016 a la 33 del 2017, hubo un total acumulado de 681 mujeres embarazadas con sospecha de Zika identificadas en el país, 125 de las cuales han sido confirmadas en laboratorio por reacción en cadena de polimerasa. Se reali-zó una revisión bibliográfica de 30 artículos tomando como referencia: artículos de revis-tas, normas y recomendaciones menores de 5 años de haber sido publicados o aquellos con importancia histórica, con el fin de brin-dar información útil al lector acerca del tema. Zika es una enfermedad que puede generar un impacto negativo en la salud de la niñez, dejando secuelas a largo plazo...(AU)

Diplejía facial como variante inusual del síndrome de Guillain-Barré: primer caso reportado en Venezuela / Facial diplegia as unusual variant of Guillain-Barré syndrome: first case reported in Venezuela

El síndrome de Guillain-Barré (SGB) es la causa más común de parálisis generalizada aguda. El SGB es una polirradiculoneuropatia aguda inflamatoria desmielinizante que generalmente se presenta como una parálisis que inicia en miembros inferiores y luego progresa de forma ascendente y simétrica. El presente trabajo, tiene como objetivo, informar un caso de diplejía facial como manifestación inicial de SGB. Paciente masculino, 37 años de edad, diabético tipo 2, que luego de ocho días de haber padecido una sinusitis aguda, presentó de forma gradual, cefalea hemicraneana derecha, derramamiento salival y disartria. En la exploración neurológica se observó ausencia bilateral de los pliegues frontales, lagoftalmos bilateral acompañado de epífora, signo de Bell bilateral y derramamiento salival a través de ambas comisuras labiales. A las 48 horas de su ingreso hospitalario, presentó paresia en ambos miembros superiores. El estudio del líquido cefalorraquídeo reportó 1,1 células/mm³ representadas en su totalidad por linfocitos de aspecto normal, y proteínas totales 196,9mg/dL. La electromiografía fue compatible con polineuropatía desmielinizante aguda de predominio motor con mayor afectación facial. Con los hallazgos clínicos y paraclínicos se realizó el diagnóstico de SGB. Se inició tratamiento a base de plasmaféresis e inmunoglobulina endovenosa, con posterior mejoría de la clínica. La diplejía facial forma parte de las variantes regionales del SGB. A pesar que cerca del 60% de los pacientes con SGB presentan debilidad facial en el curso del trastorno, ésta habitualmente es precedida por debilidad en extremidades. El presente caso permite evidenciar que el SGB puede debutar clínicamente como una diplejía facial.

The Guillain-Barré syndrome (GBS) is the most common cause of acute generalized paralysis. GBS is an acute inflammatory demyelinating polyradiculoneuropathy. It usually presents as a paralysis that starts in the lower limbs and then progresses symmetrically upward. The present study reports a case of bilateral facial palsy as the initial manifestation of GBS. This is a report of a case of a 37-year-old male, diabetic, that eight days after having suffered acute sinusitis, gradually presented with right hemicranial headache, dysarthria and sialorrhea. The neurological examination disclosed the absence of the bilateral frontal folds, accompanied by epiphora, bilateral lagophthalmos, bilateral Bell sign and salivary drooling through both commissures of lips. At 48 hours after hospital admission the patient showed paresis in both upper limbs. The cerebrospinal fluid analysis reported 1.1cells/mm³, fully represented by lymphocytes of normal aspect and total proteins were 196.9 mg/dL. The electromyography was consistent with acute demyelinating polyneuropathy, with a predominant motor component and a major facial involvement. With the clinical and laboratory findings, a diagnosis of GBS was established. Treatment was started with plasmapheresis and intravenous immunoglobulin, with the subsequent improvement of the clinic. The facial diplegia is part of the regional variants of GBS. Although about 60% of GBS patients present with facial weakness, it is usually preceded by weakness in the limbs. This case makes evident that GBS may present clinically as a facial diplegia.

[Clinical features of Guillain-Barré syndrome in 41 patients admitted to a public hospital]. / Características epidemiológicas del síndrome de Guillain-Barré en población chilena: estudio hospitalario en un período de 7 años.

BACKGROUND: Guillain-Barré syndrome (GBS) is the commonest cause of acute flaccid paralysis worldwide, with an incidence of 0.6-4 per 100.000 inhabitants per year. It affects all age groups and carries an incapacity burden of up to 20%. AIM: To describe the features of GBS in adult Chilean patients admitted to a tertiary care hospital. MATERIAL AND METHODS: Review of medical records of 41 patients aged 17 to 81 years (30 males) admitted to a public hospital with the diagnosis of GBS between 2003 and 2009. According to clinical and electrophysiological criteria, the patients were classified into different varieties of GBS. RESULTS: The incidence of GBS was higher in males (2.7:1) and the demyelinated GBS variety was found in 66% of cases. According to the Hughes’ disability score, patients treated with plasmapheresis, showed non-statistically significant better outcomes than those treated with intravenous immunoglobulin. CONCLUSIONS: In this group of patients the demyelinated variety of GBS was more common than the axonal type. Although not statistically significant, the better response to plasmapheresis is encouraging and should prompt a controlled study.

Facial diplegia as unusual variant of Guillain-Barré syndrome: first case reported in Venezuela. / Diplejía facial como variante inusual del síndrome de Guillain-Barré: primer caso reportado en Venezuela.

The Guillain-Barré syndrome (GBS) is the most common cause of acute generalized paralysis. GBS is an acute inflammatory demyelinating polyradiculoneuropathy. It usually presents as a paralysis that starts in the lower limbs and then progresses symmetrically upward. The present study reports a case of bilateral facial palsy as the initial manifestation of GBS. This is a report of a case of a 37-year-old male, diabetic, that eight days after having suffered acute sinusitis, gradually presented with right hemicranial headache, dysarthria and sialorrhea. The neurological examination disclosed the absence of the bilateral frontal folds, accompanied by epiphora, bilateral lagophthalmos, bilateral Bell sign and salivary drooling through both commissures of lips. At 48 hours after hospital admission the patient showed paresis in both upper limbs. The cerebrospinal fluid analysis reported 1.1cells/mm3, fully represented by lymphocytes of normal aspect and total proteins were 196.9 mg/dL. The electromyography was consistent with acute demyelinating polyneuropathy, with a predominant motor component and a major facial involvement. With the clinical and laboratory findings, a diagnosis of GBS was established. Treatment was started with plasmapheresis and intravenous immunoglobulin, with the subsequent improvement of the clinic. The facial diplegia is part of the regional variants of GBS. Although about 60% of GBS patients present with facial weakness, it is usually preceded by weakness in the limbs. This case makes evident that GBS may present clinically as a facial diplegia.

Feature selection for better identification of subtypes of Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is a neurological disorder which has not been explored using clustering algorithms. Clustering algorithms perform more efficiently when they work only with relevant features. In this work, we applied correlation-based feature selection (CFS), chi-squared, information gain, symmetrical uncertainty, and consistency filter methods to select the most relevant features from a 156-feature real dataset. This dataset contains clinical, serological, and nerve conduction tests data obtained from GBS patients. The most relevant feature subsets, determined with each filter method, were used to identify four subtypes of GBS present in the dataset. We used partitions around medoids (PAM) clustering algorithm to form four clusters, corresponding to the GBS subtypes. We applied the purity of each cluster as evaluation measure. After experimentation, symmetrical uncertainty and information gain determined a feature subset of seven variables. These variables conformed as a dataset were used as input to PAM and reached a purity of 0.7984. This result leads to a first characterization of this syndrome using computational techniques.

[Electrophysiological subtypes of Guillain-Barré syndrome in Mexican adults]. / Subtipos electrofisiológicos del síndrome de Guillain-Barré en adultos mexicanos.

INTRODUCTION: Guillain-Barré syndrome (GBS) is an autoimmune polyradiculoneuropathy subdivided in demyelinating and axonal types. There is no established frequency about the electrophysiological subtypes in Mexico. OBJECTIVE: to determine the frequency of electrophysiological subtypes of GBS in Mexican patients. MATERIAL AND METHODS: The study design was descriptive and retrospective. Patients with GBS older than 15 years without coexisting major diseases were selected retrospectively from a three-year period. These patients should have met the clinical and electrophysiological criteria of GBS. Motor nerve conduction studies were made of the median, ulnar, tibial and peroneal nerves, and antidromic sensory conduction studies were performed in the median, ulnar and sural nerves. Descriptive statistics, analysis of variance and chi(2) test were used. RESULTS: The study included fifty-one patients with median age of 45.5 years (range 16-79); 37 men and 14 women, with a ratio man-woman 2.6:1; 37% were observed in winter (p = 0.56). The electrophysiological subtypes were acute motor axonal neuropathy (AMAN) 39 %; acute inflammatory demyelinating polyneuropathy (AIDP) 23.5 %; mixed neuropathy (MN) 20%; and acute motor sensory axonal neuropathy (AMSAN) 17.5 %. CONCLUSIONS: the most frequent electrophysiological subtype in Mexican patients was AMAN. Other frequent subtypes were MN and AMSAN. Axonal variants were the predominant types.

[Unusual variants of Guillain-Barré syndrome in infancy]. / Variantes inusuales del síndrome de Guillain-Barré en la infancia.

AIMS: To identify unusual variants within a paediatric population of patients with Guillain-Barré syndrome (GBS), to determine the frequency of their occurrence and to describe their clinical and electrophysiological characteristics. PATIENTS AND METHODS: The medical records of 179 patients diagnosed with GBS were reviewed. Those who strictly satisfied the Asbury criteria were excluded. RESULTS: Twenty patients, with a mean age of 7.6 years at the onset of symptoms, presented the following clinical variants: multiple cranial polyneuropathy (4 cases), Miller Fisher syndrome (MFS) (3 cases), pharyngeal-cervical-brachial palsy (PCBP) (2 cases), combined MFS and PCBP (3 cases), paraparesis (4 cases), palpebral ptosis without ophthalmoplegia (1 case), ophthalmoplegia without ataxia (1 case), paresis of the abducent nerve with paresthesias (1 case), and saltatory (1 case). Albuminocytologic dissociation was reported in 77.8% of patients and neuroconduction with a demyelinating pattern was noted in 75%. Patients progressed favourably in 94.4% of cases. CONCLUSIONS: In our study, 11.2% of a population of children with GBS presented unusual variants and did not meet the criteria established by Asbury et al. Recognising these variants of GBS in patients with complex pictures such as those described here enables therapy to be established quickly. The question remains as to whether these variants represent a clinical response to different antibodies or to a regional susceptibility of the host.