Importancia de la electrofisiología ocular en el diagnóstico de las distrofias retinianas / Importance of ocular electrophysiology in the diagnosis of retinal dystrophies

Antecedentes y objetivo: El diagnóstico de las distrofias retinianas es complejo y se basa en estudio oftalmológico completo, estudio genético y los estudios electrofisiológicos (EEF). En este estudio pretendemos evaluar el papel de las pruebas electrofisiológicas y del médico solicitante en el diagnóstico de las distrofias de retina. Materiales y métodos: Estudio observacional retrospectivo. Se seleccionaron 50 pacientes atendidos en el Servicio de Neurofisiología del Hospital Universitario Virgen Macarena. Se valoró el sexo, la edad, el hospital de origen, motivo por el que se solicitó los EEF, diagnóstico de presunción tras examen oftalmológico, EEF realizados, estudio genético y el diagnóstico definitivo tras realización de EEF. Se elaboró un sistema de clasificación que otorga a cada caso un valor comprendido entre 0 y 2, en función de la contribución de las pruebas electrofisiológicas al diagnóstico final. Resultados: La edad media fue 44,34 ± 18,03 años (60% mujeres). Retinosis pigmentaria, neuropatía óptica y enfermedad de Stargardt fueron los diagnósticos más frecuentes. Los EEF modificaron el diagnóstico de presunción en el 48% de los casos, confirmaron el diagnóstico en el 44% y no aportaron información en el 8%. La contribución de los EEF fue mayor en pacientes atendidos en el Hospital Universitario Virgen Macarena y cuando se solicitaban por hallazgos en la exploración (p = 0,001). Los falsos positivos para distrofia retiniana fueron del 60% en pacientes no valorados en dicho hospital. Conclusiones: Las pruebas electrofisiológicas y el manejo especializado de los pacientes con distrofias retinianas desempeñan un papel importante en el diagnóstico de estas patologías

Background and objective; The diagnosis of retinal dystrophies is complex and is based on complete ophthalmological study, genetic study and electrophysiological studies (EPS). In this study, we intend to evaluate the role of electrophysiological and medical tests in the diagnosis of retinal dystrophies. Material and methods: A retrospective observational study was conducted on 50 selected patients that attended the Neurophysiology Department of the University Hospital Virgen Macarena. An analysis was made of the variables that included, gender, age, referral hospital, reason for which the EPS was requested, applied EPS, genetic study, presumed diagnosis, and definitive diagnosis after EPS. A classification system was subsequently developed, which gives each case a value between 0 and 2, depending on the contribution of the electrophysiological tests to the final diagnosis. Results: The mean age was 44.34 ± 18.03 years (60% women). Retinitis pigmentosa (24%), optic neuropathy (12%), and Stargardt's disease (8%) were the most frequent diagnoses. The EPS modified the presumed diagnosis in 48% of the cases, confirmed the diagnosis in 44%, and did not provide any useful information in 8%. The contribution of the EPS was greater in patients seen in the HUVM and when requested by findings in the examination (P = .001). The false positives in the diagnosis of retinal dystrophy were 60% in patients not evaluated by the University Hospital Virgen Macarena. Conclusions: Electrophysiological test and specialised management of patients with retinal dystrophies play an important role in the diagnosis of these conditions

Importance of ocular electrophysiology in the diagnosis of retinal dystrophies. / Importancia de la electrofisiología ocular en el diagnóstico de las distrofias retinianas.

BACKGROUND AND OBJECTIVE: The diagnosis of retinal dystrophies is complex and is based on complete ophthalmological study, genetic study and electrophysiological studies (EPS). In this study, we intend to evaluate the role of electrophysiological and medical tests in the diagnosis of retinal dystrophies. MATERIAL AND METHODS: A retrospective observational study was conducted on 50 selected patients that attended the Neurophysiology Department of the University Hospital Virgen Macarena. An analysis was made of the variables that included, gender, age, referral hospital, reason for which the EPS was requested, applied EPS, genetic study, presumed diagnosis, and definitive diagnosis after EPS. A classification system was subsequently developed, which gives each case a value between 0 and 2, depending on the contribution of the electrophysiological tests to the final diagnosis. RESULTS: The mean age was 44.34 ±18.03 years (60% women). Retinitis pigmentosa (24%), optic neuropathy (12%), and Stargardt's disease (8%) were the most frequent diagnoses. The EPS modified the presumed diagnosis in 48% of the cases, confirmed the diagnosis in 44%, and did not provide any useful information in 8%. The contribution of the EPS was greater in patients seen in the HUVM and when requested by findings in the examination (P=.001). The false positives in the diagnosis of retinal dystrophy were 60% in patients not evaluated by the University Hospital Virgen Macarena. CONCLUSIONS: Electrophysiological test and specialised management of patients with retinal dystrophies play an important role in the diagnosis of these conditions.

[Atypical Guillain-Barre syndrome clustering: is it necessary to reconsider the diagnostic criteria and microbiological protocol?] / Agrupacion de casos de sindrome de Guillain-Barre atipico: es necesario redefinir los criterios diagnosticos y los protocolos microbiologicos?

INTRODUCTION: Guillain-Barre syndrome is classically defined as a symmetrical ascending acute polyradiculoneuropathy, although there are atypical variants that make diagnosis difficult. CASE REPORTS: The medical data of six patients in our hospital area are collected during the first quarter of 2013. Lumbar punctures, imaging, neurophysiological studies, ganglioside antibodies and serologies have been proposed in all cases. We focus on the atypical features as late hyporeflexia, increased frequency of asymmetry and distal paresis and initial fever. From a neurophysiological point of view, all patients presented sensorimotor axonal forms. The most consistent datas in early studies is the F wave's alteration. A Miller Fisher variant associated with faciocervicobraquial paresis and cerebral reversible vasoconstriction syndrome has been detected. A bilateral brachial paresis and lumbar polyradiculopathy in the context of influenza A infection is other interesting case. The saltatory variant with cranial nerve involvement and lower limbs paresis has been demonstrated in one patient. Bands in cerebrospinal fluid are positive in three cases and anti-ganglioside antibodies in one patient. The syndrome of inappropriate secretion of antidiuretic hormone may explain some of the hyponatremias registered. The first line of treatment are inmunoglobulins in all patients. Plasmapheresis exchanges has been used as an additional therapy in four cases. CONCLUSIONS: These clusters of six axonal cases with atypical clinical features justifies the need for knowledge of these variants in order to achieve an early treatment. Late hyporeflexia and brachialfaciocervico, saltatory and lumbar forms should be considered in the spectrum of Guillain-Barre syndrome. The etiological study should rule out a lots of pathogens as influenza A.

TITLE: Agrupacion de casos de sindrome de Guillain-Barre atipico: es necesario redefinir los criterios diagnosticos y los protocolos microbiologicos?Introduccion. El sindrome de Guillain-Barre se define clasicamente como una polirradiculopatia aguda simetrica ascendente, si bien existen variantes atipicas que dificultan el diagnostico. Casos clinicos. Se recogen las historias clinicas de seis pacientes de nuestra area hospitalaria durante el primer trimestre de 2013. Se han realizado punciones lumbares, electroneurograma-electromiograma y analiticas con autoinmunidad en todos los casos. El conjunto de la muestra destaca por la presencia de caracteristicas atipicas, como hiporreflexia tardia, mayor frecuencia de asimetria y afectacion distal, asi como fiebre inicial. Desde el punto de vista neurofisiologico, todos los pacientes presentan formas axonales de tipo sensitivomotoras y las alteraciones de la onda F son el dato mas precoz. Se identifica una variante de sindrome de Miller Fisher asociada a paresia faciocervicobraquial y sindrome de vasoconstriccion cerebral reversible. Otro caso auna las variantes de paresia braquial bilateral y polirradiculopatia lumbar en el contexto de infeccion aguda por influenza A. La variante saltatoria ha sido demostrada en otro paciente. Todos los pacientes han recibido tratamiento con inmunoglobulinas, y en dos de ellos se sumo la plasmaferesis como terapia adicional. Conclusiones. La agrupacion de seis casos axonales con caracteristicas clinicas atipicas justifica la necesidad del conocimiento de estas variantes para lograr un diagnostico y un tratamiento precoz. La hiporreflexia tardia y las formas faciocervicobraquiales, saltatorias y lumbares deben considerarse dentro del espectro del sindrome de Guillain-Barre. El estudio etiologico debe incluir el cribado de numerosos patogenos, entre los que debe incluirse el virus influenza A.

[Statistical (Poisson) motor unit number estimation. Methodological aspects and normal results in the extensor digitorum brevis muscle of healthy subjects]. / Estimación del numero de unidades motoras en un musculo mediante la técnica estadística (Poisson). Aspectos metodológicos y parámetros normales en el extensor digitorum brevis.

INTRODUCTION: Among the differents techniques for motor unit number estimation (MUNE) there is the statistical one (Poisson), in which the activation of motor units is carried out by electrical stimulation and the estimation performed by means of a statistical analysis based on the Poisson s distribution. OBJECTIVES: The study was undertaken in order to realize an approximation to the MUNE Poisson technique showing a coprehensible view of its methodology and also to obtain normal results in the extensor digitorum brevis muscle (EDB) from a healthy population. SUBJECTS AND METHODS: One hundred fourteen normal volunteers with age ranging from 10 to 88 years were studied using the MUNE software contained in a Viking IV system. RESULTS: The normal subjects were divided into two age groups (10 59 and 60 88 years). The EDB MUNE from all them was 184 49. Both, the MUNE and the amplitude of the compound muscle action potential (CMAP) were significantly lower in the older age group (p< 0.0001), showing the MUNE a better correlation with age than CMAP amplitude ( 0.5002 and 0.4142, respectively p< 0.0001). CONCLUSION: Statistical MUNE method is an important way for the assessment to the phisiology of the motor unit. The value of MUNE correlates better with the neuromuscular aging process than CMAP amplitude does.

Estimación del número de unidades motoras en un músculo mediante la técnica estadística (Poisson). Aspectos metodológicos y parámetros normales en el extensor digitorum brevis / Statistical (Poisson) motor unit number estimation. Methodological aspects and normal results in the extensor digitorum brevis muscle of healthy subjects

Introducción. Entre las distintas técnicas para la estimación del número de unidades motoras funcionales dentro de un músculo (MUNE) se encuentra la que describió Daube (1995), en la que la activación de las unidades motoras se realiza por estimulación eléctrica, y la estimación mediante un análisis estadístico basado en la distribución de Poisson. Objetivos. Realizar una aproximación a la técnica MUNE-Poisson y ofrecer una visión comprensible de su metodología. Asimismo, proporcionar valores normales de la MUNE en el extensor digitorum brevis en una población de sujetos sanos. Sujetos y métodos. Se estudian 114 sujetos normales de edades comprendidas entre los 10 y los 88 años mediante el método estadístico de estimación de unidades motoras, disponible en el software de un equipo Viking IV. Resultados. La MUNE en el extensor digitorum brevis fue de 184ñ49. Los sujetos se dividieron en dos grupos de edad (10-59 y 60-88 años). La MUNE y la amplitud del potencial de acción muscular compuesto (CMAP) fueron significativamente menores en el grupo de mayor edad (p< 0,0001); la MUNE mostró una mayor correlación con la edad que la amplitud. (-0,5002 y -0,4142; p< 0,0001). Conclusión. El método estadístico para la estimación de unidades motoras (MUNE-Poisson) es una importante forma de aproximación a la fisiología de la unidad motora. El valor de la MUNE refleja mejor el fenómeno de envejecimiento de la unidad motora que la amplitud del CMAP (AU)

Introduction. Among the differents techniques for motor unit number estimation (MUNE) there is the statistical one (Poisson), in which the activation of motor units is carried out by electrical stimulation and the estimation performed by means of a statistical analysis based on the Poisson’s distribution. Objectives. The study was undertaken in order to realize an approximation to the MUNE-Poisson technique showing a coprehensible view of its methodology and also to obtain normal results in the extensor digitorum brevis muscle (EDB) from a healthy population. Subjects and methods. One-hundred-fourteen normal volunteers with age ranging from 10 to 88 years were studied using the MUNE software contained in a Viking IV system. Results. The normal subjects were divided into two age groups (10-59 and 60-88 years). The EDB MUNE from all them was 184±49. Both, the MUNE and the amplitude of the compound muscle action potential (CMAP) were significantly lower in the older age group (p< 0.0001), showing the MUNE a better correlation with age than CMAP amplitude (-0.5002 and -0.4142, respectively p< 0.0001). Conclusion. Statistical MUNE method is an important way for the assessment to the phisiology of the motor unit. The value of MUNE correlates better with the neuromuscular aging process than CMAP amplitude does (AU)