[Application of the motor unit number estimation (MUNE-Poisson) statistical technique in patients with neurogenic processes]. / Aplicación en pacientes con procesos neurogénicos de la técnica estadística de estimación del número de unidades motoras (MUNE-Poisson).

INTRODUCTION: Little research has been conducted on applying the statistical estimation of the number of motor units (the MUNE statistic) in the diagnosis of neurogenic processes. AIMS: To determine the sensitivity of this test in patients with different neurogenic processes and to disseminate and clarify its basic methodological aspects. SUBJECTS AND METHODS: Both the conventional calculation and the modified version of the MUNE-Poisson put forward by Shefner et al (MUNEm) were used to carry out unilateral studies of the extensor digitorum brevis muscle in 82 patients who had previously been clinically and electromyographically diagnosed with sensory-motor axonal polyneuropathy (36 cases), unilateral L5 radiculopathy (26 patients) and second motor neuron disease (20 cases). RESULTS: Overall sensitivity of the two methods was 81.7% and 82.9%, respectively, with no significant differences between them. Similarly, the sensitivity of the MUNE studies does not differ statistically according to the diagnosis. Patients who had a compound muscle action potential (CMAP) with a reduced amplitude displayed significantly higher sensitivity in MUNE studies (94.8%) than those who exhibited a normal CMAP (69.7%) (p < 0.001). CONCLUSIONS: Although routine use of the MUNE statistical method is unnecessary in daily practice, it should be considered for use in processes in which conventional muscle electromyography, especially involving distal ones, offers doubtful results or the aim is to follow the progression of certain neurogenic processes.

Aplicación en pacientes con procesos neurogénicos de la técnica estadística de estimación del número de unidades motoras (MUNE-Poisson) / Application of the motor unit number estimation (mune-poisson) statistical technique in patients with neurogenic processes

Introducción. Existe poca experiencia sobre la aplicación de la estimación estadística del número de unidades motoras (MUNE estadístico) en el diagnóstico de procesos neurogénicos. Objetivos. Determinar la sensibilidad de dicho test en pacientes con distintos procesos neurogénicos y difundir y aclarar los aspectos metodológicos fundamentales de aquél. Sujetos y métodos. Se ha estudiado mediante MUNE-Poisson, utilizando el calculo convencional y el modificado propuesto por Shefner et al (MUNEm), unilateralmente el músculo extensor digitorum brevis de 82 pacientes previamente diagnosticados clínica y electromiográficamente de polineuropatía axonal sensitivomotora (36 casos), radiculopatía L5 unilateral (26 pacientes) y enfermedad de la segunda motoneurona (20 casos). Resultados. La sensibilidad global de ambos métodos ha sido de 81,7 y 82,9%, respectivamente, sin diferencias significativas entre ellos. La sensibilidad de los estudios MUNE tampoco es estadísticamente diferente según el diagnóstico. Los pacientes que presentaron amplitud del potencial muscular compuesto (CMAP) reducida en amplitud mostraron significativamente mayor sensibilidad en los estudios MUNE (94,8%) que los que exhibieron un CMAP normal (69,7%) (p < 0,001). Conclusión. Aunque es innecesario utilizar rutinariamente en la práctica diaria el método MUNE estadístico, sí se debe considerar su empleo en procesos en los que la electromiografía convencional de músculos, sobre todo distales, presenta resultados dudosos, o se pretende seguir la evolución de ciertos procesos neurogénicos

Introduction. Little research has been conducted on applying the statistical estimation of the number of motor units (the MUNE statistic) in the diagnosis of neurogenic processes. Aims. To determine the sensitivity of this test in patients with different neurogenic processes and to disseminate and clarify its basic methodological aspects. Subjects and methods. Both the conventional calculation and the modified version of the MUNE-Poisson put forward by Shefner et al (MUNEm) were used to carry out unilateral studies of the extensor digitorum brevis muscle in 82 patients who had previously been clinically and electromyographically diagnosed with sensory-motor axonal polyneuropathy (36 cases), unilateral L5 radiculopathy (26 patients) and second motor neuron disease (20 cases). Results. Overall sensitivity of the two methods was 81.7% and 82.9%, respectively, with no significant differences between them. Similarly, the sensitivity of the MUNE studies does not differ statistically according to the diagnosis. Patients who had a compound muscle action potential (CMAP) with a reduced amplitude displayed significantly higher sensitivity in MUNE studies (94.8%) than those who exhibited a normal CMAP (69.7%) (p < 0.001). Conclusions. Although routine use of the MUNE statistical method is unnecessary in daily practice, it should be considered for use in processes in which conventional muscle electromyography, especially involving distal ones, offers doubtful results or the aim is to follow the progression of certain neurogenic processes

[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)

[Intraoperative electroneurophysiological monitoring of basal cranial nerve surgery]. / Monitorización intraoperatoria electroneurofisiológica en la cirugía de los nervios craneales de la base del cráneo.

INTRODUCTION: Since 1980 when intraoperative monitoring was introduced or acoustic nerve surgery, the technique rapidly was outspreaded to the other basal cranial nerves, and today is the most important and indispensable piece of work first of all because of its effectiveness in the prevention of the neurologic deficits. OBJECTIVE: The aim of this work is to describe the basic requisites needed (personnel, equipment, stimulation and recording electrodes, patient handling), as well as to review the different techniques used (electromyography and electroneurography) in the motor cranial nerve monitorization (facial, motor trigeminal, extraocular muscles, glossopharyngeal, vagus, spinal accessory and hypoglossal) and the sensitive cranial nerves (optic, sensitive trigeminal, and acoustic) especially with evoked potentials. Finally, we pointed out the non-neurologic structures monitoring during the surgery of the posterior fossa.

A case of hemidiaphragmatic paralysis after an anti-G suit failure.

This paper reports a case of left hemidiaphragmatic paralysis in an instructor pilot and his later recuperation. This incident was provoked by a failure in the anti-G suit, which remained inflated after the aircraft completed the maneuver that had originated the inflation. The spontaneous recuperation of both the respiratory functional test and the neurophysiological pattern are consistent with a Type II Seddon's axonotmesis of the phrenic nerve. Considering the short time of regeneration (6 months), this lesion must have involved the distal portion of the phrenic nerve.