[Functional recovery in hemifacial transplants in rats]. / Recuperación funcional del trasplante hemifacial en ratas.

INTRODUCTION: There are a number of different options open to the surgeon for the reconstruction of the face and scalp, but when tissue loss is very extensive, good aesthetic and functional recovery is not possible. Not only must the damaged tissues be replaced, but motor and sensorial functioning also has to be restored. AIM: To evaluate the functional recovery of hemifacial allografts in rats. MATERIALS AND METHODS: Twenty-one hemifacial flaps were transplanted from Long-Evans rats to Wistar-Lewis rats, under immunosuppression monotherapy with tacrolimus. Prior to the operation, anatomical and allograft viability studies were conducted. Two groups of transplanted rats were formed: with or without nerve repair. In the nerve repair group, end-to-end suture was employed to repair the infraorbital branch of the trigeminal nerve and the buccolabial, upper mandibular marginal and zygomatico-orbital branches of the facial nerve. Sensory recovery was evaluated by filming traction of the whiskers, whereas motor recovery was assessed by blind tests using electromyography studies of the mystacial muscles and electroneurography of the facial nerve. At eight weeks, the animals were sacrificed and biopsy samples were taken from the mystacial region. RESULTS: The facial flap was successfully lifted in 10 cases. In the nerve repair group both clinical and electrophysiological recovery were observed at six weeks, whereas biopsy samples taken in the eighth week showed recovery of the nerve fascicles. CONCLUSIONS: The hemifacial flap can be transplanted. By repairing the nerves of the allograft, it is possible to achieve its functional recovery, as can be confirmed clinically, electrophysiologically and histopathologically. To date, this is the first evidence of functional recovery following a hemifacial transplant in rats.

[The vestibulocollic reflex: assessment and characteristics of vestibular-evoked myogenic potentials analysed by age groups]. / Reflejo vestibulocervical. Valoracion y caracteristicas de los potenciales vestibulares miogenicos evocados analizados por tramos de edad.

INTRODUCTION: Obtaining vestibular-evoked myogenic potentials (VEMP) by means of the vestibulocollic reflex is a readily available technique that provides an image of vestibular functioning and is useful for evaluating the pathologies that involve compromise of the anatomical pathway of the reflex. Although normal patterns do exist, responses vary at different ages. AIM: To obtain reference values of the vestibulocollic reflex according to different age groups. SUBJECTS AND METHODS: We studied 40 volunteers with no symptoms of auditory or vestibular compromise. Each ear was stimulated separately by a series of clicks (sounds lasting 0.1 s; 3 pps; intensities of 100 dB nHL and 85 dB nHL) and recordings were made in the sternocleidomastoid muscles by means of surface electrodes as patients who were lying on their backs contracted these muscles as they lifted their heads. We studied the latency of the initial p13-n23 positive-negative potential and the peak-to-peak amplitude. The existence of later n34-p44 potentials was evaluated. RESULTS: No statistically significant differences were found between genders or between the two ears. We did not find any differences between the latencies of the waves according to the intensity of the stimulus, but there is a relationship between the amplitude of the p13-n23 potential and the intensity of the stimulus. The latencies of the responses in children under 10 years of age differ from those of the other groups, but no differences were found among those over the age of 11. CONCLUSIONS: The VEMP display steady and easily identifiable latencies. We obtained different reference values for latency in children under the age of 10 and those over 11 years old. The amplitude decreases with the intensity of the stimulus.

[Vestibular evoked myogenic potential: a contribution to the vestibular physiology and pathology knowledge. Quantitative patterns in healthy subjects]. / Potencial vestibular miogénico evocado: un aporte al conocimiento de la fisiología y patología vestibular. Patrones cuantitativos en la población normal.

INTRODUCTION: Vestibulocollic reflex is a muscular reflex which is activated by acoustic stimulation. It shows two components: the first one, the vestibular evoked myogenic potential (VMEP) related to the vestibular pathway and the second, to the auditive pathway. The VMEP potential could be useful for vestibular physiology and pathology knowledge. OBJECTIVE: To determine the VMEP's parameters of normality and to evaluate influential factors such as age, sex or stimulation intensity. MATERIAL AND METHODS: Prospective study of the VCR in 40 healthy individuals, distributed in 4 groups according to their age. Stimulation was carried out at 100db and 85db on each ear independently. RESULTS: There are not differences between both ears and sexes. Normal latency levels must be separated between two groups of age: older and younger than 11 years old. Normal absolute values of amplitude response differ depending on muscular contraction, age and stimulation intensity. It is more representative to consider the difference between the values obtained in the two ears of the same individual than to consider the absolute values.

Recuperación funcional del trasplante hemifacial en ratas / Functional recovery in hemifacial transplants in rats

Existen distintas opciones reconstructivas de cara y cuero cabelludo, pero cuando la pérdida de tejidoses muy extensa, no es posible una buena recuperación estética y funcional. Es preciso no sólo reemplazar los tejidos dañados, sino que se pueda restaurar la función motora y sensitiva. Objetivo. Evaluar la capacidad de recuperación funcional del aloinjerto hemifacial en ratas. Materiales y métodos. Se trasplantaron 21 colgajos hemifaciales desde ratas Long-Evans aratas Wistar-Lewis, bajo monoterapia de inmunosupresión con tacrolimus. Previamente se realizó un estudio anatómico y de la viabilidad del aloinjerto. Formamos dos grupos de ratas trasplantadas: sin y con reparación nerviosa. En el grupo de reparación nerviosa se procedió a la sutura terminoterminal de la rama infraorbitaria del nervio trigémino y de las ramas bucolabial,marginal mandibular superior y cigomaticoorbitaria del nervio facial. La recuperación sensitiva se valoró mediante la filmación de la tracción de los bigotes, mientras que la recuperación motora se hizo de forma ciega mediante electromiografía de la musculatura mistacial y electroneurografía del nervio facial. Trascurridas ocho semanas, los animales fueron sacrificados y se tomaron biopsias de la región mistacial. Resultados. El colgajo facial se elevó con éxito en 10 casos. En el grupode reparación nerviosa se observó recuperación, tanto clínica como electrofisiológica, llegada la sexta semana, mientras que las biopsias obtenidas en la octava semana mostraron recuperación de los fascículos nerviosos. Conclusión. El colgajo hemifacial puede trasplantarse. Se puede obtener, mediante reparación nerviosa del mismo, una recuperación funcional delaloinjerto, valorable de forma clínica, electrofisiológica e histopatológica. Hasta el momento, ésta es la primera evidencia de recuperación funcional después de un trasplante hemifacial en ratas

There are a number of different options open to the surgeon for the reconstruction of the face andscalp, but when tissue loss is very extensive, good aesthetic and functional recovery is not possible. Not only must the damaged tissues be replaced, but motor and sensorial functioning also has to be restored. Aim. To evaluate the functional recovery ofhemifacial allografts in rats. Materials and methods. Twenty-one hemifacial flaps were transplanted from Long-Evans rats to Wistar-Lewis rats, under immunosuppression monotherapy with tacrolimus. Prior to the operation, anatomical and allograft viability studies were conducted. Two groups of transplanted rats were formed: with or without nerve repair. In the nerverepair group, end-to-end suture was employed to repair the infraorbital branch of the trigeminal nerve and the buccolabial, upper mandibular marginal and zygomatico-orbital branches of the facial nerve. Sensory recovery was evaluated by filming traction of the whiskers, whereas motor recovery was assessed by blind tests using electromyography studies of the mystacialmuscles and electroneurography of the facial nerve. At eight weeks, the animals were sacrificed and biopsy samples were taken from the mystacial region. Results. The facial flap was successfully lifted in 10 cases. In the nerve repair group both clinical and electrophysiological recovery were observed at six weeks, whereas biopsy samples taken in the eighth weekshowed recovery of the nerve fascicles. Conclusions. The hemifacial flap can be transplanted. By repairing the nerves of the allograft, it is possible to achieve its functional recovery, as can be confirmed clinically, electrophysiologically and histopathologically.To date, this is the first evidence of functional recovery following a hemifacial transplant in rats

Reflejo vestibulocervical. Valoración y características de los potenciales vestibulares miogénicos evocados analizados por tramos de edad / The vestibulocollic reflex. assessment and characteristics of vestibular-evoked myogenic potentials analysed by age groups

Introducción. La obtención de potenciales vestibulares miogénicos evocados (PVME) mediante la realización del reflejo vestibulocervical es una técnica de fácil obtención que da una imagen de la función vestibular y es útil para valorar las patologías que impliquen afectación de la vía anatómica del reflejo. Aunque existen patrones normales, a distintas edades podemos encontrar variaciones en las respuestas. Objetivo. Obtener valores de referencia por tramos de edad del reflejo vestibulocervical. Sujetos y métodos. Estudiamos a 40 voluntarios sin síntomas de afectación auditiva o vestibular. Se estimula mediante clics (sonidos de 0,1 s de duración; 3 pps; intensidades de 100 dB nHL y 85 dB nHL), cada oído por separado, y se registra en los músculos esternocleidomastoideos mediante electrodos de superficie mientras el paciente los contrae al alzar la cabeza desde el decúbito supino. Hemos estudiado la latencia del potencial positivo-negativo inicial p13-n23 y la amplitud pico-pico. Se valora la existencia de potenciales más tardíos n34-p44. Resultados. No encontramos diferencias estadísticamente significativas entre géneros ni entre ambos oídos. No observamos diferencias entre latencias de las ondas en función de la intensidad del estímulo, y existe una relación entre la amplitud del potencial p13-n23 y la intensidad del estímulo. Las latencias de las respuestas en menores de 10 años difieren del resto de grupos, pero no existen diferencias en los mayores de 11 años. Conclusiones. Los PVME muestran unas latencias estables y fácilmente identificables. Obtenemos los valores de referencia de latencia diferentes para menores de 10 años y para los mayores de 11. La amplitud decrece en función de la intensidad del estímulo

Introduction. Obtaining vestibular-evoked myogenic potentials (VEMP) by means of the vestibulocollic reflex is a readily available technique that provides an image of vestibular functioning and is useful for evaluating the pathologies that involve compromise of the anatomical pathway of the reflex. Although normal patterns do exist, responses vary at different ages. Aim. To obtain reference values of the vestibulocollic reflex according to different age groups. Subjects and methods. We studied 40 volunteers with no symptoms of auditory or vestibular compromise. Each ear was stimulated separately by a series of clicks (sounds lasting 0.1 s; 3 pps; intensities of 100 dB nHL and 85 dB nHL) and recordings were made in the sternocleidomastoid muscles by means of surface electrodes as patients who were lying on their backs contracted these muscles as they lifted their heads. We studied the latency of the initial p13-n23 positive-negative potential and the peak-to-peak amplitude. The existence of later n34-p44 potentials was evaluated. Results. No statistically significant differences were found between genders or between the two ears. We did not find any differences between the latencies of the waves according to the intensity of the stimulus, but there is a relationship between the amplitude of the p13-n23 potential and the intensity of the stimulus. The latencies of the responses in children under 10 years of age differ from those of the other groups, but no differences were found among those over the age of 11. Conclusions. The VEMP display steady and easily identifiable latencies. We obtained different reference values for latency in children under the age of 10 and those over 11 years old. The amplitude decreases with the intensity of the stimulus

Potencial vestibular miogénico evocado: un aporte al conocimiento de la fisiología y patología vestibular. Patrones cuantitativos en la población normal / Vestibular evoked myogenic potential: a contribution to the vestibular physiology and pathology knowledge. Quantitative patterns in healthy subjects

Introducción: El reflejo vestibulocervical es un reflejo muscular que se activa mediante estimulación acústica. Presenta dos componentes: el primero, que es el potencial vestibular miogénico evocado (PVME) se relaciona con la vía vestibular y el segundo con la vía auditiva. El PVME puede ser útil para el conocimiento de la fisiología y patología vestibular. Objetivo: Determinar los parámetros de normalidad del PVME y evaluar factores influyentes como edad, sexo o intensidad de estimulación. Material y métodos: Estudio prospectivo del RVC en 40 sujetos sanos que se distribuyeron en 4 grupos, estratificados según su edad. Se realizó la estimulación a 100 db y 85 db a cada oído por separado. Resultados: No existen diferencias entre ambos oídos ni ambos sexos. Los valores normales de latencias se deben separar en dos grupos de edad: mayores y menores de 11 años. Los valores normales absolutos de la amplitud de la respuesta varían en función de la contracción muscular, de la edad y de la intensidad de estimulación. Es más representativo considerar la diferencia entre las respuestas de los dos oídos de un mismo sujeto que los valores absolutos

Introduction: Vestibulocollic reflex is a muscular reflex which is activated by acoustic stimulation. It shows two components: the first one, the vestibular evoked myogenic potential (VMEP) related to the vestibular pathway and the second, to the auditive pathway. The VMEP potential could be useful for vestibular physiology and pathology knowledge. Objective: To determine the VMEP’s parameters of normality and to evaluate influential factors such as age, sex or stimulation intensity. Material and methods: Prospective study of the VCR in 40 healthy individuals, distributed in 4 groups according to their age. Stimulation was carried out at 100db and 85db on each ear independently. Results: There are not differences between both ears and sexes. Normal latency levels must be separated between two groups of age: older and younger than 11 years old. Normal absolute values of amplitude response differ depending on muscular contraction, age and stimulation intensity. It is more representative to consider the difference between the values obtained in the two ears of the same individual than to consider the absolute values