Síndrome de atrapamiento del nervio cutáneo anterior: una causa de dolor abdominal crónico en niños frecuentemente pasada por alto / Anterior cutaneous nerve entrapment syndrome: a frequently overlooked cause of chronic abdominal pain in children

El síndrome de atrapamiento del nervio cutáneo anterior (ACNES) con frecuencia no se tiene presente enel diagnóstico diferencial del dolor abdominal crónico(DAC).Presentamos el caso de un varón de 11 años conDAC estudiado previamente en servicios de urgencia ydigestivo sin detectar patología orgánica, sugiriéndoseun origen psicosomático. En la exploración mostró doloren la pared abdominal localizado en el área de la ramaterminal del nervio intercostal T11, con signo de Carnettpositivo y respuesta favorable a la inyección con anestésico local en el punto gatillo. Los potenciales evocadossomatosensoriales revelaron neuropatía del nervio delmúsculo recto anterior derecho. Se diagnosticó de ACNES. Como tratamiento se administró en el punto gatillouna inyección subfascial ecoguiada de lidocaína y dexametasona. Tras cuatro meses, permanece asintomático.Para el tratamiento de ACNES en población pediátrica, recomendamos una estrategia terapéutica escalonadacomenzando con inyecciones en el punto gatillo y reservar la neurectomía anterior para cuando estas fracasan.(AU)

Anterior cutaneous nerve entrapment syndrome(ACNES) is often overlooked in the differential diagnosis of chronic abdominal pain (CAP).An 11-year-old boy with CAP previously studied inemergency and digestive services without detectingorganic pathology, suggesting a psychosomatic origin.On examination, he showed pain in the abdominal walllocated to the area of the terminal branch of the T11intercostal nerve, with a positive Carnett’s sign and afavorable response to injection with local anestheticat the trigger point. Somatosensory evoked potentialsrevealed right anterior rectus nerve neuropathy. Hewas diagnosed with ACNES. As treatment, an ultrasound-guided subfascial injection with lidocaine anddexamethasone into the trigger point was administered. After four months, he remains asymptomatic.For the treatment of ACNES in pediatrics patients,a step-up strategy should be applied, starting with trigger point injections of lidocaine and dexamethasoneand reserving anterior neurectomy for those cases withlimited effect of these injections.(AU)

[Anterior cutaneous nerve entrapment syndrome: a frequently overlooked cause of chronic abdominal pain in children].

Anterior cutaneous nerve entrapment syndrome (ACNES) is often overlooked in the differential diagnosis of chronic abdominal pain (CAP). An 11-year-old boy with CAP previously studied in emergency and digestive services without detecting organic pa-thology, suggesting a psychosomatic origin. On examination, he showed pain in the abdominal wall located to the area of the terminal branch of the Th11 intercostal nerve, with a positive Carnett's sign and a favorable response to injection with local anesthetic at the trigger point. Somatosensory evoked potentials revealed right anterior rectus nerve neuropathy. He was diagnosed with ACNES. As treatment, an ultrasound-guided subfascial injection with lidocaine and dexame-thasone into the trigger point was administered. After four months, he remains asymptomatic. For the treatment of ACNES in pediatrics patients, a step-up strategy should be applied, starting with trigger point in-jections of lidocaine and dexamethasone and reserving anterior neurectomy for those cases with limited effect of these injections.

[Workshop on electroretinography and visual evoked potentials]. / Taller de electrorretinografía y potenciales evocados visuales.

Studies of vision using electrophysiological techniques are tests which record functional alterations in very early phases of a disease. Full field flash ERG evaluates the integrity of the cones, rods and bipolar cells. It is obtained by photopsic stimulation with Ganzfeld and contact lens corneal electrodes or, alternatively, gold leaf or anchor electrodes. Five responses must be obtained: that of the rods, a maximum, oscillatory potentials, that of the cones and a flicker response. Pattern ERG is a response of the ganglionic cells, which is obtained by pattern reversal morphoscopic stimulation, with a bandwidth between 1 and 60 Hz. The fundamental waves (0.5 5 mV) are P50 (luminance) and N95 (pattern specific). This is of great value in the early diagnosis of glaucoma. VEP are electrical fields that are recorded in the calcarine cortex. They give information about alterations in the optic nerve, chiasm, radiations and cortex. Pattern VEP is obtained with a visual angle of between 13 and 14 . The fundamental wave P100 is evaluated according to its latency and amplitude, and by comparing it with a healthy eye. Flash VEP is only used on patients who do not collaborate or who present an opacity of media.

Taller de electrorretinografía y potenciales evocados visuales / Workshop on electroretinography and visual evoked potentials

Las técnicas electrofisiológicas de la visión son pruebas que registran alteraciones funcionales en fases muy precoces de la enfermedad. El flash-ERG de campo completo valora la integridad de conos, bastones y células bipolares. Se obtiene por estimulación fotópsica con Ganzfeld y electrodos corneales de lentilla o, alternativamente, de lámina de oro o de ancla. Se deben conseguir cinco repuestas: la propia de los bastones, una máxima, los potenciales oscilatorios, la correspondiente a los conos y una respuesta flicker. El pattern-ERG es una respuesta de las células ganglionares. Se obtiene por estímulo morfoscópico de damero reversible, con ancho de banda entre 1 y 60 Hz. Las ondas fundamentales (0,5-5 mV) son la P50 (luminancia) y la N95 (pattern-específica). Es de gran utilidad en el diagnóstico precoz del glaucoma. Los PEV son campos eléctricos registrados en la corteza calcarina. Informan de alteraciones del nervio óptico, quiasma, radiaciones y corteza. El pattern-PEV se obtiene con un ángulo visual de 13 a 14º. La onda fundamental P100 se valora según su latencia y amplitud, y en comparación con el ojo sano. El flash-PEV sólo se utiliza en pacientes que no colaboran o que presentan una opacidad de medios (AU)

Studies of vision using electrophysiological techniques are tests which record functional alterations in very early phases of a disease. Full-field flash ERG evaluates the integrity of the cones, rods and bipolar cells. It is obtained by photopsic stimulation with Ganzfeld and contact lens corneal electrodes or, alternatively, gold leaf or anchor electrodes. Five responses must be obtained: that of the rods, a maximum, oscillatory potentials, that of the cones and a flicker response. PatternERG is a response of the ganglionic cells, which is obtained by pattern reversal morphoscopic stimulation, with a bandwidth between 1 and 60 Hz. The fundamental waves (0.5-5 mV) are P50 (luminance) and N95 (pattern-specific). This is of great value in the early diagnosis of glaucoma. VEP are electrical fields that are recorded in the calcarine cortex. They give information about alterations in the optic nerve, chiasm, radiations and cortex. Pattern-VEP is obtained with a visual angle of between 13 and 14º. The fundamental wave P100 is evaluated according to its latency and amplitude, and by comparing it with a healthy eye. Flash-VEP is only used on patients who do not collaborate or who present an opacity of media (AU)

[Electrophysiological study of the anomalous innervation of the hand]. / Estudio electrofisiológico de la inervación anómala de la mano.

INTRODUCTION: The innervation of the hand frequently differs from the usual description that we can find in text books. The most frequent anomalies consist on communications among the median and cubital nerves at level of either forearm (Martin-Gruber anastomosis) or to more distal level (Richie-Cannieu anastomosis), although they are not the only possibilities. OBJECTIVE: To study from a electrophysiological point of view or the variants of the normality in the innervation of the hand and to define their functional characteristics. PATIENTS AND METHODS: We performed an electromyographic and electroneurographic studies on patients that suffered wounded (fundamentally) or other pathologies in the forearm. RESULTS: The presence of double innervation in abductor pollicis brevis and opponens pollicis muscles has been verified in 2.48% of the patients. Although, it has not been possible to determine the prevalence of other anomalies, the presence of several types of anastomosis has been observed: Martin-Gruber types I and III, as well as the incomplete innervation on the part of the cubital nerve of the muscles of the tenar muscles (only of the opponens pollicis). The correct methodology is fundamental in the electrophysiological study, so several pitfalls can take place. It would be desirable to employ techniques that minimize the problems of dispersion of the current, by means of needles. CONCLUSION: It is very important to keep in mind these variations of the normality in the innervation of the hand, specially when pronostic and surgical treatment are considered.

[Study of electroretinogram components using pattern inversion in the early diagnosis of glaucoma]. / Etude des composants de l'électrorétinogramme par inversion de damier dans le diagnostic précoce du glaucome.

Current electrophysiological techniques that help guide the diagnosis of glaucoma include pattern-electroretinogram (PERG) and pattern-visual evoked potential (PEVP) recordings. However, PERG has been recognized over the last decade as a good indicator of retinal ganglion cell function. One hundred seventy one eyes corresponding to 89 subjects were studied using both PERG (gold foil electrodes) and PEVP recordings. Two groups respectively including 32 subjects with ocular hypertension (OHT) and 27 subjects with simple chronic glaucoma (SCG) were compared with a control group composed of 30 healthy age-matched subjects. In regard to PERG recordings, the amplitudes of the P50 and N95 components were measured, but statistically significant differences were shown only for the N95 amplitudes both SCG (P < 0.01) and OHT (P < 0.05) groups. The amplitude and latency of the PEVP P100 component were analyzed. P100 latency was significantly delayed (P < 0.05) in SCG patients only. These findings suggest that the amplitude of the N95 component is the most sensitive electrophysiological parameter for early glaucoma detection.