Utilidad del dúplex transcraneal en la Neurología: serie de casos / Useful of transcranial duplex in neurology: case series

RESUMEN El ultrasonido es una herramienta ampliamente utilizada en Medicina, en diferentes áreas como ginecología, cirugía y neurología, tiene una gran variedad de indicaciones, tales como: el estudio del vasoespasmo en hemorragia subaracnoidea, cambios de flujo en estenosis intracraneana e incluso evaluar "in vivo" la actividad de algunas medidas terapéuticas. A continuación se presenta una serie de los casos más relevantes recogidos en el Hospital Universitario Mayor que fueron llevados a dúplex transcraneal y sus resultados. De igual manera una breve revisión sobre las patologías más frecuentes que se pueden encontrar mediante este estudio. El dúplex transcraneal ofrece entonces un medio diagnóstico de rápida evaluación que otorga información fehaciente para la toma de decisiones tanto en el servicio de urgencias como en hospitalización, pero se trata de una herramienta con la que se tiene poca experiencia en el país, por lo que estos hallazgos son pioneros y deben complementarse con estudios de mayor peso.

SUMMARY Ultrasound is a tool that is widely used in medicine in different areas such as gynecology or surgery. In neurology, it has a broad variety of indications, related to the study of vasospasm and subarachnoid haemorrhage, besides of flux changes in intracranial stenosis and it helps to evaluate the activity of some therapeutic measures. In this article we present some of the most relevant cases collected in the Hospital Universitario Mayor, wich were taken to a trans cranial duplex and we provide a short revision about most frequent pathologic that can be found through this study. The transcranial duplex offers a diagnose possibility of fast evaluation that takes reliable information to make choices in the emergency room as in the hospitalized. Although this procedure does not have many experience in the country, it is important to mention that these findings turn out to be an innovating solution to a quick diagnose that should be complemented with further information.

Influencia del sistema nitridérgico en la respuesta contráctil a fenilefrina de anillos de vasos usados en revascularización coronaria / Modification of phenylephrine induced contraction of human vessel rings by L-arginine and L-arginine methyl ester

Background: Endothelial dysfunction is associated to a lower production of nitric oxide and a reduction of endothelium mediated vasodilation. Aim: To study the effects of pharmacological agents that modify nitric oxide synthetase (NOS) activity on tension changes induced by phenylephrine in rings of internal mammary and radial arteries and saphenous vein. Material and methods: Vessel rings of 7 to 10 mm length were obtained from 32 patients subjected to coronary vascular surgery Fourteen samples of radial artery, 12 samples of internal mammary artery and 15 samples of saphenous vein were obtained. A maximal contraction was induced with KC1 and dose response curves for phenylephrine (FE) in the absence or presence of L-arginine and L-arginine methyl ester (L-NAME), were constructed. Results: The tension induced by FE in internal mammary artery and saphenous vein reached a maximum, near 90 percent of 80 mM KCl-induced contraction, but in the radial artery, it reached a maximum of 63 percent (p <0.05). In all vessels, the dose response curves were significantly shifted to the right by L-arginine and to the íeft by L-NAME. Conclusions: Pre-incubation of human rings with L-ARG or L-NAME, changed the response to FE induced contraction, which may be related to different degrees of endothelial nitric oxide production or NO sensitivity. The basal NO production in radial artery seems to be larger than the other vessels.