La epilepsia se refiere a un grupo de trastornos caracterizados por crisis recurrentes, que pueden ir acompañadas de convulsiones. El cannabis y las terapias a base de cannabis han demostrado tener efectos beneficiosos en varios tipos de epilepsia, a través de diferentes mecanismos biológicos.
Anticonvulsivo
Cerca del 60% de todas las crisis epilépticas son convulsivas, lo que significa que van acompañadas de convulsiones que se caracterizan por las contracciones rápidas, e involuntarias, de los músculos que pueden hacer que todo el cuerpo sufra temblores o sacudidas sin control. El tipo más común es la convulsión tónico-clónica, que consiste en un corto período de inmovilidad seguido de un temblor incontrolable. Ambos ataques epilépticos, los acompañados por convulsiones, y los que no, son causados por una actividad excesiva en las neuronas del cerebro. Si la actividad es grave y prolongada, las convulsiones pueden ocasionar daños en el tejido cerebral, sobre todo en los niños pequeños, cuando el cerebro todavía está en desarrollo. El síndrome de Dravet es sólo uno de los tipos de epilepsia que aparecen durante la infancia y que pueden causar daños neurológicos.
Hace siglos, si no milenios, que los seres humanos conocen las propiedades anticonvulsivas del cannabis. En 1947, los investigadores analizaron las propiedades anticonvulsivantes de los cannabinoides. En un primer estudio, realizado en la Universidad de Sydney en 1974, se demostró que Δ⁹-THC administrado en dosis elevadas tenía un efecto anticonvulsivo en ratones, a los que se les había hecho sufrir convulsiones administrándoles descargas eléctricas y químicas. Se observó que el CBD aumentaba este efecto del Δ⁹-THC, aunque los investigadores no pudieron comprobar que el CBD fuese eficaz por si mismo.
Desde entonces, varios estudios han demostrado que, de hecho, el CBD posee propiedades anticonvulsivas importantes por si solo, además de potenciar los efectos de Δ⁹-THC. Un estudio, elaborado en 2001, demostró que Δ⁹-THC y el análogo sintético de Δ⁹ THC, WIN 55.212-2, ejercen un efecto al agonizar los receptores CB₁. El CBD ejerce sus efectos de una forma diferente, ya que no agoniza el receptor CB₁ sino que actúa como un antagonista débil.
Revisión Bibliográfica
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