What Causes Numbness In Left Arm And Finger After Being Shot In Neck?

i ve been shot in the neck by a 9mm hand gun and even though it was my left side in the trapezium musle it should of hit my artteries my i have loss of felling in my left arm only when i am in an extened posistion , its burns like hell and 3 of my finger will not work , but when i am out of this posistion there fine ,