 [ Symptoms ] i have anterior cruciate ligament tear…do i need surgery [ Disease ] what sodium does is it causes neurons to fire or to send signals this is essential to brain activity and muscle response including the heart i am unsure as to how long the body can survive without sodium but he is likely having low neuron activity thus possibly leading into something of a coma note i am a high school student with no research done on this sort of topic and biology 30 as my latest information so i could be wrong