Terminal spreading depolarization and electrical silence in death of human brain

Of course this has me thinking of possible interventions - maybe a substance that interacts with neuron cell walls to stop Na/Ca/K leakage? Of course, it would have to be fast-acting, non-toxic on the way in, reversible, and non-toxic on the way out.

Could any experts comment and inform if such a thing is inside the realm of possibility as we know it?

Does the shut down of spontaneous activity due to lack of oxygen/blood account for why people pass out in choke-holds? Or is this a different process?