I am so sorry that you had this happen to you. Do you know if his OD involved oxygen loss to his brain leading to damage and deterioration of motor function? It is my understanding that this is the result of the brain being starved of oxygen for as little as 5 minutes. I do not know if the condition is reversible you say he has his mental facalties which is great because it shows he can recover in my eyes, it may be a long road full of rehabilitation for his injuries but the brain has a remarkable way of rebounding he may have to relearn it all but if his higher level activities is still there then i would like to believe since hes capable of learning he will relearn that which was lost.
Side note, this was always a fear of mine i almost lost my fiance to this on several occasions and i breathed for her when she couldnt for long enough to learn the hard way but we got away somehow. Your story moves me in ways i cant express as i have held someone i love begging for them to be ok and not leave me alone here, it is easier to have issues then people tend to believe, Its like 3-5 minutes with no oxygen to damage your brain. It was very irresponsible of me and it is still a motivation for me to hug her and tell her i love her when i think about almost losing her in a drug den on a bed with other junkies pressuring me not to call and when i finally said "fuck all of you i am not losing her here" and started calling she came to and said "whats up why is everyone upset"
Please keep us updated I am not sure where this does belong its almost darkside but i feel this should be a basic discussion too as we are all one overdose away from this.