I also understand what you mean with a numbness, though mine is a mixture of the head space feeling heavier than normal, combined with a possible "numb" like sensation, but like as you say.. not pins and needles, something a bit different. But noticeable as a change..
I started seeing light when I close my eyes resting, a day and two days after big doses of DMT..
Now I meditate morning and night every day, and I can see small loops of light string and soft spirals, quite small.. in front of my vision, with my eyes closed. Noticeable light source though, like DMT light, and I walk around most of the day with a feeling in my head I've never had before DMT... I am not sure if it's numbness / heavy or if it's just far more open, and it's perceiving more than it used to, you just feel different. It's a nice feeling however, and you can feel quite blissed out and "at one" with the source in meditation after a while of practise and time. I found the DMT has helped me learning meditation and being able to quiet the mind and knowing the body and thought isn't who I actually am.
The feeling I get is the universe is an awake expanding, ever creating mind, that has no beginning and no end, is both male and female, matter and anti matter, physical and non physical, light and dark. And we are just carrying that light imagination as our consciousness, but in this 3d world and body we have an ego and "personality" through free will, for learning and experiencing physical from non physical, though it's an illusion, everything is living through the same mind. Exploring DMT is not exploring other dimensions, it's exploring within yourself, your own imagination.. you just don't know who you really are. Everyone is that one universal mind, exploring themselves.