I'm remembering that in prior editions there was a risk of magic loss associated with Deadly wounds. I'm still brushing up up on 4E rules and am either completely missing the entry or it's simply gone away with the changes in editions?

Well, except for drugs (and addictions) nothing has any negative consequences anymore. BUT there are optional rules for severe injuries (Augmented, Page 121); Magic Loss is not mentioned but can be added (The whole rules pretty much say: Glitch/critical glitch: GM says what is wrong).

They also dropped the rules for stim patches being bad for mages, which we only realized last game session. I think the mage is going to be packing a bunch of those from now on.

Street Magic p. 31 answers your question.

Seems strange, this means the only way that a character can become a burn out is actively choosing that route, my conception of a Burned-Out Mage was he'd lost some of his magic somewhere along the way and was making up for it with chrome. Leading to a slippery slope as more chrome caused more magic loss...

It still exists as optional rules, but was removed from core rules. Makes sense to me, it seems really harsh to penalize in that manner.

Personally, I prefer the Severe Wounds optional rule in Augmentation (p120) for when someone rolls a glitch or critical glitch on damage resistance. And you can combine the two as well, making magic loss or even essence loss (only critical glitches I would imagine) just another possible outcome of Severe Wounds and either picking the most appropriate to the situation, or rolling the dice and letting fate decide.

*Edit: Whoops, I just realized Summerstorm already said all this.

As noted above, Street Magic (p. 31) covers Magic Loss, and Augmentation (pp.120–122) covers Severe Wounds, Heavy Damage, and Critical Glitches.

IMHO, critical glitches are so rare as to not matter, and regular glitches are too common for something as severe as magic loss (in my players opinion). Hence a combined ruling.

A glitch on 1) a damage resistance test, 2) when receiving medical treatment, or 3) any test while under the effects of a stim patch (or related drugs) – the character must make an Edge (1) test. Failing the edge test results in Magic Loss.

For when they do happen, and the player cannot (or does not) use edge to negate them, critical glitches under the same circumstances do not allow an edge test, just go on to Magic Loss.

As noted above, Street Magic (p. 31) covers Magic Loss, and Augmentation (pp.120–122) covers Severe Wounds, Heavy Damage, and Critical Glitches.

IMHO, critical glitches are so rare as to not matter, and regular glitches are too common for something as severe as magic loss (in my players opinion). Hence a combined ruling.

A glitch on 1) a damage resistance test, 2) when receiving medical treatment, or 3) any test while under the effects of a stim patch (or related drugs) – the character must make an Edge (1) test. Failing the edge test results in Magic Loss.

For when they do happen, and the player cannot (or does not) use edge to negate them, critical glitches under the same circumstances do not allow an edge test, just go on to Magic Loss.