If the circumstances of this poem are a personal one, I am sorry for your pain, if not, there are many whom this does depict and again I reflect and feel sad.  So, your poem is a success in that it inspires empathy and it conveys the position of a stroke victim.  

Iambic meter is adhered to.  L2 is the roughest, but your substitutions are within generally accepted margins.  L3&L4 is not a complete sentence - a slight tweak could easily fix it.     
Although your final couplet probably says exactly what you want to say, it feels a bit disjointed in phrasing.  

mg

i wait with baited breath... L, cricket

Stroke

When one brain cell explodes, creating strife,
my life implodes into a free-fall night.
When waterfalls of blood cascade, death's knife
has cut love’s thermal cap, and rigged our flight.
While death lays claim, we live to end our woes
on cliffs we climb or drugs that quicken days.
As we yield blame to those we call our foes,
my stroke stains nights with gloomy blacks and grays.
Which case would stretch the truth - my empty shell
or thoughts to bring old patterns to an end?
Whose tears can ripple over pits of hell,
then face the pace, death set, that will not bend?

I trust our marriage, more than death, maintains
a Love to overcome my wheel-chair chains.

© cricket 

[caveat: this was also posted to the work shop (my error)-  ] (caps removed for this forum) (corrected spelling of word marriage, added a comma, changed word 'by' to word on)