The acer is about 10-12 feet tall. This year it appears to be almost dead with no growth above a couple of new shoots sprouting from the base (see attached photo) – all the main branches above two feet from the ground seem pretty desiccated. Is there anything I can do to save it?
It sounds as if the tree itself has died and that your tree is growing from the root stock.
I would prune the suckers from the tree.
Do the branches snap and break on the tree?
You can scratch the bark of the tree, if you see green underneath, the tree is still alive.
Trees can die for many reasons, weather, pests, disease, water issues and for reasons that can't be identified.
Here are some links with more information.