I don't know about dimension 4, but for high dimensions this is a well-known open problem.  I don't think much progress has been made on it for a while.  I recommend Ranicki's lecture notes from Siebenmann's retirement conference for a good summary about what is known about this and related problems:
http://www.maths.ed.ac.uk/~aar/slides/orsay.pdf

EDIT : Hot off the press is a <a href="http://arxiv.org/abs/1303.2354">paper</a> of Manolescu claiming to disprove the conjecture of Galewski-Stern and construct manifolds in all dimensions $\geq 5$ which are not homeomorphic to simplicial complexes.