  Current-induced spin torque and magnetization dynamics in the presence of
spin diffusion in magnetic textures is studied theoretically. We uncover an
additional torque on the form \sim{\bm\nabla}^2[{\bf M}x({\bf u}\cdot{\bm
\nabla}){\bf M}], where {\bf M} is the local magnetization and {\bf u} is the
direction of injected current. This torque is inversely proportional to the
square of the domain wall width (\approx\frac{1}{W^2}) and strongly depends on
the domain wall structure. Whereas its influence remains moderate for
transverse domain walls, it can significantly increase the transverse velocity
of vortex cores. Consequently, the spin diffusion can dramatically enhance the
non-adiabaticity of vortex walls.
