  Vortices are known to play a key role in the dynamics of the quantum
trajectories defined within the framework of the de Broglie-Bohm formalism of
quantum mechanics. It has been rigourously proved that the motion of a vortex
in the associated velocity field can induce chaos in these trajectories, and
numerical studies have explored the rich variety of behaviors that due to their
influence can be observed. In this paper, we go one step further and show how
the theory of dynamical systems can be used to construct a general and
systematic classification of such dynamical behaviors. This should contribute
to establish some firm grounds on which the studies on the intrinsic
stochasticity of Bohm's quantum trajectories can be based. An application to
the two dimensional isotropic harmonic oscillator is presented as an
illustration.
