Figure 1.

Diagram displaying the genesis of the spontaneous component of central pain. Damage to the spinothalamocortical pathway in subjects whose inhibitory systems at cortical levels are dysfunctional sets off a cascade of effects leading to a basin of attraction of neural activity centered in the somatosensory cortical areas which feeds onto the thalamus via a massive feedback from cortex to sensory thalamus. By interrupting this descending input, the generator is interrupted (from ref. 5, with permission).