In the past years, neuroimaging techniques provided a better insight into mechanisms involved in the development and maintenance of chronic pain. Chronic pain does not develop as a simple direct result of activity in nociceptive fibres following a traumatic event, but rather represents a consequence of dynamic plastic changes in sensory, affective and cognitive systems and related neuronal networks. The functional neural changes associated with pain include both adaptive compensatory changes, as well as maladaptive changes that may contribute to dysfunction of involved anatomical and physiological systems. In accordance, research findings indicated that patients with some chronic pain syndromes developed functional reorganisation of certain brain structures (for example in somatosensory -- or motor cortices). Since research studies have shown that reversal of pathological cortical changes in chronic-pain patients is accompanied by pain relief, a modulation of brain excitability seems to be a promising approach to address pain related to central hyperexcitability. This book discusses this topic and how brain stimulation techniques aim to selectively enhance adaptive patterns of neural activity, suppress the maladaptive ones, and restore the balance in disturbed neuronal networks.