CONCEPT: Crossover Efficacy Pain Trial in Motor Cortex Stimulation for Intractable Neuropathic Pain

Inclusion Criteria: * CPSP or TGN/facial pain refractory to other medical treatments * Pain \> 1 year prior to baseline * Pain intensity with an average daily VAS score \> 5 demonstrated by 12 ratings across 4 days * Stable pain medication for \> 1 month prior to baseline Exclusion Criteria: * CPSP with important paresis/severe motor deficit in the area of pain * TGN/facial pain with complete deafferentation pain * Atypical facial pain, i.e. when objective evidence for neuropathic facial pain syndromes is lacking and when specific psychological and behavioral factors can be identified * Pain associated with malignant neoplastic disease anywhere in the body or head * History of epilepsy * Presence of a deterioration of cognitive functions