Chronic pain in painful post-traumatic trigeminal neuropathy, formerly called trigeminal deafferentation pain (TDP) or anesthesia dolorosa, is virtually incurable neuropathic pain. In severe cases, no effective method has yet been established. A 58-year-old woman presented with chronic dysesthetic pain in the right side of her face that had persisted for 8 years. It was caused by percutaneous balloon compression for an unexplained, persistent right gingival pain. The TDP did not respond to any medications or radiosurgery. Considering the typical occipital neuralgia that occurred later, the incomprehensible gum pain was interpreted as referred trigeminal pain from occipital neuralgia. Decompression of the greater occipital nerve improved occipital neuralgia; however, TDP did not respond to internal neurolysis or invasive brain stimulation. The last attempt was made to administer an intrathecal opioid because of pain sufficiently severe to cause suicidal ideation. Trial administration of intrathecal opioids had some effect on pain relief. Although incomplete, the effects of intrathecal morphine infusion were maintained up to 1 year later. Invasive neurosurgical interventions should be cautiously performed for continuous pain in persistent idiopathic facial pain and referred facial pain cases that do not show typical neuralgic pain in primary trigeminal neuralgia because of the risk of TDP.