Adult-Onset NREM Parasomnia with Hypnopompic Hallucinatory Pain: A Case Report

We report the case of a 43-year-old woman presenting with nocturnal episodes of pain and screaming during sleep starting at age 30. There was no childhood or family history of parasomnia. The events had gradually become more frequent over the years, occurring in the first half of the night within 2 h of sleep onset. There were no triggers, and she had partial amnesia for the events. A diagnosis of adult-onset sleep terrors was made on clinical grounds and supported polysomnographically. Seizures and periodic limb movements were excluded as triggering factors. There was some mild sleep disordered breathing (predominantly non-desaturating hypopnea with a propensity for REM sleep of debatable significance). Imaging of the brain and spine and neurophysiological investigations ruled out lesions, entrapments, or neuropathies as possible causes of pain. Treatment (clonazepam, paroxetine, or gabapentin) was poorly tolerated and made no difference to the nocturnal episodes, while trazodone worsened them. This is the first report of hypnopompic psychic pain in association with a NREM parasomnia. We hypothesize that the pain may represent a sensory hallucination analogous to the more commonly recognized visual NREM parasomnia-associated hypnopompic visual hallucinations and that, as such, it may arise during arousal of the sensory neocortex as confabulatory response.