title: Massive opioid resistance in an infant with a localized metastasis to the midbrain periaqueductal gray.
abstract: We report the case of a 4-month-old infant with terminal malignancy who had systemic metastases and a localized metastasis to the dorsal midbrain periaqueductal gray (PAG). Extraordinary doses of opioids (dose equivalent of 2680 mg morphine sulfate/h, i.v.) were required to achieve adequate analgesia. The behavior of the infant, interpreted as being representative of a response to pain, may have been an aversive reaction due to the location of the lesion in the dorsal PAG. We propose that the lesion in the PAG impaired the responsiveness of this infant to the effect of opioids. This report is to alert clinicians to the possible role of the PAG in impaired opioid responsiveness in patients with terminal malignancy, as well as the possibility that pain-like signs (e.g., tachycardia, tachypnea, vocalization, facial grimacing) may indicate an aversive reaction rather than pain in non-verbal patients.
authors.affiliation: Pain Treatment Service, Division of Hematology and Oncology, Children's Hospital, Boston, MA 02115 USA Departments of Anesthesia, Children's Hospital, Boston, MA 02115 USA Department Medicine, Children's Hospital, Boston, MA 02115 USA Department Pathology, Children's Hospital, Boston, MA 02115 USA Department of Pediatric Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA USA Department of Anesthesia, Harvard Medical School, Boston, MA USA Department Pediatrics, Harvard Medical School, Boston, MA USA Department Pathology, Harvard Medical School, Boston, MA USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Collins
authors.forename: Charles B
authors.initials: CB
authors.lastname: Berde
authors.forename: Holcombe E
authors.initials: HE
authors.lastname: Grier
authors.forename: Dara B
authors.initials: DB
authors.lastname: Nachmanoff
authors.forename: Hannah C
authors.initials: HC
authors.lastname: Kinney
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000151:congenital / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D007231:Infant, Newborn; D008297:Male; D008636:Mesencephalon; D009020:Morphine / Q000627:therapeutic use*; D010166:Palliative Care; D010487:Periaqueductal Gray; D018335:Rhabdoid Tumor / Q000151:congenital / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary
chemical_list: D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D009020:Morphine