title: A previously undescribed branch of the pterygopalatine ganglion.
abstract: BACKGROUND
  Endonasal and infrazygomatic pterygopalatine ganglion (PPG) block for facial pain provides pain relief in a broader area than expected on anatomic grounds. The aim of this study was to search for neural structures in the pterygopalatine fossa (PPF) that could explain unexpected pain relief after PPG blockage.
  
  
  METHODS
  The neural PPF content was explored through human cadaver study and nerve-specific staining. Five human PPF specimens were dissected as whole-mount preparations with the aid of an operation microscope and stained for acetylcholinesterase. One of these specimens was partially sectioned and analyzed through nitric oxide synthase (NOS) immunohistochemistry.
  
  
  RESULTS
  A previously unknown nerve was identified. The nerve runs between the PPG and the ophthalmic nerve and was identified in all five specimens. NOS-containing nerve fibers were present but did not occupy the complete nerve area.
  
  
  CONCLUSIONS
  Because it is likely that the nerve contains sensory fibers, our findings may provide an anatomic basis for unexplained pain relief in the ophthalmic area after PPG blockage.
authors.affiliation: Division of Surgical Specialties, Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Central Military Hospital, the Netherlands. oomenkarin@hotmail.com
authors.forename: Karin P
authors.initials: KP
authors.lastname: Oomen
authors.forename: Michelle
authors.initials: M
authors.lastname: Ebbeling
authors.forename: Jacob A
authors.initials: JA
authors.lastname: de Ru
authors.forename: Gerrit J
authors.initials: GJ
authors.lastname: Hordijk
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Bleys
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000718:Anatomy, Regional; D002102:Cadaver; D003027:Cluster Headache / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D003042:Cocaine / Q000627:therapeutic use; D003389:Cranial Nerve Diseases / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D004210:Dissection; D005157:Facial Pain / Q000517:prevention & control / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008442:Maxillary Nerve / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009407:Nerve Block; D019001:Nitric Oxide Synthase / Q000276:immunology / Q000378:metabolism; D009882:Ophthalmic Nerve / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D056739:Pterygopalatine Fossa / Q000033:anatomy & histology / Q000294:innervation* / Q000601:surgery; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000473:pathology; D012668:Trigeminal Ganglion / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014277:Trigeminal Neuralgia / Q000473:pathology / Q000503:physiopathology / Q000628:therapy
chemical_list: D019001:Nitric Oxide Synthase; D003042:Cocaine