title: Orbital pain and unruptured carotid-posterior communicating artery aneurysms: the role of sensory fibers of the third cranial nerve.
abstract: Intact aneurysms of the carotid siphon at the point of take-off of the posterior communicating artery may exhibit orbital pain, whether associated with oculomotor palsy or not as a warning symptom prior to rupture. In order to explain this symptom the hypothesis of a sensory pathway within the third cranial nerve, which is liable to compression by the enlarging aneurysm sac, has been investigated. Data from human autopsy material show evidence of sensory ganglion cells within the rootlets of the oculomotor nerve; furthermore, studies in animals prove that the third nerve contains sensory fibers which run proximally along the nerve bundles, enter the brainstem and reach the spinal trigeminal nucleus. These fibers come from the ophthalmic division of the fifth nerve and join the third nerve at the level of the lateral wall of the cavernous sinus. Although a number of questions remain to be solved, the presence of a sensory pattern within the third nerve could account for fronto-orbital pain from enlarging aneurysms impinging on the third nerve itself.
authors.affiliation: First Division of Neurosurgery, Bellaria Hospital, University of Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Lanzino
authors.forename: A
authors.initials: A
authors.lastname: Andreoli
authors.forename: F
authors.initials: F
authors.lastname: Tognetti
authors.forename: P
authors.initials: P
authors.lastname: Limoni
authors.forename: F
authors.initials: F
authors.lastname: Calbucci
authors.forename: R
authors.initials: R
authors.lastname: Bortolami
authors.forename: M L
authors.initials: ML
authors.lastname: Lucchi
authors.forename: E
authors.initials: E
authors.lastname: Callegari
authors.forename: C
authors.initials: C
authors.lastname: Testa
mesh_terms: D000818:Animals; D002340:Carotid Artery Diseases / Q000473:pathology / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000503:physiopathology; D002415:Cats; D004285:Dogs; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D000882:Haplorhini; D006261:Headache / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000473:pathology / Q000503:physiopathology; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure; D009619:Nociceptors / Q000503:physiopathology*; D009802:Oculomotor Nerve / Q000473:pathology / Q000503:physiopathology*; D009886:Ophthalmoplegia / Q000473:pathology / Q000503:physiopathology; D009915:Orbit / Q000098:blood supply / Q000294:innervation*; D012756:Sheep; D013045:Species Specificity; D013126:Spinal Nerve Roots / Q000473:pathology / Q000503:physiopathology; D013552:Swine; D014276:Trigeminal Nerve / Q000473:pathology / Q000503:physiopathology; D014277:Trigeminal Neuralgia / Q000473:pathology / Q000503:physiopathology; D014278:Trigeminal Nuclei / Q000473:pathology / Q000503:physiopathology; D014279:Trigeminal Nucleus, Spinal / Q000473:pathology / Q000503:physiopathology