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.

Recovery of Ophthalmoplegia after Endovascular Treatment of Intracranial Aneurysms

“…9 Compression of the pain sensory afferent fibers, which are recruited from the ophthalmic division of the trigeminal nerve and which lie within the periphery of the oculomotor nerve, causes ipsilateral orbitofacial pain. 10 Compressive lesions of the cavernous sinus may lead to localized oculomotor or abducens CN dysfunction and Horner syndrome. 11 Evolution of ocular motor nerve (third, fourth, and sixth) paresis after endovascular therapy has been reported in the literature: Beyond sporadic reports with ONP resolution after coiling of PcomA aneurysms, 12 a literature review concerning series including Ն3 aneurysms revealed a mean rate of 46.6% complete recovery after endovascular treatment of 118 (55/118) aneurysms that caused ophthalmoplegia (Table 5).…”

Cluster headache and intracranial aneurysm

“…Thus, oculomotor palsy, when in association with ipsilateral orbitofacial pain, strongly indicates impending aneurysmal rupture. Compression of pain sensory afferent fibres of the ophthalmic division of the f f trigeminal nerve present in the third cranial nerve by the aneurysm is alleged by some as the cause of the orbital headache [25]. In this regard, Berardinelli et al [26] identified unmyelinated fibres in the oculomotor, trochlear and abducens nerves, and suggested that they are sensory in nature and are involved in the transport of pain signals arising from the trigeminal territory.…”

Incomplete Oculomotor Nerve Palsy Caused by an Unruptured Internal Carotid-Anterior Choroidal Artery Aneurysm-Case Report-

“…[4][5][6][7]10,13) Orbital pain or headache sometimes proceed to oculomotor nerve palsy which frequently involves the pupil. The external ocular movement is partly disturbed or the eye position becomes exotropic resulting in double vision.…”