Title: Localization of Lesions of the Oculomotor Nerve: Recent Concepts
Abstract: The anatomic features of the third cranial nerve (the oculomotor nerve) and the localization of lesions that affect it are reviewed. Recent considerations of the organization of the oculomotor fascicles in the ventral mesencephalon, the superior and inferior divisional palsies localized proximal to the cavernous sinus, and the possibility of the localization of ischemic oculomotor palsies to the mesencephalon rather than a peripheral site are emphasized. The characteristic manifestations of nuclear lesions (unilateral palsy of the third cranial nerve, weakness of the ipsilateral and contralateral superior rectus muscles, and bilateral incomplete ptosis) are described, as are other variations of nuclear involvement. Although proptosis is typically associated with orbital masses, it may also result from lesions of the cavernous sinus or (rarely) an intracranial lesion. Metastatic orbital tumors often are the first evidence of systemic spread in patients with cancer; infiltrative and mass lesions are the most common. Aberrant regeneration of the oculomotor nerve may occur months to years after the occurrence of an oculomotor lesion. The anatomic features of the third cranial nerve (the oculomotor nerve) and the localization of lesions that affect it are reviewed. Recent considerations of the organization of the oculomotor fascicles in the ventral mesencephalon, the superior and inferior divisional palsies localized proximal to the cavernous sinus, and the possibility of the localization of ischemic oculomotor palsies to the mesencephalon rather than a peripheral site are emphasized. The characteristic manifestations of nuclear lesions (unilateral palsy of the third cranial nerve, weakness of the ipsilateral and contralateral superior rectus muscles, and bilateral incomplete ptosis) are described, as are other variations of nuclear involvement. Although proptosis is typically associated with orbital masses, it may also result from lesions of the cavernous sinus or (rarely) an intracranial lesion. Metastatic orbital tumors often are the first evidence of systemic spread in patients with cancer; infiltrative and mass lesions are the most common. Aberrant regeneration of the oculomotor nerve may occur months to years after the occurrence of an oculomotor lesion. Several recent publications have addressed the localization of lesions that involve cranial nerve III (the oculomotor nerve). In this article, some of these important contributions will be reviewed. The nuclear complex of the third cranial nerve (Fig. 1) extends rostrocaudally near the midline in the midbrain at the level of the superior colliculus, and it lies ventral to the sylvian aqueduct. One unpaired column (the most dorsal, which contains the Edinger-Westphal nucleus rostrally and the subnucleus of the levator palpebrae superioris caudally) and four paired rostrocaudal columns can be distinguished in the nuclear complex. Of the four paired subnuclei, the most medial innervate the superior rectus muscles. Each medial subnucleus has axons that extend to the opposite eye, but the decussation occurs within the nuclear complex, and the decussating fibers actually transverse the contralateral subnucleus for the superior rectus muscle. The lateral three oculomotor subnuclei have axons that extend to ipsilateral eye muscles; fibers of the dorsal subnucleus extend to the inferior rectus muscle, and fibers of the intermediate subnucleus extend to the inferior oblique muscle. Although the ventral subnucleus was thought to innervate the medial rectus muscle, recent studies have demonstrated that neurons supplying this muscle are distributed into three separate areas of the oculomotor nucleus.1Büttner-Ennever JA Akert K Medial rectus subgroups of the oculomotor nucleus and their abducens internuclear input in the monkey.J Comp Neurol. 1981; 197: 17-27Crossref PubMed Scopus (159) Google Scholar Within the substance of the midbrain, the fascicular portion of the oculomotor nerve crosses the medial longitudinal fasciculus and decussating fibers of the superior cerebellar peduncle. The axons then diverge widely to transverse the red nucleus before exiting the anterior aspect of the midbrain, medial to the cerebral peduncles. The proposed organization of fascicular fibers within the ventral midbrain tegmentum will be discussed in the subsequent material. Upon reaching the subarachnoid space, each oculomotor nerve passes between the superior cerebellar and the posterior cerebral artery, courses near the medial uncus of the temporal lobe, and then pierces the dura mater just lateral to the posterior clinoid process to enter the lateral wall of the cavernous sinus. Here the oculomotor nerve is superior to the trochlear nerve and the abducens nerve and medial to the ophthalmic branch of the trigeminal nerve (Fig. 2). The oculomotor nerve then reaches the superior orbital fissure, which it transverses to enter the orbit (Fig. 3). Within the anterior cavernous sinus, superior orbital fissure, or posterior orbit, the oculomotor nerve divides into a superior ramus, which supplies the superior rectus muscle and the levator muscle of the eyelid, and an inferior ramus, which supplies the medial and inferior rectus muscles, the inferior oblique muscle, and the ciliary ganglion (parasympathetic fibers to pupillary constrictors). As discussed subsequently, segregation of fibers into superior and inferior groups may occur before anatomic division in the cavernous sinus—perhaps even at a fascicular level.Fig. 3Diagram of superolateral view of cranial nerves in cavernous sinus and orbit.(From Brazis PW, Masdeu JC, Biller J: Localization in Clinical Neurology. Second edition. Boston, Little, Brown and Company, 1990.)View Large Image Figure ViewerDownload (PPT) Pure unilateral lesions of the oculomotor nucleus are rare. Paresis of isolated muscles innervated by oculomotor branches is almost always due to a lesion of their branches within the orbit or to disease processes that affect the muscle or myoneural junction. Nuclear lesions, however, may cause isolated weakness of one of the muscles innervated by the oculomotor nerve, except the superior rectus muscle (crossed innervation noted previously), the levator palpebrae superioris (a single caudal subnucleus innervates the levators bilaterally), the pupillary constrictors (visceral nuclei are spread throughout the oculomotor nucleus), and the medial rectus muscle (three separate subnuclei). Thus, isolated unilateral palsies of the inferior rectus muscle have been associated with lesions of the inferior rectus subnucleus.2Pusateri TJ Sedwick LA Margo CE Isolated inferior rectus muscle palsy from a solitary metastasis to the oculomotor nucleus.Arch Ophthalmol. 1987; 105: 675-677Crossref PubMed Scopus (35) Google Scholar, 3Roper-Hall G Burde RM Inferior rectus palsies as a manifestation of atypical IIIrd cranial nerve disease.Am Orthopt J. 1975; 25: 122-130PubMed Google Scholar, 4Warren W Burde RM Klingele TG Roper-Hall G Atypical oculomotor paresis.J Clin Neuro Ophthalmol. 1982; 2: 13-18Google Scholar More characteristic of nuclear involvement is unilateral palsy of the third cranial nerve in conjunction with weakness of the ipsilateral and contralateral superior rectus muscles and bilateral incomplete ptosis. Occasionally, only the superior rectus muscle contralateral to the lesion is involved.4Warren W Burde RM Klingele TG Roper-Hall G Atypical oculomotor paresis.J Clin Neuro Ophthalmol. 1982; 2: 13-18Google Scholar, 5Eustace P Partial nuclear third nerve palsies.Neuro-ophthalmology. 1985; 5: 259-262Crossref Scopus (8) Google Scholar Because some corticofugal and colliculofugal (supranuclear) pathways for the control of horizontal saccades may travel in the mesencephalic tegmentum near the oculomotor nucleus, unilateral infarctions of the midbrain-diencephalic junction may cause an ipsilateral nuclear oculomotor lesion associated with palsy of contralateral horizontal saccades (restriction of abduction in the contralateral eye may be overcome by the oculocephalic reflex).6Masdeu JC Rosenberg M Midbrain-diencephalic horizontal gaze paresis.J Clin Neuro Ophthalmol. 1987; 7: 227-234Crossref Scopus (22) Google Scholar Inasmuch as pathways for ipsilateral horizontal smooth ocular pursuit also travel through the midbrain,7Kato I Watanabe J Nakamura T Harada K Hasegawa T Kanayama R Mapping of brainstem lesions by the combined use of tests of visually-induced eye movements.Brain. 1990; 113: 921-935Crossref PubMed Scopus (25) Google Scholar ipsilateral smooth ocular pursuit might be expected to be decreased in patients with some midbrain lesions.8Zackon DH Sharpe JA Midbrain paresis of horizontal gaze.Ann Neurol. 1984; 16: 495-504Crossref PubMed Scopus (53) Google Scholar Bilateral palsies of the third cranial nerve but with sparing of the levator muscles of the eyelid may be caused by bilateral nuclear lesions that spare the central caudal levator subnucleus.9Elliott RL Encephalitis with ophthalmoplegia.Confin Neurol. 1969; 31: 194-197Crossref PubMed Scopus (4) Google Scholar, 10Keane JR Zaias B Itabashi HH Levator-sparing oculomotor nerve palsy caused by a solitary midbrain metastasis.Arch Neurol. 1984; 41: 210-212Crossref PubMed Scopus (33) Google Scholar Conversely, isolated bilateral ptosis and sparing of the extraocular muscles and pupils have been described with lesions that involve the levator subnucleus and spare more rostral oculomotor subnuclei.11Conway VH Rozdilsky B Schneider RJ Sundaram M Isolated bilateral complete ptosis.Can J Ophthalmol. 1983; 18: 37-40PubMed Google Scholar, 12Growdon JH Winkler GF Wray SH Midbrain ptosis: a case with clinicopathologic correlation.Arch Neurol. 1974; 30: 179-181Crossref PubMed Scopus (55) Google Scholar Oculomotor fascicular lesions often accompany nuclear lesions because the paramedian branches near the top of the basilar artery often feed both structures. Complete fascicular lesions cause ipsilateral involvement of all the oculomotor innervated muscles and sparing of the contralateral eye. A fascicular localization for an oculomotor nerve palsy is suggested by concomitant damage of neighboring mesencephalic structures and pathways. For example, damage to the red nucleus will cause contralateral ataxia and "rubral" tremor (Claude's syndrome), whereas larger lesions that affect, in addition, the subthalamic region produce contralateral choreiform movements (Benedikt's syndrome). More caudal fascicular lesions may involve the ipsilateral brachium conjunctivum below the decussation; thus, cerebellar abnormalities ipsilateral to the oculomotor palsy may result (Nothnagel's syndrome). Anterior lesions that affect the cerebral peduncle cause contralateral hemiparesis (Weber's syndrome). Other manifestations of mesencephalic lesions that cause fascicular oculomotor palsies include disorders of gaze and convergence, somnolence, peduncular hallucinosis, and paucity of speech or even mutism.9Elliott RL Encephalitis with ophthalmoplegia.Confin Neurol. 1969; 31: 194-197Crossref PubMed Scopus (4) Google Scholar Contralateral abduction may be impaired ("pseudo-abducens palsy"), perhaps because of excessive convergence.12Growdon JH Winkler GF Wray SH Midbrain ptosis: a case with clinicopathologic correlation.Arch Neurol. 1974; 30: 179-181Crossref PubMed Scopus (55) Google Scholar, 13Caplan LR "Top of the basilar" syndrome.Neurology. 1980; 30: 72-79Crossref PubMed Google Scholar, 14Masdeu J Brannegan R Rosenberg M Dobben G Pseudo abducens palsy with midbrain lesions (abstract).Ann Neurol. 1980; 8: 103Google Scholar "Midbrain corectopia" and pupillary irregularity have also been associated with midbrain lesions and may even be intermittent.15Selhorst JB Hoyt WF Feinsod M Hosobuchi Y Midbrain corectopia.Arch Neurol. 1976; 33: 193-195Crossref PubMed Scopus (33) Google Scholar Rarely, fascicular lesions of the third cranial nerve develop in isolation without other ocular motor or neurologic involvement present to suggest a mesencephalic site of damage.16Keane JR Isolated brain-stem third nerve palsy.Arch Neurol. 1988; 45: 813-814Crossref PubMed Scopus (42) Google Scholar, 17Shuaib A Murphy W Mesencephalic hemorrhage and third nerve palsy.J Comput Tomogr. 1987; 11: 385-388Abstract Full Text PDF PubMed Scopus (34) Google Scholar Bilateral isolated fascicular oculomotor palsies in which the pupils were spared have been described in a patient with mesencephalic lymphoma.18Wilkins DE Samhouri AM Isolated bilateral oculomotor paresis due to lymphoma.Neurology. 1979; 29: 1425-1428Crossref PubMed Scopus (36) Google Scholar Fascicular lesions may cause palsies of the oculomotor nerve limited to specific oculomotor-innervated muscles; this finding suggests that a topographic arrangement of the fascicles occurs intra-axially. For example, fascicular lesions have resulted in the following situations: (1) isolated inferior oblique paresis;19Castro O Johnson LN Mamourian AC Isolated inferior oblique paresis from brain-stem infarction: perspective on oculomotor fascicular organization in the ventral midbrain tegmentum.Arch Neurol. 1990; 47: 235-237Crossref PubMed Scopus (102) Google Scholar (2) a unilateral fixed, dilated pupil unassociated with other neurologic dysfunction;20Shuaib A Israelian G Lee MA Mesencephalic hemorrhage and unilateral pupillary deficit.J Clin Neuro Ophthalmol. 1989; 9: 47-49Google Scholar (3) paresis of the inferior oblique, superior rectus, medial rectus, and levator muscles and sparing of the inferior rectus muscle and pupil;17Shuaib A Murphy W Mesencephalic hemorrhage and third nerve palsy.J Comput Tomogr. 1987; 11: 385-388Abstract Full Text PDF PubMed Scopus (34) Google Scholar, 21Nadeau SE Trobe JD Pupil sparing in oculomotor palsy: a brief review.Ann Neurol. 1983; 13: 143-148Crossref PubMed Scopus (93) Google Scholar and (4) paresis of the inferior oblique, superior rectus, medial rectus, levator, and inferior rectus muscles and pupillary sparing.21Nadeau SE Trobe JD Pupil sparing in oculomotor palsy: a brief review.Ann Neurol. 1983; 13: 143-148Crossref PubMed Scopus (93) Google Scholar, 22Breen LA Hopf HC Farris BK Gutmann L Pupil-sparing oculomotor nerve palsy due to midbrain infarction.Arch Neurol. 1991; 48: 105-106Crossref PubMed Scopus (60) Google Scholar These reports prompted Castro and associates19Castro O Johnson LN Mamourian AC Isolated inferior oblique paresis from brain-stem infarction: perspective on oculomotor fascicular organization in the ventral midbrain tegmentum.Arch Neurol. 1990; 47: 235-237Crossref PubMed Scopus (102) Google Scholar to propose that individual oculomotor fascicles in the ventral mesencephalon are arranged topographically from lateral to medial as follows: inferior oblique, superior rectus, medial rectus and levator palpebrae, inferior rectus, and pupillary fibers (Fig. 4). This model perhaps also serves the description of "superior division" oculomotor palsies (that is, paresis of the superior rectus and levator muscles without involvement of other groups) associated with intra-axial midbrain lesions,23Ksiazek SM Repka MX Maguire A Harbour RC Savino PJ Miller NR Sergott RC Bosley TM Divisional oculomotor nerve paresis caused by intrinsic brainstem disease.Ann Neurol. 1989; 26: 714-718Crossref PubMed Scopus (78) Google Scholar, 24Hriso E Miller A Masdeu JC Monocular elevation weakness and ptosis: an oculomotor fascicular syndrome? (abstract).Neurology. 1990; 1: 309Google Scholar, 25Guy JR Day AL Intracranial aneurysms with superior division paresis of the oculomotor nerve.Ophthalmology. 1989; 96: 1071-1076Abstract Full Text PDF PubMed Scopus (30) Google Scholar which suggest that the levator fibers are probably lateral to the medial rectus fibers. As Abdollah and Francis26Abdollah A Francis GS Intraaxial divisional oculomotor nerve paresis suggests intraaxial fascicular organization (letter to the editor).Ann Neurol. 1990; 28: 589-590Crossref PubMed Scopus (16) Google Scholar pointed out, however, with this organization it would be difficult to attribute reported "inferior division" intra-axial paresis23Ksiazek SM Repka MX Maguire A Harbour RC Savino PJ Miller NR Sergott RC Bosley TM Divisional oculomotor nerve paresis caused by intrinsic brainstem disease.Ann Neurol. 1989; 26: 714-718Crossref PubMed Scopus (78) Google Scholar, 27Abdollah A Francis G Demyelinating disease presenting as a partial oculomotor nerve paresis (abstract).Can J Neurol Sci. 1989; 16: 285Google Scholar to a single midbrain lesion. Although superior and inferior divisional palsies have classically been localized to anterior cavernous sinus or posterior orbital lesions, such reports support the contention that a divisional oculomotor nerve pattern may occur from damage at any location along the course of the oculomotor nerve, from the fascicle to the orbit.23Ksiazek SM Repka MX Maguire A Harbour RC Savino PJ Miller NR Sergott RC Bosley TM Divisional oculomotor nerve paresis caused by intrinsic brainstem disease.Ann Neurol. 1989; 26: 714-718Crossref PubMed Scopus (78) Google Scholar Impairment of the third cranial nerve, usually in conjunction with relative or total pupillary sparing, occurs in patients with diabetes mellitus. Postmortem examination in three patients demonstrated pathologic changes in the intracranial (cavernous sinus or subarachnoid) peripheral portion of the nerve28Dreyfus PM Hakim S Adams RD Diabetic ophthalmoplegia: report of case with postmortem study and comments on vascular supply of human oculomotor nerve.Arch Neurol Psychiatry. 1957; 77: 337-349Crossref Scopus (151) Google Scholar, 29Asbury AK Aldredge H Hershberg R Fisher CM Oculomotor palsy in diabetes mellitus: a clinico-pathological study.Brain. 1970; 93: 555-566Crossref PubMed Scopus (278) Google Scholar, 30Weber RB Daroff RB Mackey EA Pathology of oculomotor nerve palsy in diabetics.Neurology. 1970; 20: 835-838Crossref PubMed Google Scholar and led to the concept that diabetic oculomotor palsies are due to peripheral nerve ischemia. Isolated fascicular palsies of the third cranial nerve and pupillary sparing, however, have been reported in patients with mesencephalic infarcts detected on magnetic resonance imaging.22Breen LA Hopf HC Farris BK Gutmann L Pupil-sparing oculomotor nerve palsy due to midbrain infarction.Arch Neurol. 1991; 48: 105-106Crossref PubMed Scopus (60) Google Scholar In a study of 11 adult patients with diabetes and an isolated palsy of the third cranial nerve (8 with pupillary sparing), 10 had abnormal masseter reflexes, 3 had a lesion (evident on magnetic resonance imaging) in the ipsilateral oculomotor fasciculus, and 3 had subsequent mild brain-stem signs.31Hopf HC Gutmann L Diabetic 3rd nerve palsy: evidence for a mesencephalic lesion.Neurology. 1990; 40: 1041-1045Crossref PubMed Google Scholar These findings led the authors to conclude that an isolated "diabetic" oculomotor palsy, with or without pupillary sparing, is much more likely on the basis of a focal mesencephalic infarct than a peripheral lesion. Further studies and pathologic confirmation are needed to determine whether these conclusions are justified. Pupillary dilatation and unresponsiveness, with variable paresis of extraocular muscle function, are characteristic of compression of the third cranial nerve in the subarachnoid space, usually by uncal herniation or by an aneurysm of the internal carotid artery or posterior communicating artery. With unruptured cerebral aneurysms, oculomotor paresis may be incomplete, with at least one element of nerve dysfunction (that is, ptosis, mydriasis, or weakness of extraocular muscles) absent.32Bartleson JD Trautmann JC Sundt Jr, TM Minimal oculomotor nerve paresis secondary to unruptured intracranial aneurysm.Arch Neurol. 1986; 43: 1015-1020Crossref PubMed Scopus (55) Google Scholar Rarely, aneurysmal partial oculomotor nerve paresis may be transient and clear spontaneously.33Greenspan BN Reeves AG Transient partial oculomotor nerve paresis with posterior communicating aneurysm: a case report.J Clin Neuro Ophthalmol. 1990; 10: 56-58Google Scholar Compressive subarachnoid lesions may occasionally spare the pupil, perhaps because even distribution of the pressure of the lesion allows the relatively pressure-resistant, small-caliber pupillomotor fibers to escape injury or because the lesion compresses only the inferior portion of the nerve and thus spares the dorsally situated pupillomotor fibers.21Nadeau SE Trobe JD Pupil sparing in oculomotor palsy: a brief review.Ann Neurol. 1983; 13: 143-148Crossref PubMed Scopus (93) Google Scholar, 34Kissel JT Burde RM Klingele TG Zeiger HE Pupil-sparing oculomotor palsies with internal carotid-posterior communicating artery aneurysms.Ann Neurol. 1983; 13: 149-154Crossref PubMed Scopus (149) Google Scholar Ptosis has been described in isolation as the sole manifestation of oculomotor compression by an aneurysm of the posterior communicating artery.35Good EF Ptosis as the sole manifestation of compression of the oculomotor nerve by an aneurysm of the posterior communicating artery.J Clin Neuro Ophthalmol. 1990; 10: 59-61Crossref Scopus (3) Google Scholar Superior division or inferior division oculomotor paresis may occur with subarachnoid lesions. For example, superior division paresis has been associated with an aneurysm of the superior cerebellar-posterior cerebral artery junction that compressed and flattened the interpeduncular oculomotor nerve from below,25Guy JR Day AL Intracranial aneurysms with superior division paresis of the oculomotor nerve.Ophthalmology. 1989; 96: 1071-1076Abstract Full Text PDF PubMed Scopus (30) Google Scholar and isolated inferior division involvement has occurred with parasellar tumors (for example, meningioma or schwannoma).36Carlow TJ Johnson JK Parasellar tumors: isolated pupil-sparing 3rd nerve palsy (abstract).Neurology. 1990; 1: 309Google Scholar Inferior division involvement in the latter situation was pupil-sparing, perhaps because of insidious tumor growth that spared pressure-resistant pupillomotor fibers. In the cavernous sinus, compressive lesions often involve the other ocular motor nerves and the ophthalmic branch of the trigeminal nerve. The clinical findings are similar when the region of the superior orbital fissure is involved; however, with space-occupying lesions, proptosis strongly indicates localization to the superior orbital fissure.37Greenberg HS Deck MDF Vikram B Chu FCH Posner JB Metastasis to the base of the skull: clinical findings in 43 patients.Neurology. 1981; 31: 530-537Crossref PubMed Google Scholar Combined oculomotor paresis and sympathetic denervation (Horner's syndrome) are virtually pathognomonic of a lesion of the cavernous sinus. Compressive lesions of the cavernous sinus may also spare the pupil because they often preferentially involve only the superior division of the oculomotor nerve that has no pupillomotor fibers38Trobe JD Glaser JS Post JD Meningiomas and aneurysms of the cavernous sinus: neuro-ophthalmologic features.Arch Ophthalmol. 1978; 96: 457-467Crossref PubMed Scopus (80) Google Scholar or the superior aspect of the nerve anterior to the point where the pupillomotor fibers descend in their course near the inferior oblique muscle. The pupillary "sparing" with lesions of the anterior cavernous sinus may be more apparent than real; concomitant injury of nerve fibers to both the pupillary sphincter and the dilator can result in a midposition, fixed pupil.34Kissel JT Burde RM Klingele TG Zeiger HE Pupil-sparing oculomotor palsies with internal carotid-posterior communicating artery aneurysms.Ann Neurol. 1983; 13: 149-154Crossref PubMed Scopus (149) Google Scholar With chronic lesions, aberrant regeneration (see subsequent discussion) may result in apparent pupillary sparing. Compressive pupil-sparing isolated oculomotor palsies (mimicking diabetic oculomotor palsy) have thus been described with entities such as a mucocele of the sphenoid sinus that originates from the clinoid process39Johnson LN Hepler RS Yee RD Batzdorf U Sphenoid sinus mucocele (anterior clinoid variant) mimicking diabetic ophthalmoplegia and retrobulbar neuritis.Am J Ophthalmol. 1986; 102: 111-115Abstract Full Text PDF PubMed Scopus (62) Google Scholar or from compression by a persistent primitive trigeminal artery.40Tibbs PA Walsh JW Minix MB Persistent primitive trigeminal artery and ipsilateral acquired blepharoptosis.Arch Neurol. 1981; 38: 323-324Crossref PubMed Scopus (2) Google Scholar Lesions of the medial cavernous sinus may affect only the ocular motor nerves but spare the more laterally located ophthalmic branch of the trigeminal nerve and thus result in painless ophthalmoplegia. An isolated oculomotor palsy may be the initial or sole sign of a pituitary tumor;41Saul RF Hilliker JK Third nerve palsy: the presenting sign of a pituitary adenoma in five patients and the only neurological sign in four patients.J Clin Neuro Ophthalmol. 1985; 5: 185-193Google Scholar indeed, ptosis may be the initial manifestation of such a lesion.42Yen MY Liu JH Jaw SJ Ptosis as the early manifestation of pituitary tumour.Br J Ophthalmol. 1990; 74: 188-191Crossref PubMed Scopus (18) Google Scholar In immunosuppressed patients (for example, those with acquired immunodeficiency syndrome [AIDS] or those who have undergone transplantation), infection of the cavernous sinus may develop. Previously, Mucor organisms were usually involved, but now Aspergillus must also be considered.43Spoor TC Hartel WC Harding S Kocher G Aspergillosis presenting as a corticosteroid-responsive optic neuropathy.J Clin Neuro Ophthalmol. 1982; 2: 103-107Google Scholar Orbital lesions are characterized by muscle paresis associated with proptosis and, at times, optic neuropathy. Orbital masses may cause progressive unilateral visual failure associated with swelling of the optic disk (followed by atrophy) and the occurrence of opticociliary shunt vessels. These vessels are seen in the region of the disk or at the margins of the optic disk and represent anastomotic channels between the central retinal vein and the peripapillary choroidal venous system that are enlarged in an effort to bypass compressed optic nerve venous channels.44Boschetti NV Smith JL Osher RH Gass JDM Norton EWD Fluorescein angiography of optociliary shunt vessels.J Clin Neuro Ophthalmol. 1981; 1: 9-30Google Scholar, 45Masuyama Y Kodama Y Matsuura Y Sawada A Harada K Tsuchiya T Clinical studies on the occurrence and the pathogenesis of optociliary veins.J Clin Neuro Ophthalmol. 1990; 10: 1-8Crossref Scopus (6) Google Scholar Although proptosis is characteristic of orbital masses, it may also occur with lesions of the cavernous sinus and may rarely even be due to an intracranial lesion (for example, a tumor of the middle cranial fossa may exert pressure on the veins of the cavernous sinus and thus cause intraorbital venous congestion).46Acers TE Pseudo-orbital apex syndrome.Am J Ophthalmol. 1979; 88: 623-625PubMed Scopus (5) Google Scholar Investigators should be aware that, rather than causing proptosis, scirrhous carcinoma of the breasts or other tumors metastatic to the orbit may cause progressive fibrotic changes (posterior traction and tethering) and destruction of the orbital wall that results in enophthalmos.47Thompson PD Wise RJS Kendall BE Enophthalmos and metastatic carcinoma of the breast (letter to the editor).J Neurol Neurosurg Psychiatry. 1985; 48: 1305-1306Crossref PubMed Scopus (8) Google Scholar, 48Goldberg RA Rootman J Cline RA Tumors metastatic to the orbit: a changing picture.Surv Ophthalmol. 1990; 35: 1-24Abstract Full Text PDF PubMed Scopus (271) Google Scholar Gaze-evoked amaurosis (perhaps due to decreased blood flow to the retina or optic nerve during movement of the eye) may also occur, most often with cavernous hemangiomas and meningiomas of the optic nerve sheath.49Bradbury PG Levy IS McDonald WI Transient uniocular visual loss on deviation of the eye in association with intraorbital tumours.J Neurol Neurosurg Psychiatry. 1987; 50: 615-619Crossref PubMed Scopus (29) Google Scholar, 50Orcutt JC Tucker WM Mills RP Smith CH Gaze-evoked amaurosis.Ophthalmology. 1987; 94: 213-218Abstract Full Text PDF PubMed Scopus (37) Google Scholar Metastatic orbital tumors may often be the first site of systemic spread in patients with cancer. 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Infiltrative and mass lesions are by far the most common. Superior and inferior divisional paresis of the oculomotor nerve is classically localized to lesions of the posterior orbit (or anterior cavernous sinus), the site at which division of the nerve has been substantiated anatomically. As previously noted, however, the functional division of the oculomotor nerve is present probably even at the fascicular level, and a divisional pattern may occur from damage anywhere along the course of the nerve.23Ksiazek SM Repka MX Maguire A Harbour RC Savino PJ Miller NR Sergott RC Bosley TM Divisional oculomotor nerve paresis caused by intrinsic brainstem disease.Ann Neurol. 1989; 26: 714-718Crossref PubMed Scopus (78) Google Scholar Months to years after the occurrence of an oculomotor lesion, clinical findings of aberrant regeneration of the nerve may be seen. Such findings variably include elevation of the eyelid on downward gaze (pseudo-Graefe's sign) or on adduction, depression of the eyelid during abduction, limitation of elevation and depression of the eye with occasional retraction of the eyeball on attempted vertical gaze, adduction of the eye on attempted elevation or depression, and suppression of the vertical phase of the opticokinetic response. Dissociation of the light and near reflexes of the pupil often occurs, and the pupil may constrict on adduction or downward gaze. Aberrant regeneration to the iris sphincter may be too weak to constrict the pupil, but on slit-lamp examination, clear segmental contraction of the sphincter may be seen when movement of the eye in any oculomotor-mediated direction is attempted (Czarnecki's sign).52Cox TA Czarnecki's sign as the initial finding in acquired oculomotor synkinesis (letter to the editor).Am J Ophthalmol. 1986; 102: 543Google Scholar This gaze-evoked segmental constriction of the pupil may occur in portions of the sphincter that are unreactive to light, and other segments of the pupil have normal reactions to light without Czarnecki's sign.53Cox TA Goldberg RA Rootman J Tonic pupil and Czarnecki's sign following third nerve palsy.J Clin Neuro Ophthalmol. 1991; 11: 55-56Google Scholar Aberrant regeneration may occur after oculomotor damage due to trauma, aneurysm, and other causes, but it is seldom caused by ischemic (for example, diabetic) neuropathy. Rarely, aberrant regeneration of the third cranial nerve may develop without a history of oculomotor palsy (primary aberrant regeneration). Primary aberrant regeneration has occurred unilaterally in patients with intracavernous meningioma, aneurysm, or trigeminal neuroma54Boghen D Chartrand J-P Laflamme P Kirkham T Hardy J Aube M Primary aberrant third nerve regeneration.Ann Neurol. 1979; 6: 415-418Crossref PubMed Scopus (39) Google Scholar, 55Cox TA Wurster JB Godfrey WA Primary aberrant oculomotor regeneration due to intracranial aneurysm.Arch Neurol. 1979; 36: 570-571Crossref PubMed Scopus (38) Google Scholar, 56Miller NR Fourth edition. Walsh and Hoyt's Clinical Neuro-ophthalmology. Vol 2. Williams & Wilkins, Baltimore1985: 680Google Scholar and bilaterally in a patient with abetalipoproteinemia (Bassen-Kornzweig syndrome).57Cohen DA Bosley TM Savino PJ Sergott RC Schatz NJ Primary aberrant regeneration of the oculomotor nerve: occurrence in a patient with abetalipoproteinemia.Arch Neurol. 1985; 42: 821-823Crossref PubMed Scopus (12) Google Scholar A pseudo-Graefe phenomenon has been noted apparently contralateral to a regenerated paretic third cranial nerve.58Guy J Engel HM Lessner AM Acquired contralateral oculomotor synkinesis.Arch Neurol. 1989; 46: 1021-1023Crossref PubMed Scopus (21) Google Scholar Months after a traumatic right oculomotor paresis, infraduction during adduction of the nonparetic left globe was associated with elevation of the left upper eyelid. Moreover, combined oculomotor-abducens synkinesis has been described after severe head trauma that resulted in misdirection of nerve fibers to the right medial rectus and right lateral rectus muscles.59Packer AJ Bienfang DC Aberrant regeneration involving the oculomotor and abducens nerves.Ophthalmologica. 1984; 189: 80-85Crossref PubMed Scopus (18) Google Scholar On attempted adduction, the right eye slightly abducted, but it adducted on attempts at abduction; in addition, attempts at abduction resulted in pupillary constriction.
Publication Year: 1991
Publication Date: 1991-10-01
Language: en
Type: review
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 57
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