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Show J. Clin. Neuro-ophth'llmol. 2: 103-107, 1982. Sudden Visual Loss and a Chiasmal Syndrome Due to an Intrachiasmatic Vascular Malformation JOHN E. CARTER, M.D. JAMES WYMORE, M.D. LINDA ANSBACHER, M.D. WILLIAM S. REID, M.D. Abstract A 48-year-old woman presented with a chief complaint of visual loss and bitemporal hemianopia. A similar episode of temporal visual field loss had occurred 34 months earlier and spontaneously resolved. Computerized tomography demonstrated a suprasellar mass. Angiography was normal. At surgery a venous angioma of the optic chiasm with a fresh hematoma was found and removed. Intrachiasmatic vascular malformation is an unusual finding which should be considered in the differential diagnosis in patients with a chiasmaI syndrome. Intrachiasmatic vascular malformations represent an unusual cause of acute visual loss. We present a case of venous angioma of the optic chiasm. Case Report A 48-year-old woman first presented to her ophthalmologist in January 1978, complaining of a shadow which had appeared in the temporal visual field of the right eye 6 weeks previously and then resolved gradually. Visual acuity, pupillary reactions, and confrontation visual fields were normal but perimetry was not carried out. Funduscopy was normal except for the presence of a horseshoe tear in the temporal periphery of the left eye. This tear was thought to be the cause of the transient visual symptom. Confusion regarding which eye was involved was attributed to the 6-week time lapse or to the right visual field symptoms expected from the temporal retinal location of the tear in the left eye. A retinal surgeon was consulted, agreed From the Departments of Neurology (JEC). Ophthalmology GEe, JW). and Pathology (LA), University of Missouri Health Sciences Center, and the Division of Neurosurgery, University of Tennessee Hospital. Knoxville, Tennessee (W5R). September 1982 with this impression, and cryosurgery was performed. A routine exam in May 1980 was normal except for the retinal break which was sealed with cryotherapy scars. Perimetry was not carried out at that time. The patient experienced no further visual symptoms nor were there any headaches or other medical complaints until November 1980, when she awoke one morning and found that a shadow had appeared in the temporal visual field of each eye. When she was reexamined by her ophthalmologist the visual acuity in each eye was 20/200 and there was a bitemporal hemianopia on confrontation testing. Automated static perimetry verified the bitemporal visual field defects (Fig. 1). There were no other neurological complaints and no significant past medical history. Neurological examination was normal except for the visual deficit. The patient underwent CT scanning which was initially interpreted as being normal. When the scan was repeated with a different angle to the baseline and coronal views, a small lesion in the region of the optic chiasm was seen (Figs. 2-4). Arteriography was performed and was normal. The patient underwent a frontotemporal craniotomy. At surgery the chiasmal region including the right internal carotid artery, the A-I segments of both anterior cerebral arteries, and the anterior communicating artery were visualized and normal. The chiasm was swollen and markedly discolored by what appeared to be a hematoma within the substance of the chiasm itself (Fig. 5). As the pia of the dorsal surface of the chiasm was opened, a hematoma began to extrude spontaneously. When the hematoma had been completely cleared there were abnormal blood vessels seen within the chiasm which had the appearance of a small vascular malformation. The vascular malformation was removed (Fig. 6). The pathologic specimen (Fig. 7) showed dilated thin-walled vascular channels with mild gliosis in 163 Figure 1. Bitemporal visual field defect demonstrated preoperatively by perimetry performed with a Fieldmaster perimeter. Figure 2. N(llll'Ilh.111ll'd IT ''''.In d,'m"",,tr.lli"!\ m.",,, 1"",,)11 III thl' ,upr,,,dl.lf ,i,tl'rn. Figure 3. With contrast, the suprasellar mass is seen to enhance. Journal of Clinical Neuro-ophthalmology Figure 4. Cor,'n.t) section .llso dem,'nstr.ttes .tn enh.tncing suprdselldr mdSS. The line.lr densities e>.lending I.lter.llly from eithE'r side of the m.tss .tre the middle cerebr.tl .trteries visible due 10 Ihe contr.tst injecti,'n. Figure 5. Swollen optic chidsm. Subpial hematom.t is visible '>II the surface of the chidsm from intrachidsm.tlit· ht'm"rrh.tge from the vdsculdr malformdtion. VM: v.tscul.tr m.,lf"rm"tillll. LACA: left .Interior cerebrdl drtery. LON: left "ptic Ilt'rvl'. RON: right optic nerve. ICA: right interndl carotid .trtt'ry. RACA: right anterior cerebral artery. September 1982 Clfter, Wymore, Ansbacher, Reid Figure 6. Following surgicdl removdl of the v.tsculdr malform. ttion .t cdvity c.tn be seen within the chidsm which extends towJrd the right optic nerve. adjacent tissue. No arteries were seen and there were no arteriolized veins found. A diagnosis of venous angioma was made. Immediately postoperatively, the patient noted subjective improvement in her visual fields. When she was seen by her ophthalmologist 7 weeks after surgery the visual acuity was finger-counting at 2 ft in the right eye and 20/20 in the left eye. Little change had occurred in the automated perimetry performed on the right eye but the lower quadrant of the temporal field of the left eye w.\s now int.let (Fig. 8). Discussion In 1951, Margolis et .11.' called attention to sm.1ll angiomatous malformations .1S a source of intracerebral hematomas. In 1050, Crawford and Russell~ first applied the trrm "cryptic v<lscular malformation" to this group of small .mgiomas which were not detectable by .mgiography or other clinical rxaminations and which were occasionally responsible for spontaneous intracerebral hemorrhage. Increasingly sensitive diagnostic techniques have resulted in more effective diagnosis of these small vascular malformations with computerized tomography being the most sensitive technique available today.:! 165 Intr,1Chi,l~m,ltic V,lsculJr MJlformJtion Figure 7. Four dilated, thin-walled vessels are pictured. surrounded by hemorrhagic stroma. The dark material in the left comer represents fibrin. (H & E. reduced from x250.) Figure 8. Poslopcr,lliv(' visual fidds p('rform('d wilh ,I Fi('ldmasl('r perimeter show minimal change in the field of the right eye but ('nIMg('m('nt of Ih(' I('mporal fi('ld and int,let (('nlral vision in th(' left eye. Journal of Clinical Neuro-ophthalmology Cryptic vascular malformations may be categorized as capillary telangiectasias, venous angiomas, or arteriovenous malformations. Unlike large arteriovenous malformations which are found predominantly supratentorially, cryptic vascular malformations have an equal incidence above and below the tentorium.4 Intrinsic vascular malformations of the optic chiasm are rare and have been reported only twice before.5 . 6 Both patients were in their 30s and both presented with a chief complaint of visual loss and headache. In one case" the patient described 3 weeks of progressive visual loss in one eye and was found to have a central scotoma with a temporal visual field defect in the asymptomatic eye. The other case6 had two episodes of visual loss and headache over a 6-month period of time. The first episode had cleared. At the time of the second episode he had a mild loss of acuity in one eye and a bitemporal visual field defect. In both of these cases angiography was normal but computerized tomography demonstrated the lesion. Hemorrhage into the chiasm has been reported in an additional seven7-9 cases and termed "chiasmal apoplexy" by Maitland et al.9 In two of the cases/· 9 the source of the hemorrhage was a chiasmatic glioma. The source of the hemorrhage in those cases not associated with tumor has been identified only in the cases of Fermaglich et al.,~ Roski et .11.,6 and the present case. In the remainder of the cases the source of bleeding has been assumed to be venous or cryptic vascular malformations although no abnormal vessels were seen at the time of surgery. Although chiasmal hemorrhage may present with a sudden onset or a more subacute course, headache is an almost invariable symptom in preViously published cases. The subject of the present report did not have headache associated with either of her episodes of visual loss. She shared other features with the earlier cases including normal angiography with diagnosis being possible only through the use of computed tomography. The sudden onset and the recovery which occurred September 1982 Carter, Wymore, Ansbacher, Reid after her first episode of visual loss are strongly suggestive of a vascular disease process, although this presentation might be confused with demyelinating optic neuritis which involved the optic chiasm. The differential diagnosis in any patient presenting with a chiasmal syndrome, with or without headache, should include intrachiasmatic vascular malformation. References I. Margolis, G., Odom, G., Woodhall, B., and Bloor, B.: The role of small angiomatous malformations in the production of intracerebral hematomas. 1. Neurosurg. 8: 564-575, 1951. 2. Crawford, J.V., and Russel, D.5.: Cryptic arteriovenous and venous hamartomas of the brain. 1. Neurol. Neurosurg. Psychiatry 19: 1-11, 1956. 3. Terao, H., Hori, T., Matsutani, M., and Okeda, R.: Detection of cryptic vascular malformations by computerized tomography. 1. Neurosurg. 51: 546-551, 1979. 4. McCormick, W., and Nofzinger, J.: "Cryptic" vascular malformations of the central nervous system. 1. Neurosurg. 24: 865-875, 1966. 5. Fermaglich, J.. Kaffah. J., and Manz. H.: Venous angioma of the optic chiasm. Ann. Neurol. 4: 470-471, 1978. 6. Roski, R., Gardner, J., and Spetzler, R.: Intrachiasmatic arteriovenous malformation. 1. Neurosurg. 54: 540-541, 1981. 7. Schneider, R.C, Kriss, F.C, and Falls, H.F.: Prechiasmal infarction associated with intrachiasmal and suprasellar tumors. 1. Neurosurg. 32: 197-208,1970. 8. Riishede, L and Seedorff, H.H.: Spontaneous hematoma of the optic chiasma. Report of a case. Acta Ophthalmol. 52: 317-322, 1974. 9. Maitland, CG., Abiko, 5.. Hoyt, W.F., et .11.: Chiasmal apoplexy. Report of four cases. 1. Neurosurg. 56: 118-122, 1982. Write for reprints to: John E. Carter, M.D., Department of Neurology, University of Missouri Health Sciences Center, Columbia, Missouri 05212. 167 |
