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Show Journal of Clinical Neuro-ophthalmology 13(3): 163-170, 1993. Ocular Pulsation in Neurofibromatosis A Clinical/Neuroradiologic Correlation J. Lawton Smith, M.D. and Brian C. Bowen, Ph.D., M.D. '\) 1993 Raven Press, Ltd., New York A 61-year-old woman presented with early cataract formation in an eye which had been pulsating synchronously with her heart beat all of her life. This report presents the first, to our knowledge, three dimensional reconstruction CT images of this form of neurofibromatosis 1. It also documents by MRI and MRA the association of an asymptomatic carotid-ophthalmic junction aneurysm ipsilateral to the sphenoid dysplasia. Key Words: Neurofibromatosis I-Sphenoid dysplasia- Pulsating exophthalmos-Carotid-ophthalmic junction aneurysm-Three dimensional CT images. From the Department of Ophthalmology and Neuroradiol: ogy Section, Department of Radiology, University of Miami School of Medicine, Miami, Florida, U.S.A. Address correspondence and reprint requests to Dr. J. L. Smith, Bascom Palmer Eye Institute, P.O. Box 016880, MiamI, FL 33101-6880, U.S.A. 163 The following case is reported for three reasons: (a) it is the first instance we have encountered in which a patient presented with an early cataract in the seventh decade of life in an eye with pulsating exophthalmos present since birth due to congenital sphenoid dysplasia; (b) it presents the first, to our knowledge, three-dimensional reconstruction computed tomographic (CT) images of this form of neurofibromatosis 1; (c) it documents by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) the association of an asymptomatic carotid-ophthalmic junction aneurysm ipsilateral to the bony defect. CASE REPORT A 61-year-old woman was seen June 29, 1992 through the courtesy of Dr. Magruder. Her chief complaint was decreasing vision in the left eye for 2 years. Present illness revealed that the patient was the product of a full-term uneventful pregnancy and had a normal early growth and development. No eye problem had been noted early by her family. However, she stated that for as long as she could remember her left eye had always pulsated synchronously with her heart beat. She noted no subjective bruit with this, but stated that at times the left eye would be more prominent than the right eye, and at other times the left eye would be more recessed than the right eye. This could vary with stress, fatigue, cold weather, pulse rate, and head position. In 1974 Dr. Magruder found 20/20 corrected vision in both eyes. In 1984 she began to note the gradual onset of diplopia, with a small right hyperdeviation in upgaze. She was given 4 diopters base down prism on the left eye, which helped. In 1990 her corrected vision was 20/20 right and 20/25 left. However, during the past 2 years, the left eye vision decreased further, a 25-diopter esotropia 164 f. L. SMITH AND B. C. BOWEN FIG. 1. Sphenoid dysplasia. (A,S) Three-dimensional reconstruction of coronal and (C) oblique CT sections. The orbital surface of the greater wing of the sphenoid (open arrow in Fig. A) and the superior orbital fissure (short arrow in Fig. A) are present on the right and absent on the left. I Clin Neuro-ol'hthallllol. Vol. 13. No.3. 1993 OCULAR PULSATION IN NEUROFIBROMATOSIS 165 was described, and an orbital ultrasound was performed. This revealed decreased reflectivity in the left upper orbit, and prompted a magnetic resonance (MR) scan on March 4, 1992. The findings subsequently led to neuro-ophthalmologic consultation. Past history revealed chronic sinusitis, intrinsic asthma, and labile hypertension. She had numerous skin lesions on arms, trunk, face, and chin, and one previously excised from her chin had been called a "neurofibroma." She gave a history of endometriosis and ovarian cysts, had been infertile, and 10 years ago had a hysterectomy. The patient had no headaches of consequence, had never had a seizure or loss of consciousness, and all in all had enjoyed excellent health all of her life. Family history revealed that her mother, who died at age 90, had some skin lesions on her face. A brother died in childhood of pneumonia but had significant eyelid ptosis. A first cousin had "a lot of freckles." The family history was otherwise negative. Examination revealed a best-corrected vision of 20/15 + 1 in right eye and 20/40 + 1 in left eye with glasses, but left eye vision was 20/20 + 1 with a pinhole. There was a right hyperphoria of 11 diopters at distance, but she was orthophoric at near. She identified 11/15 color plates with each eye. A definite facial asymmetry was present with left brow higher than the right. There was manifest pulsating exophthalmos on the left, without a bruit. Pupils were 3 mm bilaterally, reacted 2+ to light, and there appeared to be a subtle afferent pupil on the left. Corneal reflex was symmetrically intact in both eyes. The ductions of the right eye were full. The left eye showed a full range of adduction and downgaze, but there was a slight limitation of abduction and also of upgaze. The facial asymmetry raised the question as to whether there was slight facial hemiatrophy on the right or facial hemihypertrophy on the left. The patient stated she had always worn a one-half size larger shoe on the right than on the left foot. Hearing was intact to whispered voice bilaterally. Perimetric visual fields were normal. Slit lamp examination revealed clear corneas with essentially normal irides. Early cataractous changes were seen on the left with a bit of cortical clouding and some posterior subcapsular change. A few small nevi were seen on the right elbow, and some freckles on lower extremities. Applanation tensions were 12 in both eyes. Ophthalmoscopy revealed a normal disc in the right eye but for FIG. 2. Sphenoid dysplasia. Coronal CT section through the posterior right orbit. The left orbit is enlarged with flattening of the orbital plate of the frontal bone. The left temporal lobe (arrow) and subarachnoid space protrude into the orbit. The left ocular muscles and optic nerve are displaced medially. perhaps 1 or 2 small drusen on temporal side of the disc. The left eye showed modest temporal disc pallor, with 1 or 2 small drusen on the temporal side of the disc, but fundus periphery was otherwise normal in both eyes. FIG. 3. Sphenoid dysplasia. Coronal CT section through the apex of the right orbit. On the right. the optic canal (long arrow) and the superior orbital fissure (curved arrow) are normal. On the left, the basisphenoid and lesser wing of the sphenoid are hypoplastic. with an absent anterior clinoid process and slanted planum sphenoidale (short arrow). The left middle cranial fossa is enlarged. I Oill Neuro-ophlhalmol. Vol. 13. No.3. 1993 166 J. L. SMITH AND B. C. BOWEN FIG. 4. Sphenoid dysplasia. Coronal MR section (proton density-weighted) through the sella turcica. The pituitary gland is located to the right of the midline and the infundibulum (arrow) is obliquely oriented. Enlargement of the left hemicranium (macrocranium) is accompanied by an increase in size of the left lateral ventricle and subarachnoid spaces. The impression was (a) pulsating exophthalmos, left, associated with orbital encephalocele with congenital sphenoid dysplasia, due to neurofibromatosis; (b) left cranial asymmetry with a larger left hemisphere, minimal facial asymmetry, slightly larger right foot size; and (c) an early cataract noted on the left. The patient was given new glasses with appropriate prism and a stronger reading add and became asymptomatic at that point. Neuroimaging studies (plain films, computed tomography (CT) scan, MRI, and MRA scans) were obtained; selected images are seen in Figs. 1-11. DISCUSSION Neurofibromatosis (von Recklinghausen's disease) is the most commonly encountered phakomatosis or neurocutaneous syndrome. It is transmitted by autosomal dominant inheritance. The most common feature of the entity is the neurofibroma, a tumor arising from Schwann cells and fibroblasts of the neurilemmal sheath of peripheral nerve. Two forms of the disease are now described. Neurofibromatosis 1, carried on chromosome 17, is characterized by peripheral nerve sheath tumors associated with characteristic cutaneous cafe-au-lait spots. In addition to neurofibro- JClin Neuro-ophthalmol, Vol. 13, No.3, 1993 FIG. 5. Left internal carotid aneurysm (ICA) involving the origin of the ophthalmic artery. Axial CT scans at the level of the optic nerves. The left temporal lobe, subarachnoid space, and meninges (short arrows) protrude into the left orbit, resulting in exophthalmos. The ocular muscles and optic nerve are medially displaced. A minimally hyperdense mass (long arrow) is seen anterior and to the left of the dysplastic sella in the region of the carotid siphon. Thinning of the adjacent bone suggests erosion. FIG. 6. Left ICA involving origin of ophthalmic artery. Axial MR section (T2-weighted) at the same level as Fig. 9A. The protruding left temporal lobe and subarachnoid space are again seen. The meningeal border between CSF and orbital fat is accentuated due to a chemical shift (misregistration) effect. The mass (long arrow) identified in Fig. 5 demonstrates a "signal void," characteristic of flowing blood. Enlargement of th~ left middle cranial fossa and left side of the postenor fossa are accompanied by an increase in the subarachnoid space and thinning of the low-signal occipital bone (short arrow). OCULAR PULSATION IN NEUROFIBROMATOSIS 167 mas, the disorder may be associated with other tumors of the central nervous system. Gliomas of optic nerve and chiasm are the most frequent intracranial tumors, but glioblastoma, meningioma, hypothalmic hamartomas, and other tumors mayoccur, and, rarely, pheochromocytoma. Neurofibromatosis 2 is less common, is carried on chromosome 22, is also autosomal dominant, and is characterized by acoustic neuromas (vestibular schwannomas), which are usually bilateral. These patients may also have associated meningiomas and astrocytomas. A recent NIH Acoustic Neuroma Consensus Statement (1) listed the following diagnostic criteria for differentiation of these two forms of neurofibromatosis. Neurofibromatosis 1 may be diagnosed in Caucasians when two or more of the following are present: 1. Six or more cafe-au-lait macules whose greatest diameter is >5 mm in prepubescent patients and>15 mm in postpubescent patients 2. Two or more neurofibromas of any type or one plexiform neurofibroma 3. Freckling in the axillary or inguinal region 4. A distinctive osseous lesion as sphenoid dys- FIG. 7. Left ICA involving origin of ophthalmic artery. One slice (source image or partition) from a 3D timeof- flight MR angiography acquisition. The previously identified mass (long arrow) is a 13-mm aneurysm of the anterior carotid siphon. The prOXimal ophthalmic artery (short arrows) is identified anterior to the aneurysm. FIG. 8. Left ICA involving origin of ophthalmic artery. MR angiogram (axial projection image). The aneurysm (long arrow) is approximately in the midline. The "cavernous" and "supraclinoid" portions (so called since there is no left anterior clinoid process) of the left ICA siphon are superimposed. The horizontal segment (curved arrow) of the petrous portion of the left ICA is elongated as a result of the skull base asymmetry. Also, the M1 segment (short arrow) of the left middle cerebral artery is more anteriorly directed than the right. The ophthalmic arteries are not seen due to partial volume effects. plasia or thinning of long bone cortex with or without pseudoarthrosis 5. Optic glioma 6. Two or more Lisch nodules (iris hamartomas) 7. A parent, sibling, or child with neurofibroma-tosis 1 on the basis of the previous criteria. Neurofibromatosis 2 may be diagnosed when one of the following is present: 1. Bilateral 8th nerve masses seen by MRI with gadolinium 2. A parent, sibling, or child with neurofibromatosis 2 and either unilateral 8th nerve mass or anyone of the following: a. Neurofibroma b. Meningioma c. Glioma d. Schwannoma e. Posterior capsular cataract or opacity at a young age. It is evident that the patient reported here has neurofibromatosis 1. One of us (J.L.S.) believes I Cli" Neuro-ophthalmol, Vol. 13, No.3, 1993 168 J. L. SMITH AND B. C. BOWEN (.A) (8) FIG. 9. Left ICA involving origin of ophthalmic artery. (A) Coronal and (B) sagittal projection MR angiograms. The left carotid siphon is dilated at two sites separated by a narrower "waist." The smaller proximal (short arrow) and larger distal (long arrow) dilatations involve the "cavernous" and "supraclinoid" portions of the ICA. The larger, distal dilatation has lower signal intensity, probably due to slower or more complex blood flow. The waist (smallest arrow) corresponds to the site where the ICA would be expected to penetrate the dura. In the coronal angiograms, the basilar artery is partially superimposed on the left ICA. In the sagittal angiograms, the right ICA siphon is partially superimposed on the distal dilatation of the left ICA siphon. that there is considerably more overlap of clinical signs of these two forms of neurofibromatosis than is readily apparent by these formal delineations of the syndrome, and the reason the distinction has been made is because of the different chromosomes involved, rather than on the clinical aspects of the disease. A recent report on visual impairment in patients with neurofibromatosis 2 from the JClin Neuro-ophthalmol. Vol. 13, No.3, 1993 FIG. 10. Left ICA involving origin of ophthalmic artery. Osseous dysplasia involving left parietal, occipital, and sphenoid bones. Lateral skull radiograph shows two low density areas (straight arrows) in the left parietal bone adjacent to the lambdoid and occipitomastoid sutures. There is a low density within the occipital bone, and only one anterior clinoid process (curved arrow) of the sphenoid bone is identified. OCULAR PULSATION IN NEUROFIBROMATOSIS 169 FIG. 11. Left ICA involving origin of ophthalmic artery. Axial T2-weighted MR section at the level of the centrum semiovale. Prominent nodular hyperintense foci (arrows) are seen in the left hemisphere white matter. Such lesions have been observed in all patients of all ages with neurofibromatosis and have been attributed to the presence of hamartomas or atypical glial cells. In an elderly individual, ischemic changes must also be considered. Note the enlargement of the left hemicranium with increased subarachnoid space. A portion of the enlarged left lateral ventricle is medial to the posterior arrow. National Eye Institute (2) revealed that in a series of 54 patients, 51 with bilateral vestibular schwannomas, that one-third of the patients had decreased visual acuity related to the underlying disorder. Causes of decreased vision were cataracts, damage in the optic pathways, macular hamartomas, and corneal opacities. Five patients had severe neuro-ophthalmic lesions: optic glioma led to enucleation in one patient and to decreased vision in another; presumed chiasmal glioma caused legal blindness in another patient; one patient had finger- counting vision from compressive optic neuropathy due to meningioma, and anuther had irreversible visual loss in one eye due to longstanding papilledema. Visual field loss due to long-standing papilledema was present in three other patients. The paper concluded that the high frequency of visual impairment in neurofibromatosis 2 justified ophthalmologic evaluation of all patients. The detection of an asymptomatic significantly sized ophthalmic-carotid junction aneurysm in this patient merits comment. Vascular lesions in neurofibromatosis are most often in the abdominal aorta or its renal artery branches, but have been found in coronary, carotid, and vertebral arteries. Hypertension due to aortic coarctation or on a renovascular basis has been the most common clinical manifestation, but aneurysms with hemorrhage are more serious complications (3-4). Greene et a1. (5) believe that the vascular lesions in neurofibromatosis are due to mesodermal dysplasia. They proposed two basic types of vascular lesions. The first type is associated with larger vessels such as aorta, carotid, and proximal renal arteries, which are surrounded by neurofibromatous or ganglioneuromatous tissue. Intimal proliferation, thinning of the media, and fragmentation of elastic tissue leading to stenosis or aneurysm formation mayor may not be found. The second type is not a neural malformation but probably a dysplasia of small vessels. Salyer and Salyer (6) proposed that the pathogenesis of all the types of arteriallesions was the same, namely, the proliferation of Schwann cells within arteries with secondary degeneration changes, for example, fibrosis, resulting in lesions with different clinical appearances. Finally, the management of the defects in our patient should be mentioned. Her initial complaint of difficulty reading was relieved by appropriate change in her glasses. It was the opinion of senior neuroradiologists at both the University of Miami and the University of California that the aneurysm should be followed conservatively in this patient. Cataract surgery should be deferred on the left eye as long as feasible with good vision in the right eye. The question of how the cataract surgery should be done, if required, on the left eye raised interesting suggestions. These varied from operating under general anesthesia (to avoid a retrobulbar anesthetic injection into the prolapsed temporal lobe in orbit); to attempting neurosurgical repair of the major defect in orbital roof preoperatively to prevent the eye from moving during cataract surgery; to doing a lumbar puncture preoperatively to remove cerebrospinal fluid to dampen the oscillations of the brain and hence globe during cataract surgery; and otherwise conventional cataract surgery but using additional suturing of the wound to attempt to prevent wound dehiscence postoperatively with the constantly moving eye. The consensus to date has been to follow this patient as conservatively as possible. The experience of other physicians with management of any similar problems would be appreciated. Acknowledgments: Grateful acknowledgment is given to the Orlando Regional Medical Center, Department of Radiology, Orlando, Florida for providing the computed tomography, plain films, and the excellent I Clill Neuro·ophthallllol, Vol. 13, No.3. 1993 170 J. L. SMITH AND B. C. BOWEN three-dimensional computed tomographic reconstructions. Grateful acknowledgment is also given to Dr. Brock Magruder for referring this patient and to Dr. Robert Quencer and Dr. William F. Hoyt for helpful advice. REFERENCES 1. Acoustic Neuroma Consensus Statement, NIH Development Conference, December 11-13, 1991, Vol. 9, No.4. USPHS, NIH, Federal Building room 618, Bethesda, MD 20892. 2. Bouzas EA, Parry OM, Eldridge R, Kaiser-Kupfer MI. Vi-fell" ,'.'cllro·"I"IOwIIllO/' Vol. 13. No.3. 1993 sual impairment in patients with neurofibromatosis 2. Neurology 1993;43:622-3. 3. Sobata E, Ohkuma H, Suzuki S. Cerebrovascular disorders associated with von Recklinghausen's neurofibromatosis: a case report. Neurosurgery 1988;22:544-9. 4. Frank E, Brown BM, Wilson OF. Asymptomatic fusiform aneurysm of the petrous carotid artery in a patient with von Recklinghausen's neurofibromatosis. Surg Neurol 1989;32: 75-8. 5. Greene, JF Jr., Fitzwater JE, Burgess J. Arterial lesions associated with neurofibromatosis. Am J Clin Pathol 1974;62: 481-7. 6. Salyer WR, Salyer DC. The vascular lesions of neurofibromatosis. Angiology 1974;25:510-19. |
