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Show Visual Recovery After Surgical Decompression of an Occipital Intraventricular Cyst Aditya Vedantam, MD, Daniel Yoshor, MD, Rod Foroozan, MD Abstract: A 62-year-old woman presented with a chronic left homonymous visual field defect because of a right occipital cyst. Serial visual field examination documented stable visual fields for 12 months, after which there was worsening of visual fields associated with enlargement of the cyst. Surgical decompression of the occipital cyst resulted in marked improvement of the visual field defect over 9 months. This case demonstrates that surgical decompression of cystic lesions adjacent to posterior visual pathways can result in recovery of chronic visual field loss. Journal of Neuro-Ophthalmology 2014;34:255-256 doi: 10.1097/WNO.0000000000000136 © 2014 by North American Neuro-Ophthalmology Society A62-year-old woman was found to have a nonenhanc-ing right occipital cyst after undergoing computed FIG. 1. Automated perimetry and corresponding axial fluid attenuated inversion recovery images of the brain. A. At initial presentation, an incomplete left homonymous hemianopia is present with a right occipital intraventricular cyst. B. Fourteen months after the first visit, perimetry shows a complete left homonymous hemianopia associated with enlargement of the cyst. Surgical decompression was performed, and postoperative axial computed tomography reveals reduction in size of the cyst. C. At 9 months after surgery, there is near complete resolution of visual field defects. MRI performed 24 months after surgery shows continued resolution of the cyst. Departments of Neurosurgery (AV, DY) and Ophthalmology (RF), Baylor College of Medicine, Houston, Texas. The authors report no conflicts of interest. Address correspondence to Rod Foroozan, MD, Department of Ophthalmology, Baylor College of Medicine, 1977 Butler Boulevard, Houston, TX 77030; E-mail: foroozan@bcm.edu Vedantam et al: J Neuro-Ophthalmol 2014; 34: 255-256 255 Photo Essay Section Editor: Timothy J. McCulley, MD Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. tomography (CT) for headaches and dizziness. Her neu-rologist found that she had a visual field defect on con-frontation testing and referred for neuro-ophthalmic evaluation. She denied any visual symptoms and was not aware of any previous vision problems. She had pre-viously undergone surgery for pterygium on the right eye and blepharoplasty of the upper lids. Visual acuity was 20/20 in both eyes. Automated perimetry showed an incomplete left homonymous hemi-anopia (Fig. 1A). Pupils, extraocular movements, intraocu-lar pressures and funduscopic examination were normal. No immediate intervention was advised for her field defect. She subsequently underwent magnetic resonance imaging (MRI), and 3 months later, her visual field defects were stable. She was followed at 3 month intervals, and at 14 months after initial presentation, the patient reported worsening visual fields. Testing now revealed a complete left homonymous hemianopia (Fig. 1B). We advised her to see a neurosurgeon for possible surgical treatment of her intracranial cyst. The patient underwent endoscopic fenestration of her intracranial cyst, resulting in reduction in size. She reported subjective improvement in her visual fields and automated perimetry 3 months after surgery demonstrated marked improvement (Fig. 1C). She has remained stable over 2 years of follow-up. Reversibility of visual field defects following surgical decompression of parieto-occipital lesions is variable. Approximately one-third of patients with homonymous defects due to occipital lobe lesions show some improve-ment after surgical intervention (1,2). In 2 previous reports, substantial visual field recovery was documented after sur-gical decompression of occipital arachnoid cysts (3,4). Sim-ilar to these lesions, intraventricular cysts are well-circumscribed and do not infiltrate the adjacent brain parenchyma. Such findings appear to predict good visual outcome after surgical decompression. Therefore, sur-gical intervention may be considered initially in these pa-tients and not just with worsening of the visual fields. The physiological basis of visual improvement in our patient is unclear. Possible mechanisms include postopera-tive restitution of synaptic transmission and increased synaptic efficiency in the posterior visual pathways (5). Studies of patients with spontaneous recovery of visual fields indicate a contribution of neuronal plasticity, which is greater in partially affected areas bordering the field defect. On visual field testing, patients may show inconsistent and variable responses to stimuli in these areas. The moderate success of visual rehabilitation in these patients suggests that partially damaged neurons can adapt even after a consider-able time interval since initial injury (5). Intraventricular cysts include neurenteric cysts, which are rare, slow growing congenital lesions lined by secretory epithelium that bears a resemblance to gastrointestinal and respiratory epithelium. The radiologic appearance of neu-renteric cysts can closely resemble arachnoid cysts. Although epidermoid and dermoid cysts can show a similar appear-ance, these lesions usually are found in more lateral locations and show restricted diffusion on diffusion-weighted imaging. Definitive diagnosis of these intraven-tricular cystic lesions requires pathologic examination. Although rare in the supratentorial compartment, intraven-tricular cysts can exert a mass effect on adjacent neural structures (6). Affected patients often exhibit symptoms of raised intracranial pressure and cortical dysfunction attribut-able to adjacent parenchymal compression. Treatment is primarily surgical, although recurrence is reported even after total resection (7). In our patient, cyst expansion was associated with visual field deterioration. The surgical approach was planned using neuronavigation, and the cyst was entered on its postero-lateral aspect, thereby avoiding the optic radiations and visual cortex. REFERENCES 1. Kupersmith MJ, Vargas ME, Yashar A, Madrid M, Nelson K, Seton A, Berenstein A. Occipital arteriovenous malformations: visual disturbances and presentation. Neurology. 1996;46:953-957. 2. Kivelev J, Koskela E, Setala K, Niemela M, Hernesniemi J. Long-term visual outcome after microsurgical removal of occipital lobe cavernomas. J Neurosurg. 2012;117:295-301. 3. Yagi T, Ohashi Y, Nakano S, Ogawa M, Fukamachi A. A case of symptomatic arachnoid cyst of the occipital convexity in an adult. No Shinkei Geka. 2006;34:1125-1129. 4. Suzuki M, Tamaki T, Toda S, Tsuchiya M, Kogure K, Hosone M, Node Y, Teramoto A. Delayed recurrent arachnoid cyst of the occipital convexity in an elderly woman. Neurol Med Chir (Tokyo). 2009;49:134-137. 5. Kasten E, Poggel DA, Muller-Oehring E, Gothe J, Schulte T, Sabel BA. Restoration of vision II: residual functions and training-induced visual field enlargement in brain-damaged patients. Restor Neurol Neurosci. 1999;15:273-287. 6. Gauden AJ, Khurana VG, Tsui AE, Kaye AH. Intracranial neuroenteric cysts: a concise review including an illustrative patient. J Clin Neurosci. 2012;19:352-359. 7. Chaynes P, Bousquet P, Sol JC, Delisle MB, Richaud J, Lagarrigue J. Recurrent intracranial neurenteric cysts. Acta Neurochir (Wien). 1998;140:905-911. 256 Vedantam et al: J Neuro-Ophthalmol 2014; 34: 255-256 Photo Essay Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
