Visual Deterioration and Herniation of the Anterior Cerebral Artery: Unusual Presentation of an Empty Sella Syndrome Complicating Decompression of a Rathke Cleft Cyst

A 33-year-old woman presented with severe visual loss from fulminant idiopathic intracranial hypertension. Her lumbar puncture opening pressure was 97 cm H2O. Soon after lumboperitoneal shunt surgery, she had a generalized tonic-clonic seizure. Magnetic resonance imaging demonstrated frontal subarachnoid hemorrhage (SAH) and neuroimaging findings consistent with posterior reversible encephalopathy syndrome (PRES). We hypothesize that an abrupt drop in intracranial pressure after lumboperitoneal shunting led to maladjustment of cerebral vascular autoregulation, which caused SAH and PRES.

Photo Essay Section Editor: Timothy J. McCulley, MD Visual Deterioration and Herniation of the Anterior Cerebral Artery: Unusual Presentation of an Empty Sella Syndrome Complicating Decompression of a Rathke Cleft Cyst Laxminadh Sivaraju, MCh, Sumit Thakar, MCh, Alangar S. Hegde, MCh, PhD FIG. 1. Coronal T2 (A) and sagittal T1 fat-suppressed (B) magnetic resonance imaging shows recurrent sellar-suprasellar Rathke cleft cyst. Abstract: Clinical manifestations of empty sella syndrome include hypopituitarism cerebrospinal fluid rhinorrhea, headache, and visual abnormalities. A 21-year-old woman reported a 6-month history of worsening vision 3 years after decompression of a sellar-suprasellar Rathke cleft cyst. Her magnetic resonance imaging (MRI) showed a well-defined recurrent cyst in the sellar-suprasellar region causing chiasmatic compression. She underwent an endonasal, endoscopic decompression of the cyst, with subsequent improvement in her vision. A postoperative computed tomography confirmed good decompression of the cyst. Ten days after surgery, she reported sudden loss of vision in both eyes. MRI revealed an empty sella with herniation of both anterior cerebral arteries and optic chiasm into the sella. She underwent transnasal packing of the sellar floor with fat graft and bone plaques, and experienced gradual improvement in vision in her right eye. Journal of Neuro-Ophthalmology 2016;36:156-158 doi: 10.1097/WNO.0000000000000348 © 2016 by North American Neuro-Ophthalmology Society Departments of Neurosurgery (LS, ST, ASH), Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bangalore, India. The authors report no conflicts of interest. Address correspondence to Laxminadh Sivaraju, MCh, Department of Neurosurgery, Sri Sathya Sai Institute of Higher Medical Sciences, Whitefield, Bangalore 560066, India; E-mail: [e-mail] 156 T hree years after transcranial decompression of a sellarsuprasellar Rathke cleft cyst (RCC), a 21-year-old woman presented with headache and worsening vision for 6 months. Her medical history was unremarkable and general physical examination was normal. Visual acuity was 20/ 60, right eye, and 20/40, left eye. She had temporal visual fold loss in the right eye, whereas the field in the left eye was full. Brain magnetic resonance imaging (MRI) showed a well-defined, peripherally enhancing, recurrent cyst measuring 3.5 · 1.7 · 1.2 cm in the sellar-suprasellar region compressing the optic chiasm and infundibular stalk (Fig. 1). The pituitary gland was not seen separately from the lesion. She underwent an endoscopic endonasal decompression of the cyst, and a portion of the cyst wall that was adherent to the arachnoid was left behind. The arachnoid itself was thickened, and this was presumed to be related to previous surgery. Postoperatively, her vision improved to 20/40, right eye and 20/30, left eye. Brain computed tomography confirmed decompression of the cyst. Ten days after surgery, the patient reported sudden loss of vision and was found to have no light perception in each eye. Her fundus examination was unremarkable bilaterally. Brain MRI demonstrated an empty sella with downward herniation of both the anterior cerebral arteries (ACAs) and the optic chiasm into the sella (Fig. 2A, B). There was no concurrent hydrocephalus. Diffusion-weighted sequences revealed multiple left-sided infarcts in the distribution of Sivaraju et al: J Neuro-Ophthalmol 2016; 36: 156-158 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay FIG. 2. Contiguous coronal T2 images reveal herniation of (A) the anterior cerebral arteries (white arrows) and (B) optic chiasm (black arrows) into the sella. Diffusion-weighted imaging demonstrates ischemic infarctions in the distribution of the left anterior cerebral artery (C) and left lenticulostriate artery (D). E. Axial T2 scan shows left lenticulostriate stroke (arrow). the anterior cerebral and lenticulostriate arteries (Fig. 2C, D). These were attributed to vasospasm. In view of her emergent requirement for surgery, a cerebral angiogram was not performed. During exploratory surgery, arachnoid was seen bulging into the sellar floor obscuring direct visualization of the optic chiasm and ACAs. Fat graft was packed into the sella to elevate the arachnoid and bone plaques were used to reinforce reconstruction of the sellar floor. At discharge, the patient could see hand movements with her right eye and perceive light with her left eye. A follow-up MRI showed elevation of the ACAs and the chiasm by the fat graft in the sellar floor (Fig. 3). Eight months later, visual acuity was 20/60, right eye, and light perception, left eye. RCC is an uncommon, benign cyst of the sellarsuprasellar region that is lined with tall, well-differentiated, ciliated columnar epithelium with goblet or ciliated cells (1,2). The primary treatment in symptomatic cases is decompression of the cyst and excision of its wall, with the Sivaraju et al: J Neuro-Ophthalmol 2016; 36: 156-158 endoscopic transphenoidal route being the preferred surgical approach (3,4). Common complications after RCC surgery include recurrence, cerebrospinal fluid rhinorrhea, and endocrine dysfunction (1). Visual deterioration is uncommon but may be seen in conjunction with empty sella syndrome (ESS) (5-8). This unusual syndrome is characterized by herniation of the subarachnoid space into the sella. It can occur in the presence of a normal pituitary gland (primary ESS) or after damage to the pituitary gland (secondary ESS). Conditions such as pseudotumor cerebri, steroid therapy, obesity, multiparity, autoimmune disease, and deficiency of the diaphragma sellae predispose to the occurrence of primary ESS. Secondary ESS typically occurs in the setting of radiation therapy, pituitary apoplexy, and after excision of a sellar tumor (9,10). Visual abnormalities in this syndrome are attributed to traction and vascular injury to the herniated anterior visual pathway structures (5,6,11) and, after RCC surgery, to tethering of the visual 157 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay FIG. 3. Coronal T2 scans after reconstruction of the sellar floor. A. There is elevation of the anterior cerebral arteries (arrow). B. The optic chiasm (arrow) is in a normal position. apparatus to the cyst wall after decompression of the cyst contents (6). In our patient, we postulate that vascular injury rather than a traction was primarily responsible for visual loss. Herniation of the ACAs into the sella led to vasospasm resulting in ischemia to both the anterior visual pathways and the left cerebral hemisphere. Various surgical methods advocated to counter the downward traction of the visual apparatus include packing of the sellar floor, elevation of the depressed diaphragma sellae, detethering of the optic chiasm and chiasmapexy with silicone materials (5,6,11-13). Results of such interventions, however, have been variable. STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: L. Sivaraju, S. Thakar; b. Acquisition of data: L. Sivaraju, S. Thakar; c. Analysis and interpretation of data: L. Sivaraju, S. Thakar. Category 2: a. Drafting the article: L. Sivaraju, S. Thakar, A. S. Hegde; b. 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