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Man presents with decreased vision after extubation
Posterior segment exam showed blurred disc margins, disc hemorrhages and obscuration of the vessels.
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A 50-year-old African-American man with a medical history of hypertension, hyperlipidemia and renal cell carcinoma was transferred to Lahey Medical Center for decreased vision in his right eye during a prolonged hospital course. He recently had undergone a partial nephrectomy that was complicated by internal bleeding, wound dehiscence, bowel perforation and sepsis. He required two additional surgeries, and he remained intubated for 5 days. Several days after extubation, the patient noticed decreased vision in his right eye while undergoing hemodialysis. He also reported experiencing headaches and hearing intracranial noises. Additionally, he developed significant pain at the site of his right internal jugular hemodialysis catheter. He denied any ocular pain at the time.
Examination
Uncorrected visual acuity was count fingers at 2 feet in the right eye and 20/25 in the left eye. The right pupil was minimally reactive to light while the left pupil constricted briskly to light. There was a significant 3+ afferent pupillary defect of the right eye. IOP was within normal limits in both eyes. Confrontational visual fields revealed superior constriction in the right eye but no defects in the left eye. Extraocular movements were full in both eyes. The patient was able to identify none of the 10 Ishihara color plates in the right eye and 9 of 10 plates in the left eye.
Anterior segment exam was unremarkable in both eyes. Posterior segment examination showed marked edema of bilateral optic nerves with blurring of the disc margins, disc hemorrhages and obscuration of the vessels in both eyes (Figure 1). The macula and periphery were unremarkable in both eyes. OCT of the optic discs showed significant swelling of the bilateral nerves. Humphrey visual field 30-2 testing showed global depression in the right eye with minimal sparing inferiorly and 360° constriction in the left eye with central sparing (Figure 2).
During his admission, a CT scan of the brain was unremarkable with no visible mass. An emergent lumbar puncture revealed a significantly elevated opening pressure at 41 cm of H2O. He noted an immediate improvement in his headache as well as his vision after the lumbar puncture. The cerebrospinal fluid was sent for culture and cytology, but the results were unremarkable. MRI and MRV of the head and neck showed patency of the major dural venous sinuses. The neuroradiologist did not see any other abnormalities.
Images: Witkin D, Athappilly G
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Decreased vision
Papilledema can be caused by a mass lesion, hydrocephalus, cerebral sinus thrombosis, subdural or epidural hematomas, arteriovenous malformation, subarachnoid hemorrhage or an infectious process. Papilledema can also be idiopathic, but this is a diagnosis of exclusion.
The exam and testing were not consistent with hypertensive optic neuropathy, ischemic optic neuropathy or pseudopapilledema. The MRI excluded mass lesion, hydrocephalus, intracranial hematoma and subarachnoid hemorrhage. Cytology from the lumbar puncture showed no signs of an infectious process. Idiopathic intracranial hypertension seemed less likely given that the patient was an athletic 50-year-old man with no risk factors. The patient had been experiencing pain at the site of his right internal jugular hemodialysis catheter, so there was a question of whether there may be a thrombus in this area, but no thrombus was identified. The initial working diagnosis at this point was intracranial hypertension secondary to a combination of anemia, hypertension, hyponatremia and kidney disease affecting the cerebrospinal fluid dynamics.
Diagnosis
In order to preserve the remaining vision, the decision was made to perform optic nerve sheath fenestration of the right eye. After the procedure, visual acuity in the right eye improved to 20/400 and visual acuity in the left eye remained stable at 20/20. The patient had a repeat lumbar puncture several days after the optic nerve sheath fenestration. However, this continued to show an elevated opening pressure at 38 cm of H2O. Not satisfied with the initial working diagnosis, the neurologists, interventional neuroradiologists and ICU teams continued to search for a cause of the intracranial hypertension.
The patient was noted to have a pulmonary embolism on the day after the optic nerve sheath fenestration. The patient had an ultrasound of his upper extremities that revealed a deep venous thrombosis in the right brachial vein and superficial thrombi in both upper extremities. Now it was apparent that the patient was in a hypercoagulable state, so the interventional neuroradiologist reviewed the previous MRI and MRV images again for a cerebral sinus thrombosis that could have caused the papilledema. This time, an area of focal narrowing was seen at the right transverse/sigmoid junction suspicious for venous outflow obstruction. Additionally, the right transverse sinus was found to be dominant with a hypoplastic left transverse sinus (Figure 3).
Discussion
This patient was in a hypercoagulable state and developed a deep vein thrombosis and pulmonary embolism. He had multiple risk factors for hypercoagulability, including prolonged immobilization, recent malignancy, multiple central lines and anemia. In this case, a thrombus was never clearly identified within the dural sinuses, but there was an area of focal stenosis at the right transverse/sigmoid sinus junction that may have been caused by the thrombotic process. He also had a mildly hypoplastic left transverse sinus with dominant right transverse sinus, a common variant found in up to 21% of males. Due to this configuration, an isolated narrowing of the right transverse sinus could cause intracranial hypertension due to the already reduced flow of the hypoplastic left transverse sinus. Symptoms of intracranial hypertension can occur when the pressure gradient across the venous system is greater than 4 mm Hg due to obstruction.
The patient underwent a cerebral venogram, and a stent was placed in the area of focal narrowing in the right transverse/sigmoid sinus junction. During the procedure, the pressure gradient along the area of obstruction was noted to be elevated at 23 mm Hg. After stent placement, this decreased to 0 mm Hg. He tolerated the procedure well with resolution of headaches and intracranial noises. His vision remained stable at 20/400 in the right eye and 20/20 in the left eye. He was bridged to Coumadin (warfarin) before discharge, with a therapeutic INR goal of 2.5 to 3.5 due to the intracranial stent. While the stent was therapeutic in this case, it did come with significant risks including bleeding, infection and thrombosis. The patient will now require lifelong anticoagulation.
Conclusion
Given that the area of focal stenosis in the right sinus was not identified early, this patient underwent optic nerve sheath fenestration as an urgent attempt to preserve visual function. Improved detection of venous sinus abnormalities in the future may help avoid optic nerve sheath fenestration. Ultimately, this patient retained 20/20 central visual acuity in the left eye and has not lost significant overall function in performing his activities of daily living.
- References:
- Durst CR, et al. J Neurointerv Surg. 2016;doi:10.1136/neurintsurg-2015-012147.
- Goyal G, et al. Neurointervention. 2016;doi:10.5469/neuroint.2016.11.2.92.
- Honarmand AR, et al. Interv Neuroradiol. 2016;doi:10.1177/1591019915622160.
- MacIntosh PW, et al. Surv Ophthalmol. 2014;doi:10.1016/j.survophthal.2014.01.010.
- Woodall MN, e al. BMJ Case Rep. 2013;doi:10.1136/bcr-2013-010513.
- For more information:
- Deborah Witkin, MD, and Geetha Athappilly, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.
- Edited by Jessica Moon, MD, and Emily C. Wright, MD. They can be reached at the New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.