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Woman presents with loss of peripheral vision
Examination showed bilateral severe optic disc swelling and disc hemorrhages.
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A 41-year-old obese woman presented to the New England Eye Center with complaints of severe headaches, nausea and vomiting, and progressive loss of peripheral vision in both eyes over the previous 2 weeks. She denied having similar symptoms in the past and otherwise felt well.
Her medical history was significant for hypertension during her last pregnancy, but she was not on any medications. She had no ocular history and only endorsed occasional alcohol use. She denied smoking or illicit drug use.
Examination
On examination, the patient’s best corrected visual acuity was 20/800 in the right eye and 20/40 in the left eye. Her pupillary response was normal in both eyes, without an afferent pupillary defect. Extraocular motility and IOP were within normal limits bilaterally. Confrontation visual field testing showed severe constriction in each eye.
Anterior segment exam of both eyes was unremarkable. Dilated fundus exam revealed severe optic disc swelling bilaterally with disc hemorrhages and peripapillary hard exudates worse in the right eye (Figures 1a and 1b). Also visible were dilated and tortuous retinal vessels as well as an area of subretinal fluid tracking from the optic nerve into the fovea in the right eye, as seen on optical coherence tomography (Figures 1c and 1d). Humphrey visual field testing showed constricted visual fields bilaterally (Figures 1e and 1f).
Figure 1. (A, B) Color fundus photographs showed severe optic disc swelling with disc hemorrhages, blunting of the cup and blurring of disc vessels on both sides. (C, D) Spectral domain OCT of the macula showed severe optic disc swelling in both eyes and subfoveal subretinal fluid tracking from the optic nerve in the right eye. (E, F) 30-2 Humphrey visual field testing revealed severe constriction in both eyes. (G) MRI FLAIR images revealed periventricular hyperintensities bilaterally.
Images: Ho J, Hedges TR
What is your diagnosis?
Bilateral disc swelling
The differential diagnosis of bilateral disc swelling is large and includes malignant hypertension, idiopathic intracranial hypertension, intracranial mass, bilateral optic neuropathy and ischemic optic neuropathy.
Malignant hypertension is due to failure of normal autoregulation with an abrupt rise in systemic vascular resistance. It usually occurs with systolic blood pressure higher than 180 mm Hg and diastolic blood pressure higher than 120 mm Hg. Elevated cerebrospinal fluid (CSF) opening pressure may also occur in about two-thirds of patients with hypertensive encephalopathy, thus a reason for transient papilledema in these patients. MRI testing may show bilateral white matter changes best seen on T2-weighted images, with improvement upon normalization of blood pressure. The most common cause of visual impairment in the setting of malignant hypertension is optic nerve infarction with rapid blood pressure reduction, so care must be taken not to reduce blood pressure too quickly. Additionally, after stabilization of blood pressure, patients will need to be screened for possible stroke, as the relative risk of stroke is 18 times higher in patients with a history of malignant hypertension.
Idiopathic intracranial hypertension (IIH) is a disorder associated with increased intracranial pressure in the absence of other intracranial pathology, including tumors. Patients may present with headache, nausea and vomiting, and low-pitched pulsatile tinnitus. The most common visual disturbance is visual field loss, specifically an enlarged blind spot, overall constriction or an inferonasal field deficit. Fundus exam reveals papilledema, and radiologic imaging shows no other cause for elevated intracranial pressure. A lumbar puncture will confirm an elevated opening pressure of more than 25 cm H2O with a normal CSF composition.
An intracranial mass may also cause papilledema secondary to reduced CSF outflow. Patients may present with a variety of visual complaints, from transient visual obscuration to visual field loss. Imaging is thus an integral part in evaluating patients with papilledema.
Acute-onset optic neuropathy may be the result of inflammatory, infiltrative or ischemic etiologies. Patients can present with visual field defects, abnormal pupillary response and dyschromatopsia. In a young patient, eye pain on movement in combination with other neurological symptoms may be suggestive of optic neuritis secondary to multiple sclerosis. While it is typically unilateral, bilateral disease has been described. More commonly, bilateral optic neuritis in the form of papillitis typically affects children after viral infections; however, in rare cases, it may occur in adults. Treatment with corticosteroids in these cases may be beneficial.
Infiltrative optic neuropathy may occur with systemic malignancies, including multiple myeloma, leukemia, lymphoma and carcinoma. Upon workup, MRI of the brain and orbits may reveal enhancement of the optic nerve and lumbar puncture may reveal abnormal cell types. Optic nerve sheath biopsy may need to be considered for definitive diagnosis in the absence of obvious systemic malignancy.
Diagnosis and management
After initial examination of the patient, further testing was performed, including a blood pressure measurement of 250/140. MRI and MRA of the brain revealed periventricular hyperintensities but no evidence of intracranial mass or venous sinus thrombosis (Figure 1g). A lumbar puncture was also performed, which showed an opening pressure of 50 cm H2O. Aside from an elevated protein, the patient’s CSF composition was normal. During her hospital stay, secondary causes of hypertension, including pheochromocytoma and renal artery stenosis, were ruled out.
The patient was started on oral acetazolamide 1 g twice a day and discharged home. On follow-up, her blood pressure improved and repeat lumbar puncture showed a normal opening pressure and CSF composition. Her vision was 20/40 in each eye with improvement in papilledema (Figures 2a and 2b) and decreased subretinal fluid in the right eye as seen on OCT (Figures 2c and 2d). Her visual fields, however, did not improve. Oral acetazolamide was eventually stopped due to improvement in her symptoms and exam as well as findings of renal insufficiency on subsequent blood tests. Repeat MRI a few months later showed improvement in periventricular white matter changes (Figure 2e), but subsequent lumbar puncture was elevated to 36 cm H2O. Given the persistence of elevated opening pressure in the context of now normal blood pressure, this patient was diagnosed with IIH exacerbated by acute hypertensive emergency.
Figure 2. (A, B) Color fundus photographs showed improvement in the degree of papilledema, with decreased disc margin and retinal vessel blurring and reduced number of disc hemorrhages, exudates and vascular tortuosity in both eyes. (C, D) Macular OCT also showed improvement in optic disc swelling as well as resolution of subretinal fluid in the right eye. (not shown) 30-2 Humphrey visual field testing did not show improvement in visual field constriction. (E) Repeat brain MRI showed improvement in the periventricular white matter hyperintensities as compared with baseline.
Discussion
Idiopathic intracranial hypertension is a condition that occurs most commonly in obese women. It can occur in any age group, but the average age of onset is around 30 years. Patients typically present with headaches, and transient visual obscurations may occur in about two-thirds of patients with papilledema. The diagnostic criteria of IIH are via the modified Dandy criteria, which include symptoms of increased intracranial pressure, including headache, nausea and vomiting; transient obscurations; an absence of localizing neurological signs, except for abducens nerve palsy; an awake and alert patient; normal radiological imaging without thrombosis; lumbar puncture with opening pressure greater than 25 cm H2O and normal CSF composition; and no other possible explanation for the increased intracranial pressure.
This is a case of how a hypertensive emergency may exacerbate underlying IIH. Multiple studies have found that hypertension is more common in patients with IIH compared with age-matched controls. Furthermore, it also appears to be associated with a worse visual prognosis. Corbett et al found that in 57 patients with IIH, legal blindness or severe visual impairment occurred in 24.5% of all patients compared with 61.5% of patients with a history of hypertension. It is not clear why hypertension exacerbates IIH, but it has been hypothesized that the optic discs in patients with severe hypertensive retinopathy may be more vulnerable to insult.
Current treatment approaches for IIH are both medical and surgical. All patients should be counseled regarding weight loss because data show faster recovery in patients who lost at least 2.5 kg.
The mainstay of medical therapy is carbonic anhydrase inhibitors, such as acetazolamide, which reduce the rate of CSF production. These medications, however, should be used with caution in patients with a sulfa allergy and those with underlying renal insufficiency. Loop diuretics, such as furosemide, may be used as an adjunct to acetazolamide. Corticosteroids are mainly indicated for use in the acute phase before surgery. Long-term use may lead to weight gain, thus worsening IIH. Serial lumbar punctures are sometimes used to control acute symptoms and disease, but the effects are transient and frequently uncomfortable for patients.
Surgery is indicated after failure of medical therapy. Optic nerve fenestration improves papilledema but only modestly decreases intracranial pressure. Thus, it is indicated for patients who have significant papilledema but only limited symptoms of increased intracranial pressure. Finally, ventriculoperitoneal or lumboperitoneal shunts have also been shown to relieve symptoms and reduce papilledema in IIH. However, the benefit of the procedure must be weighed against the risk for infections and recurrent shunt failures.