Case Report

‘Benign’ Condition Causes Headaches for Patient

Acute headaches, field defects and papilledema indicated pseudotumor cerebri. Here’s how a multidisciplinary approach helped this patient.

She also complained of an apparent loss of peripheral vision in her left eye and said she saw spots. She also reported periods of tunnel vision.

Her family physician attributed the headaches and visual disturbances to ocular migraines, for which the doctor prescribed furosemide. The patient had a history of gout and hypertension. She was taking allopurinol and Vasotec (enalapril) at the time of this visit, and she reported no known medical allergies. She wore corrective lenses for full-time use.

Diagnostic Data
The patient’s entering visual acuities were 20/25+2 O.D. with -1.75D sphere and 20/25 O.S. with -1.25D sphere. Confrontation fields were apparently normal in both eyes. An external examination proved normal, and extraocular muscle motions were full and smooth in quality with no apparent diplopia. Pupils were round, reactive to light and devoid of an afferent defect. There was no change in the refraction. Anterior segment examination was normal. IOPs were 15mm Hg O.D., 16mm Hg O.S. 

An automated 24-2 visual field evaluation revealed enlarged blind spots bilaterally with an infero-nasal arcuate defect O.S. Dilated funduscopy revealed a dramatic elevation of both optic nerve heads and hazing of the nerve rims. This was accompanied by surrounding venous engorgement and peripapillary flame hemorrhages. 

Diagnosis
The patient’s vague visual complaints, intense acute-onset headaches, dramatic visual field defects and accompanying papilledema all suggested pseudotumor cerebri.

Treatment and Follow-up
We immediately referred this patient to a neuro-ophthalmologist for consultation. Imaging results (CT and MRI) returned normal, confirming the diagnosis.

Her opening intracranial pressures (as performed by lumbar puncture) were 450mm H2O. The cerebrospinal fluid was clear, indicating the absence of protein, inflammatory cells or glucose. This helped rule out an infectious or inflammatory etiology. The neuro-ophthalmologist prescribed oral Diamox (acetazolamide) 250mg qid to decrease cerebrospinal fluid production, which in turn would reduce intracranial pressure. We asked the patient to return in 2 weeks.

The papilledema and subjective complaints abated within 2 months. Another lumbar puncture revealed a significant decrease in intracranial pressures. The neuro-ophthalmologist returned the patient to our practice for ongoing follow-up care every 6 months. This included monitoring the optic nerve health and periodic visual field evaluations.

Discussion
Pseudotumor cerebri (PTC), also known as idiopathic intracranial hypertension, is a disorder highlighted by an elevated intracranial pressure without an accompanying space-occupying lesion or evidence of ventriculomegaly.^1,2

Headaches, papilledema and visual field anomalies without any evidence of systemic disease characterize this disorder. PTC has not been associated with a wide variety of systemic and neurological disorders that typify hydrocephalus and more malignant forms of intracranial hypertension. However, because it can mimic a variety of other diseases (such as brain tumors, meningitis, systemic lupus erythematosis, etc.), PTC is generally a diagnosis of exclusion.¹ 

Not the benign entity that it was once thought to be, PTC can cause vision loss and visual field defects.¹ So, prompt diagnosis and proactive therapy are vital in newfound cases. 

PTC is likely to affect obese women between the ages of 20 and 44.³ Headaches are reported in 94% of cases and present as painful and pulsatile in nature. This can lead many practitioners to mistake these for migraine or vascular headaches.3 Preverbal children generally present as irritable and infants are typically lethargic.⁴ Some patients present with diplopia, since the condition can cause a cranial nerve VI palsy.^1,3

Pseudotumor cerebri may be self-limiting. Treatment is indicated when the patient’s headaches are considered debilitating or an obvious visual defect occurs. Vision loss occurs in some cases due to progressive optic atrophy. Visual field defects can be in the form of arcuate or nasal defects, centrocecal scotomas and concentric contractions and hemianopic defects. 

The cause of pseudotumor cerebri is largely unknown. It has been linked to the use of steroids, tetracycline, NegGram (nalidixic acid), amiodarone, cyclosporine, vitamin A and oral contraceptives.^1,2,5-9 It also has been associated with nonspecific viral infections and chronic obstructive pulmonary disease (COPD). In addition, endocrine conditions such as hypoparathyroidism and Addison’s disease have been reportedly linked to PTC.¹

In children, cases have been associated with otitis media, mastoiditis and lateral sinus thrombosis.⁴ One isolated case has been linked to a trabeculectomy and another to cessation of Diamox in a glaucoma patient.¹⁰

PTC corresponds to a significant elevation of intracranial pressure (ICP) to more than 200mm H2O. In pseudotumor cerebri the cerebrospinal fluid is clear in composition, suggesting that no infectious or malignant etiology is to blame. 

The rise in intracranial pressure occurs due to the inability of the arachnoid villa of the brain to absorb the fluid.¹ Unlike hydrocephalus, PTC does not induce ventricular dilation and is not potentially life threatening. 

Papilledema (swelling of the optic nerve disc with accompanying vessel engorgement) is the most common clinical sign of pseudotumor cerebri. Possible causes of papilledema include: 

• Compressive. Compressive (intracranial) brain lesions typically include lymphomas, medulloblasto- mas, gliomas, astrocytomas and meningiomas. These tumors can affect the brain’s various lobes, its ventricles and the cerebellum. PTC is classified within this category. 
• Ischemic. Disorders such as hypertension, diabetes, anterior ischemic optic neuropathy and car- diopulmonary insufficiencies can cause unilateral papilledema.
• Inflammatory. Such inflammatory problems as multiple sclerosis, optic neuritis, neuroretinitis and vascular retinitis can cause unilateral disc edema. 
• Infectious. In rare instances, infectious diseases such as malaria, meningitis, syphilis, mononucleosis, sandfly fever and cryptococcosis have been implicated in causing bilateral disc edema.¹
• Trauma. 

A comprehensive case history, laboratory tests and neuroimaging are necessary to differentiate the two conditions. Although both are similar in appearance, rises in intracranial pressure, accompanying constitutional signs (i.e., headaches and nausea) and disc edema do not manifest in pseudopapilledema. Nor do they herald serious systemic disease or space-occupying lesions of the brain.

More common cases of pseudopapilledema include buried optic nerve drusen, ophthalmoscopic distortion due to high hyperopia or astigmatism, Bergmeister’s papilla, medullated nerve fibers, tilted disc and tumors of the optic disc (i.e., gliomas, meningiomas, neurofibromas, etc.).^1,2

In PTC, associated ocular problems such as choroidal striae, exudates, subretinal hemorrhages and pigmentary disturbances have been reported.¹¹ These, however, have not been implicated in significant vision loss. 

Chronic optic disc edema generally causes vision loss and/or visual field defects. Sudden vision loss (no light perception) is extremely rare. More serious vision loss has also been attributed to choroidal neovascularization, preretinal hemorrhages, central retinal occlusion and macular edema.¹²

The medical and surgical treatment of pseudotumor cerebri is still evolving. The severity of vision loss or vision defects determines treatment. Management of mild cases initially involves a weight reduction program and/or purging the patient’s system of any potentially causative medications.1 Moderate cases may require pharmacological intervention such as carbonic anhydrase inhibitors (Diamox or furosemide). Some clinicians have used more controversial approaches, including oral steroids, glycerol or digoxin, with some success. Doctors have used intravenous methylprednisone in severe cases.¹³

Surgical treatments for PTC can include optic nerve sheath decompression (ONSD) and lumbo-peritoneal shunting.^14,15 ONSD is re- served for cases of vision loss secondary to papilledema. This treatment seeks to relieve elevated intracranial pressure by surgically draining fluid through incisions on the meningeal sheath of the optic nerve head. 

Papilledema and headaches have been noted to resolve within 48 hours of the procedure. Complications, however can include pupillary dysfunction, choroidal scarring and peripapillary hemorrhaging.^1,2,14,15 Also, the Optic Nerve Sheath Decompression Trial found mixed results, and patients with advanced disease had a poor prognosis of recovery.¹⁴

This patient presented to our office with classic signs and symptoms of pseudotumor cerebri. A multidisciplinary approach which included neuroimaging, laboratory resources and medical comanagement helped diagnose and treat this patient’s problem and has been largely successful in similar cases.
 

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11. Castellaria AA, Sugino IK, Nasir M. et al. Clinicopathological correlation of an excised choroidal neovascular membrane in pseudotumor cerebri. Br J Ophthalmol 1997;81: 994-1000.
12. Carter SR, Seiff SR. Macular changes in pseudotumor cerebri before and after optic nerve sheath fenestration. Ophthalmology 1995;102(6):937-41.
13. Liu GT, Glaser JS, Schatz NJ. High-dose methylprednisolone and acetazolamide for vision loss in pseudotumor cerebri. Am J Ophthalmol 1994;118:88-96.
14. Mauriello JA, Shaderowsky P, Gizzi M, et al. Management of visual loss after optic nerve sheath decompression in patients with pseudotumor cerebri. Ophthalmology 1995; 102(3):441-5.
15. Liu GT, Volpe NJ, Schatz NJ, et al. Severe sudden visual loss caused by pseudotumor cerebri and lumboperitoneal shunt failure. Am J Ophthalmol 1996;122 (1):129-31.
16. Friedberg MA, Rapuano CJ. Wills Eye Hospital Manual of Office and Emergency Room Diagnosis and Treatment. Philadelphia: Lippincott, 1990:272-4.

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© Review of Optometry OnLine
September 15, 2000