Visual Field Defects in Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

VISUAL FIELD DEFECTS IN IDIOPATHIC INTRACRANIAL HYPERTENSION (PSEUDOTUMOR CEREBRI) MICHAEL W A L L , M.D., WILLIAM M. HART, JR., AND RONALD M. BÜRDE, M.D. St. Louis, Missouri

M.D.,

Idiopathic intracranial hypertension (pseudotumor cerebri) produces loss of visual field and visual acuity. We conducted a retrospective study of 12 patients (all female, ranging in age from 6 to 44 years) using computerized visual field analysis. In seven of the 12 patients, the visual field loss appeared to be permanent, and follow-up was too short for the final outcome to be determined in two others. The visual field defects were those known to be associated with optic disk lesions. The most common were blind spot enlargement (all 12 cases), isopter constriction (nine cases), and loss on the nasal side of the visual field (seven cases), especially in the inferonasal quadrant. Four patients had diminished visual acuities. The reversibility of the visual field defects was correlated with the presence (nonreversible) or absence (reversible) of ophthalmoscopic signs of chronic papiUedema. Because visual loss is reversible if treatment is begun before the onset of the optic disk changes associated with chronic papiUedema, patients with idiopathic intracranial hyper­ tension should be monitored carefuUy with frequent perimetric and visual acuity testing. Idiopathic intracranial hypertension, 1 also known as benign intracranial hyper­ tension,2 pseudotumor cerebri, 3 and otitic hydrocephalus,4 is a syndrome char­ acterized by increased intracranial pres­ sure with its attendant signs and symp­ toms in an alert patient with a normal mental status, but without localized neu­ rologic findings. There is no evidence of

Accepted for publication Aug. 9, 1983. From the Departments of Neurology (Drs. Wall and Bürde); Neurological Surgery (Dr. Bürde); and Ophthalmology (Drs. Hart and Bürde), Washington University School of Medicine, St. Louis, Missouri. This study was supported in part by grant EY02044 from the National Eye Institute (Dr. Hart) and by a grant from Research to Prevent Blindness, Inc., New York, New York. Reprint requests to Ronald M. Bürde, M.D., Department of Ophthalmology, Box 8096, 660 S. Euclid Ave., St. Louis, MO 63110. 654

deformity or obstruction of the ventricu­ lar system, and neurodiagnostic findings are otherwise normal except for increased cerebrospinal fluid pressure. The signs and symptoms of increased intracranial pressure include headache, nausea and vomiting, papiUedema, diplopia, sixth cranial nerve pareses, transient visual obscurations, and loss of visual function (including visual acuity and visual field).2·6"7 The visual field defects in idiopathic intracranial hypertension are the same as those reported to occur in papiUedema from other causes and are, therefore, nonspecific.5,8,9 These defects include enlargement of the physiologic blind spot,7,10 constriction of isopters,2,5,11 loss of inferonasal portions of the visual field,11,12 central, paracentral, and cecocentral scotomas,2 altitudinal patterns of loss,13 and

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arcuate scotomas. 14 The visual loss may be progressive and severe, leading to total blindness. Because loss of vision is the only per­ manent form of morbidity associated with pseudotumor cerebri, we decided to study the development of visual field defects in a population of patients with this disorder, and to determine what ef­ fects various forms of therapy may have had on their course. SUBJECTS AND METHODS

From 1974 through 1980 48 cases of idiopathic intracranial hypertension were referred here for evaluation. These pa­ tients fit the criteria for the diagnosis of idiopathic intracranial hypertension. All 48 patients had blind spot enlargement and 15 had additional visual field defects. All visual field examinations had been done with a Goldmann projection perim­ eter, and a minimum of two isopters (one peripheral and one central) had been recorded for each eye. Additionally, the physiologic blind spot had been mapped with the central target. We excluded three of the patients with manifest visual field defects: one with concurrent diabet­ ic retinopathy, one with unreproducible visual field findings, and one with a focal motor seizure disorder with transient third cranial nerve pareses. We conduct­ ed a retrospective study of the remaining 12 patients in regard to visual symptoms, visual acuity, and the morphologic nature and course of the associated visual field defects. The visual field findings were record­ ed, stored, and analyzed in a mini­ computer system. 1516 We used machine algorithms for the detection and charac­ terization of visual field defects. 17 The abnormalities detected included general­ ized isopter constriction (age corrected), blind spot enlargement, defects obeying the horizontal meridian (nasal steps and altitudinal defects), central, paracentral,

655

cecocentral, and arcuate scotomas, and "splitting" or loss of fixation by peripheral isopters. The criteria defining these de­ fects have been described. 1516 The patients ranged in age from 6 to 44 years and all were female (Table 1). With the exception of Patient 6, who was 6 years old, all were obese. In only one case (Patient 8, who had lateral sinus thrombosis) were we able to determine the cause of the condition. In Case 2 there was a small parasagittal arteriovenous fistula between the middle meningeal artery and the sagittal sinus, but the late phases of the cerebral angiogram demonstrated patency of the durai sinus­ es. Two patients (Cases 2 and 12) had systemic hypertension. One patient had empty sella syndrome. Ten of the 12 patients complained of visual distur­ bances. Six experienced transient visual obscurations, and four noted blurring. Only one patient complained of diplopiä. Four patients had diminished visual acui­ ties. All of the patients had papilledema, but there was marked variation in the extent of elevation of the optic disks. Eight of the patients had associated abnormalities of the optic disks (including hemor­ rhages, exudates, gliosis, or pallor). One of these patients had apparent optociliary shunt vessels on the optic disks. All had enlarged blind spots, and nine of the 12 had isopter constriction (Table 2). Seven of the 12 had defects to the nasal side of the visual field, including simple reduc­ tion in isopter area as well as inferonasal nerve fiber bundle (sector defects). There were two with temporal sector defects, and one with an inferior altitudinal hemianopic pattern of loss. Six had cen­ tral visual field defects (within 30 degrees of fixation), other than simple isopter constriction or blind spot enlargement. Three of these had paracentral scotomas, three had arcuate scotomas, and two had cecocentral scotomas. Patient 2 had a

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TABLE 1 CLINICAL FINDINGS AND VISUAL FIELD DEFECTS IN 12 PATIENTS WITH IDIOPATHIC INTRACRANLAL HYPERTENSION

Patient No.,'Sex, Length of Age (yrs) Follow-up

Visual Symptoms

Visual Acuity R.E. L.E.

Ocular Findings

Cerebrospinal Fluid Pressure (mm H 2 0)

1, F, 22

2 wks

Diplopia

20/30 20/40

Papilledema and superficial hemorrhages and exudates in both eyes

300

2, F, 44

5 yrs

Blurring

20/20 20/400 Papilledema and hypertensive retinopathy in both . eyes; hemorrhagic macular scar in L.E.

285

3, F, 40

3 yrs

Transient obscura20/20 20/20 tions and blurring

Papilledema in both eyes

420

4, F, 22

1 mo

None

20/20 20/20

Papilledema in both eyes

475

5, F, 28

6 mos

Transient obscura20/20 20/20 tions and blurring

6, F, 6

5 yrs

None

20/40 20/50

Papilledema in both eyes

455

7, F, 29

7 mos

"Decreasing" vision

20/50 20/80

Papilledema in both eyes; no exudates, hemorrhages, or gliosis

260

F, 31

11 yrs

Transient obscurations

20/20 20/20

Papilledema and gliosis at optic disk margins

400

3 yrs

Transient obscura20/20 20/25 tions and blurring in both eyes

Papilledema and gliosis of optic disks in both eyes

530

Transient obscurations

Papilledema and gliosis of optic disks in both eyes

9, F, 27

10, F, 44 2.5 yrs

20/20 20/20

Papilledema with gliosis in L.E.

*A1I test results were normal except for the following: For Patient 2, the skull X-ray films showed an enlarged sella and the pneumoencephalogram showed an empty sella; the angiogram showed a small durai arteriovenous malformation. For Patient 4, computed tomography showed small ventricles. For Patient 7, computed tomography showed small ventricles. For Patient 8, the cerebral angiogram showed left lateral sinus thrombosis.

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TABLE 1 (Continued) Neurodiagnostic Tests*

Visual Field Findings

Comments

Skull X-ray films Computed tomography Isotope brain scan

Isopter constriction and enlarged blind spot in both eyes

Partial resolution of defects but follow-up was too short to determine final outcome

Skull X-ray films Pneumoencephalogram Angiogram Computed tomography Isotope brain scan

Enlarged blind spots and inferonasal nerve fiber bundle defects in both eyes; cecocentral scotoma

Empty sella syndrome; protracted course in L.E.; no recovery from visual field defects

Electroencephalogram Skull X-ray films Isotope brain scan Computed tomography

Enlarged blind spots and central isopter constriction in both eyes

Initial recovery after lumbar punctures; relapse 3 yrs later; recovery after lumbar puncture

Computed tomography Skull X-ray films Isotope brain scan Arteriogram

Isopter constriction in R.E.; enlarged blind spot in both eyes

Recovery after acetazolamide treat­ ment; no follow-up of visual field defects

Skull X-ray films Computed tomography Isotope brain scan Carotid angiogram Vertebral angiogram

Enlarged blind spot and generalized isopter constriction in both eyes; inferotemporal and inferonasal sector defects in L.E.

Papilledema resolved but infero­ temporal nerve fiber bundle de­ fect in L.E. persisted

Skull X-ray films Computed tomography Isotope brain scan Cerebral angiogram Pneumoencephalography

Markedly enlarged blind spots in both eyes, in arcuate pattern; cecocen­ tral and paracentral scotomas in R.E.; inferonasal nerve fiber bundle defect in L.E.

Visual field defects resolved ex­ cept for enlarged blind spots in both eyes; visual acuity recovered to 20/20 in both eyes

Skull X-ray films Isotope brain scan Cerebral angiogram Computed tomography

Markedly enlarged blind spots and isopter constriction in arcuate pattern in both eyes

Papilledema and visual field de­ fects resolved completely; visual acuity remained 20/40 in both eyes

Skull X-ray films Cerebral angiogram

Enlarged blind spots in both eyes; inferonasal sector defect in L.E.

Visual field defects persisted for 7 mos after relief of intracranial hypertension

Computed tomography Isotope brain scan

Enlarged blind spots and isopter con­ striction in both eyes; infero­ temporal sector defect in L.E.

Papilledema resolved; blurring, gliosis at optic disk margin, and visual field defects persisted

Skull X-ray films Computed tomography Cerebral angiogram Pneumoencephalogram

Enlarged blind spots, isopter con­ striction, inferior arcuate de­ fects, and altitudinal hemianopsia in both eyes

Papilledema, enlarged blind spots, and isopter constriction re­ solved but altitudinal and arcuate defects persisted

Table 1 continued on next pages

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TABLE 1 (Continued) CLINICAL FINDINGS AND VISUAL FIELD DEFECTS IN 12 PATIENTS WITH IDIOPATHIC INTRACRANIAL HYPERTENSION

Patient No., Sex, Length of Age (yrs) Follow-up

Cerebrospinal Visual Symptoms

Visual Acuity R.E. L.E.

Ocular Findings

Fluid Pressure

(mm H20)

11, F, 22 3 yrs

Blurred vision

20/20 20/20

Papilledema, optic atrophy, nerve fiber bundle de­ fects, and optociliary shunt vessels in both eyes; right 6th nerve paresis

410

12, F, 32 3 mos

Visual obscurations

20/20 20/25

Papilledema with gliosis and hypertensive retinopathy in both eyes

500

dense central scotoma from macular dam­ age caused by extensive hemorrhage. We attributed this defect to the hypertensive retinopathy and not to the papilledema. We have selected six of the 12 cases for more detailed discussion. CASE REPORTS

blind spot enlargement in both eyes, and temporal and nasal nerve fiber bundle defects in the left eye (Fig. 2). Although the papilledema resolved sponta­ neously after a single lumbar puncture, the visual field defects in the left eye remained. Case 6—This 6-year-old girl, initially examined for otitis media and headaches after chickenpox, was noted to have papilledema and was hospitalized. Neurologic and neurodiagnostic findings were nor-

Case 5—This 28-year-old obese woman had a six-month history of headaches, visual obscurations, and blurred vision. Visual acuity was 20/20 in both eyes, ocular motility was normal, and both optic disks were blurred and elevated. In the left eye gliotic changes were observed over the nasal portions of the optic disk (Fig. 1). General physical and neurologic findings were normal, as were the results of skull radiographs, computed tomographic and isotope brain scans, and cerebral angiography. Kinetic perimetry showed generalized isopter constriction and TABLE 2 VISUAL FIELD DEFECTS

Defect

No. of Patients

Enlarged blind spot Constriction Nasal loss Central loss Temporal nerve fiber bundle defect Altitudinal defects Peripheral scotomas

12 9 7 6 2 1 1

Fig. 1 (Wall, Hart, and Bürde). Case 5, left eye. The chronicity of the papilledema is shown by the gray pallor on the optic disk surface (gliosis) that obscures the course of smaller blood vessels. The larger vessels are outlined by perivascular sheathing.

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659

TABLE 1 (Continued) Neurodiagnostic Tests*

Visual Field Findings

Comments

Skull X-ray films Computed tomography Cerebral angiogram

Enlarged blind spots, marked isopter constriction, dense nasal hemianopsia, and paracentral scotomas in both eyes

Refractory course with frequent relapses; surgical fenestration of optic nerve sheaths; nearnormal visual acuity despite ex­ tensive visual field loss

Computed tomography

Enlarged blind spots, isopter con­ striction, and nasal sector defect in both eyes; paracentral scotoma in R.E.

Isopter constriction and enlarged blind spots resolved; paracentral scotoma and sector defect per­ sisted

mal except for a lumbar puncture that showed an opening pressure of 453 mm H2O. A transfemoral arteriogram failed to demonstrate a mass lesion, and there was no evidence of venous sinus thrombosis present. A computed tomographic scan of the head, pneumoencephalogram, isotope cistemogram, and tests for many causes of pseudotumor were all nega­ tive. Six months later the child had a mild left sixth nerve paresis. Her visual acuity was R.E.: 20/40 and L. E. : 20/50. Perimetry showed a paracentral scotoma and a cecocentral scotoma in the right eye and an arcuate scotoma in the left eye. The blind spots were enlarged in both eyes. Treatment with various com­ binations of serial lumbar punctures, acetazolamide, glycerol, digoxin, and a low-salt diet failed to reduce intracranial pressure. Eighteen months after the child was first examined, her visual acuity was R.E.: 20/50 and L.E.: 20/30. Extraocular movements were full. She had bilateral papilledema with blurring of the optic disk margins and increased venous tortuosi­ ty. Perimetry showed a nasal step and nasal loss in the left eye and enlarged blind spots in both eyes. An examination five months later showed a visual acuity ofR.E.: 20/30 and L.E.: 20/25. Perimetry found only blind spot enlargement in both eyes. Seven months later the cerebrospinal fluid pres­ sure decreased to less than 240 mm H2O and the medications were discontinued. The patient was asymptomatic 5.5 years after the onset of symptoms and her visual acuity was 20/20 in both eyes. Ophthalmoscopic findings were normal with complete resolution of the papilledema. Perime­ try showed only a slight enlargement of the blind spots in both eyes. Case 7—This 29-year-old obese woman had a six-month history of decreasing vision and frontal headaches. Her visual acuity was R.E.: 20/50 and

L.E.: 20/80. Ocular motility was normal. The optic disks appeared to be elevated, blurred, and ruddy (Fig. 3). Kinetic perimetry showed generalized con­ striction of isopters, most prominent in the left eye. There was also extreme enlargement of the blind spot in an arcuate pattern in both eyes (Fig. 4). Visualevoked potentials showed slightly decreased ampli­ tudes; these were interpreted as probably normal. General physical and neurologic findings were nor­ mal. A lumbar puncture showed an opening pressure of 260 mm H2O. The cerebrospinal fluid findings were normal. The patient was treated with serial lumbar punc­ tures. Her headaches improved, and five months later her visual acuity was R.E.: 20/40 and L.E.: 20/50. The optic disk margins were still blurred nasally, and the visual field defects persisted. Seven months after the initial examination, visual acuity remained 20/40 in each eye, but the visual field defects had resolved. The optic disks then had only mild blurring of the nasal margins. Case 9—This 27-year-old obese woman had a one-year history of decreased visual acuity and visual obscurations. Neurologic and neurodiagnostic findings were normal except for a lumbar puncture opening pressure of 530 mm H2O. Her visual acuity was R.E.: 20/20 and L.E.: 20/25. She had chronic papilledema with optic disk gliosis and hyperemia in both eyes. There were no spontaneous venous pulsa­ tions. Extraocular movements were normal. Perime­ try showed enlarged blind spots in both eyes and central isopter constriction and a temporal nerve fiber bundle defect in the left eye. The patient was treated for the next two years with serial lumbar punctures, acetazolamide, and glycer­ ol. Symptoms and findings remained unchanged, as did the visual field defect in the left eye. Case 10—This 44-year-old obese woman had noted

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Fig. 2 (Wall, Hart, and Bürde). Case 5. Temporal sector defect in the left eye is an example of a nonreversing type of visual field defect. This defect corresponds to an area of the retina supplied by nerve fibers crossing the nasal border of the optic disk.

the onset of headaches and visual obscurations one year before being examined. Her referring physician noted papilledema. Findings from skull radiographs, pneumoencephalography, and cerebral angiography performed elsewhere were reported to have been

Fig. 3 (Wall, Hart, and Bürde). Case 7, left eye. Papilledema is unassociated with any findings of chronicity, such as gliosis or pallor. Note that smaller blood vessels remain unobscured on the surface of the optic disk.

normal. She continued to complain of repeated visual obscurations in the right eye. Her visual acuity was 20/20 in each eye. There was bilateral papilledema with 2 to 3 diopters of elevation plus hyperemia and gliosis of both optic disks. Kinetic perimetry showed blind spot enlargement in both eyes. The visual obscurations and headaches were re­ lieved after serial lumbar punctures during a oneyear period. The patient later experienced blurring of vision in the right eye, and ophthalmoscopy showed persistent papilledema with surface hemor­ rhages on both optic disks. Kinetic perimetry showed an altitudinal pattern of loss in the inferior hemifield of the right eye, as well as central isopter constric­ tion, inferior arcuate defects, and blind spot enlarge­ ment in both eyes (Fig. 5, top). A computed tomographic scan of the head gave normal results, and serial lumbar punctures were continued. Two months later repeat perimetry disclosed a progress­ ing visual field defect in the right eye with the development of an inferior paracentral scotoma. Within the next six months, despite continued serial lumbar punctures, the visual field defects progressed to include inferior altitudinal defects with dense inferior arcuate and paracentral scotomas. Therapy was unchanged, and during die next year the papille­ dema gradually improved. Blurring of the optic disk margins and gliosis of the surfaces of both optic disks persisted, however (Fig. 6). The visual field defects showed partial resolution, but a persistent pattern of inferior altitudinal loss and blind spot enlargement remained (Fig. 5, bottom). Case 12—This 32-year-old obese woman with hy­ pertension and chronic renal failure had a two-month

VOL. 96, NO. 5

IDIOPATHIC INTRACRANIAL HYPERTENSION

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Fig. 4 (Wall, Hart, and Bürde). Case 7. Central isopters are constricted and the blind spots enlarged in an arcuate pattern. These findings were typical of reversible types of visual field defects.

history of visual obscurations and difliise headaches. Her visual acuity was R.E.: 20/20 and L.E.: 20/25. She had chronic papilledema with gliosis in both eyes (Fig. 7), and hypertensive retinopathy with arteriolar narrowing and irregular caliber of the retinal vessels. There was, however, no retinal vascular disease sufficient to account for a visual field defect. Kinetic perimetry showed generalized constriction of central isopters and blind spot enlargement in both eyes and a large paracentral scotoma in the left eye (Fig. 8, top). There were nasal defects in both eyes. General physical and neurologic findings were otherwise nor­ mal. A computed tomographic scan of the head gave normal findings. A lumbar puncture showed an open­ ing pressure of 500 mm H2O, and the results of cytologie and chemical studies of the cerebrospinal fluid were normal. A percutaneous renal biopsy specimen showed nephrosclerosis. The patient was treated with furosemide, 80 mg, and glycerol, 60 mg, daily. Two months later the papilledema had resolved, and perimetry showed resolution of die blind spot enlargement and central isopter constriction, but inferonasal sector defects in both eyes persisted (Fig. 8, bottom). RESULTS

No type of therapy consistently reduced symptoms or changed signs. Spon taneous resolution was apparent in some Oral hyperosmotics, corticosteroids, car bonic anhydrase inhibitors, and weight reduction diets produced varying de

grees of relief (from total to none at all). The most common therapy, serial lumbar punctures, appeared to have been the most reliable means of decreasing intracranial pressure. Resolution of the papil­ ledema and coincident recovery from vis­ ual field defects, after reductions in intracranial pressure, showed a number of common features among the 12 cases. The reversible components of papillede­ ma included the edema itself, shown in the degree of optic disk elevation and surrounding retinal folds, and hyperemia of the optic disks. Those features that did not resolve were those associated with chronic optic disk changes (gliosis, pallor, hard exudates, visible nerve fiber bundle defects, and optociliary shunt vessels). Although hemorrhages and exudates dis­ appeared with time, they were usually associated with changes suggesting chronicity. They were consequently more likely to be associated with nonreversing types of visual field defects. The most frequently reversible visual field defects included concentric isopter constriction

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Fig. 5 (Wall, Hart, and Bürde). Case 10. Visual fields before (top) and after (bottom) reduction in intracranial pressure. The altitudinal defect in the right eye (corresponding to the optic disk with the greater extent of gliosis) persisted. The relatively dense arcuate scotoma in the left eye largely resolved, leaving only a residual nasal step in one central isopter.

and blind spot enlargement. Defects that reversed less often included nasal steps, arcuate scotomas, and paracentral and peripheral scotomas. Among those that did not reverse at all were dense sector defects and altitudinal hemianopsias. All of these are manifestations of nerve fiber bundle defects and bear a striking simi­

larity to the visual field defects character­ istically associated with disorders affect­ ing the anterior optic nerve. In Cases 2, 5, and 8 to 12, the visual field defects did not fully recover after a reduction in intracranial pressure and resolution of the papilledema. In Cases 3, 6, and 7 reduc­ tion in intracranial pressure was followed

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663

Fig 6 (Wall, Hart, and Bürde). Case 10. Left, Right eye. Right, Left eye. The chronic features of papilledema are most evident in the right eye, especially in the extent of gliosis over the inferior portions of the optic disk.

by resolution of the optic disk findings of papilledema and recovery from the visual field defects. Patients 1 and 4 had no defects other than blind spot enlarge­ ment and isopter constriction, but these patients were not followed up long enough for their outcomes to be deter­ mined. Figure 3 shows the appearance of the optic disk in the left eye of Patient 7. This is a representative example of papillede­ ma uncomplicated by associated findings of chronicity of optic nerve damage. The visual fields of this patient (Fig. 4) illus­ trate the common finding of isopter con­ striction and blind spot enlargement. These defects disappeared completely, and the papilledema recovered after con­ trol of the intracranial hypertension. The left optic disk of Patient 5 (Fig. 1) is an example of the changes found in chronic papilledema. A gray pallor on the nasal optic disk surface obscures the smaller underlying blood vessels from view, and perivascular sheathing of the larger vessels is evident. These findings are characteristic of so-called gliosis,

changes thought to be caused by glial proliferation on the optic disk. The visual field for this eye (Fig. 2) shows a tempor-

Fig. 7 (Wall, Hart, and Bürde). Case 12, left eye. Chronic papilledema with gliosis shown by gray, opaque tissue covering underlying small vessels. The optic disk of right eye had same findings. Small white inclusion bodies within the substance of the optic disk (seen here in the superotemporal quadrant) were often found in association with gliosis.

664

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Fig. 8 (Wall, Hart, and Bürde). Case 12. Visual fields before (top) and after (bottom) reduction in intracranial pressure. Blind spot enlargement and central isopter constriction were reversed, but the inferonasal sector defect (nasal step) in the left eye and the nasal paracentral scotoma in the right eye did not recover.

al sector defect corresponding to the pat­ tern expected with damage to nerve fiber bundles passing over the nasal border of the optic disk. Another example of chronic papilledema, associated with nonrecovering visual field defects, is the left eye of Patient 12 (Fig. 7). Again the surface of the optic

disk appears to be covered by a gray, opaque tissue, and there are a n u m b e r of small, glistening inclusions within the substance of the optic disk, predominant­ ly in the superotemporal quadrant. The visual field pattern found in this case (Fig. 8, top) consisted of blind spot enlargement, isopter constriction, and an

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IDIOPATHIC INTRACRANIAL HYPERTENSION

inferonasal sector defect. The sector de­ fect was manifested as a series of isopter discontinuities along the nasal horizontal meridian (a nasal step) in conjunction with sector-shaped indentations of the isopter boundaries, with the apices of the indentations pointing in the general di­ rection of the physiologic blind spot. This pattern was characteristic of the most common form of nonreversing visual field defect (an inferonasal sector or arcuate defect). Changes that occurred in this pattern after reduction in intracranial pressure (Fig. 8, bottom) included the expansion of the central isopter and re­ duction in size of the blind spot. The sector defect, by contrast, not only per­ sisted but appeared to be more sharply defined. The visual field changes in Case 10 showed a correlation between the extent of ophthalmoscopically visible signs of chronic papilledema and the extent of recovery of visual field defects. The optic disk of the right eye of Patient 10 had undergone extensive gliosis, particularly over its inferior half (Fig. 6, left). This process had progressed to completely ob­ scure the major vessels from view. The left optic disk (Fig. 6, right) also showed signs of chronicity, but these were much less prominent, shown by the unobscured course of the major vessels on its surface. Figure 5, top, shows the changes in the visual field defects observed in this case. The visual field,defect in the right eye consisted of a dense, inferior altitudinal pattern of loss that failed to resolve after reduction of intracranial pressure. The defect in the left eye, by contrast, con­ sisted of a dense, inferior arcuate scotoma that for the most part resolved, leaving only a residual nasal step in one central isopter (Fig. 5, bottom). DISCUSSION

There have been many retrospective studies of patients with idiopathic intra­

665

cranial hypertension.2,5"7,11,14,18"30 Excluding blind spot enlargement (which may be universal), visual field defects were docu­ mented in 10%. Of the 48 patients we reviewed, 15 had such defects. Of these, we excluded three, leaving 12 of 45 with visual field defects. In only three of the previously reported series28"30 did the pa­ tients undergo detailed visual field test­ ing. In two of these studies 18 of 83 patients had visual field defects attribut­ ed to the intracranial hypertension. 28,29 In the third series almost one half of the 114 eyes evaluated had visual field defects other than blind spot enlargement. 3 0 The true incidence may be lower than report­ ed because both our study and that of Corbett and associates 30 suffered from a selection bias for more severe or refracto­ ry cases. Other than blind spot enlargement, the most common types of defects have been isopter constriction and loss of inferonasal portions of the visual field (3.5% and 4 . 1 % respectively). Of our 45 patients, nine had isopter constriction and seven had nasal (especially inferonasal) loss. The discrepancies between our visual field findings and those in other series may have been the result of less complete visual field testing in the earlier series (for example, enlarged blind spots were documented in only 30% of the previous­ ly reported cases). Arcuate scotomas have been found in patients with papilledema 31 and idiopath­ ic intracranial hypertension 10,11 and we demonstrated arcuate scotomas in three of our patients. Two of our patients had temporal sector defects, a defect also noted by Corbett and associates. 30 One of our patients had an inferior altitudinal defect, a finding reported in one patient by Rush 29 and in another case by Greer. 1 3 Central or paracentral scotomas were re­ ported in 3.3% of the patients in the previous studies, whereas 9% (four of 45) of our patients had central or paracentral

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defects apparently related to the in­ creased intracranial pressure. In previous reports 1.5% of the patients described became totally blind in one or both eyes. Although we observed examples of severe visual field loss, none of our patients suffered total loss of vision. Of clinical importance was the associa­ tion found between the ophthalmoscopic signs of chronic papilledema and the more permanent forms of visual field de­ fects. This association was noted in Pa­ tients 2, 5, and 8 to 12. Patients 1, 3, 4, 6, and 7 had none of the chronic features of papilledema. Within this group resolu­ tion of the optic disk findings of papille­ dema was associated with recovery from the visual field defects in three patients (Cases 3, 6, and 7). Follow-up was insuffi­ cient for us to determine visual field reversal in Patients 1 and 4 whose deficits were limited to blind spot enlargement and isopter constriction. It is generally accepted that visual acu­ ity remains normal in papilledema except when the condition is long-standing. 31 " 33 Four of our 45 patients had diminished visual acuities, compared with a total of 16.4% in the previous combined series. However, previous investigators have not usually stated whether the visual acuities they reported were obtained with the best possible optical corrections. It has been pointed out that loss of visual acuity associated with idiopathic intracranial hy­ pertension is more frequent than loss associated with papilledema from intra­ cranial tumors. 2,25 The most common symptom in our group of 12 patients with visual field defects was visual obscurations (six cases), whereas this symptom was noted in only 11.2% of the previously described patients. Visual obscurations are tran­ sient episodes of blurred vision, usually lasting less than 30 seconds and followed by complete restoration of the previous

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visual acuity. 31 The attacks may be mo­ nocular or binocular. They do not appear to be correlated with the degree of intra­ cranial hypertension or with the extent of optic disk edema. 34 Although this symp­ tom is considered by some to be an indication for surgical decompression or shunting, 32,35 other investigators do not believe it correlates well with the eventu­ al visual outcome.28"30,36 We found no rela­ tionship between the symptom of visual obscurations and either the course or the severity of visual field defects. All of the adult patients with visual loss in our study were both obese and female. Wilson and Gardner 11 reported that 48 of their 61 patients with idiopathic intracra­ nial hypertension were obese women. Greer 13 reviewed 20 cases of idiopathic intracranial hypertension occurring in obese women and noted that 17 of these patients had blurring of vision or com­ plaints of decreased visual acuity. Six of the 20 had documented decreased visual acuities. These returned to normal after treatment in five. He noted that blind spot enlargement had been found in 11 of these patients, but made no other com­ ments about visual field examinations. Corbett and associates 30 reported that of 14 patients with permanent severe visual loss, 13 were female and 14 were obese. Eight of 13 patients with systemic hyper­ tension had permanent severe visual loss. In 11 cases of idiopathic intracranial hy­ pertension in which otitis was an appar­ ent factor, there was no evidence of visual loss. 2 It appears that obese and hyperten­ sive women may be at greater risk for visual field defects than others with idio­ pathic intracranial hypertension. Our series was too limited for us to draw conclusions about the relative effica­ cy of various forms of therapy. The most common medical regimens included re­ peated lumbar punctures, diuretics, de­ hydration, corticosteroids, and weight-

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reduction diets. Surgical forms of therapy included various shunting and decom­ pression procedures: lumbar-subarachnoid peritoneal shunts, optic nerve sheath fenestration, and cranial decom­ pression. There are no data to prove that surgical therapy effectively prevents vis­ ual loss in idiopathic intracranial hyper­ tension. A number of ophthalmoscopic criteria have been proposed as indicators of the need for surgical intervention.^ 3 6 · 3 7 These include optic disk elevation of more than 5 diopters, narrowing of retinal arterioles, rapid onset of optic disk swelling, engorgement of retinal veins, and exten­ sive hemorrhages. Other proposed crite­ ria include progressive loss of visual acu­ ity or visual field, pronounced visual obscurations, extreme degrees of intra­ cranial hypertension, 3 7 and electrophysiologic (visual-evoked potential) findings indicating damage to the optic nerve (S. H. Wray, oral communication, Sept. 1980). We found no strong correlation between visual symptoms and either the extent or the reversibility of visual field defects. A definite correlation does exist between the signs of chronic papilledema and the permanency of apparent visual field defects. The available retrospective data lead us to recommend that most patients with idiopathic intracranial hypertension and visual loss be treated initially with daily serial lumbar punctures. We realize that in normal individuals the cerebrospinal fluid pressure should return to normal within one to two hours 38 after a lumbar puncture. In a patient with an abnormal regulatory mechanism, as in idiopathic intracranial hypertension, there are no data as to the effect of such a procedure in decreasing intracranial pressure. Also, repeat lumbar puncture may produce small rents in the dura and arachnoid, allowing continual although short-term

667

egress of cerebrospinal fluid into the epidural space. If there is no improvement after the third such procedure, 7 it is un­ likely to be beneficial. We would then begin treating the patient with orally administered acetazolamide, 60 mg/kg of body weight per day in divided doses, that is, 2 to 4 g/day. 39 This dosage of acetazolamide far exceeds that generally used, but this is the dosage needed to decrease cerebrospinal fluid secretion. This dosage of acetazolamide is often as­ sociated with systemic side effects includ­ ing gastrointestinal upset, perioral and digital tingling, acid-base imbalance, and irritability. There is a theoretical advan­ tage to the use of methazolamide because it more readily penetrates the bloodbrain barrier 40,41 and can be used in small­ er amounts. However, even these lower levels cause drowsiness. If patients can­ not tolerate these dosages of carbonic anhydrase inhibitors or there is no amel­ ioration of the condition, we would use a two-week course of oral corticosteroids (for example, prednisone, 60 mg/day) which would be discontinued if there was no response by the end of the first week. With the initiation of therapy the patients should begin a weight-reduction program with the help of a dietician, although they seldom do. Other diuretic and hyperosmotic agents have been recommended; there is little evidence as to their efficacy. If this regimen fails and there is progres­ sive visual loss, we recommend surgery such as lumbar subarachnoid-peritoneal shunt or optic nerve fenestration. We have not used the term benign intracranial hypertension because any disorder that has a 22% to 25% incidence of permanent visual impairment, 2,B,3 ° a 10% to 27% incidence of visual field de­ fects, a 9% to 16% incidence of loss of visual acuity, and a 1.5% incidence of blindness should not be thought of as benign. The designation "pseudotumor"

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AMERICAN JOURNAL O F O P H T H A L M O L O G Y

is inappropriate since there is no inflam­ matory mass masquerading as a neo­ plasm. We agree with the proposal of Bucheit and associates,1 that the disorder be called idiopathic intracranial hyper­ tension. Our results indicated that pa­ tients with this disease must be followed up carefully with frequent reexamination of both visual acuity and visual fields. Treatment can prevent fur­ ther visual loss and reverse some of the visual defects if it is initiated early enough. REFERENCES 1. Bucheit, W., Burton, C , Haag, Β,, and Shaw, D.: Papilledema and idiopathic intracranial hyper­ tension. Report of familial occurrence. N. Engl. J. Med. 280:938, 1969. 2. Foley, J. : Benign forms of intracranial hyper­ tension. "Toxic" and "otitic" hydrocephalus. Brain 78:1, 1955. 3. Warrington, W. B.: Intracranial serous effu­ sions of inflammatory origin. Meningitis or ependymitis serosa. Meningism with a note on "pseudotumors" of brain. Q. J. Med. 7:93, 1914. 4. Symonds, C. P.: Otitic hydrocephalus. Brain 54:55, 1931. 5. Boddie, H. G., Banna, M., and* Bradley, W. G.: "Benign" intracranial hypertension. Brain 97:313, 1974. 6. Paterson, R., DePasquale, N., and Mann, S.: Pseudotumor cerebri. Medicine 40:85, 1961. 7. Weisberg, L. A. : Benign intracranial hyperten­ sion. Medicine 54:197, 1975. 8. Rönne, H.: Über das Vorkommen von Nervenfaserndefekten im Gesichtsfelde und besonders über den nasalen Gesichtsfeldsprung. Arch. Augenheilkd. 74:180, 1913. 9. Scott, G. I.: Traquair's Clinical Perimetry, 7th ed. St. Louis, C. V. Mosby, 1957, pp. 210-213. 10. Jefferson, A., and Clark, J.: Treatment of benign intracranial hypertension by dehydrating agents with particular reference to the measurement of the blind spot area as a means of recording improvement. J. Neurol. Neurosurg. Psychiatry 39:627, 1976. 11. Wilson, D. H., and Gardner, W. J.: Benign intracranial hypertension with particular reference to its occurrence in fat young women. Can. Med. Assoc. J. 95:102, 1966. 12. Dersh, J., and Schlezinger, N. S.: Inferior nasal quadrantanopsia in pseudotumor cerebri. Arch. Neurol. 1:695, 1959. 13. Gréer, M.: Benign intracranial hypertension. In Vinken, P., and Bruyn, G. W. (eds.): Handbook of

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Clinical Neurology. New York, American Elsevier, 1974, vol. 16, p. 152. 14. Cross, A. C : The papilledema of toxic hydro­ cephalus. Trans. Ophthalmol. Soc. U.K. 68:181, 1948. 15. Hart, W. M., and Becker, B.: Visual field changes in ocular hypertension. Arch. Ophthalmol. 95:1176, 1977. 16. Hart, W. M., and Hartz, R. K.: Computer processing of visual field data. I. Recording, storage and retrieval. Arch. Ophthalmol. 99:128, 1981. 17. Hart, W. M.: Computer processing of visual field data. II. Automated pattern analysis of glaucomatous visual fields. Arch. Ophthalmol. 99:133, 1981. 18. Davidoff, L. M.: Pseudotumor cerebri. Be­ nign intracranial hypertension. Neurology 6:605, 1956. 19. Dandy, W. E.: Intracranial pressure without brain tumor. Ann. Surg. 106:492, 1937. 20. Giller, H., and Cogan, D. G.: Papilledema as the outstanding sign in meningeal hydrops. Arch. Ophthalmol. 48:567, 1952. 21. Dunn, J., Baker, G. S., and Wageman, H. P.: Pseudotumor cerebri. A review and report of 4 cases. Proc. Staff Meet. Mayo Clin. 30:505, 1955. 22. Bradshaw, P.: Benign intracranial hyperten­ sion. J. Neurol. Neurosurg. Psychiatry 19:28, 1956. 23. Lysak, W. R., and Svien, H. J.: Long term follow-up of patients with diagnosis of pseudotumor cerebri. K Neurosurg. 25:284, 1966. 24. Rabinowicz, I. M., Ben-Sira, I., and Zauberman, H.: Preservation of visual function in papille­ dema. Observed for 3 to 6 years in a case of benign intracranial hypertension. Br. J. Ophthalmol. 52:236, 1968. 25. Giudetti, B., Giuffre, R., and Gambacorta, D. : Follow-up studies of 100 cases of pseudotumor cerebri. Acta Neurochir. 18:259, 1968. 26. Johnston, I., and Paterson, A.: Benign intra­ cranial hypertension. I. Diagnosis and prognosis. Brain 97:289, 1974. 27. Vassilouthis, J., and Uttley, D.: Benign intra­ cranial hypertension. Clinical features and diagnosis using computed tomography and treatment. Surg, Neurol. 12:389, 1979. 28. Bulens, C , DeVries, W. A. E. J., and van Crevel, H.: Benign intracranial hypertension. A ret­ rospective and follow-up study. J. Neurol. Sei. 40:147, 1979. 29. Rush, J. A.: Pseudotumor cerebri. Clinical profile and visual outcome in 63 patients. Mayo Clin. Proc. 55:541, 1980. 30. Corbett, J. J., Savino, P. J., Thompson, H. S., Kansu, T., Schatz, N. J., Orr, L., and Hopson, D.: Visual loss in pseudotumor cerebri. Followup of 57 patients from five to 41 years and a profile of 14 patients with permanent severe visual loss. Arch. Neurol. 39:461, 1982. 31. Huber, A.: Eye Sign and Symptoms in Brain Tumors. St. Louis, C. V. Mosby, 1976, pp. 109-113.

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32. Holmes, G. : The prognosis of papilledema. Br. J. Ophthalmol. 21:337, 1937. 33. Glaser, J. S.: Neuro-ophthalmology. Hagerstown, Harper and Row, 1978, p. 79. 34. Hayreh, S. S.: Optic disc edema in raised intracranial pressure. VI. Associated visual distur­ bances and their pathogenesis. Arch. Ophthalmol. 95:1566, 1977. 35. Smith, J. L.: Pseudotumor cerebri. Trans. Am. Acad. Ophthalmol. Otolaryngol. 62:432, 1958. 36. Cogan, D. G.: Blackouts not obviously due to carotid occlusion. Arch. Ophthalmol. 66:180, 1961. 37. Zuidema, G. D., and Cohen, S. J.: Pseudo­ tumor cerebri. J. Neurosurg. 11:433, 1954.

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38. Johnston, I., and Paterson, A.: Benign intra­ cranial hypertension. II. CSF pressure and circula­ tion. Brain 97:301, 1974. 39. Gucer, G., and Viemstein, L.: Longterm intracranial pressure recording in the manage­ ment of pseudotumor cerebri. J. Neurosurg. 49:256, 1978. 40. Maren, T. H.: Carbonic anhydrase. Chemis­ try, physiology, and inhibition. Physiol. Rev. 47:595, 1967. 41. Maren, T. H., Haywood, J. R., Chapman, D. K., and Zimmerman, T. J.: The pharmacology of methazolamide in relation to the treatment of glauco­ ma. Invest. Ophthalmol. Vis. Sei. 16:730, 1977.