Surgical Management of Idiopathic Intracranial Hypertension in Pregnancy

Idiopathic intracranial hypertension (IIH) is a disease typically affecting overweight or obese women of childbearing age and characterized by increased intracranial pressure (ICP) without an alternative etiology. The annual incidence of IIH has; been increasing over time, strongly correlated with increasing obesity (1).

Perspective Surgical Management of Idiopathic Intracranial Hypertension in Pregnancy Sam Karimaghaei, MD, Subahari Raviskanthan, MBBS, Cina Karimaghaei, MD, Peter W. Mortensen, MD, Amina I. Malik, MD, Yi J. Zhang, MD, Andrew G. Lee, MD I diopathic intracranial hypertension (IIH) is a disease typically affecting overweight or obese women of childbearing age and characterized by increased intracranial pressure (ICP) without an alternative etiology. The annual incidence of IIH has been increasing over time, strongly correlated with increasing obesity (1). Recent estimates of IIH incidence from a primarily Caucasian population are 1.8 per 100,000 people, with the highest incidence of 22 per 100,000 in female patients with obesity aged 15–44 years (1). The prevalence of IIH has been reported to be 2%–12% among pregnant women (2,3). While isolated case reports have suggested that pregnancy may be a risk factor for the development of IIH, a controlled study by Digre et al (2) suggested that it is not. In their study, Digre et al also found that there are similar rates of spontaneous abortion between IIH and non-IIH patients, subsequent pregnancies do not increase the recurrence risk of IIH, and the visual outcomes are similar in pregnant and nonpregnant IIH patients (2). However, pregnancy may exacerbate preexisting IIH, likely due to its associated weight gain (4). In this article, we review the literature on the surgical management of IIH in pregnancy and describe indications for surgery, surgical options, and risks. We also propose an algorithm for considering possible surgical management of IIH in pregnancy. McGovern Medical School (SK), The University of Texas Health Science Center at Houston, Houston, Texas; Department of Ophthalmology (SR, PWM, AIM, AGL), Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas; Department of NeuroOphthalmology (SR), Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia; Department of Neurology (SR), Alfred Health, Melbourne, Victoria, Australia; Department of Neurology (SR), Royal Melbourne Hospital, Melbourne, Victoria, Australia; School of Medicine (CK), University of Texas Medical Branch, Galveston, Texas; Department of Neurosurgery (YJZ), Houston Methodist Hospital, Houston, Texas; Departments of Ophthalmology, Neurology, and Neurosurgery (AGL), Weill Cornell Medicine, New York, New York; Department of Ophthalmology (AGL), University of Texas Medical Branch, Galveston, Texas; Department of Ophthalmology, University of Texas MD Anderson Cancer Center (AGL), Houston, Texas; Texas College of Medicine (AGL), Bryan, Texas; and Department of Ophthalmology (AGL), The University of Iowa Hospitals and Clinics, Iowa City, Iowa. The authors report no conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Address correspondence to Andrew G. Lee, MD, Department of Ophthalmology, Blanton Eye Institute Houston Methodist Hospital, 6560 Fannin Street, Suite 450, Houston, TX 77030; E-mail: aglee@ houstonmethodist.org Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 DISEASE ENTITY Epidemiology Case–control studies have shown a similar prevalence of pregnancy in the IIH cohort and matched controls, and no causal relationship between pregnancy and IIH has been identified (5,6). One retrospective series noted that 8.3% of patients were pregnant at the time of their initial IIH diagnosis (similar to the population prevalence in age- and sex-matched patients), and 12.5% of patients had IIH relapses during pregnancy (7). There is no evidence of different outcomes, increased abortion rates, or additional risks for future pregnancies in pregnant and nonpregnant IIH patients. Therefore, pregnancy is not an absolute contraindication in IIH patients (2,3,8). However, given that pregnancy may exacerbate IIH, patients should ensure that their disease is well controlled before attempting pregnancy (4). Other findings regarding pregnancy in IIH suggest that onset may occur at almost any time within pregnancy, but it typically occurs in the first half of pregnancy (2). In 1 review, 16% occurred before conception or within the first 7 weeks, 33% in the first trimester, 42% in the second trimester, and 9% in the third trimester (9). The average gestation at onset was 14.4 weeks, and the latest reported case was 33-week pregnant at diagnosis (2). Clinical Manifestations of Idiopathic Intracranial Hypertension in Pregnancy The symptoms of IIH in pregnant and nonpregnant patients are similar, with headache occurring in up to 90% of cases (10). Multiple different headache phenotypes have been described, generally worsening with Valsalva-type maneuvers (due to increased ICP), and associated with nausea, vomiting, and photophobia (4,11). Permanent vision loss, the most concerning feature of IIH, is more common in fulminant IIH patients, who make up 10%–20% of IIH patients (4,10). Management of Idiopathic Intracranial Hypertension in Pregnancy Medical Management of Idiopathic Intracranial Hypertension in Pregnancy The primary goals of management for IIH are vision preservation and symptom control. Nonsurgical 419 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Perspective management of IIH includes diet and weight loss, analgesics, diuretics, and corticosteroids (4). However, the safety of medical management in pregnancy should be considered. Diet and Weight Loss Because obesity and recent weight gain are strongly associated with the development of IIH, weight loss is generally recommended to nonpregnant, overweight patients with IIH. However, in pregnant patients, recommendations are to limit weight gain to necessary and expected amounts, where possible. Marked weight gain may predict visual deterioration, and weight loss alone can resolve the papilledema (8). In nonpregnant patients, loss of 5%–10% of total body weight may alleviate IIH symptoms (12). However, in pregnant patients, weight loss increases the risk of ketosis in the fetus, so women with IIH are recommended to restrict their weight gain to 20 pounds during pregnancy rather than actively lose weight (2,4,10). Huna-Baron and Kupersmith (3) reported 12 pregnant women with IIH; of whom, 3 had improved symptoms after diagnostic lumbar puncture (LP) and weight control through a caloric-restricted non–ketosis-producing diet, but there is insufficient evidence for this to be a general recommendation. Analgesics Headache management should be selected with caution during pregnancy. Acetaminophen is safe in pregnancy, but nonsteroidal anti-inflammatory drugs should be avoided in the third trimester due to the risk of oligohydramnios and premature closure of the fetal ductus arteriosus. Opioids cross the placenta and need to be used with caution. Regular opioid use during pregnancy can also result in neonatal abstinence syndrome and withdrawal symptoms in the neonate (4). Diuretics Acetazolamide, a carbonic anhydrase inhibitor, reduces cerebrospinal fluid (CSF) production by 6%–50%, and it is considered standard medical therapy for IIH. However, its use during pregnancy is controversial. The US Food and Drug Administration (FDA) previously classified acetazolamide as a pregnancy class C drug (animal studies have demonstrated adverse effects on the fetus but no adequate, well-controlled studies in humans exist) (10). Two cases of possible teratogenicity from acetazolamide have been reported (10,13). A 22year-old woman G2P0 was treated with 750-mg acetazolamide daily from age 13 years after an episode of uveitic glaucoma requiring enucleation of 1 eye 4 years later, and she was also being treated with dicyclomine (FDA category B in pregnancy), and iron and folic acid supplements. Her first pregnancy resulted in a first trimester spontaneous abortion. Her acetazolamide therapy was discontinued in the second pregnancy at 19 weeks of gestation, and she presented at 27 weeks of gestation with spontaneous rupture of membranes, and the subsequently, stillborn baby had a sacrococcygeal teratoma (13). A second more recent case of ectrodactyly, ectodermal 420 dysplasia, and cleft palate syndrome diagnosed at birth in the setting of maternal acetazolamide use (1,000 mg/day) for IIH has also been reported. Some reports of neonatal metabolic acidosis have also been reported (14). As a result of these patients, some suggest avoiding acetazolamide during the first 20 weeks of gestation, but other authors are less convinced, and no clear consensus guideline exists (8,15). There is no increased risk in spontaneous abortion in pregnant patients taking acetazolamide, and the largest observational studies have not reported birth defects in those patients taking acetazolamide (16,17). Like acetazolamide, loop diuretics decrease CSF production. Furosemide, also a category C drug, may have increased incidence of patent ductus arteriosus in preterm infants. Thiazide diuretics, including hydrochlorothiazide, are contraindicated in pregnancy because of the risk for fetal growth restriction (category D) (4). Given the availability of relatively safer diuretics, the risks of thiazide use typically outweighs the benefits. Topiramate Topiramate is often considered for acetazolamide-intolerant patients and has carbonic anhydrase inhibitor, headache, and weight loss properties. It has a category D classification and very little safety data in humans (unlike acetazolamide), and it is, therefore, not currently recommended in pregnancy (10). Corticosteroids Corticosteroids (category B in pregnancy) are occasionally used in the treatment of IIH, typically when there is significant and rapidly progressive visual decline acutely, or as temporizing measures before definitive surgery (10). While considered safer than category C drugs, the maternal risk of weight gain, acne, hyperglycemia, hypertension, osteoporosis, and psychosis make corticosteroids less desirable in the management of IIH (8). There have also been some reports of low birthweight associated with corticosteroids (10). Surgical Management in Pregnancy As with nonpregnant patients with IIH, patients with progressive visual loss or intractable headache might benefit from surgical management acutely or after failing maximum medical therapy. Optic nerve sheath fenestration (ONSF) is often recommended when severe visual dysfunction or rapid deterioration of vision is present. Patients with intractable, medically refractory, and severe headache with or without progressive visual dysfunction may benefit from CSF diversion procedure (CSF shunt). Although decompressive craniectomy was used in the past as a surgical treatment of IIH, this aggressive neurosurgical procedure is now rarely used in IIH. Table 1 summarizes the current literature on the surgical management of IIH during pregnancy and associated patient outcomes. Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Perspective Serial Lumbar Puncture Serial LP can improve neurological symptoms and decrease the risk of permanent vision loss (18). LP is not contraindicated in pregnancy, and there is reported efficacy for improvement in both headache and vision in pregnant patients with IIH (3,4,8,10). There have been 28 patients who received therapeutic serial LP (up to 11 LP in 1 report) (2,11,18–30). Further details regarding the frequency of LP, indications for repeat LP (symptoms or regular timing) were not available in many cases, and assessment and analysis of patient outcomes overall is challenging because most patients also received other interventions concurrently. Ghali et al and Huna-Baron and Kupersmith found that serial LP led to improved IIH symptoms (3,31). A prospective case series by Eissa et al (18) of 7 patients demonstrated an 86% success rate using single or serial LP in controlling IIH symptoms (3 patients required more than 1 LP), but they recommended shunting in cases with progressive visual deterioration despite repeated LP. Badve et al described repeated LP leading to the resolution of blurred vision, intermittent blindness, headache, neck pain, lightheadedness, weakness, nausea, and vomiting in a patient who developed IIH in pregnancy. This patient was unique in that she did not require repeat LP until 11.5 weeks after her first LP, which was a significantly longer time interval than typically reported (21). The role of serial LP in IIH in pregnancy remains controversial. Some patients in the literature received regular scheduled LP regardless of symptoms or examination findings, whereas others had serial LP only on the basis of worsening clinical syndromes. Most were in conjunction with other medical therapies and conservative management (31,32). Other experts recommend the use of serial LP for symptom relapses or as a temporizing measure until more definitive treatment, such as CSF shunting or ONSF, is performed (9,32–34). Optic Nerve Sheath Fenestration ONSF surgery was first described by De Wecker (35) in 1872 as a blind incision in the meninges surrounding the optic nerve in order to relieve elevated intracranial pressure. The efficacy of ONSF as a possible treatment for papilledema was further described by Hayreh (36) in 1964 in a study in rhesus monkeys. Since its initial description, ONSF has been described in treatment for multiple optic nerve diseases, including IIH, cryptococcal meningitis, retrobulbar silicone oil, optic nerve malignancies, and vestibular schwannoma (37). The most common and best-studied indication for ONSF, however, remains IIH. ONSF is generally recommended for cases of IIH with progressive vision loss despite maximum medical management or in cases of rapid and severe visual loss (i.e., fulminant IIH). One review of IIH patients showed significant improvement in headaches in half of patients after ONSF (38). In a large retrospective study of 158 eyes, Banta and Farris (39) found Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 that ONSF for the treatment of IIH resulted in stabilization or improvement of visual acuity in 94% of eyes and stabilization or improvement of visual fields in 88% of eyes. ONSF is believed to be a relatively safe procedure in pregnancy-related IIH, although data on this are limited with only 5 previously reported cases (2–4,29,40,41). Of these, 2 were performed as either the only intervention, or within 24 hours of presentation for severe visual symptoms, and the other 3 were performed in combination with other medical and surgical interventions. Postoperative visual outcomes included visual acuity ranging from 20/25 to no light perception, Huna-Baron and Kupersmith (3) reported a case of refractory IIH in a pregnant patient treated with ONSF, resulting in improved visual acuity and a normal pregnancy outcome. However, Zamecki et al reported an unusual case of severe visual loss in a pregnant woman with IIH. After presenting with a visual acuity of 20/100 in the right eye and no light perception in the left eye and failing to improve after a brief course of medical management and LP, a combination of bilateral ONSF and lumbar drain resulted in visual improvement in the right eye to 20/40 (40). Shapiro et al (29) reported a case in which a pregnant IIH patient with visual dysfunction refractory to LP shunting (worst visual acuity was light perception in the right eye and 20/400 in the left eye) had improved vision after ONSF —this patient was initially trialed with serial LP, steroids, and diuretics before surgical intervention, and her visual acuity improved to 20/20 in the right eye and 20/30 in the left eye. Other advantages of ONSF compared with shunting procedures in pregnant patients are the overall shorter operative and anesthesia time—in 1 study, the average surgical time for ONSF was only 27 minutes (42,43). Failure rates of ONSF range from 10% to 32% (8). While the procedure is considered safe in pregnancy, there are still risks involved, including the most dreaded complication of vision loss. The risk of blindness from ONSF has been reported to be 1%–2% (44). Other potential risks of this surgery include anisocoria, diplopia, transient blindness, conjunctival blebs, chorioretinal scarring, and death (8,45). However, most complications are transient and considered benign in comparison to the vision-threatening nature of IIH (8). Overall, Schiffman et al (46) suggested that ONSF may be the most appropriate surgical intervention for pregnant patients with IIH because there are less follow-up complications compared with shunting. Cerebrospinal Fluid Shunting Because the ventricles are normal or smaller in size in IIH patients, LP shunting has historically been preferred to VP shunting, as it was less hazardous and easier to perform (8,47). However, there is very limited evidence-based information to guide decision making in selecting a CSF shunting method. More recent articles seem to suggest a shift in support from LP shunting to VP shunting as the preferred 421 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Author, Year (Reference Number) Age, Years Gravidity/ Gestation G3P2 3.5 months G3P2 4.5 months G4P2 3 months G3P1 5 months Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 New Diagnosis/ Established Diagnosis Symptom Duration Management (in Chronological Order) Not reported 3 weeks Not reported 2 months Not reported 2 months Not reported 1 month New Not reported Not reported Not reported N/A N/A New w7 weeks LPS New 1 month Steroids, diuretics, serial LP days 20, 30, 41 1 day trial of conservative management (steroids, chlorthalidone), then ONSF Diuretics, serial LP · 3 Acetazolamide, serial LP · 3 Serial LP, acetazolamide, steroids, LPS Greer, 1963 (22) 27 Greer, 1963 (22) 23 Greer, 1963 (22) 37 Greer, 1963 (22) 30 Nickerson, 1965 (57) 19 Jefferson, 1976 (58) 38 Caroscio, 1978 (59) 20 Keltner, 1979 (47) 20 Palop, 1979 (28) 20 Shekleton, 1980 (41) 30 G2P1 34 weeks New 3 days Kassam, 1983 (25) 24 New 8 days Kassam, 1983 (25) 27 New 2 days Kassam, 1983 (25) 32 G3P2 20 weeks G4P2 22 weeks G3P2 22 weeks New 3 weeks Kassam, 1983 (25) 18 New 3 weeks Digre, 1984 (2) 20 New 4 weeks Digre, 1984 (2) 25 New 8 weeks Steroids, acetazolamide, serial LP Right decompressive craniotomy Diuretics, urea, 2 · LP Digre, 1984 (2) 32 New 8–10 weeks Unilateral ONSF G2P1 Not reported Not reported Not reported G2P1 28 weeks G1P0 4 months G2P1 32 weeks G1P0 20 weeks G1P0 29 weeks G7P3 12 weeks G2P0 14 weeks Right subtemporal decompression Right subtemporal decompression Right subtemporal decompression Serial LP · 6 (over 2 weeks), weight loss, low-calorie diet, diuretics Temporal burr hole decompression Subtemporal decompression Serial LP Pseudotumor Outcome Visual Outcome Recurrent Disease? Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Not reported Resolution (timeframe not specified) Improvement Not reported Not reported Enlarged blind spot OS Ongoing blind spot enlargement N/A Ongoing 5 years later Not reported Mild visual loss Not reported Not reported Not reported Not reported Resolution 4 months postpartum Resolution within 3 months Resolution postpartum Resolution within 3 months Resolution within 1 month postpartum Resolution within 1 month postpartum LP shunt removed 3 months later, symptom resolution Not reported Resolution within 1 month Resolution within 5 months Resolution within 9 months Ongoing mildly decreased visual acuity OU N/A Not reported Normal Not reported Normal Not reported Normal No Not reported Not reported Moderate visual loss Normal Moderate visual loss No No No Perspective 422 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Table 1. Reported patients in the literature undergoing surgical intervention during pregnancy for idiopathic intracranial hypertension Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 Author, Year (Reference Number) Age, Years Gravidity/ Gestation G3P2 16 weeks G2P1 32 weeks G2P1 13 weeks G3P0 12 weeks New Diagnosis/ Established Diagnosis Symptom Duration New 8 weeks Established Unknown Salt restricted diet, 2 · LP LPS replacement New Unknown Serial LP New w1 week New Unknown New Unknown New Unknown Management (in Chronological Order) Digre, 1984 (2) 24 Digre, 1984 (2) 32 Abouleish, 1985 (19) 31 *Thomas, 1986 (30) 22 Shapiro, 1995 (29) 24 Shapiro, 1995 (29) 22 Shapiro, 1995 (29) 22 Shapiro, 1995 (29) 36 G1P0 25 weeks New Unknown Lesny†, 1999 (26) 32 New 1–2 weeks Kim, 2000 (49) 21 G1P0 Unknown G1P0 18 weeks New Unknown LPS, subsequent revision of LPS Martínez-Varea, 2002 (27) 35 G2P0 32 weeks Established Unknown Huna-Baron, 2002 (3) 26 Established Unknown Huna-Baron, 2002 (3) 25 Established Unknown Huna-Baron, 2002 (3) 22 Established Unknown Huna-Baron, 2002 (3) 21 Established Unknown Zamecki, 2007 (40) 22 Not reported 6 months Not reported 5 months Not reported 6 months Not reported 6 months G6P2 13 weeks Acetazolamide, serial LP (2 per week), LPS at time of Cesarean section Acetazolamide, steroids, ONSF, LPS Diet, 2 days continual CSF drainage Steroid, LP · 2 New 1 day Heckathorn, 2010 (23) 26 New Not reported G1P0 26 weeks G1P0 20 weeks G2P1 27 weeks G1P0 30 weeks Regular red blood cell exchange, weekly serial LP Acetazolamide, serial LP, LPS Serial LP, steroids, diuretics, LPS Serial LP, steroids, diuretics, LPS after 2 weeks Serial LP, steroids, diuretics, LPS after 2 weeks, ONSF 1 week later Diuretics, 11 · LP Continual CSF drainage Steroids, bilateral ONSF, lumbar drain Diuretics, steroids, serial LP, lumbar drain Pseudotumor Outcome Visual Outcome Recurrent Disease? Resolution (unknown timeframe) Resolution 2 months after delivery Resolution postpartum Normal No Moderate visual loss Normal Yes Not reported Not reported Yes Improvement by 3-month follow-up Improvement by 3-months follow-up Improvement within 4 weeks Small peripheral scotomas Residual peripheral scotoma OD Small peripheral scotoma No Improvement within 3 months No No No Mildly reduced visual acuity No Not reported Normal Not reported Some improvement in symptoms Significant visual loss OD with optic atrophy. Normal vision OS Not reported Not reported Slight visual improvement by discharge Not reported Not reported Not reported Ongoing visual acuity loss Enlarged blind spot Not reported Not reported Enlarged blind spot Not reported Not reported Enlarged blind spot Not reported Not reported No light perception OS, decreased visual acuity OD, bilateral optic disc pallor Not reported Not reported Not reported Not reported Not reported Perspective 423 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. (Continued ) Author, Year (Reference Number) Age, Years G1P0 15 weeks G2P1 17 weeks New Diagnosis/ Established Diagnosis Symptom Duration Management (in Chronological Order) Pseudotumor Outcome Visual Outcome Recurrent Disease? New Sudden onset 6 · LP, acetazolamide Not reported Not reported Not reported New 10 days 3 · LP Normal vision No Not reported No Not reported No Not reported No Not reported Not reported Resolution of symptoms Not reported Not reported Jacopin-Bruneau, 2010 (24) Badve, 2011 (21) 20 Eissa, 2016 (18) 27 Multiparous 12 weeks New Not reported Serial LP Eissa, 2016 (18) 33 New Not reported Serial LP Eissa, 2016 (18) 30 New Not reported Serial LP Drissi, 2017 (48) 25 New 38 New Rapid symptom onset 2 weeks Acetazolamide, LPS Dogan‡, 2018 (11) Alves, 2021 (20) 21 G1P0 18 weeks G1P0 11 weeks Not reported 13 weeks Multiparous 7 weeks Multiparous 18 weeks New 3 days 2 · LP * 21 Gravidity/ Gestation Serial LP, VPS Resolution of symptoms 1 week postpartum Required shunt insertion after delivery Resolution of symptoms Resolution of symptoms Not reported Resolution within 3 years Improvement with acetazolamide and 2 further LP Not reported This patient had hemoglobin sickle cell disease, and thus a secondary cause for symptoms. This patient had recently undergone in vitro fertilization and had ovarian hyperstimulation syndrome at the time of her IIH diagnosis. This patient had a previous kidney transplant with multiple immunosuppressive medications and may have had other risk factors for the development of intracranial hypertension rather than IIH. CSF, cerebrospinal fluid; IIH, idiopathic intracranial hypertension; LP, lumbar puncture; LPS, lumboperitoneal shunt; OD, in the right eye; ONSF, optic nerve sheath fenestration; OS, in the left eye; OU, in both eyes; VPS, ventriculoperitoneal shunt. † Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 ‡ Perspective 424 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. (Continued ) Perspective CSF diversion option, especially with the wide adoption of stereotactic image–guided surgical navigation in neurosurgery. Most of these studies were not specific to pregnant patients, but given that neither LP nor VP shunting is contraindicated in pregnancy, we believe that these studies can apply to an otherwise normal pregnancy. In pregnancy, there have been 11 reported cases of lumboperitoneal shunt (LPS) insertion (reported between 1979 and 2017), and only 1 case of ventriculoperitoneal shunt (VPS) insertion (reported in 2018) in pregnant IIH patients (2,3,11,25,27,29,47–49). Of these patients, most had tried other less invasive treatments before undergoing shunting. Two patients who proceeded directly to LPS included a 21year-old woman G1P0 18 weeks of gestation who had severe visual symptoms at the time of onset, and a patient with a known diagnosis of IIH who had her LPS replaced (2,49). The high number of LPS compared with VPS performed in pregnant patients is not well explained within the literature. Direct comparison of LPS and VPS in nonpregnant populations overall suggest that VPS may be more effective with less complications than LPS especially since the advent of programmable valves with VPS. Abubaker et al compared the effect of VP shunts with programmable valves against LP shunts for the treatment of 25 patients with IIH. They found that both LP and VP shunts are effective in the immediate postoperative period. While failure rates were slightly higher for VP shunts (14%) compared with LP shunts (11%), revision rates were much higher with LP shunts (60%) compared with VP shunts (30%) (50). Tarnaris et al compared LP and VP shunting in 34 patients with IIH who underwent CSF diversion. They found no significant difference between VP and LP shunt in both headache and visual outcomes, but patients with LP shunting suffered more complications and first-time revisions than patients with VP shunt. VP shunts tended to last longer than LP shunts, but the difference was not statistically significant (51). In a review of case series and case reports of VP and LP shunts in IIH, Feldon found that papilledema resolved in all cases in which a VP shunt was performed. In contrast, papilledema resolved in 22.7% of cases in which LP shunt was performed and improved in 15.9% of cases, but information regarding papilledema resolution was not available for 61.4% of LP shunt cases (52). CSF shunting has a number of potential complications, including intracranial hypotension, shunt occlusion, and valve malfunction. Infection, back pain, abdominal pain, and disconnection of shunt tubing are also possible. The risk of valve malfunction is estimated at 27.5% in pregnant patients, likely from functional obstruction secondary to increasing intra-abdominal pressure from the gravid uterus (8). Increasing abdominal pressures can also mechanically obstruct LP shunts laterally. LP shunting also has risks of leading to iatrogenic cerebellar tonsillar herniation (acquired Chiari malformation) (53). Despite the literature, in clinical practice, VP shunts seem more common currently and Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 would likely be more appropriate in the pregnant IIH population than LP shunts. Venous Sinus Stenting Debate is still ongoing regarding whether transverse sinus stenosis is a cause for IIH or a manifestation. A systematic review and meta-analysis by Nicholson et al of venous sinus stenting demonstrated that among 20 articles from 18 centers and a total of 474 patients, the overall rate of improvement in papilledema was 93.7%, improvement or resolution of headache was 79.6%, and resolution of pulsatile tinnitus was 90.3%. The overall rate of recurrence of IIH symptoms after stent placement was 9.8%, and major complications occurred at a rate of 1.9% (34). There is only 1 case report in the medical literature describing venous sinus stenting in pregnancy. Kamdar et al (54) described a pregnant woman in her first trimester (13 weeks) with IIH and found to have a left transverse–sigmoid sinus junction stenosis with a markedly elevated transstenotic pressure gradient of 50 mm Hg who had an improvement in symptoms after venous sinus stenting. This patient’s improvement is similar to that reported among nonpregnant patients. While there is insufficient data available regarding outcomes and safety of venous sinus stenting in pregnancy, the case report by Kamdar et al suggested that the procedure may be a reasonable option among pregnant patients with medically refractory IIH who are found to have venous sinus stenosis as an etiologic factor. While not common, complications of venous sinus stenting include stent migration, venous sinus perforation, in-stent thrombosis, subdural hemorrhage, post-stent headaches, and recurrent stenosis proximal to the stent (55). There is also uncertainty of therapeutic dual antiplatelet medication use after venous sinus stenting during pregnancy and delivery— aspirin is classified as FDA category D, clopidogrel FDA category B, and newer agents category C–D (56). PROPOSED ALGORITHM FOR SURGICAL TREATMENT OF IDIOPATHIC INTRACRANIAL HYPERTENSION IN PREGNANCY Similar to nonpregnant patients with IIH where conservative management is available and possible, limiting weight gain and medications are typically first line. If needed, 500 mg of oral acetazolamide twice a day can be considered and uptitrated if necessary, usually after 20 weeks of gestation and in consultation with obstetrics and the patient. Where there are indications for rapid ICP reduction, shortterm steroids might be considered as a temporizing, depending on the gestational age and in conjunction with the treating obstetrics team. A single LP for diagnosis and consideration for serial LP could be made on an individual basis especially in patients who cannot tolerate or refuse acetazolamide. Patients with fulminant IIH or who fail are noncompliant with, or 425 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Perspective intolerant of maximum medical and conservative therapy may require surgery even in pregnancy. A lumbar drain may be useful as a temporizing measure in consultation with neurosurgery and obstetrics in fulminant IIH of pregnancy. Both CSF shunting and ONSF may be appropriate, based on the speed of symptom progression and tolerance of medications. As in nonpregnant IIH cases, VP shunting with a programmable valve may be considered for intractable, refractory, and debilitating headache vs ONSF for primarily visual loss. The role of venous stenting in IIH in pregnancy remains ill defined. CONCLUSION The medical management of IIH in pregnancy is complicated by the category C classification of acetazolamide and relative contraindication of substantial weight loss, which are primary treatment for nonpregnant individuals with IIH. Therefore, attention should be given to close follow-up through each trimester of the pregnancy. As in nonpregnant IIH cases, maximum medical therapy should be pursued before consideration of the surgical options for treatment of IIH in pregnancy, unless there is rapid symptom progression or severe symptoms. There is a lack of robust controlled studies in pregnancy-related IIH, and therefore, no firm, evidence-based surgical recommendations can be made, and further studies are required. Multidisciplinary care coordination and individualized treatments are required to ensure optimal patient outcomes. METHOD OF LITERATURE SEARCH A review of PubMed was performed with search phrases “idiopathic intracranial hypertension”, OR “benign intracranial hypertension” OR “pseudotumor cerebri” combined with “pregnancy”, searching through all articles on the database from 1966 to August 2021 (the time of the literature review). A total of 187 articles were identified. All articles involving surgical interventions in pregnant patients with IIH are included in Table 1. Cases where a single LP was performed for diagnosis were not included; however, in patients who had serial LP, the initial diagnostic LP was included in the quantification of how many LP were performed, where the information was available. Cases of intracranial hypertension where review of the article analysis suggested a possible secondary cause are also included in Table 1, with notes below the table to add in qualifying information regarding these cases. Articles, as well as the references cited in relevant articles, were reviewed and discussed where relevant within the article to support the conclusions. Where articles were not available in English, Google Translate was utilized to identify whether they were appropriate for inclusion. STATEMENT OF AUTHORSHIP Conception and design: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee; Acquisition of 426 data: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee; Analysis and interpretation of data: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee. Drafting the manuscript: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee; Revising the manuscript for intellectual content: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee. Final approval of the completed manuscript: S. Karimaghaei, S. Raviskanthan, C. Karimaghaei, P. W. Mortensen, A. I. Malik, Y. J. Zhang, A. G. Lee. REFERENCES 1. Kilgore KP, Lee MS, Leavitt JA, Mokri B, Hodge DO, Frank RD, Chen JJ. Re-evaluating the incidence of idiopathic intracranial hypertension in an era of increasing obesity. Ophthalmology. 2017;124:697–700. 2. Digre KB, Varner MW, Corbett JJ. Pseudotumor cerebri and pregnancy. Neurology. 1984;34:721–729. 3. Huna-Baron R, Kupersmith MJ. Idiopathic intracranial hypertension in pregnancy. J Neurol. 2002;249:1078–1081. 4. Thirumalaikumar L, Ramalingam K, Heafield T. Idiopathic intracranial hypertension in pregnancy. Obstet Gynaecol. 2014;16:93–97. 5. Giuseffi V, Wall M, Siegel PZ, Rojas PB. Symptoms and disease associations in idiopathic intracranial hypertension (pseudotumor cerebri): a case-control study. Neurology. 1991;41:239–244. 6. Ireland B, Corbett JJ, Wallace RB. The search for causes of idiopathic intracranial hypertension. A preliminary case-control study. Arch Neurol. 1990;47:315–320. 7. Pollak L, Zohar E, Glovinsky Y, Huna-Baron R. Reevaluation of presentation and course of idiopathic intracranial hypertension —a large cohort comprehensive study. Acta Neurol Scand. 2013;127:406–412. 8. Tang RA, Dorotheo EU, Schiffman JS, Bahrani HM. Medical and surgical management of idiopathic intracranial hypertension in pregnancy. Curr Neurol Neurosci Rep. 2004;4:398–409. 9. Peterson CM, Kelly JV. Pseudotumor cerebri in pregnancy. Case reports and review of literature. Obstet Gynecol Surv. 1985;40:323–329. 10. Kesler A, Kupferminc M. Idiopathic intracranial hypertension and pregnancy. Clin Obstet Gynecol. 2013;56:389–396. 11. Dogan EA, Dogan S, Goksu ET, Ozkaynak S, Aktan C, Mendilicioglu I. Ventriculoperitoneal shunt treatment in a pregnant renal transplant recipient with idiopathic intracranial hypertension: case report and review of the literature. Neurol Neurochir Pol. 2018;52:401–405. 12. Portelli M, Papageorgiou PN. An update on idiopathic intracranial hypertension. Acta Neurochir (Wien). 2017;159:491–499. 13. Worsham F, Beckman EN, Mitchell EH. Sacrococcygeal teratoma in a neonate. Association with maternal use of acetazolamide. JAMA. 1978;240:251–252. 14. Ibrahim A, Hussain N. Brief report: metabolic acidosis in newborn infants following maternal use of acetazolamide during pregnancy. J Neonatal Perinatal Med. 2020;13:419–425. 15. Chih A, Patel B. Idiopathic intracranial hypertension in pregnancy. Fed Pract. 2015;32:36–40. 16. Lee AG, Pless M, Falardeau J, Capozzoli T, Wall M, Kardon RH. The use of acetazolamide in idiopathic intracranial hypertension during pregnancy. Am J Ophthalmol. 2005;139:855–859. 17. Falardeau J, Lobb BM, Golden S, Maxfield SD, Tanne E. The use of acetazolamide during pregnancy in intracranial hypertension patients. J Neuroophthalmol. 2013;33:9–12. 18. Eissa EM, Daker LI, Shaban MM, Hegazy MI. Lumbar puncture as a single modality for treatment of idiopathic intracranial Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Perspective 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. hypertension during pregnancy. Egypt J Neurol Psychiatry Neurosurg. 2016;53:33–36. Abouleish E, Ali V, Tang RA. Benign intracranial hypertension and anesthesia for cesarean section. Anesthesiology. 1985;63:705–707. Alves S, Sousa N, Cardoso L, Alves J. Multidisciplinary management of idiopathic intracranial hypertension in pregnancy: case series and narrative review. Braz J Anesthesiol. 2021 Mar 20. doi: 10.1080/ 01676830.2021.1880444 Badve M, McConnell MJ, Shah T, Ondecko-Ligda KM, Poutous GW, Vallejo MC. Idiopathic intracranial hypertension in pregnancy treated with serial lumbar punctures. Int J Clin Med. 2011;02:9–12. Greer M. Benign intracranial hypertension. III. Pregnancy. Neurology. 1963;13:670–672. Heckathorn J, Cata JP, Barsoum S. Intrathecal anesthesia for cesarean delivery via a subarachnoid drain in a woman with benign intracranial hypertension. Int J Obstet Anesth. 2010;19:109–111. Jacopin-Bruneau L, Gommier B, Pierre F, Boog G. Hypertension intracrânienne bénigne et grossesse. Propos de deux cas. J Gynecol Obstet Biol Reprod. 2010;39:246–250. Kassam SH, Hadi HA, Fadel HE, Sims W, Jay WM. Benign intracranial hypertension in pregnancy: current diagnostic and therapeutic approach. Obstet Gynecol Surv. 1983;38:314–321. Lesny P, Maguiness SD, Hay DM, Robinson J, Clarke CE, Killick SR. Ovarian hyperstimulation syndrome and benign intracranial hypertension in pregnancy after in-vitro fertilization and embryo transfer. Hum Reprod. 1999;14:1953–1955. Martínez-Varea A, Diago-Almela VJ, Abad-Carrascosa A, Perales-Marín A. Progressive visual loss in a pregnant woman with idiopathic intracranial hypertension. Eur J Obstet Gynecol Reprod Biol. 2012;163:118. Palop R, Choed-Amphai E, Miller R. Epidural anesthesia for delivery complicated by benign intracranial hypertension. Anesthesiology. 1979;50:159–160. Shapiro S, Yee R, Brown H. Surgical management of pseudotumor cerebri in pregnancy: case report. Neurosurgery. 1995;37:829–831. Thomas E. Recurrent benign intracranial hypertension associated with hemoglobin SC disease in pregnancy. Obstet Gynecol. 1986;67:7S–9S. Ghali AA, El-Seidy E, Hussein TR, Mostfa M. Idiopathic intracranial hypertension in pregnant women. Egypt J Neurol Psychiatr Neurosurg. 2009;46:141–150. Evans RW, Friedman DI. Expert opinion: the management of pseudotumor cerebri during pregnancy. Headache. 2000;40:495–497. Friedman DI, Jacobson DM. Idiopathic intracranial hypertension. J Neuroophthalmol. 2004;24:138–145. Nicholson P, Brinjikji W, Radovanovic I, Hilditch CA, Tsang ACO, Krings T, Mendes Pereira V, Lenck S. Venous sinus stenting for idiopathic intracranial hypertension: a systematic review and meta-analysis. J Neurointerv Surg. 2019;11:380–385. De Wecker L. On incision of the optic nerve in cases of neuroretinitis. Int Ophthalmol Cong Rep. 1872;4:11–14. Hayreh SS. Pathogenesis of oedema of the optic disc. Doc Ophthalmol. 1968;24:289–411. Sobel RK, Syed NA, Carter KD, Allen RC. Optic nerve sheath fenestration: current preferences in surgical approach and biopsy. Ophthalmic Plast Reconstr Surg. 2015;31:310–312. Brazis PW. Clinical review: the surgical treatment of idiopathic pseudotumour cerebri (idiopathic intracranial hypertension). Cephalalgia. 2008;28:1361–1373. Karimaghaei et al: J Neuro-Ophthalmol 2022; 42: 419-427 39. Banta JT, Farris BK. Pseudotumor cerebri and optic nerve sheath decompression. Ophthalmology. 2000;107:1907–1912. 40. Zamecki KJ, Frohman LP, Turbin RE. Severe visual loss associated with idiopathic intracranial hypertension (IIH) in pregnancy. Clin Ophthalmol. 2007;1:99–103. 41. Shekleton P, Fidler J, Grimwade J. A case of benign intracranial hypertension in pregnancy. Br J Obstet Gynaecol. 1980;87:345–347. 42. Malik AI, Xu J, Lee AG. Outcomes of optic nerve sheath fenestration from superomedial eyelid crease approach. Orbit. 2021 Feb 15:1–9. doi: 10.1080/01676830.2021.1880444 43. Karmaniolou I, Petropoulos G, Theodoraki K. Management of idiopathic intracranial hypertension in parturients: anesthetic considerations. Can J Anaesth. 2011;58:650–657. 44. Mudumbai RC. Optic nerve sheath fenestration: indications, techniques, mechanisms and, results. Int Ophthalmol Clin. 2014;54:43–49. 45. Park DSJ, Park JSY, Sharma S, Sharma RA. Idiopathic intracranial hypertension in pregnancy. J Obstet Gynaecol Can. 2021 Nov;43:1292–1295. 46. Schiffman JS, Scherokman B, Tang RA, Dorotheo EU, Prieto P, Varon J. Evaluation and treatment of papilledema in pregnancy. Compr Ophthalmol Update. 2006;7:187–202. 47. Keltner JL, Miller NR, Gittinger JW, Burde RM. Pseudotumor cerebri. Surv Ophthalmol. 1979;23:315–322. 48. Drissi J, Hachi A, Adlani L, Kouach J, Moussaoui D, Dehayni M. Hypertension intracrânienne idiopathique: à propos d’un cas rare associé à la grossesse. Pan Afr Med J. 2017;27:143. 49. Kim K, Orbegozo M. Epidural anesthesia for cesarean section in a parturient with pseudotumor cerebri and lumboperitoneal shunt. J Clin Anesth. 2000;12:213–215. 50. Abubaker K, Ali Z, Raza K, Bolger C, Rawluk D, O’Brien D. Idiopathic intracranial hypertension: lumboperitoneal shunts versus ventriculoperitoneal shunts—case series and literature review. Br J Neurosurg. 2011;25:94–99. 51. Tarnaris A, Toma AK, Watkins LD, Kitchen ND. Is there a difference in outcomes of patients with idiopathic intracranial hypertension with the choice of cerebrospinal fluid diversion site: a single centre experience. Clin Neurol Neurosurg. 2011;113:477–479. 52. Feldon SE. Visual outcomes comparing surgical techniques for management of severe idiopathic intracranial hypertension. Neurosurg Focus. 2007;23:E6–E7. 53. Chumas PD, Armstrong DC, Drake JM, Kulkarni AV, Hoffman HJ, Humphreys RP, Rutka JT, Hendrick EB. Tonsillar herniation: the rule rather than the exception after lumboperitoneal shunting in the pediatric population. J Neurosurg. 1993;78:568–573. 54. Kamdar H, Gullo T, Strohm T. Idiopathic intracranial hypertension in a pregnant female improved with venous sinus stenting (4990). Neurology. 2021;96(15 suppl):4990. 55. Dave SB, Subramanian PS. Pseudotumor cerebri: an update on treatment options. Indian J Ophthalmol. 2014;62:996–998. 56. Yarrington CD, Valente AM, Economy KE. Cardiovascular management in pregnancy: antithrombotic agents and antiplatelet agents. Circulation. 2015;132:1354–1364. 57. Nickerson CW, Kirk RF. Recurrent pseudotumor cerebri in pregnancy. Report of 2 cases. Obstet Gynecol. 1965;26:811–813. 58. Jefferson A, 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. 1976;39:627–639. 59. Caroscio JT, Pellmar M. Pseudotumor cerebri: occurrence during the third trimester of pregnancy. Mt Sinai J Med. 1978 Jul-Aug;45:539–541. 427 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.