Increased Intra-abdominal Pressure Exacerbates Idiopathic Intracranial Hypertension

Clinical Correspondence Section Editors: Robert Avery, DO Karl C. Golnik, MD Caroline Froment, MD, PhD An-Guor Wang, MD Increased Intra-abdominal Pressure Exacerbates Idiopathic Intracranial Hypertension Scott J. Bowman, MD, Shira S. Simon, MD, MBA, Nicholas J. Volpe, MD I diopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a condition characterized by increased intracranial pressure (ICP) that most classically presents in obese women of child-bearing age. Patients develop signs and symptoms of elevated ICP including headache, back pain, transient visual obscurations, vision loss, diplopia, and pulse synchronous tinnitus. Almost all patients with IIH have papilledema, and some can present with sixth cranial nerve palsy. In the IIH Treatment Trial, w97% of enrolled patients were women, with an average body mass index of .39 (1). IIH has also been found in patients taking vitamin A derivatives, tetracycline-class antibiotics, recombinant growth hormones, lithium, and corticosteroids. Hormonal changes may play a role as well; however, the exact mechanism remains unclear. One pathophysiologic theory for the increase in ICP in patients with IIH posits that increased intra-abdominal pressure causes a cascade effect in obese patients, and this could increase pleural pressure, leading to increased cardiac filling pressure, subsequent increased intracranial venous pressure, and then impeded venous return from the brain, which would increase ICP (2). A 27-year-old woman presented with a medical history significant for obesity with recent weight gain and no significant ocular history. She complained of “glare and blur” in her vision over the past 2 months and pulse synchronous tinnitus. She endorsed a 40-pound weight gain over the past several months, with associated headaches. She had normal neuroimaging, and a lumbar puncture revealed an elevated opening pressure. She was being treated with acetazolamide 500 mg twice daily. She had no other risk factors and no medication exposures known to be associated with IIH. Examination was significant for a visual acuity of 20/25 in both eyes without an afferent pupillary defect as well as grade III papilledema. She had a mildly enlarged blind spot on computerized perimetry. She was maintained on 500 mg acetazolamide twice daily, successfully lost weight, and returned 3 months later with largely resolved disk swelling and symptoms. Acetazolamide was then tapered off. Two years later, she had a repeat flare associated with weight gain while off of acetazolamide, although the patient maintained full visual fields. This episode resolved with restarting acetazolamide and a 20-pound weight loss. Within 4 weeks of a neuro-ophthalmologic examination demonstrating no papilledema while off of acetazolamide (Fig. 2, December 9, 2019) and 5 years after her initial presentation, she underwent a full body liposuction procedure including the abdomen, back, and legs, resulting in Department of Ophthalmology (SB, SSS, NJV), Northwestern University Feinberg School of Medicine, Chicago, Illinois; and Department of Neurology (SSS), Northwestern University Feinberg School of Medicine, Chicago, Illinois. The authors report no conflicts of interest. Address correspondence to Nicholas J. Volpe, MD, Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, 645 N Michigan Avenue, Chicago, IL 60611; E-mail: nvolpe@ mm.org e164 FIG. 1. Patient appeared wearing abdominal binding suit with foam inserts when she presented on January 8, 2020, with exacerbation of papilledema 3 weeks after the liposuction procedure. Bowman et al: J Neuro-Ophthalmol 2023; 43: e164-e166 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence FIG. 2. Optic disc photographs of the right (A) and left (B) eyes before (December 9, 2019) liposuction, during the acute exacerbation (January 8, 2020) postliposuction of the right (C) and left eyes (D). The constrictive body suit was removed after her first neuro-ophthalmology visit on January 8, 2020. Gradual resolution of papilledema after suit removal and treatment with Diamox in the right (E) and left eyes (F) with residual pallor seen on February 20, 2020, in the right (G) and left eyes (H). significant weight reduction. Two weeks after the liposuction procedure, she noted recurrent headaches, pulse synchronous tinnitus, and subsequent vision loss in the right eye. She took acetazolamide 3 times a week when these symptoms started and presented to the clinic 3 weeks after the liposuction procedure. At that visit, she was noted to have recurrent disk edema (Fig. 2, January 8, 2020) and significant visual field loss in the right eye. Further questioning revealed that after the liposuction procedure, she was not placed on antibiotics or steroids but was wearing a constrictive abdominal suit with postoperative protocol instructions requiring the patient to force styrofoam sheets under the constrictive elastic suit (Fig. 1). The patient was instructed to remove the body suit, and acetazolamide was restarted at 1,000 mg twice daily. Magnetic resonance venography of the brain was normal. Two weeks later, acetazolamide was increased to 2,000 mg twice daily. Within 1 month, the optic disc edema and elevated ICP-associated symptoms had resolved (Fig. 2, February, 7, 2020), and there was no progression or recovery of her visual field loss in the right eye. Patient remains off therapy without weight gain and has had no recurrent flare of her disease since that time. DISCUSSION The exact pathophysiology of increased ICP in patients with IIH remains obscure. Ultimately, IIH likely develops for Bowman et al: J Neuro-Ophthalmol 2023; 43: e164-e166 several different reasons; the female predominance suggests at least some component of sex hormones as a contributing factor. In addition, as aforementioned, one theory links obesity to central venous hypertension, which in turn decreases venous return from the brain. This case demonstrates a temporal and potentially causal relationship between increased intra-abdominal pressure and an IIH flare. Previous studies showed that a continuous negative abdominal pressure device (ABSHELL) lowered intraabdominal pressure in patients with IIH and improved the severity of headaches and pulse synchronous tinnitus as well as urinary bladder pressure, a proxy for intra-abdominal pressure (3). Interestingly, when removed from the negative abdominal pressure device, patients in this study experienced a near immediate recurrence of IIH symptoms, which then resolved when the device was used again. In severely obese patients, central venous pressure can be elevated beyond normal values because the increased intraabdominal pressure in obese patients increases intrathoracic pressure, leading to increased cardiac filling pressures (4). It has been proposed that the increased pleural pressure results in increased superior vena caval pressure tracking back to the brain and causing intracranial hypertension seen in IIH (2). In this setting, IIH may be secondary to venous engorgement rather than excessive production or decreased absorption of cerebral spinal fluid. In addition, recent modeling of Starling law forces suggests that intracranial fluid and intracranial pressure are related to a combination of e165 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence hydrostatic and osmotic pressure gradients adjacent to the blood–brain barrier (5), gradients which could likely be affected by increased central venous pressure. This case supports this pathophysiologic theory that decreased venous return from increased intra-abdominal pressure can contribute to the recurrence of increased ICP. Interventions aimed at lowering intra-abdominal pressure such as bariatric surgery or negative abdominal pressure devices could play a role in the treatment of IIH refractory to medical therapy. Patients and surgeons should also be made aware of this unusual complication of such devices worn to enhance healing after liposuction procedures. STATEMENT OF AUTHORSHIP Conception and design: S. Bowman, N. J. Volpe, S. S. Simon; Acquisition of data: S. Bowman, N. J. Volpe, S. S. Simon; Analysis and interpretation of data: S. Bowman, N. J. Volpe, S. S. Simon. Drafting the manuscript: S. Bowman, N. J. Volpe, S. S. Simon; Revising it for intellectual content: S. Bowman, N. J. Volpe, S. S. Simon. Final approval of the completed manuscript: S. Bowman, N. J. Volpe, S. S. Simon. e166 ACKNOWLEDGMENTS All authors attest that they meet the current ICMJE criteria for authorship. REFERENCES 1. The NORDIC Idiopathic Intracranila Hypertension Study Group Writing Committee. Effect of acetazolamide on visual function in patients with idiopathic intracrnial hypertension and mild visual loss: the idiopathic intracranial hypertension treatment trial. JAMA. 2014;311:1641–1651. 2. Sugerman H, Windsor A, Bessos M, Wolfe L. Intra-abdominal pressure, sagittal abdominal diameter and obesity comorbidity. J Intern Med. 1997;241:71–79. 3. Sugerman HJ, Felton WL III, Sismanis A, Saggi BH, Doty JM, Blocher C, Marmarou A, Makhoul RG. Continuous negative abdominal pressure device to treat pseudotumor cerebri. Int J Obes Relat Metab Disord. 2001;25:486–490. 4. Mizunoya K, Saito H, Morimoto Y. Evaluation of external reference levels for central venous pressure measurements of severely obese patients in the supine position. J Anesth. 2018;32:558–564. 5. Linninger AA, Xu C, Tangen K, Hartung G. Starling forces drive intracranial water exchange during normal and pathological states. Croat Med J. 2017;58:384–394. Bowman et al: J Neuro-Ophthalmol 2023; 43: e164-e166 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.