Idiopathic Intracranial Hypertension After Avoidant/Restrictive Eating Disorder

Clinical Correspondence Section Editors: Robert Avery, DO Karl C. Golnik, MD Caroline Froment, MD, PhD An-Guor Wang, MD Idiopathic Intracranial Hypertension After Avoidant/Restrictive Eating Disorder Ashtyn Zapletal, Subahari B. Raviskanthan, MBBS, Peter W. Mortensen, MD, Andrew G. Lee, MD I diopathic intracranial hypertension (IIH), or pseudotumor cerebri, is defined as increased intracranial pressure (ICP) with normal cerebrospinal fluid content and a neuroimaging study without an intracranial lesion or other identifiable cause. Although the exact mechanism of IIH is unknown, it is most often associated with obese women of child-bearing age (1,2). We report a case of IIH in an underweight patient with avoidant/restrictive food intake disorder after intentional weight gain as part of her treatment for her eating disorder. A 19-year-old woman presented with a 1-week history of blurred vision, binocular vertical diplopia, headache, and retroorbital pressure. Her medical history was significant for anxiety, depression, and anorexia nervosa. She was under an eating disorder management program, and her body mass index (BMI) had increased from underweight at 18 to normal at 20.66 kg/m2 (normal 18.5–24.9) with a weight gain of 35 pounds over the preceding few months. Her medications were significant for sertraline and olanzapine, and she had an etonogestrel (Nexplanon) implant in situ, inserted 2 years prior. She smoked 6 cigarettes daily and drank alcohol socially. On examination, her visual acuity was 20/50 in the right eye and 20/20 in the left eye. Her pupils were isocoric without a relative afferent pupillary defect. Extraocular motility examination showed a right hypertropia and suspected cranial nerve IV palsy in the right eye. Slitlamp examination was normal in both eyes. Dilated fundus Texas A and M College of Medicine (AZ), Dallas, Texas; Department of Ophthalmology (SR, PWM, AGL), Blanton Eye Institute, 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; University of Texas MD Anderson Cancer Center (AGL), Houston, Texas; Texas A and M 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. All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work as a whole, and have given their approval for this version to be published. Address correspondence to Andrew G. Lee, MD, Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, 6560 Fannin Street 450, Houston, TX 77030; E-mail: aglee@ houstonmethodist.org Zapletal et al: J Neuro-Ophthalmol 2023; 43: e171-e172 examination revealed Grade III optic disc edema in both eyes. Noncontrast computed topography (CT) of the brain and MRI of the brain and orbits with contrast were normal. Magnetic resonancewith no evidence of venous sinus thrombosis. Lumbar puncture showed an elevated opening pressure of 50 cm of H20 (normal range ,25 cm of H20). Cerebrospinal fluid analysis was unremarkable. She met the modified Dandy criteria and was diagnosed with IIH. Acetazolamide 500 mg twice per day was commenced, as well as a 3-day course of high-dose thiamine given her nutritional risk factors. Three months after discharge from the hospital, the patient was seen in the neuro-ophthalmology clinic. The visual acuity had improved to 20/20 in both eyes. Her cranial nerve 4 palsy and diplopia had resolved, and her optic disc edema had improved to Grade 2 in both eyes. Automated perimetry (automated visual field 24-2) showed nonspecific scatter in the right nasal field but was otherwise unremarkable. The OCT of the retinal nerve fiber layer showed a thickness of 98 mm in the right eye and 124 mm in the left eye. Her weight had overall been stable, with mild fluctuations within 3 pounds of her new baseline weight. Over the next 6 months, she remained clinically stable on acetazolamide, with the normal visual acuity and visual fields and postpapilledema atrophy on clinical examination and OCT. Although IIH remains idiopathic and a diagnosis of exclusion, several risk factors have been identified, including female sex, obesity, and being of reproductive age (3). Additional risk factors have been suggested, including antibiotics (e.g., tetracyclines), vitamin A, and corticosteroid withdrawal (1). There is a strong association between weight gain in both overweight individuals and those of normal BMI and IIH. There is less literature however regarding the association of IIH with individuals with low or subnormal BMI (such as in anorexia or other malnutritional states) and intentional rapid weight gain. In the setting of eating disorder treatment, proposed mechanisms by which IIH could occur include vitamin A replacement and hyperleptinemia (3–5). Anorexia and malnutritional states have been associated with multiple metabolic derangements, with reports in e171 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence children linking nutritional deficiencies from cystic fibrosis or failure to thrive to raised ICP (5). These cases specifically suggest the role of vitamin A replacement in the development of IIH. Vitamin A analogs, such as retinoic acid, have previously been linked to IIH in a mechanism believed to be related to increased uptake and activation of vitamin A within adipocytes (1,2). However, as reported in those with chronic nutritional deficiencies, normalization of vitamin A from previously low levels is also believed to cause increased ICP (5). This makes the interesting connection between vitamin A supplementation and IIH that could be extended to eating disorder treatment of anorexia nervosa because the increased number of adipocytes may harbor higher levels of vitamin A. Another hypothesis for intracranial hypertension could be related to leptin. Leptin is a hormone derived from adipocytes that is roughly proportional to the fat content of the body. Leptin functions to signal to the body that adequate fat stores have been achieved and food intake is no longer required (1). The role of leptin in IIH is believed to be prothrombotic, creating microthrombi within the venous sinuses and leading to increased ICP (3). Individuals with anorexia characteristically have low levels of leptin, given their decreased body fat content. However, because nutrition is restarted, leptin rises to normal or even supratherapeutic levels (4). This provides a potential link between hyperleptinemia and IIH in the setting of weight gain from eating disorder management. Most patients with IIH are recommended to have weight loss as a treatment because IIH is known to be a disorder of young, obese women, and weight gain is a known precipitating factor for the disease. Like refeeding syndromes in intentional restrictive eating disorders or in e172 unintentional starvation syndromes, rapid weight gain can produce metabolic derangements. To the best of our knowledge, IIH has not been described in the English language ophthalmic literature as a consequence of intentional rapid weight gain after dietary and psychological treatment of anorexia nervosa. Clinicians should consider intracranial hypertension as a possible complication of rapid weight gain in all patients, even those who are underweight. STATEMENT OF AUTHORSHIP Conception and design: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee; Acquisition of data: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee; Analysis and interpretation of data: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee. Drafting the manuscript: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee; Revising it for intellectual content: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee. Final approval of the completed manuscript: A. Zapletal, S. Raviskanthan, P. W. Mortensen, A. G. Lee. REFERENCES 1. 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