Endovascular Stenting in a Transgender Patient With Idiopathic Intracranial Hypertension

Abstract

Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure (ICP) of unknown etiology. Common presenting symptoms include headache, transient obscuration of vision (TOV), diplopia, and pulsatile tinnitus (1). Transverse venous sinus stenosis may be observed on magnetic resonance venography (MRV) in 30%–93% of IIH cases (2). In cases where focal venous sinus stenosis is observed with a cerebral venous pressure gradient >8 mm Hg, endovascular stenting is often considered a viable treatment option (2). Most IIH cases occur in overweight women between 20 and 40 years of age (1). With the advent of testosterone therapy in gender reassignment, there have been cases of IIH occurring in karyotypically female patients during female-to-male gender reassignment. Most of these patients were successfully treated with medical management, but none have been treated with endovascular stenting (3). In this report, we present a patient diagnosed with IIH while undergoing female-to-male gender reassignment who was successfully managed with endovascular stenting. A 36-year-old patient (karyotypically 46XX) undergoing female-to-male reassignment was referred to neuro-ophthalmology for a 6-month history of constricting visual fields, TOVs lasting seconds, headache, dizziness, and “ear popping.” Three months before his neuro-ophthalmology visit, he was found to have papilledema and the opening pressure was 21 cm H2O on lumbar puncture. At our initial evaluation, he was taking acetazolamide 1 g/day. His hormone therapy consisted of testosterone cypionate 100 mg injected intramuscularly every week for 50 months before symptom onset. His body mass index was 25 kgm2. Visual acuities were 20/20 in each eye, with normal pupillary testing and full extraocular movements. There was bilateral papilledema, more marked in the left eye. Whereas the right visual field was full, there was a nasal field loss in the left eye. MRV indicated mild narrowing of the left transverse sinus and a partially occluded right transverse sinus (Fig. 1A). Optical coherence tomography (OCT) indicated retinal nerve fiber layer (RNFL) measurements of 91 µm in the right eye and 140 µm in the left eye. His IIH medications were changed to daily acetazolamide 1.5 g, furosemide 20 mg, and topiramate 25 mg. This led to slight decrease in headaches, some improvement in papilledema but no improvement in visual field testing.FIG. 1.: Cerebral venous sinus studies. A. On magnetic resonance venography, there is stenosis (arrow) of the right transverse sinus 4 months before endovascular stenting. Internal carotid angiography of right transverse sinus stenosis (arrows) before (B) stent placement. The stenosis is no longer present after the stenting procedure (C). RT ICA, right internal carotid artery.The patient was referred to neuroradiology, and central venous pressure gradients (CVPG) across transverse sinuses were 13.5 mm Hg bilaterally. Due to lack of improvement after 5 months of medical management and bilaterally elevated CVPG, he underwent endovascular stenting. The right transverse sinus appeared slightly dominant compared to the left with narrowing at the distal aspects of both transverse sinuses (Fig. 1B). Before stent placement, average pressure gradient across the torcula and right sigmoid sinus was 12.7 mm Hg based on 3 separate measurements. After stent placement, average pressure gradient was 2.7 mm Hg. The internal carotid artery angiogram indicated proper positioning of a widely patent stent at the distal aspect of the right transverse sinus without residual stenosis (Fig. 1C). One month later, the patient reported resolution of headaches and TOVs. OCT revealed some residual RNFL thinning (84 µm in the right eye and 77 µm in the left eye). At 6-month follow-up, the patient was doing well without headaches, his papilledema had resolved, and automated visual fields were full. MRV indicated that the stent remained patent. Our transgender patient undergoing female-to-male reassignment with testosterone therapy developed IIH. Previously reported IIH cases in transgender patients were all female-to-male reassignment and, like ours, all patients received testosterone therapy (3). In 3 cases, patients were successfully managed with medical treatment by altering testosterone therapy and adding acetazolamide. One patient achieved remission with optic nerve sheath fenestration, and another had an emergent lumboperitoneal shunt (3). Unlike previous reports, our patient had transverse sinus stenosis with elevated CVPG and was managed with endovascular stenting without the need to change the testosterone treatment. It is likely that hormones play a role in the pathophysiology of IIH (1). Although no study has successfully proven a link between estrogen and IIH, one report suggested hyperandrogenism was associated with earlier onset of IIH in women (4). This was positively correlated with increased circulating levels of testosterone and androstenedione but not with levels of estradiol. In addition, polycystic ovarian syndrome, a hyperandrogenic metabolic disorder, has been associated with IIH (1,2). Transverse sinus stenosis is commonly associated with IIH, but the role of hormones in the relationship between transverse sinus stenosis and increased ICP remains unknown. In our patient, we were unable to conclusively determine whether the etiology of the stenosis was extrinsic secondary to elevated ICP or intrinsic due to the anatomy of the venous sinus. The presence of venous sinus stenosis was not specifically discussed in previous transgender female-to-male reassignment cases receiving testosterone. It may be that a “second hit” is required for patients with predisposing venous sinus anatomy to develop IIH (5). Testosterone may be a contributor to that “second hit.” STATEMENT OF AUTHORSHIP Category 1: a. Conception and design: K. Kogachi, A. Konstas, R. Karanjia, and A. A. Sadun; b. Acquisition of data: K. Kogachi, A. Konstas, R. Karanjia, and A. A. Sadun; c. Analysis and interpretation of data: K. Kogachi, A. Konstas, R. Karanjia, and A. A. Sadun. Category 2: a. Drafting the manuscript: K. Kogachi; b. Revising it for intellectual content: K. Kogachi, A. Konstas, R. Karanjia, and A. A. Sadun. Category 3: a. Final approval of the completed manuscript: K. Kogachi, A. Konstas, R. Karanjia, and A. A. Sadun.