Supplementary Material for: Cerebrospinal Fluid Leak and Idiopathic Intracranial Hypertension (IIH) in a Transgender Male: Is IIH Hormonally Mediated?

Background: The pathophysiology of Idiopathic intracranial hypertension (IIH) is not fully characterized, and less is known about its development in transgender patients. Several cases of IIH in transgender patients have been reported, but fewer cases have been published that identify a cerebrospinal fluid (CSF) leak as a complication of IIH in this population. These patients can serve as an important study population, as an association between exogenous testosterone use in karyotypical females and development of IIH may support a hormonally-mediated mechanism of development of this disease.
Case: We describe the case of a 33-year-old obese (BMI: 30.58 kg/m2) female-to-male (FTM) transgender patient on exogenous testosterone for 15 years who presented with 1-month of acute on chronic headache with profuse rhinorrhea. Fundoscopic exam revealed disc pallor and edema consistent with a Frisen Gade 3 papilledema. Nasal secretion was positive for beta-2 transferrin, consistent with CSF. Computed tomography (CT) head demonstrated a 5-mm defect in the medial left middle cranial fossa, bilateral optic nerve prominence and tortuosity, and abnormal arachnoid granulations concerning for IIH. After a successful endoscopic endonasal repair of the left lateral sphenoid recess leak, our patient continued to report headaches, was started on acetazolamide, and noted improvement in symptoms.
Conclusion: The case described herein further supports the growing body of evidence that implicates a hormonal mechanism of action in the development of IIH. Importantly, it also addresses the need for increased study and conversation about rare neurologic diseases in transgender patients.