Discussion
Both NF1 and SCD individually may cause unique complications that when combined can be worsened. Patients with sickle cell disease have an increased risk of vasculopathies. NF1 has been shown to increase the risk of peripheral and cerebral vascular abnormalities in the pediatric patient. Neurofibromatosis type 1-associated vasculopathy is an acquired condition that can affect all sized vasculature, most notably causing aneurysms or stenoses of the aortic, renal and mesenteric circulation6. Therefore, routine screening for hypertension is recommended due to renovascular disease as well as coarctation of the aorta7. Additionally, moyamoya disease and other cerebral vasculopathies have been routinely observed; therefore, screening with an MRV/MRA brain is recommended for evaluation of moyamoya, arteriovenous malformation, and strokes8.
Similarly, SCD increases the risk of micro and macro vasculopathies, which causes the development of pulmonary hypertension, stroke, leg ulcerations, priapism, and other organ dysfunctions9. In this patient, her MRI brain showed a remote infarct in the right frontal lobe showing a silent stroke. Both her NF1 and SCD increases her risk of having strokes, pulmonary hypertension, and other vascular complications that need routine screening9-11.
IH can be caused by cerebral vascular abnormalities including intracranial venous sinus thrombosis and venous sinus stenosis12.  Several reports have shown occurrence of cerebral venous and sinus thrombosis in SCD and NF113-14. Other causes of intracranial hypertension in NF1 include intracranial mass as well as aqueductal stenosis3,15. This patient had no vascular or structural abnormality noted on brain imaging.
Many studies have shown a relationship between IH and SCD4-5. Hydroxyurea increases fetal hemoglobin, which has been reported to cause IH and increased risk of cerebral vascular abnormalities16-17. When hydroxyurea was discontinued, the IH improved in some patients4-5. In our patient, after discontinuing hydroxyurea and starting acetazolamide, her OCT RFNL became normal. Her fetal hemoglobin dropped to 15.7%. We are unable to determine if hydroxyurea was the cause of IH or if she developed idiopathic intracranial hypertension, since the increased pressure resolved with both the discontinuation of hydroxyurea and usage of acetazolamide. Prospective evaluation of patients such as the one presented are needed in order to determine if increases in fetal hemoglobin cause IH or if another etiology may be to blame. Additionally, more genetic studies are needed to show if there is a link between NF1 and SCD.