Case Report
An 8 year-old African American female with severe sickle cell (HgSS)
disease diagnosed at birth was confirmed to have NF1 at 13 months of age
with > 6 cafe au lait macules over 5mm in diameter,
freckling in the axillary regions (Crowe’s sign) and significant family
history as the mother of child has 6 other children, 3 of whom have NF1
including herself. The patient’s SCD course was complicated by splenic
sequestration necessitating splenectomy at 3 years of age. She was
started on Hydroxyurea at 5 years of age and since has had a good
hematologic and clinical response in that she did not require
hospitalizations or emergency intervention for a severe vaso-occlusive
crisis. She followed with ophthalmology annually to screen for
ophthalmologic associations with SCD and NF1 beginning at age 6 years.
She was also seen by neurology to evaluate for possible brain
vasculopathies as well as learning delays associated with NF1. Routine
brain imaging surveillance with MRI/MRA had been normal except for a T2
hyperintensity in the right frontal lobe periventricular white matter
related to a remote infarct and slightly prominent lenticulostriate
vessels noted initially when she was 5 years of age (Supplemental Fig.
S1). She has been neurologically asymptomatic.
When she was 7 years of age, she was noted to have incidental
papilledema. Subsequent work up revealed MRI/MRA brain w/wo contrast and
MRI orbits w/wo showed no masses or new changes compared to prior
imaging. A lumbar puncture was then performed showing an opening
pressure of 34cm H2O confirming the clinical suspicion of IH. She was
asymptomatic at the time, but was started on 250 mg PO BID of
acetazolamide orally while at the same time the hydroxyurea was
discontinued, as reports had shown high fetal hemoglobin could cause
intracranial hypertension. Her fetal hemoglobin was 30.5% which was
otherwise an ideal response to the disease modifying agent in a patient
with severe SCD.
Papilledema was noted to persist several weeks after starting
acetazolamide, so the dose was titrated up and the patient was referred
for pediatric neuro-ophthalmic evaluation. Ancillary testing performed 3
months later during pediatric neuro-ophthalmic evaluation confirmed
normal retinal nerve fiber layer (RNFL) analysis with mild peripapillary
hyperreflective ovoid mass-like structures (PHOMS) at the present dose
of acetazolamide 425 mg PO BID (Fig. 1). The patient was then tapered
off acetazolamide over the period of 1 month, and repeat testing
performed 7 months later confirmed presence of normal RNFL analysis in
both eyes with congenital anomaly of both optic nerves (Supplemental
Fig. S2). Since optical coherence tomography (OCT) RNFL was normal and
the patient continued to have no symptoms, hydroxyurea was restarted 5
months after initial diagnosis of IH and her fetal hemoglobin at that
time was 15.7%. Table 1 shows her hemoglobin electrophoresis trend. She
has been feeling well with no worsening in the ophthalmological exam
while off acetazolamide.