Supplementary Material for: Bilateral Meckel’s Cave Cephalocele Presenting as Cranial Nerve VI Palsy: A Case Report

Introduction
Meckel’s cave cephalocele, also known as petrous apex cephalocele (PAC), is a rare cystic lesion caused
by herniation of the cerebrospinal fluid into the Meckel’s cave. Bilateral PACs are exceptionally rare,
with only 21 reported cases. PACs may present with headache, diplopia, tinnitus, or cranial nerve
palsy.
Case presentation
A 74-year-old male presented with acute onset headache, vision changes, and gait instability. His
medical history included hypertension and melanoma. Examination revealed a left cranial nerve VI
palsy. Initial imaging with head CT and CTA showed no acute intracranial abnormalities but revealed
moderate chronic sinusitis. Magnetic resonance imaging demonstrated large bilateral Meckel’s cave
cephaloceles, more prominent on the left, with mass effect on the inferior margins of the cavernous
sinus. Steroid treatment was initiated for suspected influenza-associated cranial neuropathy. Follow-
up did not reveal an immediate improvement. However, after several weeks of steroid treatment, his
symptoms improved significantly. The patient deferred surgical intervention.
Conclusions
This case highlights a rare presentation of bilateral PACs with cranial nerve VI palsy. Although
surgical intervention may be definitive, conservative treatment can provide relief of symptoms in select
cases. More research is needed to guide optimal management strategies.