Undiagnosed Normocephalic Pancraniosynostosis Presenting as Bilateral Abducens Nerve Palsy.

Primary pancraniosynostosis is a rare variant of craniosynostosis in which the major cranial sutures prematurely fuse. Single-suture craniosynostosis is often recognized early in life due to an abnormal head shape. In contrast, primary pancraniosynostosis may be diagnosed later in life due to a grossly normal head shape and size. As such, these children can present with symptoms related to chronically elevated intracranial pressure (eg, vision loss or cognitive impairment). This report highlights a patient with primary pancraniosynostosis associated with unique neurologic sequelae-namely, bilateral abducens nerve palsy. A 9-year-old boy presented to the ophthalmologist with a 1-month history of double vision, drifting of his right eye toward the nasal bridge, and intracranial hypertension evident with papilledema. Physical examination was notable for mild bitemporal narrowing. A computed tomography study demonstrated radiologic thumbprinting, diffuse osseous sclerosis, and fusion of the bilateral coronal, sagittal, metopic, and lambdoid sutures. The patient underwent emergent cranial vault expansion with fronto-orbital advancement. Papilledema had resolved 4 months following surgery. At 2-year follow-up, abducens nerve palsy and head shape were significantly improved. This study brings attention to an unreported presenting symptom of pancraniosynostosis (bilateral abducens nerve palsy). This information may lead to quicker diagnosis and treatment of pancraniosynostosis-induced intracranial hypertension, which is critical to prevent long-term sequelae.