Introduction: Patients with Chiari type 1 malformation (CM1) may present primarily with visual symptoms. The presence of papilledema without hydrocephalus, with associated visual troubles, indicating raised intracranial pressure (ICP), has been rarely reported in the literature. The purpose of this study was to follow the clinical evolution after decompressive surgery and to examine the relationship between CM1 and papilledema.
Methods: We report on a series of five children, aged 5 to 14 years, presenting with CM1 on magnetic resonance imaging (MRI) ranging from 7 to 12 mm of tonsillar herniation, without associated hydrocephalus. Symptoms consisted in headache, diminished visual acuity, diplopia or retro-orbital pain. Ophtalmological evaluation showed bilateral papilledema in all of them and intraorbital Doppler sonography demonstrated a reversed flow in the superior ophthalmic vein in two children. Dilatation of the optic nerve sheaths and flattening of the posterior aspect of the globes, reflecting raised ICP, were observed on MRI in all of them. Surgery consisted in posterior fossa decompression with C1 laminectomy and duraplasty.
Results: Following surgery (follow-up: 1 year to 5 years), all children improved clinically. Papilledema completely resolve in only one case and improved in another. In the remaining three, papilledema was unchanged and intraorbital Doppler sonography demonstrated a persisting reversed flow of the superior ophthalmic vein, despite normalized intracranial pressure during postoperative monitoring in two children.
Conclusions: Patients with CM1 and papilledema from increased ICP may benefit from suboccipital decompression. Following surgery, the significance of a persisting papilledema despite clinical and radiological improvement, as we encountered in three of our patients, remains enigmatic.
Patient Care: Clinicians should be aware of the neuro-opthalmological presentation in children with CM1, and the radiological signs in MRI and intra-orbital Doppler sonography, and their utility in the postoperative follow-up.
Learning Objectives: By the conclusion of the session, participants should be able to appreciate in children with CM1 the existance of 1) predominantly visual symptoms, 2) the spectrum of opthalmological diagnostic tools in this context, 3)the presence of papilledema without hydrocephalus, and they should discuss persisting pailledema without raised ICP in the postoperative course.