Progressive, asymptomatic papilledema as the presenting sign of a Chiari I malformation.

BACKGROUND: Chiari I malformation (CM1) is the caudal herniation of the cerebellar tonsils into the foramen magnum. It can cause several neurological signs and symptoms, or be asymptomatic. Papilledema is a potential, but unusual, manifestation of CM1. While CM1 is often asymptomatic, papilledema is less likely to be. We present the first reported case of a progressive, asymptomatic papilledema as the sole presenting sign of a CM1;

CASE REPORT: A 39 year old woman presented without neurological symptoms and was found to have optic disc edema. Humphrey visual fields were normal and B-scan showed no drusen. On a subsequent visit, optical coherence tomography showed advanced disc edema. Neuroimaging revealed a CM1. The patient was referred for neurological consultation for the management of the papilledema secondary to CM1;

CONCLUSIONS: This case represents the importance of a thorough ocular examination, as the patient's asymptomatic neurologic condition would not have been diagnosed without the discovery of the papilledema.