Trigeminal neuralgia as the sole manifestation of an Arnold-Chiari type I malformation: case report.

Arnold-Chiari type I malformations usually manifest clinically with short-lasting headaches typically involving the occipital-nuchal region and precipitated by the Valsalva maneuver, coughing, sudden postural change, or physical exertion. We describe the case of an adult patient who presented with symptomatic trigeminal neuralgia caused by an Arnold-Chiari type I malformation. Unlike previous cases, the malformation involved the trigeminal ophthalmic division alone.