Positional headache associated with a dilated cyst of the septum pellucidum

Abstract

Objective: A cavum septum pellucidum is an anatomical variant that is usually considered an incidental finding of little clinical significance. This is a fluid-containing structure between the lateral ventricles whose walls exhibit lateral bowing and are 10-mm apart or greater. It has been hypothesized that enlarged cysts of this type may cause hydrocephalus and resultant headache (HA), but there have been very few reports in the literature and even fewer reports of successful treatments. Methods: We describe a patient with subacute onset of positional HA who was found to have a large dilated cavum cyst on magnetic resonance imaging. Results: The patient underwent endoscopic fenestration of the cyst, which eradicated his HAs. Conclusions: We hypothesize that this patient's large cavum septum pellucidum cyst was causing intermittent, positional hydrocephalus and thus HAs. This is a very unusual but highly treatable cause of positional HA that could be overlooked easily. © Association of Military Surgeons of the U.S. All rights reserved.