Clinical and radiological characteristics of the cyst of the septum pellucidum in endoscopically treated patients

Abstract

Introduction: The cavum of the septum pellucidum occurs in up to 15% of adults and is considered as an anatomical variant. How- ever, some patients reveal symptoms which are associated with the evolution from the cavum in the form of a cyst of the septum pelludum. Cyst incidence is much lower. The pathomechanism and risk factors of such changes are not fully understood. Among the theories for the formation of the cyst, most attention is given to the hypothesis of the mechanism of the valve in the flow of cerebrospinal fluid. However, this statement can be validated only on the basis of direct observation, which can be made in vivo only with the help of the endoscopic method. The aim of this study was to describe the clinical and radiological features coexisting with the expanding cysts of the septum pellucidum. The research also included considerations on the pathogenesis of the expanding cysts of the septum pellucidum, as well as the evaluation of the intraoperative endoscopic image.

Material and methods: The study included 27 patients of the Department of Neurosurgery Pomeranian Medical University in Szczecin, diagnosed with an expanding cyst of the septum pellucidum, who underwent neurosurgery treatment. The patients' clinical and radiological symptoms were evaluated before and after surgical intervention. Analysis of the intraoperative endoscopic images was also performed.

Results: The most common clinical symptoms in patients before surgery were similar: headache, dizziness, nausea and vomiting, advanced nervous functions disorders, and visual defects. In most cases the symptoms resolved after surgical treatment, which proves their association with the occurrence of cysts. Significant differences in radiographic measurements before and after surgery where also noted, which allowed the determination of clinical and radiological criteria for the diagnosis of expanding cysts of the septum pellucidum, and intravital intraoperative findings allowed direct proof of the cyst's filling mechanism. The obtained results allowed us to prove the hypothesis of the valve mechanism as the main factor causing the symptoms in patients with expanding cysts of the septum pellucidum, and to determine the components of the syndrome of the septum pellucidum cyst. They confirmed the validity of the selection of surgical treatment using an endoscope. Furthermore, changes in the geometry of the structures of the central nervous system observed in the analysis of radiological images before and after surgery made further research on the dynamics of this anatomical area in patients with expanding cysts of the septum pellucidum reasonable.