Magnetic Resonance Imaging in Syringomyelia: Pre- and Postoperative Results

Abstract

Up until now, none of the numerous hypotheses on the pathogenesis of syringomyelia (SM) have been confirmed. Being the protagonist of hydro-dynamic theories, GARDNER (5) explained SM by the prevention of normal CSF flow via the foramina of Luschka and Magendie, which he thought to have failed to open due to an underlying Arnold-Chiari malformation (ACM). As a consequence, the systolic CSF pressure pulse wave generated by the choroid plexus pulsation should be transmitted into a persisting central canal of the spinal cord, thus leading to pathological cavitation (“communicating syringomyelia”). Modified hydrodynamic concepts were reported by WILLIAMS (8), BALL and DAYAN (2), and DU BOULAY et al. (3). All such approaches, however, have in common the assumption of a malformation located at the craniospinal junction and leading to impaired CSF circulation and pathological CSF pulsation. The surgical therapy is therefore often focused on the dorsal decompression of the craniocervical junction besides direct shunting of the syrinx. In the present study 22 SM patients were examined using magnetic resonance imaging (MRI) in order to find indications of hydrodynamic alterations at the level of the foramen magnum and to evaluate the size and shape of the syringes. Pre- and postoperative data were compared.