The histologic structure of the filum terminale is of neuroanatomic interest and clinical importance; yet the descriptions in the medical literature are fragmentary and inadequate. Modern metallic methods have been utilized in this study to demonstrate the cytologic structure of the filum and its transition to the conus medullaris.
The filum terminale was at one time called the "nervus impar," Haller later expressing the view that it was formed by attachment of the vascular covering of the spinal cord to the coccyx (Rauber1). That the filum contains nerve tissue was soon appreciated by many investigators. Clark2 described the filum terminale as a cylindric tubule which becomes enlarged at the conus medullaris. This dilatation of the ependymal canal was called the ventriculus terminalis or the fifth ventricle by Krause.3 Saint-Remy4 was unable to find a dilatation of the ependymal canal in adults comparable to that which Krause
TARLOV IM. STRUCTURE OF THE FILUM TERMINALE. Arch NeurPsych. 1938;40(1):1-17. doi:10.1001/archneurpsyc.1938.02270070011001