Filum terminale

The filum terminale is a filament of connective tissue that extends inferiorly from the apex of the conus medullaris.

The filum terminale is continuous with the pia mater and is described as having two sections:

  • filum terminale internum: upper three quarters of the filum; covered by the spinal dura and arachnoid meninges
  • filum terminale externum: lower quarter of the filum; fuses with the investing dura mater and continues inferiorly to attach to the dorsal coccyx
  • fatty filum terminale: can be considered as a cause of tethered cord 4 or may be considered a rare (<0.5%) anatomical variant in the asymptomatic patient 3
  • ventriculus terminalis

Anatomy: Spine

Article information

rID: 29225
System: Spine
Section: Anatomy
Synonyms or Alternate Spellings:
  • Filum terminale internum
  • Filum terminale externum

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Cases and figures

  • Case 1: fatty filum terminale
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