Falx cerebelli explained

Falx cerebelli should not be confused with falx cerebri.

The falx cerebelli is a small sickle-shaped fold of dura mater projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres.^[1]

The name comes from two Latin words: falx, meaning "curved blade or scythe", and cerebellum, meaning "little brain".^[2]

Anatomy

The falx cerebelli is a small midline fold of dura mater projecting anterior-ward from the skull and into the space between the cerebellar hemispheres.^[3] It generally measures between 2.8 and 4.5 cm in length, and approximately 1–2 mm in thickness.^[4]

Attachments

Superiorly, it (with its upwardly directed base) attaches at the midline to the posterior portion of the inferior surface of the tentorium cerebelli.^[3]

Posteriorly, it attaches to the internal occipital crest; the inferior-most extremity of its posterior attachment frequently divides into two small folds that terminate at either side of the foramen magnum.^[3]

Anatomical relations

The occipital sinus is contained within the posterior extremity of the falx cerebelli where it attaches to the internal occipital crest.^[3]

Anatomical variation

In its lower portion the falx cerebelli diminishes very rapidly in height and as it descends, it can divide into two smaller folds or diverging limbs,^[5] which are lost on the sides of the foramen magnum. Other variations such as duplication,^[6] triplication,^[7] absence,^[8] and fenestration are much less common. As dural venous sinuses are concurrent with the development of dural folds, duplication of the falx cerebelli is usually associated with duplicated occipital sinus.^[9] Knowledge of these variations is important in preventing iatrogenic injuries in this region.

See also

• Falx (disambiguation) — other parts of the anatomy with names including "falx"

Notes and References

1. Book: Atlas and textbook of human anatomy. Atlas der deskriptiven Anatomie des Menschen.English. 1909. Saunders.
2. Sihler, Andrew L. (1995). New Comparative Grammar of Greek and Latin. Oxford University Press. . Retrieved 12 March 2013.
3. Book: Standring, Susan . Gray's Anatomy: The Anatomical Basis of Clinical Practice . Elsavier . 2021 . 978-0-7020-7707-4 . 42nd . [New York] . 1201341621.
4. Shoja MM, Tubbs RS, Khaki AA, Shokouhi G. A rare variation of the posterior cranial fossa: duplicated falx cerebelli, occipital venous sinus, and internal occipital crest. Folia Morphol (Warsz) 2006;65(2):171–173.
5. Book: Atlas and textbook of human anatomy. Atlas der deskriptiven Anatomie des Menschen.English. 1909. Saunders.
6. Shoja MM, Tubbs RS, Khaki AA, Shokouhi G. A rare variation of the posterior cranial fossa: duplicated falx cerebelli, occipital venous sinus, and internal occipital crest. Folia Morphol (Warsz) 2006;65(2):171–173.
7. Shoja MM, Tubbs RS, Loukas M, Shokouhi G, Oakes WJ. A complex dural-venous variation in the posterior cranial fossa: a triplicate falx cerebelli and an aberrant venous sinus. Folia Morphol (Warsz) 2007;66(2):148–51.
8. Tubbs Rs, Dockery SE, Salter G, Elton S, Blount JP, Grabb PA, Oakes WJ. Absence of the falx cerebelli in a Chiari II malformation. Clin Anat. 2002;15(3):193–195.
9. Shoja MM, Tubbs RS, Shokouhi GH, Ashrafian A, Oakes WJ. Abstract presented at the 23rd Annual Meeting of the American Association of Clinical Anatomists. Milwaukee, Wisconsin: 2006. A triple dural-venous variation in the posterior cranial fossa: A duplicated plus accessory falx cerebelli and an aberrant venous sinus.