Absent falx cerebelli: report of a rare case

The falx cerebelli is a small crescentic fold of dura mater below the tentorium cerebelli, which projects forward into the posterior cerebellar notch. Its base is directed upwards and attached to the posterior part of the inferior surface of the tentorium cerebelli in the midline; its posterior margin is attached to the internal occipital crest and contains the occipital sinus; the apex frequently dividing into two small folds which disappear at the sides of the foramen magnum. The material of our neuroanatomic study consisted of formalin-embalmed cadavers that we had in the dissection room of our Department from cadaver donors for students education. We report a case of absence of this dura mater structure from a 91-year-old female cadaver. To our knowledge, this is the first report of absent falx cerebelli in a normal human brain. The review of the literature revealed a few reports of its multiplication.