Falx cerebri (also called cerebral falx) is a large, double-fold of the dura mater that passes through a gap in the midline of the brain. Falx cerebri should not be confused with falx cerebelli, which is a fold that lies posteriorly between the two ‘cerebellar’ hemispheres. However, ‘falx cerebri’ divides the brain into two ‘cerebral’ hemispheres by following the corpus callosum. Dura mater is a thick membrane and the outermost meningeal layer. Falx cerebri is the largest fold of the dura mater among the four folds (or septa). Falx cerebri attached anteriorly with the ethmoid bone where it lies very closely with frontal and ethmoid nasal sinuses. It is related with tentorium cerebelli posteriorly. Several important cranial venous sinuses lie within or in proximity with the falx cerebri that drain blood from the brain.
Clinical Importance – Associated Diseases/Conditions
Normal Intracranial Calcification:
Calcification of several parts of the brain occurs, typically in older populations, without showing any signs and symptoms or without having any noticeable cause. This condition poses no health risk and appears normal with aging as part of the neurodegenerative changes. Falx cerebri is undergoes calcification in approximately 10% of the elderly people.
Ossification of the Falx Cerebri:
As compared to the earlier condition, which happens to be only a process of mineralization, ossification on the other hand is process in which bony deposits are formed as a result of either a hemorrhage or trauma, or perhaps friction and may also be associated with several different conditions such as endocrine disorders, vitamin D intoxication or chronic renal failure. End result is the formation of membranous bony structures within the falx cerebri. This condition is far rarer and occurs in only 0.7% population.
It is defined as the accumulation of blood within the subdural space. It usually occurs due to head trauma and easily diagnosed on CT imaging. Mostly, this blood is contained within the spaces by falx cerebri, as well as by tentorium cerebelli.
It is a type of tumor that arises from the falx cerebri and usually has a dumbbell shape. Falcine meningiomas account for approximately 9% of all meningioma types. Patient may experience visual hallucinations and headaches.
Chondroma of Falx Cerebri:
Chondromas are benign tumors of the cartilage. They can be found attached to falx cerebri, however rarely, since chondromas only account for 0.2 – 0.3% of all brain tumors. Signs and symptoms include epilepsy and headache, and sometimes accompanied by vomiting. Treatment of choice in this case is usually a surgical resection.