The dural arterio-venous fistula (dAVF) is a vascular malformation constituted by an anomalous communication between an artery and a vein. The passage between them is direct, without the interposition of a capillary bed, located in the territory of the dura mater (one of the three layers that make up the meninges).
Cavernous angiomas (also called cavernomas) are vascular malformations formed by an agglomerate of low-flow vessels, very similar in shape to blackberries.
Their prevalence in the population is low (about 0.5%).
There is no clear etiology. It is likely that they are congenital malformations and are often associated with multiple angiomatosis.
They can be located in the brain or in the spinal cord.
The acoustic neuroma (or vestibular Schwannoma) is a benign slow-growing tumor originating from the Schwann cells of the vestibular nerve in the internal auditory meatus from where it spreads to the cerebellopontine angle.
It represents 7-8% of all intracranial tumors.
95% of acoustic neuromas are unilateral, but in cases of type 1 or type 2 neurofibromatosis, it may be bilateral or associated with other lesions.
Meningiomas are prevalently benign tumors originating in the meninges, i.e. the membranes covering the brain and the spinal cord.
They represent about 25% of all brain tumors.
They generally affect adults from 40 to 65 years of age, and are more frequent in women than in men with a 2:1 ratio. 25% of all cases are related to neurofibromatosis 2, which is a genetic syndrome.
Depending on where the meningiomas are located, they are classified as one of the following: