Falcine and Falcotentorial Meningiomas

Indications and Preoperative Considerations

• Falcine meningiomas are extradural lesions that arise from the falx cerebri. They might be classified based on their relationship with the superior sagittal sinus (SSS) into anterior, middle or posterior lesions, each requiring different techniques for surgical resection.

• Meningiomas that arise both from the falx and tentorium are named falcotentorial meningiomas. These lesions may rise in any portion of the straight and transverse sinuses, up to and including the region adjacent to the torcula.

• Clinical symptoms associated with these lesions depend on the position of the lesion. Frontal falcine meningiomas may present with headache, seizures and frontal lobe syndrome. Middle third lesions can present with contralateral leg weakness secondary to compression of the paracentral lobule, while posterior third falcine and falcotentorial meningiomas can be associated with homonymous hemianopsia or even bilateral visual deficits when bilateral tumor extension is present.

• As in parasagittal meningiomas, evaluation of the relationship of the tumor to venous sinuses and draining veins is critical. Falcine meningiomas may grow superiorly into the SSS and/or inferiorly into the inferior sagittal sinus (ISS), whereas falcotentorial lesions might be closely related to the straight sinus, ISS, transverse sinus and torcula.

• The relationship between falcine meningiomas and the callosomarginal and pericallosal artery needs to be evaluated prior to surgery. These arteries are closely related to deep seated meningiomas especially at the middle portion of the SSS.

• Preoperative work-up must include MRI with gadolinium enhancement, MRA or angiogram and MRV, so the location and vascular relation of tumor with major vessels and dural sinuses can be adequately evaluated.

• Large falcotentorial meningiomas benefit from the insertion of a lumbar drain or external ventricular drainage (EVD) before surgery.

Surgical Procedure