Those falcine meningiomas arising in the middle third of the cranial vault present a more difficult technical problem. Those located on the non dominant side usually compromise the sensory-motor strip at their posterior margin, whereas those on the dominant side involve the supplementary motor area as well.
Large tumors in the middle third of the cranial vault can be present with a progressive hemiparesis as well as organic mental syndrome and seizures that are often focal in the onset.
In addition, with lesions on the dominant side, the seizures may be heralded by speech arrest, a syndrome that derives from a compromise to the dominant supplementary motor area. They may be present as calcified mass attached to falx, being difficult to access without any damage to brain parenchyma.
In treating lesions posterior to the coronal suture, the patent longitudinal sinus cannot be removed safely in the fashion just described and excision of lateral wall infiltrated with falcine parasagittal meningioma is difficult and complex. In the past, the lateral sinus wall was sutured successively as the tumor was excised.