Description
There are usually three irregularly shaped venous spaces, or lacunae, present inside the dura mater, on either side of the superior sagittal sinus. They can be considered as the lateral extensions of the sinus. These include a small frontal, a large parietal, and intermediate occipital lacunae. The venous lacunae could potentially become confluent in elderly people and form large single spaces on either side of the superior sagittal sinus.
Most of the cerebral veins from the outer surface of the cerebral hemispheres open into the venous lacunae and numerous arachnoid granulations project into them from below. The venous lacunae also drain diploid, emissary, and meningeal veins.
