Nervus spinosus

The nervus spinous (plural: nervi spinosi), also known as the meningeal branch of the mandibular nerve, is a branch of the mandibular division of the trigeminal nerve which innervates the dura of the middle cranial fossa.

Gross anatomy

The nervus spinosus divides off the mandibular division just below the foramen ovale and just before it branches into anterior and posterior divisions. It then ascends to re-enter the head through foramen spinosum or occasionally the foramen ovale. It supplies sensation to the cartilaginous part of the Eustachian tube, the trigeminal ganglion and the posterior half of the dura of the middle cranial fossa. The anterior half is supplied by the middle meningeal nerve from the maxillary division of the trigeminal nerve.

The nerve continues to course between the squamous and petrous parts of the temporal bone, entering and supplying the mastoid antrum and the mastoid air cells.