An anomalous origin of the middle meningeal artery

Abstract

SUMMARY A human skull is described in which the middle meningeal artery probably arose bilaterally from the lacrimal artery. The branches of the middle meningeal vessels, however, were normal both in their position and distribution. This anomaly is a rare occurrence and is of neurosurgical importance.The skull, which had well-defined bony markings, was that of a 25 to 35 year old male with full dentition and was probably of Asiatic origin. The Cephalic Index was 81-2 (brachycephalic). The bones of the skull were normal and in addition there were bilateral pterion ossicles, five lambdoid sutural bones, and three parietooccipital sutural bones, two on the right and one on the left. The foramina in the base of the skull ( Fig. 1) were symmetrical and within normal limits of size and distribution with the following exceptions: there was bilateral absence of the foramen spinosum, emissary sphenoidal foramen, and foramen meningo-orbitale. The foramen innominatum was present on the right side only.The grooves on the interior of the skull indicated that the main stems of the middle meningeal arteries arose from the lateral limits of the superior orbital fissures (Fig. 2). The origin and distribution of the vessels were bilaterally symmetrical.The main stem of the vessel passed laterally for 17 mm, grooving the greater wing of the sphenoid, and ended by dividing into anterior and posterior divisions, which were normal both in their position and distribution (Fig. 3).In addition to the markings of the middle meningeal vessels, accessory meningeal, anterior and posterior ethmoidal, and some small vessels supplying the anterior and posterior cranial fossae marked the skull bilaterally. DISCUSSIONDavies and Davies (1962) state that the middle meningeal artery normally arises from the first part of the maxillary artery and enters the skull through the foramen spinosum. Its named branches are anterior, posterior, superficial petrosal, superior tympanic, branch to the trigeminal ganglion, temporal and orbital, the latter anastomosing with the recurrent meningeal branch of the lacrimal artery. The middle 874

Unilateral absence of foramen spinosum with bilateral ophthalmic origin of the middle meningeal artery: case report and review of the literature

“…The endocranial groove housing the stem of the MMA started bilaterally from the lateral edge of the SOF, similarly to the case described by Royle and Motson [29] and Diamond [6], pointing to the ophthalmic origin of the MMA. There was no groove on the lateral bone of the orbit in the case presented, and the foramen meningo-orbitale was absent bilaterally.…”

“…There was no groove on the lateral bone of the orbit in the case presented, and the foramen meningo-orbitale was absent bilaterally. In case of Royle and Motson [29], foramen meningo-orbitale was missing as well. Low [22] described 1 case in which the main stem of the MMA arose in the orbit bilaterally and passed through the foramen meningo-orbitale just lateral to the SOF, the FS being absent.…”

“…Imaging identification of the origin of the MMA is important while planning surgical and endovascular interventions in the region of the skull base. MMA was found to origin from the third part (sphenomaxillary portion) of the maxillary artery [22,31], ophthalmic artery [4,15,29,35], persistent stapedial artery [1], internal carotid artery [7,27] and basilar artery [19,30].…”

“…Royle and Motson [29] have described a case of bilateral origin of the MMA from the ophthalmic artery with bilateral absence of foramen spinosum (FS) in the adult skull. Up to our knowledge, aplasia of the conventional MMA with its origin from the ophthalmic artery in the presence of the FS of normal position and size has not been reported yet.…”

“…Bilateral absence of the FS was rarely reported [22,29]. The FS was found to be unilateral in 1% (1/100 skulls) or 1/199 (0.5%) of the foramina examined by Berge and Bergman [2].…”