Radiological features of adhesive optochiasmatic arachnoiditis

Summary

Adhesive optochiasmatic arachnoiditis (AOCA) was found to be the most common cause of an ischemic chiasmal syndrome. The etiology of AOCA is diverse: closed head injury, meningitis, radiation therapy, craniotomy for aneurysm, arteriovenous malformation or tumor, sarcoidosis, rheumatoid arthritis, or allergy to myelographic contrast medium appeared to be the cause of fibrosis and scar formation in 23 of 25 cases, while the etiology of the remaining 2 cases is unknown. The radiological features of AOCA are as follows: partial or total obliteration of suprasellar cisterns and the recesses of the third ventricle, atrophy and irregular configuration of the optic chiasm and nerves, fibrous retraction with intrasel-lar herniation of the optic chiasm, which often shows a “V” shape, occasional arachnoid cyst formation with elevation of the chiasm and indentation of the rostral third ventricle, segmental attenuation of the supraclinoid portion of the carotid, and/or main trunk of the anterior cerebral arteries, and a high incidence of empty sella (89%).