is the longest chapter in the book and perhaps the most important. Syndromes of the oculomotor nuclear complex, the fasciculus and the nerve[BluM2] include disorders such as acute dilation of the pupil due to uncal herniation, aneurysmal compression of the nerve with pupil involvement or with pupil sparing, and microinfarction of the nerve with pupil sparing due to ischemia associated diabetes mellitus. Important syndromes of the sphenocavernous sinus characterized by painful ophthalmoplegia are generally associated with multiple unilateral cranial nerve palsies. Common lesions include aneurysms, meningiomas, pituitary tumors, lymphoma, and infectious and idiopathic granulomatous infiltration (the Tolosa-Hunt syndrome). A patient with primary aberrant regeneration of the oculomotor nerve due to prolonged compression by a meningioma in the cavernous sinus is illustrated by video display.
