[Electron microscope study of the innervation of the large arteries of the base of the brain subsequent to subarachnoid hemorrhage, following aneurysmal rupture (a pathomorphologic and experimental study)].

The ultrastructure of the intraadventitial and paravasal nerve trunks of the superficial adventitial plexus in major vessels of the basis cerebri in man and in dogs under normal conditions and with a subarachnoidal hemorrhagic effusion was studied at the submucroscopic level. Unlike the ultrastructure of the intra-adventitial nerve trunks the paravasal ones, lying in the cerebrospinal fluid (CSF), have an endothelial sheath that substitutes the epineurium and also has a perineurium endowed with an abundantly developed system of basal membranes containing aplanated cells and bands of collagen fibrils. With a subarachnoidal hemorrhagic effusion was in evidence the disruption of the "CSF-neural barrier". The endothelial cells break" away and fall into the CSF, the basal membrane undergoes lysis, which, apparently, contributes to the penetration of various components of the subarachuoidally effused blood deep into the nerve trunks. This results in changes occurring in the ultrastructure of axones of the pulpous and, to a lesser extent,pulpousless nerve fibers.