[Subarachnoid hemorrhage: etiologic variants, pathogenetic features and morphology]

8 etiological variants of subarachnoidal hemorrhage are considered, its complications (rupture into the ventricles, development of the arterial spasm, brain edema) and sequelae (aseptic leptomeningitis, external hydrocephaly). Three stages in the subarachnoidal hemorrhage course are distinguished. The analysis of the vascular alterations and ventricular ependyma in cases of the rupture into the brain ventricles is performed. The study of morphological substrates of the liquor circulation in both macro- and microscopical level is recommended in all cases of subarachnoidal hemorrhage.