[Differential diagnosis of subarachnoid hemorrhage].

Differential diagnosis (DD) of subarachnoidal hemorrhage (SH) should be carried out in two directions: (1) syndromic and nosological and (2) etiological. The diagnosis of 739 verified cases of SH of different etiology was analyzed. The data on DD of SH were systematized, with specification of the concrete disease entities which are to undergo DD. The portion of each of the disease entities was defined, the DD criteria for SH of different etiology were distinguished and tabulated.