Subarachnoid hemorrhage (SAH) accounts for 5% of all strokes but its burden is relevant due to high mortality,
high disability and remarkable incidence in the young. The rupture of an intracranial aneurysm is responsible for about
85% of SAHs; 10% are represented by non-aneurysmal conditions; 5% are represented by other medical conditions such
as inflammatory or non-inflammatory lesions of cerebral artery, coagulopathy, neoplasms or drug abuse.
The clinical presentation of a subarachnoid hemorrhage can be extremely variable ranging from nearly asymptomaticity to
Neuroimaging represent the first level instrumental investigation. In case of clinical suspect of SAH and negative
neuroimaging, cerebrospinal fluid (CSF) examination is required. Following the diagnosis of SAH, determining cause and
localization of bleeding is mandatory; digital catheter angiography is the gold standard.
Rebleeding is the most frequent and severe complication of SAH. The aneurysm exclusion is the most effective treatment
for preventing rebleeding. Endovascular occlusion of the aneurysm with coils has been shown to be associated with better
short- and long-term outcomes than surgical clipping in select patients.