Pseudosubarachnoid hemorrhage

subarachnoid spaces, or in patients with cerebral venous sinus thrombosis, severe meningitis, leptomeningeal carcinomatosis,^[3] intracranial hypotension, cerebellar infarctions, or bilateral subdural hematomas.^[4]

cardiopulmonary arrest. Patients with pseudosubarachnoid hemorrhages may have worse prognoses than those with true subarachnoid hemorrhages because of underlying disease processes and decreased cerebral perfusion with elevated intracranial pressure.^[6] The identification of a pseudosubarachnoid hemorrhage as opposed to a true subarachnoid hemorrhage may therefore change a patient's treatment plan.^{[citation needed}