Medicine:Pseudosubarachnoid hemorrhage

From HandWiki

A pseudosubarachnoid hemorrhage is an apparent increased attenuation on CT scans within the basal cisterns that mimics a true subarachnoid hemorrhage.[1] This occurs in cases of severe cerebral edema, such as by cerebral hypoxia. It may also occur due to intrathecally administered contrast material,[2] leakage of high-dose intravenous contrast material into the subarachnoid spaces, or in patients with cerebral venous sinus thrombosis, severe meningitis, leptomeningeal carcinomatosis,[3] intracranial hypotension, cerebellar infarctions, or bilateral subdural hematomas.[4] In a true subarachnoid hemorrhage, there is higher attenuation on CT scans of the basal cisterns, and blood that has leaked from a vessel or formed a hematoma is more highly attenuated due to the absorption of plasma.[5] Pseudosubarachnoid hemorrhages have been observed in as much as 20% of patients resuscitated from non-traumatic 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.


  1. Dixon, Andrew. "Pseudosubarachnoid hemorrhage | Radiology Reference Article |". 
  2. Given, Curtis A.; Burdette, Jonathan H.; Elster, Allen D.; Williams, Daniel W. (1 February 2003). "Pseudo-Subarachnoid Hemorrhage: A Potential Imaging Pitfall Associated with Diffuse Cerebral Edema" (in en). AJNR. American Journal of Neuroradiology 24 (2): 254–256. PMID 12591643. PMC 7974121. 
  3. Marder, Carrie P.; Narla, Vinod; Fink, James R.; Tozer Fink, Kathleen R. (26 December 2013). "Subarachnoid Hemorrhage: Beyond Aneurysms". American Journal of Roentgenology 202 (1): 25–37. doi:10.2214/AJR.12.9749. PMID 24370126. 
  4. Coulier, Bruno (1 March 2018). "Pseudo-subarachnoid Hemorrhage". Journal of the Belgian Society of Radiology 102 (1): 32. doi:10.5334/jbsr.1509. PMID 30039044. 
  5. Ramanathan, Ramnath Santosh (2018). "Pseudo-subarachnoid Hemorrhage Sign". Annals of Indian Academy of Neurology 21 (1): 83–84. doi:10.4103/aian.AIAN_152_17. PMID 29720807. 
  6. "Pseudo-Subarachnoid Hemorrhage after Cardiac Arrest". 31 May 2020.