Pseudo-subarachnoid hemorrhage: a potential imaging pitfall associated with spontaneous intracranial hypotension.
OBJECTIVE
(1) To determine the frequency of CT mimics of subarachnoid hemorrhage (SAH) in a large cohort of subjects with spontaneous intracranial hypotension (SIH). (2) To emphasize the distinctive radiologic features of SIH.


METHODS
CT scans of 95 subjects with SIH were retrieved and reviewed to search for findings of pseudo-SAH (CT mimics of SAH in the absence of blood).


RESULTS
Pseudo-SAH radiologic findings (increased attenuation in the basilar cisterns, sylvian fissures, or along the tentorium) were detected on CT scans of 10 of the 95 SIH subjects. However, on MRI scans, these subjects exhibited the typical SIH abnormalities (diffuse pachymeningeal enhancement and brain sagging with obliteration of basilar cisterns).


CONCLUSIONS
In the emergency room, SIH should be considered in the differential diagnosis between SAH and pseudo-SAH. Although SIH and SAH can share some radiologic features, SIH has distinctive MRI and CT findings. Their recognition should obviate the need for more invasive procedures (e.g., cerebral angiography) to definitely rule out SAH and an aneurismal source of bleeding.
Neurosciences Department, Niguarda Cà Granda Hospital, Milan, Italy. Electronic address: enricoferrante@libero.it.
Enrico
E
Ferrante
Caroline
C
Regna-Gladin
Ines
I
Arpino
Fabio
F
Rubino
Lara
L
Porrinis
Mirko Maria
MM
Ferrante
Alberto
A
Citterio
D003937:Diagnosis, Differential; D006261:Headache / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D019585:Intracranial Hypotension / Q000175:diagnosis / Q000209:etiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D011859:Radiography; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging
Epidural blood patch; Headache; Pseudo-subarachnoid hemorrhage; Spontaneous intracranial hypotension