title: Pseudosubarachnoid haemorrhage in subdural haematoma.
abstract: Two patients with large bilateral subdural haematomas with patterns of non-enhanced brain computed tomography (CT) falsely suggesting coexistent subarachnoid haemorrhage are presented. The CT images showed marked effacement of the basal cisterns with hyperdense signal along the tentorium, sylvian fissure, and the perimesencephalic cisterns. In both cases, the suspicion of subarachnoid haemorrhage led to the performance of angiographic studies to rule out vascular lesions. Thus, recognition of this radiological feature is important to avoid unnecessary testing and treatment delay.
authors.affiliation: Department of Neurology, Saint Mary's Hospital, Mayo Medical Center, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Rabinstein
authors.forename: S J
authors.initials: SJ
authors.lastname: Pittock
authors.forename: G M
authors.initials: GM
authors.lastname: Miller
authors.forename: J J
authors.initials: JJ
authors.lastname: Schindler
authors.forename: E F M
authors.initials: EF
authors.lastname: Wijdicks
mesh_terms: D000368:Aged; D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral / Q000502:physiology; D020199:Hematoma, Subdural, Acute / Q000000981:diagnostic imaging*; D020200:Hematoma, Subdural, Chronic / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed