Bilateral Chronic Subdural Hematoma Presenting with Pseudo-Subarachnoid Hemorrhage Sign on Computed Tomography

Hiroshi Shima; Kazutaka Shirokane; Eiichi Baba; Atsushi Tsuchiya; Motohiro Nomura

doi:10.4103/ajns.AJNS_11_19

Bilateral Chronic Subdural Hematoma Presenting with Pseudo-Subarachnoid Hemorrhage Sign on Computed Tomography

Asian J Neurosurg. 2019 Apr-Jun;14(2):510-512. doi: 10.4103/ajns.AJNS_11_19.

Authors

Hiroshi Shima¹, Kazutaka Shirokane², Eiichi Baba², Atsushi Tsuchiya³, Motohiro Nomura²

Affiliations

¹ Department of Neurosurgery, Shima Neurosurgical and Orthopedic Clinic, Kanto Rosai Hospital, Kawasaki, Japan.
² Department of Neurosurgery, Kanto Rosai Hospital, Kawasaki, Japan.
³ Department of Neurology, Kanto Rosai Hospital, Kawasaki, Japan.

Abstract

Background: On rare occasions, cisterns are demonstrated as high-density areas on computed tomography (CT) and misdiagnosed with subarachnoid hemorrhage (SAH). This false-positive finding is called pseudo-SAH.

Patients and methods: From April 2014 to August 2018, a total of 161 patients with chronic subdural hematoma (CSDH) were treated in our hospital. For these cases, the existence of a pseudo-SAH sign on CT was retrospectively examined.

Results: One patient with bilateral CSDH showed pseudo-SAH and a further examination to evaluate vascular abnormalities causing true SAH was necessary. In three patients, the Sylvian fissures were demonstrated as high-density areas due to an atherosclerotic middle cerebral artery; however, the condition was not misdiagnosed with SAH.

Conclusion: In cases of CSDH, there is a possibility that CT demonstrates a pseudo-SAH sign. In such cases, close examinations to exclude true SAH are mandatory.

Keywords: Bilateral; chronic subdural hematoma; computed tomography; pseudo-subarachnoid hemorrhage.