Ghost Aneurysms in Acute Subdural Hematomas: A Report of Two Cases

Acute subdural hematoma (aSDH) is a common pathology encountered in neurosurgery. Although most cases are associated with trauma and injuries to draining veins, traumatic aSDH from injury to arteries or spontaneous aSDH because of a ruptured intracranial aneurysm can occur. For some patients without a clear clinical history, it can be difficult to distinguish between these etiologies purely based on radiography. The objective of this research was to describe a case series in which imaging was suggestive of the presence of distal cortical intracranial aneurysm associated with aSDH, but operative management demonstrated no evidence of aneurysm.

We retrospectively reviewed 2 patients known to have aSDH with suspicion for associated aneurysm between May 2019 and September 2019 at our institution. Data collected included demographic, clinical, and operative course, including age, gender, past medical history, presenting symptoms, and pre and postoperative imaging.

In 2 patients presenting with aSDH with preoperative radiographic imaging suggesting distal middle cerebral artery aneurysms, surgical exploration revealed no aneurysm. In both cases, noniatrogenic active arterial bleeding from an injured cortical middle cerebral artery branch was identified.

Although there are prior reports of arterial aSDH, to our knowledge, this is the first to describe the radiographic "ghost aneurysm" sign. It is important for clinicians to be aware of this potential misleading radiographic sign, which indicates active extravasation into a spherical cast of clot.