Presentation
Fall at home. Laceration to right eyebrow. Unable to recall event.
Patient Data
Biconvex blood collection overlying the right temporal lobe in the expected position of an extradural. Note, however, the absence of a fracrture (usually always present leading to rupture of a middle meningeal arterial branch), the patient's age (very unusual in an elderly person), presence of a more chronic right convexity subdural collection and the "tail" of more tyical acute subdural hematoma anteriorly (arrow).
Case Discussion
In patients with chronic subdural hematoma, adhesions can develop as part of the "membrane" producing process pathologically associated with these subdurals. The space therefore becomes loculated or walled-off, allowing venous bleeding to accumulate producing an appearance that is similar to an extradural hematoma. The point is that are under low (venous) not high (arterial) pressure exerting relatively minor pressure effect on the underlying brain unlike an extradural bleed.