ABSTRACT
Subdural hematomas, which typically, but not always, occur secondary to head trauma, may present acutely, subacutely, or in a chronic fashion; acute and subacute onsets may be characterized by delirium, whereas chronic subdural hematomas classically present with dementia. In all three varieties, blood accumulates between the dura and arachnoid; in acute subdural hematomas, this is generally due to arterial bleeding, whereas subacute and chronic subdural hematomas generally result from venous bleeding.
