Extra-axial blood collection between the dura and arachnoid layers surrounding the brain. May be due to arterial or venous bleeding, although most often occurs as a result of the disruption of bridging veins traveling to the dural venous sinuses.
Variable disease course, depending on size of hematoma, age of the patient, presenting neurologic signs/symptoms, presence of underlying coagulopathy or neoplasm, and associated injuries.
All cases of acute and acute-on-chronic subdural hematoma should be treated with an antiepileptic (e.g., phenytoin, phenobarbital, levetiracetam), as well as aggressive reversal of coagulopathy.
Surgical therapy is usually indicated for acute or chronic subdural hematomas that are expansile or causing neurologic deficit. Observation may be employed for small, stable subdural hematomas that are not causing neurologic compromise.
Control of raised intracranial pressure using head-of-bed elevation, analgesics and narcotics, intubation with hyperventilation, osmotic diuretics (mannitol) and loop diuretics, hypertonic saline, external ventricular drainage, barbiturates, mild hypothermia, or decompression hemicraniectomy may be required.
Treatment complications include stroke, seizures, vascular injury to cortical veins and arteries or dural sinuses adjacent to the hematoma, neurologic deficit, reaccumulation of subdural hematoma, coma, and death.