An acute subdural hematoma (SDH) is a rapidly clotting blood collection below the inner layer of the dura but external to the brain and arachnoid membrane.

Subdural hematomas may be mixed in nature, such as when acute bleeding has occurred into a chronic subdural hematoma.

Intracranial acute traumatic subdural hematoma

Intracranial acute spontaneous subdural hematoma

Clinically evident or subclinical seizures are common manifestation in acute subdural hematoma (aSDH); however, there is a paucity of research investigating the relationship between seizures and aSDH.

see Acute subdural hematoma diagnosis.

Hyperdense enhancing subdural effusion due to contrast extravasation has been recently described as a potential mimicker of acute subdural hematoma following a percutaneous coronary procedure.

Zamora and Lin report on 2 patients who presented with subarachnoid hemorrhage from ruptured cerebral aneurysms and who developed enhancing subdural effusions mimicking acute subdural hematomas after angiography and endovascular coil placement. In 1 case, the subdural effusions completely cleared but recurred after a second angiography. CT attenuation values higher than expected for blood, as well as the evolution of the effusions and density over time, allowed for differentiation of enhancing subdural effusions from acute subdural hematomas ¹⁾.

see Acute subdural hematoma treatment.

Acute subdural hematoma outcome.

see Acute subdural hematoma case series.

A 24-year-old female was admitted because of right sided partial seizure and acute or subacute subdural hematoma over the left cerebral convexity. She had no history of recent head trauma but performed headbanging at a punk rock concert at 3 days before admission. Since, she had a previous acute subdural hematoma on the same side after an accidental fall from a baby buggy when she was 11 months old, the present was recurrent subdural hematoma probably due to headbanging.

Headbanging has the hazardous potential to cause a subdural hematoma ²⁾.