subdural space

The subdural space is an anatomical area located between the dura mater and the arachnoid mater, two of the three protective membranes (meninges) that surround the brain and spinal cord. The meninges, from outermost to innermost, are the dura mater, arachnoid mater, and pia mater. The pia mater is closely adhered to the brain's surface, while the arachnoid mater does not follow the brain's contours. The dura mater is the thickest and toughest layer.12

The subdural space is a potential space that can fill with fluid or blood. Bleeding into this space, known as a subdural hematoma, typically occurs when bridging veins between the brain's surface and the dura mater tear, often due to head trauma. This bleeding can increase pressure within the skull and compress the brain, leading to serious neurological consequences.2