Space
Subdural space
A pathological cleavage plane near the dura–arachnoid interface
High-yield
A subdural hematoma often has a crescentic outline and can cross skull sutures. Dural reflections constrain its spread, so crossing sutures does not mean freely crossing the falx or tentorium.
Overview
There is no normal open subdural cavity. A collection develops when tissue separates near the inner dural border adjacent to arachnoid. Bridging veins pass through this region toward dural sinuses and are a frequent source of traumatic bleeding, although cortical arterial injury and other causes are also possible.
Reference facts
- Boundaries
- Clinically described at the dura–arachnoid interface; microscopic studies locate the cleavage within the weak dural border-cell layer.
- Contents
- No normal open, fluid-filled cavity. Bridging veins traverse the interface; pathological collections may contain blood, CSF-like fluid or infected material.
- Communications
- Collections can extend along a cerebral convexity and spread beyond sutures, but are constrained by attached dural reflections such as the falx and tentorium.
Clinical correlation
Brain-volume loss can increase vulnerability of bridging veins. Older adults may develop a symptomatic collection after a minor or unremembered injury, sometimes with delayed headache, confusion or weakness. Acute collections can also deteriorate rapidly; a slow presentation is not universal.
Frequently asked questions
What are the boundaries of the subdural space?
Clinically described at the dura–arachnoid interface; microscopic studies locate the cleavage within the weak dural border-cell layer.
What does the subdural space contain?
No normal open, fluid-filled cavity. Bridging veins traverse the interface; pathological collections may contain blood, CSF-like fluid or infected material.
What does the subdural space communicate with?
Collections can extend along a cerebral convexity and spread beyond sutures, but are constrained by attached dural reflections such as the falx and tentorium.