Difference Between Epidural and Subdural

The key difference between epidural and subdural stems from the type of bleeding that takes place during traumatic brain injury. Epidural bleeding occurs between the skull and the dura mater, while subdural bleeding occurs between the dura mater and the arachnoid mater.

Brain injury leads to a condition called hematoma. Hematoma is a collection of blood outside the blood vessel as a result of injury in a blood vessel wall. Hematoma leads to nervous and cognitive disorders resulting in seizures, headache, dizziness, amnesia and many more. Moreover, hematoma may result in irreversible damages to the brain and the neuronal tissues. Epidural hematoma and subdural hematoma are two types of hematoma conditions.

CONTENTS

1. Overview and Key Difference
2. What is Epidural 
3. What is Subdural
4. Similarities Between Epidural and Subdural
5. Side by Side Comparison – Epidural vs Subdural in Tabular Form
6. Summary

What is Epidural?

Epidural hematoma results from epidural bleeding. The location where the bleeding takes place during the brain injury gives it the name “Epidural”. Thus, epidural bleeding takes place between the skull and the dura mater. Dura mater is the outermost meningeal layer surrounding the brain and lining the skull.

Skull fractures, displacement of skull bones and deformed skulls are the causes for epidural bleeding. During epidural bleeding, the middle meningeal artery lacerates, leading to a heavy bleeding condition. Epidural bleeding results in headaches, hemiparesis and progressive obtundation. Patients undergo a brief loss of consciousness following epidural bleeding. However, this may last longer depending on the injury. Thus, this type of injury should be subjected to prompt treatment. Failing to do so may result in death.

What is Subdural?

Subdural bleeding during hematoma gives rise to another type of hematoma, which is a subdural hematoma. The location of bleeding differs in comparison to epidural hematoma. Thus, subdural bleeding takes place in between the dura mater and the arachnoid mater. Arachnoid mater is the middle layer that forms the meninges in the brain. Subdural bleeding results from brain injuries. Furthermore, alcoholics and old aged people are more prone to brain injuries leading to subdural bleeding. Minor head injuries may also lead to subdural bleeding. The symptoms of subdural bleeding are headaches, altered mental status, cognitive disorders and gradual deterioration of mental health, etc.

Similar to the epidural bleeding, prompt action should be taken upon brain injury to prevent subdural bleeding, which would otherwise result in death.

What are the Similarities Between Epidural and Subdural?

• Both are forms of bleeding taking place during hematoma.
• Both forms involve the dura mater of the meningeal layers.
• Symptoms such as headache, dizziness, seizures, nausea and vomiting are common to both conditions.

What is the Difference Between Epidural and Subdural?

Epidural and subdural are two types of bleeding that takes place during a brain injury. Epidural bleeding occurs between the dura mater and the skull. In contrast, subdural bleeding occurs between the dura mater and the arachnoid mater. So, this is the key difference between epidural and subdural.

Moreover, the form of injury that occurs during the two types of bleeding also differs. Epidural bleeding results from skull injuries, whereas subdural bleeding results from brain injuries. Therefore, this is another difference between epidural and subdural.

The below infographic presents more information regarding the difference between epidural and subdural.

Summary – Epidural vs Subdural

Brain and skull injury bring about many harmful effects leading to nervous and coordination impairments. During brain and skull injuries, bleeding takes place due to the trauma. The epidural bleeding takes place during a skull injury while the subdural bleeding takes place during a brain injury. There is a distinct difference between epidural and subdural bleeding depending on the location of bleeding, the type of vessels involved and the CT scan appearances of both bleeding types. However, if untreated, both may be fatal.

Reference:

1.“Epidural and Subdural.” Neuroscience Clerkship, Department of Neurology, Case School of Medicine, Available here.

Image Courtesy:

1. “Ct-scan of the brain with an subdural hematoma” By Lucien Monfils – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “EpiduralHematoma” By James Heilman, MD – Own work (CC BY-SA 4.0) via Commons Wikimedia