The Dural layers of the Central Nervous System



Most people have not heard of the dura, the membranous meningeal layers around the brain and spinal cord. Perhaps you’ve heard of an epidural or maybe even had one. An epidural is an administration of medication just above the outer layer of the dura. The dura itself is an often overlooked and undertreated part of common debilitating painful conditions such as concussion, whiplash, vertigo, neck pain, back pain and recurrent sprains and strains, especially in the ankle and hamstrings.

The dural membranes, collectively known as the meninges, are a set of three protective layers that surround and encase the brain and spinal cord. These membranes play a crucial role in protecting the central nervous system, maintaining the cerebrospinal fluid environment, and providing structural support for the brain and spinal cord. The dura consists of three layers: the dura mater, the arachnoid mater, and the pia mater.

The outermost and toughest layer of the meninges is the dura mater. It is composed of dense connective tissue and is responsible for providing a protective barrier for the brain and spinal cord. The dura mater also has several extensions that help anchor the brain within the skull and the spinal cord within the vertebral column. The dura mater contains blood vessels that supply oxygen and nutrients to the surrounding tissues.

The middle layer, called the arachnoid mater, is a delicate membrane that is located beneath the dura mater. It has a web-like appearance due to its fine, fibrous structure. The space between the arachnoid mater and the pia mater is known as the subarachnoid space, which contains cerebrospinal fluid and blood vessels. The arachnoid mater helps cushion the brain and spinal cord from sudden movements and impacts.

Finally, the innermost layer of the meninges is the pia mater, which is in direct contact with the brain and spinal cord. It is a thin and highly vascularized membrane that adheres closely to the contours of the nervous tissue, following its folds and grooves. The pia mater helps nourish the brain and spinal cord by supplying nutrients and oxygen through its blood vessels.

In terms of musculoskeletal pain and function, the dura mater is richly innervated with sensory receptors known as nociceptors. These nociceptors can respond to various stimuli, including mechanical pressure, tension, inflammation, and chemical changes. These inputs can be perceived as painful when they are threatening or excessive.

The dura is intricately connected to the musculoskeletal system through its attachments to the bones of the skull and vertebral column. Changes in the alignment or mechanics of these bones alters the delicate balance of pressure around the brain and spinal cord. Pressure changes affect the tension and position of the dura mater. This, in turn, influences the function of the nervous system and contributes to symptoms and injuries such as:
Tension headaches
Head or ear pressure
Neck pain
Thoracic outlet syndrome
Back pain
Ankle sprain
Hamstring strains

The dura can be most commonly affected by:
Physical trauma such as a fall, sport collision or car accident leading to a whiplash injury and or concussion
Musculoskeletal issues such as poor posture, muscle imbalances, or spinal misalignments can lead to tension or compression of the dura mater
And less commonly by:
Spinal and brain surgeries due to the proximity to the dural membranes
Infection within the central nervous system such as meningitis, encephalitis, abscesses, or viral infections such as Epstein-Barr virus (EBV), human immunodeficiency virus (HIV), herpes viruses, varicella zoster virus (VZV) and hepatitis C virus (HCV)

All of the above factors can result in tension and lack of extensibility within the dura that the muscular system will compensate for by tightening and protecting the area. The result is referred symptoms in other areas of the body that do not respond to a typical musculoskeletal approach. The body prioritizes the central nervous system and the surrounding dural structures over the muscles, bones and ligaments. At Ease Physio uses a variety of practical assessments for tension in the dura to show you how this lesser known structure may be impacting your mobility and function. If the dura is relevant for you, it will be assessed and treated and you will be given some fun and relaxing techniques to ease your dural tension wherever you are on your rehab journey.