fascia, chronic pain, and entrapment neuropathies

“Entrapment mononeuropathies represent a common reason for visiting primary care and outpatient neurology practices. Accurate diagnosis is paramount because these presentations can be very similar to radiculopathy or systemic neuropathy.   Numerous experimental and clinical studies have demonstrated that nerve mechanosensitivity can be heightened in the absence of nerve injury and therefore of neuropathic pain.  All the nerves in their course have direct contact with fasciae and cross them. Until now, the role of the fasciae in etiology has been underestimated.” Some cherry-picked sentences from the study being discussed today.

What do we know about nerve entrapment pathologies related to fascia?  For one, we know they are common.  A few of the titles I came across while doing a quick Google search included…..

• Medscape’s 2017 article, Nerve Entrapment Syndromes, stated…. “Entrapment neuropathies are a group of disorders of the peripheral nerves that are characterized by pain and/or loss of function (motor and/or sensory) of the nerves as a result of chronic compression.“

• A June 2014 issue of Anatomy and Cell Biology (Fascial Entrapment of the Sural Nerve and its Clinical Relevance)  “Entrapment of the nerve could be caused by compression due to fascial thickening, while the symptomatology includes sensory alterations and deficits at the nerve distribution area.”  Fascia was mentioned here 15 times, with “thickening” seemingly the prime culprit (stick around for discussion and links).

• A 2012 issue of Radiology Research and Practice (Entrapment Neuropathies in the Upper and Lower Limbs: Anatomy and MRI Features) “Peripheral neuropathies are relatively common clinical disorders.  Although nerves may be injured anywhere along their course, peripheral nerve compression or entrapment occurs more at specific locations, such as sites where a nerve courses through fibro-osseous or fibro-muscular tunnels or penetrates muscles.”  The word fibro could have been swapped out for fascia here and been just as accurate.

• A 1998 issue of Clinical Orthopedics (Anatomic Considerations of Superior Cluneal Nerve at Posterior Iliac Crest Region) dealt with a phenomenon I wrote about HERE as fairly common cause of low back pain.  “The intermediate and lateral branches of the superior cluneal nerve either pierce the thoracolumbar fascia or pass through an orifice or fissure in the thoracolumbar fascia. In two specimens, the medial branches of the superior cluneal nerve were constricted within the osteofibrous tunnel. The nerve was entrapped between the rigid fibers of the thoracolumbar fascia and the iliac crest.“

• A 1997 copy of the American Journal of Sports Medicine (Obturator Nerve Entrapment. A Cause of Groin Pain in Athletes) put it this way concerning groin pain.  “Chronic groin pain in athletes is often difficult to diagnose and treat. There are many anatomic structures in the inguinal and groin region that have the potential to cause pain. [One of these is] ‘obturator neuropathy,’ a fascial entrapment of the obturator nerve where it enters the thigh  The surgical findings are entrapment of the obturator nerve by a thick fascia overlying the short adductor muscle.“

• A 1988 issue of the Journal of Hand Surgery (Entrapment Neuropathy of the Palmar Cutaneous Branch of the Median Nerve by the Fascia of Flexor Digitorum Superficialis) stated, “At operation, constriction of the palmar cutaneous branch of the median nerve by the fascia of seemingly normal flexor digitorum superficialis was observed beneath the site of maximum tenderness.“

• In 1976, the Journal of the American Podiatric Medical Association published a study titled Proximal Peripheral Nerve Entrapment Syndromes in the Lower Extremity that, as the title would suggest, concerned this very thing.  The author defined the pathomechanics of the process as based on “altered transmission due to mechanical irritation related to anatomical neighbor impingement.“

Although that study was published when I was ten years old; a couple weeks ago a brand new study was released on this topic by renowned Italian fascia researchers, Antonio and Carla Stecco (MD’s) and physical and rehabilitation medicine specialist, CF Pirri.  The Steccos have been instrumental in educating physicians and clinicians on the importance of understanding the relationship between inflammation and fibrosis (HERE), fascial “thickening” (HERE, HERE, HERE, HERE, HERE, HERE, HERE, HERE and HERE) and something they refer to as FASCIA DENSIFICATION.  Their study, Fascial Entrapment Neuropathy, published in April’s issue of Clinical Anatomy covered more of the same ground, with some interesting new twists.

Basing these statements off of their findings in the scientific literature, the Steccos made a bold conclusion — particularly in light of the exploding prevalence of DIABETIC NEUROPATHY.  “Entrapment neuropathies are the most prevalent type of peripheral neuropathy and can have profound physical, psychological and economic impacts on patients.”  In other words, nerve entrapments are as common as they can be severe.  And all too often these entrapments revolve around FASCIAL ADHESIONS.  “Our research has underlined a finding common to many authors: fascial tissue is relevant to the etiology of entrapment neuropathy.”

The authors searched PubMed and came up with almost 22,000 potential studies for review, eventually settling on 72 that were published between the years of 1947 (just after WWII) and 2010, and fully met their criteria.   Besides those mentioned earlier, here are some of the fascial entrapment neuropathies that were spoken of by the Stecco’s team. 

• The ilioinguinal nerve (comes from the lumbar spine and innervates the scrotum in men and pubic area / labia majora in women), iliohypogastric nerve (comes from the lumbar spine and innervates the area around the hip bone), and genitofemoral nerve (comes from the lumbar spine and innervates the lower abdomen, scrotum and labia as well as the upper, inner, and front portion of the thigh).  Be aware that the most common causes of these particular nerve entrapments are HERNIA SURGERIES or injury to the OBLIQUE MUSCLES.

• I’ve dealt with MERALGIA PARESTHETICA in the past (see link).   

• PIRIFORMIS SYNDROME as well as other entrapments of the hip rotaor cuff (not to mention the mimic; CLUNEAL NERVE ENTRAPMENTS)

• Entrapments of the common peroneal nerve (lower leg, often around THE KNEE).  While these often do not cause sensory deficits, they often lead to varying degrees of motor loss as noted by a 2013 issue of JOTSR (Peroneal Nerve Entrapment at the Fibular Head...).  “The most common nerve entrapment syndrome at the lower limbs is entrapment of the common peroneal nerve (CPN) at the head of the fibula. A motor deficit is the main manifestation and the risk of permanent functional impairment is the predominant concern. Below the knee, the CPN courses around the lateral aspect of the fibular neck, where it is highly vulnerable to injury. Apart from laceration or stretching of the nerve during fractures or dislocations of the proximal fibula or ankle, idiopathic entrapment syndrome is the most common cause of loss of CPN sensory and motor function.“

• Superficial peroneal nerve entrapment (I discussed SUPERFICIAL NERVE ENTRAPMENTS IN FASCIA, including superficial peroneal nerve entrapment syndrome).

• Various entrapments of the foot that either directly or in round about ways are often related to the PLANTAR FASCIA or the POSTERIOR TIB TENDON, such as what’s seen in Tarsal Tunnel Syndrome.

• THORACIC OUTLET SYNDROME, of which there are three kinds, and can mimic CERVICAL RADICULOPATHY.

• Suprascapular Nerve Entrapment, which the authors stated was caused by “pathological changes in the gliding tissue [and] could contribute to the development of thoracic outlet syndrome“.  SNE is a rare reason for posterior shoulder problems and is often confused with SCAPLAR DYSKINESIS (or HERE) found in other more common shoulder issues.

• Radial Nerve Entrapments occur at “several potential sites,” usually causing some sort of problem on the back-hand side of the forearm, with a number of fantastic videos on YouTube for addressing these.

• Median Nerve Entrapment:  While there are many potential areas to entrap the median nerve, a 2010 issue of the American Family Physician (Peripheral Nerve Entrapment and Injury in the Upper Extremity) put it this way….  “The most common nerve entrapment injury is carpal tunnel syndrome, which has an estimated prevalence of 3 percent in the general population and 5 to 15 percent in the industrial setting.”  CTS is an entrapment of the median nerve.  The Steccos wrote that, “during surgery abnormal fibrous bands, adhesions, or neuromas could be found at sites of medial nerve entrapment.”

• Superficial radial nerve entrapments, also known as Wartenberg’s Syndrome or Cheiralgia Paresthetica are more common than most experts believe.  Tresscot and Karl’s book, Peripheral Nerve Entrapments contains a chapter called Superficial Radial Nerve Entrapment, which states “Superficial radial neuralgia is an under-recognized cause of radial wrist and thumb pain. It is misdiagnosed as wrist tendonitis, DJD of the thumb, carpal tunnel syndrome, lateral epicondylitis, and cervical radiculopathy. Careful attention to the presentation and physical exam will reveal the etiology, which will lead to a variety of treatment options.”  Although you can find a great deal of info about any of these topics on my site, I might add the ever-common DeQUERVAIN’S SYNDROME to that list as well.

• Ulnar nerve entrapment is, according to numerous sources, the second most common nerve entrapment neuropathy behind Carpal Tunnel Syndrome (it affects the palm-side of the forearm, particularly the area of the pinky).  Because this nerve comes from the neck, entrapments are commonly confused with radiculopathy (see earlier link).  The Steccos stated that, “The ulnar nerve passes through a fibrous tunnel (cubital tunnel) and related to repetitive trauma.”

Is Fascia a Leading Cause of Entrapment Neuropathies?

What are the chief causes of nerve entrapments?  “Increased fascial thickness” was at the top of the list.  But what causes increased fascial thickening?  How about repetitive trauma found in any number of sports / hobbies and jobs (“We hypothesize that, in idiopathic nerve entrapment, repetitive micro-traumas and/or overuse can transform the extracellular matrix from sol to gel in multiple regions within the deep fasciae“).  

Naturally, this leads to “increased viscosity of the ECM” — in other words, the liquid ECM becomes thicker, with less ability to lubricate tissues, which causes “loss of intra-fascicular gliding“.  Another factor is “increased pressures” such as seen in compression or even compartment syndromes.

In talking about the ability of nerves to “glide” or “slide” longitudinally (this “reduces the local stretching that would otherwise occur during limb movement“), the authors mentioned GLYCOSAMINOGLYCANS, HYALURONAN, and the “ADIPOSE TISSUE” that makes up a significant portion of the fascia.  All of which helps explain why thickening or stiffening (frequently the result of SYSTEMIC INFLAMMATION) is such a huge contributing factor for nerves that become “entrapped” in fascia (BTW, the study had a couple of excellent pictures of nerves trapped in fascia.

All of this information is wonderful, but as always, the place where the rubber meets the road is what it may take to solve the problem.

“The management of peripheral nerve entrapment syndromes depends on multiple factors including the chronicity and severity of symptoms, the underlying mechanism, and associated predisposing factors. Understanding the underlying mechanism of injury and the associated natural history is fundamental to designing an appropriate treatment strategy.” 

Whether your particular problem is chronic or acute (or more likely a combination of both — HERE), everything can be boiled down to one simple question — can your specific entrapment be successfully addressed with conservative methods or is it going to require surgery?   How might you find out? 

• First, as is the case with most health issues, ailments or injuries, start addressing the UNDERLYING INFLAMMATION.  I’m not simply talking here about using ice to diminish local swelling, but using diet and other “tools” to lessen the impact of systemic inflammation — the inflammation coursing through your body due to lifestyle choices (EPIGENETICS). 

• Second, try some tissue remodeling — it’s why people come to see us from across the country and around the world (HERE). 

• Third, leverage YouTube to your advantage.  If you have been diagnosed, for instance, with peroneal nerve entrapment, YouTube it and learn everything you can about it, including what you could be doing to resolve it non-surgically.

Part of what I’ve done for you on my site is to create a generic protocol that addresses all these factors.  It’s not a “cure-all” and it might not do anything for your particular problem, but it will provide most chronically ill or chronic pain patients with a DIY starting point (HERE).  Also, if you value the free information you find on our site, be sure and get it in front of the people you love and care about most.  A great way is still liking, sharing, or following on FACEBOOK.