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Fibromyalgia and positional cord compression


Senior Member
two interesting articles by D Holman, from Seattle (rheumatologist)


Positional cervical spinal cord compression and fibromyalgia: a novel comorbidity with important diagnostic and treatment implications.
Holman AJ1.

The variable presentation and treatment response of fibromyalgia (FM) may be related to comorbidities, including positional cervical cord compression (PC3). Prevalence of PC3 among routine referrals for rheumatology consultation was assessed over 2 random months (January and February 2006) from a 4-year experience of 1100 patients. PC3 was defined as cord abutment, compression or flattening with a spinal canal diameter of <10 mm by magnetic resonance sagittal flexion, neutral, and extension images. Of 107 referrals, 53 had FM, 32 had a connective tissue disease (CTD) without FM, and 22 had chronic widespread pain (CWP) without FM criteria. The dynamic cervical spine images were obtained in 70 patients: 49 of 53 with FM, 20 of 22 with CWP and 1 of 32 with CTD, based on history and examination. Among those who received magnetic resonance imaging [MRI], 52 patients met PC3 criteria (71% of FM group [35/49], 85% of CWP group [17/20]). Two patients had a Chiari malformation (FM), 1 had multiple sclerosis (CWP), and 1 had multiple myeloma (CWP). Extension views were required for diagnosis for 37 of these 52 (71%) subjects, as well as for 8 patients who also had cervical spinal cord flattening. The pilot data suggest that further evaluation of PC3 in a controlled trial is warranted among patients with FM and CWP.

Fibromyalgia is complex and poorly understood. Recognition of unsuspected, comorbid cervical cord compression may provide new insight into its variable presentation, leading to novel treatment considerations. Also, dissemination of this dynamic MRI protocol may promote further study of this emerging concept of cervical cord irritation.


Fibromyalgia and Positional Cervical Cord Compression Differ Only By Autonomic Nervous System Consequences: A Double-Blinded, Prospective Study

Andrew Holman, Pacific Rheumatology Reseach, Seattle, WA

In 1998, C Muhle and D Resnick proposed a corollary to cervical spinal stenosis caused by intermittent abutment of the cervical spinal cord from dynamic shifting of degenerative discs with flexion and extension of the neck.1 This positional cervical cord compression (PC3) has been documented in 54-71% of patients with fibromyalgia (FM)2,3 and was an exclusion criterion in the pramipexole FM randomized controlled trial4. In animal models, PC3 is a potent sympathetic nervous system arousal5.
In humans, PC3 is so difficult to distinguish from FM (without dynamic imaging) that its validity and impact have been questioned. Given PC3 and FM symptom overlap, a blinded study was conducted.

Methods: Patients diagnosed with fibromyalgia per American College of Rheumatology 1990 classification criteria were recruited from the Seattle area and after consent, were provided standard, non-contrast cervical spine magnetic resonance imaging (MRI) with two additional saggital flexion and extension views with spinal canal diameter measurement at each disc level. PC3 was defined by a canal narrowing below 10 mm at any level WITH clear visual abutment of the cervical spinal cord by the commensurate disc and ligamentum flavum2.
Double-blinded to the MRI results, subjects were assessed by history, physical examination, and a variety of surveys, including the Multidimensional Health Assessment Questionnaire (MDHAQ), Fibromyalgia Impact Questionnaire (FIQ), Short Form Health Survey (SF-36), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Health Assessment Questionnaire (HAQ), 16-item Quick Inventory of Depressive Symptoms (QIDS) as well as autonomic nervous system (ANS) assessment by 5-minute, frequency domain, heart rate variability (HRV) of parasympathetic, sympathetic and total power measures (Omegawave Ltd, Espoo, Finland). Statistical analysis was conducted using Wilcoxon rank-sum for continuous variables and Fisher’s exact test for categorical variables.

Results: Fifty-four patients with FM participated in this study (92% women, mean age 45.2 years). PC3 was identified in 31 of 54 subjects (57.4%). All three ANS HRV measures demonstrated statistical significance. Consistent with animal model data, parasympathetic score was lower 0.145 ± 0.067 for PC3+ patients and higher 0.198 ± 0.098 for PC3- patients (p=0.029). Sympathetic score was higher 61.0 ± 17.5 for PC3+ patients and lower 46.2 ± 15.8 for PC3- patients (p=0.005). Total power score was lower 440 ± 492 for PC3+ patients and higher 1633 ±4232 for PC3- patients (p=0.022). No clinical, historical or survey measures distinguished PC3-FM+ patients from PC3+FM+ patients.

Conclusion: This study provides the first evidence that intermittent, positional abutment of the cervical cord is a potent sympathetic arousal in humans. It also highlights the challenge of diagnosing and addressing PC3 without imaging. Further investigation will to sort out the role of PC3 in the diagnostic conundrum of FM, its pathogenesis and its treatment algorithms.


Senior Member

"Heffez has since explained that PC3 manifests the aging of an injury, one often occurring ten to thirty years previously.16
Many patients with PC3 do not recall a specific injury, but clearly the MRI demonstrates disruption of the ligamentum flavum and the corresponding disc. What the enhanced MRI clarifies is the actual severity of the anatomical disruption and impingement of the cord with varied position. And, narrowing of a cervical spinal canal (normal 13-15 mm) to 8-10mm or as low as 4-6 mm, while both painful, has very different treatment implications. Curiously, the cord is not considered injured and there is usually no tissue damage. Rather, PC3 is thought to reflect spinal cord irritation. There are no ‘cord signals’ by MRI to alert the radiologist. There is usually no evidence of spinal cord atrophy, scarring, or thinning (myelomalacia). There may be flattening of the cord, and this is not uncommonly reported on traditional C-spine MRI reports. But generally, without the extension views, it has remained enigmatic exactly why a cord would be flattened. Perhaps for some, this mystery may now have a suitable explanation in PC3. Clinically, patients with PC3 generally abhor cervical extension, such as being positioned in a hair dresser’s sink for any significant length of time, or in a dentist’s chair, looking at the stars or firework displays, reading a computer screen over reading glasses, or riding a bicycle (non-recumbent)"



Hoarder of biscuits
This is an interesting article that should interest anyone with fibromyalgia. It is written with less technical jargon.

The classic medical record notation of ‘WNL’
doesn’t always mean ‘Within Normal Limits’.
Sometimes it means ‘We Never Looked’. With the
flexion-extension C-spine MRI, we can now look -
and make more informed decisions about PC3 and
patient care.


Senior Member
Ashland, Oregon
Hi @pattismith -- Thanks for starting this thread. After reading the below linked (ProHealth) article, I decided to do a search on this forum to see if anybody had posted on Positional Cervical Compression (PC3). I can easily see how PC3 could be a factor in some people's ME/CFS. -- Below the link is a snippet from the article.

I just got done watching a very good 10-minute video "How To Fix Forward Head Posture - 3 Easy Exercises (From a Chiropractor)", which I thought has the potential to successfully treat (or improve) PC3 and/or other neck issues. The video has over 32K Likes.

What Is Positional Cervical Compression Really All About?

What is Positional Cervical Compression (PC3)

Positional cervical compression occurs when parts of the spinal cord in the neck are compressed – but only in certain positions. In cases of PC3, the cervical spinal cord is most often compressed during neck extension, when the patient tilts their head backward, say, to look up at the sky. In cases of PC3, a number of structures can compress the cervical cord with the neck in extension, including displaced discs from trauma or degenerative disc disease, an injured ligamentum flavum (a spinal ligament often linked to stenosis, or the narrowing of the spinal canal), or the Chiari 1 malformation (a congenital disorder that compresses brain and spinal cord structures).

Dr. Heffez believes PC3 has been overlooked as a possible cause of fibromyalgia due to the fact that diagnostic MRIs are almost always taken with the cervical spine in a neutral position. In order to see PC3 in an MRI, the neck has to be in positions other than neutral, with images ideally compared in a neutral position as well as in flexion (looking down toward the toes) and in extension (looking up overhead).

Symptoms of PC3

PC3 can cause both widespread referred pain and neurological symptoms, due to the intermittent, positional compression of the cervical cord. However, each patient is different, and some do not show symptoms. However, when symptoms are present, they can include:
  • Diffuse muscle pain
  • Worsening pain with neck extension
  • Neck discomfort
  • Fatigue
  • Sleep disturbances
  • Balance problems
  • Dizziness
  • Gait issues
  • Grip strength discrepancy
  • Numbness
The list of symptoms can vary from one person to another, and more research is needed to fully understand PC3 and the profound effect it may have on fibromyalgia patients.
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Senior Member
After reading about the link between PC3 and Fibro, and between SFN and Fibro, it appears to me that pain in the spine may be the result of altered small nerve fibers going to the spinal discs and spinal muscles.