High Prevalence of Perineural Cysts in Patients with Fibromyalgia and Chronic Fatigue Syndrome

[JenB]

Paper:
https://academic.oup.com/painmedicine/advance-article-abstract/doi/10.1093/pm/pnaa410/6015822

Abstract

Objective
Pain in fibromyalgia (FM) and chronic fatigue syndrome (CFS) is assumed to originate from central sensitization. Perineural cysts or Tarlov cysts (TCs) are nerve root dilations resulting from pathologically increased cerebrospinal fluid pressure. These cysts initially affect sensory neurons and axons in dorsal root ganglia and produce sensory symptoms (pain and paresthesia). Symptomatic TC (STC) patients often complain about widespread pain and fatigue. Consequently, STC patients may initially be diagnosed with FM, CFS, or both. The objective of this study was to document the prevalence of TCs in patients diagnosed with FM or CFS.

Design
A retrospective study.

Setting
An outpatient clinic for musculoskeletal disorders.

Subjects
Patients diagnosed with FM according to the 1990 American College of Rheumatology criteria or with CFS according to the 1994 Centers for Disease Control criteria were selected.

Methods
Review of lumbar and sacral magnetic resonance imaging scans including TCs ≥5 mm in size.

Results
In total, 197 patients with FM, CFS, or both underwent magnetic resonance imaging. Ninety-one percent were women. The mean age was 48.1 (±11.9) years. TCs were observed in 39% of patients, with a mean size of 11.8 (±5.2) mm. In males, the prevalence was 12%, vs. 42% in females.

Conclusions
In patients diagnosed with FM or CFS, the prevalence of TCs was three times higher than that in the general population. This observation supports the hypothesis that STCs, FM, and CFS may share the same pathophysiological mechanism, i.e., moderately increased cerebrospinal fluid pressure, causing irritation of neurons and axons in dorsal root ganglia.

 

[JenB]

Here’s my take on the significance:

Tarlov cysts are “dilated nerve root sheaths filled with cerebrospinal fluid (CSF),” and so are somewhat analogous to the observation of excess fluid in the optic nerve sheath, found by Bragee, et. al in their paper on ME/CFS, hypermobility, and intracranial hypertension. In other words, this is where CSF fluid goes if there is too much of it or if there are local areas of elevated pressure due to obstructions.

For those new to Tarlov cysts, below are some references on the links between Tarlov cysts and intracranial hypertension. Either way, this strikes me as another datapoint suggesting intracranial hypertension might be *quite common* in our patient population. (See also Higgins’ work on intracranial hypertension in ME/CFS.)

My additional assumption is that the significance is less that ME/CFS patients who have Tarlov cysts should be directly treated for them, but rather, that this is an additional sign that can suggest: a) intracranial/intraspinal pressure and/or b) the presence of a connective tissue disorder in some patients, and that the task is to find the underlying cause of the pressure that caused the cyst.

I know this paper uses the Fukuda criteria and a 1990 ACR criteria (presumably, because this was a retrospective study). As bad as those criteria are, my assumption is that criteria are more likely to obscure signal than to create it. It would be great to see this replicated prospectively, in a more well-defined cohort.

Tarlov cysts and intracranial hypertension:

Rodrigues, Thiago P., Mariana Athaniel Silva Rodrigues, Italo Capraro Suriano, and Samuel Tau Zymberg. "Idiopathic intracranial hypertension associated with symptomatic perineural cysts: presentation of 2 cases."&nbsp;<em>World Neurosurgery</em>&nbsp;119 (2018): 17-19.&nbsp;www.sciencedirect.com/science/article/abs/pii/S1878875018316784

Hulens, Mieke, Ricky Rasschaert, Frans Bruyninckx, Wim Dankaerts, Ingeborg Stalmans, Peter De Mulder, and Greet Vansant. "Symptomatic Tarlov cysts are often overlooked: ten reasons why—a narrative review."&nbsp;<em>European Spine Journal</em>(2019): 1-12.&nbsp;link.springer.com/article/10.1007/s00586-019-05996-1

Hulens, Mieke, Wim Dankaerts, Ricky Rasschaert, Frans Bruyninckx, Ingeborg Stalmans, Greet Vansant, and Peter De Mulder. "Hydrocephalus associated with multiple Tarlov cysts."&nbsp;<em>Medical hypotheses</em>&nbsp;130 (2019): 109293.&nbsp;www.sciencedirect.com/science/article/abs/pii/S0306987719306024​

 

[voner]

here is a site for the "Tarlov Cyst Disease Foundation", for those who are (like me) are interested in learning about Tarlov Cysts.

https://www.tarlovcystfoundation.org/info/

 

[JenB]

FWIW, I have Tarlov cysts but they are asymptomatic. I also had excess fluid in my optic nerve sheath. Subjectively, the excess optic nerve sheath fluid has definitely improved or resolved. I’d be curious to see if the Tarlov cysts are still present or have resolved, also.

 

[Pyrrhus]

The full article can be downloaded from here:
https://www.researchgate.net/public...s_with_Fibromyalgia_and_Chronic_Fatigue_Syndr