Some arachnoiditis patients are given the "catch-all" diagnosis of chronic fatigue syndrome (CFS/ME) or fibromyalgia (FMS).

From the survey results and other anecdotal accounts, it seems more likely that these non-specific conditions are actually part of the arachnoiditis syndrome.

Goldstein ([1]) has described CFS as a limbic encephalopathy. In his paper, he writes at length about the "associated illnesses" such as fibromyalgia and carpal tunnel syndrome (CTS).

He attributes many of the widespread symptoms to trigger points, which are involved with problems such as Temperomandibular Pain and Dysfunction Syndrome (TMPDS).

Many of the symptoms he describes correlate closely with those experienced by arachnoiditis patients. He also discusses allergic rhinitis and intolerance of odours, which brings in a similarity with MCS.

Fibromyalgia (FMS) is defined as the presence of both chronic widespread pain and the finding of 11/18 tender points on examination, although only about 20% of FMS patients have this combination (these are most likely to be female). Clauw and Crofford, in their recent paper on fibromyalgia, ([2]) note:

"There is no clear diagnosis for the other 80% of individuals with less than 11/18 tender points, but it is likely that these persons, like FMS patients, also have pain that is ?central'  (i.e. not due to inflammation or damage of structures) rather than peripheral in nature."

In an earlier paper ([3]), Crofford et al. noted that patients with FMS exhibit neurohormonal perturbations and disturbed autonomic activity.

In 2002, Crofford published a paper([4])  on the hypothalamic-pituitary-adrenal axis abnormalities, noting that there is

"evidence of HPA axis involvement in acute and chronic pain"

but that

" it is unclear if the observed HPA axis abnormalities reflect pre-existing vulnerability to the FM spectrum of disease, or whether chronic somatic symptoms alter HPA activity."

A recent study in the University of Florida ([5]) has found that FMS patients suffer from severe pain in response to repeated non-painful stimuli such as pressure on the skin.

This is very reminiscent of the pain experienced by arachnoiditis patients. Researchers have hypothesised that this problem in FMS occurs after an injury to the central nervous system, which, of course, is precisely the event in arachnoiditis.

Recent research ([6]) suggests a link between Chiari malformation and/or cervical stenosis to fibromyalgia.  Many of the symptoms of Chiari or cord compression in the cervical region are also seen in arachnoiditis patients.   
 
FMS/MPS COMPLEX:

This is a 'double whammy': MPS is a pain condition and FMS is a pain amplification condition: it is synergistic: the whole is greater than the sum of its parts. Myofascial pain syndrome (MPS)

This condition causes muscular pain, which can be relatively widespread. Pain is caused by nodules (knots) causing areas of irritation in the muscle or fascia associated with the muscle (myofascia is a thin, virtually translucent film wrapped around muscle); these are known as trigger points (TrP), which are areas of irritation within extremely tight bands of muscle and or fascia.

Autonomic manifestations of myofascial pain:

* vasomotor: blood vessel constriction : causing an area that is cold to the touch

* pilomotor: goose bumps in the affected area

Matchstick test: firm indentations made with the blank end of a matchstick in the affected area will take longer to disappear than in unaffected areas.  (Source: Myofascial Information Network, Washington, USA)

[1] Goldstein J.A. The Diagnosis of CFS as a limbic encephalopathy.

[2] Clauw DJ, Crofford LJ Best Pract Res Clin Rheumatol 2003 Aug; 17(4): 685-701 Chronic widespread pain and fibromyalgia: what we know and what we need to know.
[3] Crofford LJ, Engleberg NC, Demitrack MA Baillieres Clin Rheumatol 1996 May; 10(2): 365-78 Neurohormonal perturbations in fibromyalgia.
[4] Crofford LJ Endocrinol Metab Clin North Am. 2002 Mar; 31(1): 1-13 The hypothalamic-pituitary-adrenal axis in the pathogenesis of rheumatic diseases.

[5] Article by Eric Benjamin Lowe, Gainesville, Florida, May 20 1999 about the work of Dr. Roland Staud et al at University of Florida.

[6] Milhorat, State University of New York; study of 364 patients with Chiari.