APPENDIX I: AUTOIMMUNE ASPECTS

The following data may be noted to clarify the ideas about the autoimmune aspect of arachnoiditis. They are unfortunately random, as there is a paucity of medical literature relating to this topic. However, my aim is to give the reader an idea of how the hypothesis mentioned in the article came about.

MacDonald ([80]) noted that 18% of the general population carry a factor in the blood (Histamine Release Factor HRF) which causes a dramatically potentiated, sustained autoimmune reaction to foreign substance in the people who carry this factor. As this factor may be implicated in autoimmune responses, this may be relevant in explaining why there is only a minority of patients with arachnoiditis who develop the condition to a clinically significant degree.

There seems, from anecdotal evidence, to be a significant proportion of arachnoiditis patients who have autoimmune problems.

Vasculitic neuropathies are seen in Rheumatoid Arthritis, Sjogren’s, Behcet’s syndrome and Systemic Lupus Erythomatosus. The commonest disorder that seems to be diagnosed concurrently with arachnoiditis is Sjogren’s syndrome. Various authors describe neurological aspects of this disorder, although there has been no direct reference to a link with arachnoiditis, however, there are similar clinical features between the two conditions ([81]). Kumazawa et al attribute the chronic sensory neuropathy occasionally seen in Sjogren’s to dorsal root ganglionitis with T-cell invasion. ([82]). They also describe autonomic dysfunction in Sjogren’s syndrome.

Nitsche et al ([83]) suggest that neurological features are seen frequently in overlap syndrome (a clinical picture of multiple coexistent autoimmune disorders, also known as Mixed Connective Tissue Disease MCTD), and that occasionally a demyelinating type

picture of central nervous system involvement may be seen. It is possible that arachnoiditis is part of the clinical spectrum of MCTD.

Tesavibul ([84]) suggests that there are subsets of Multiple Autoimmune Syndrome (MAS) and of particular interest is his proposed Type 2, which includes Sjogren’s syndrome, Rheumatoid arthritis, Primary Biliary Cirrhosis, Scleroderma and Autoimmune thyroid disease. (There are isolated cases of each of these disorders seen in patients with arachnoiditis).

There is also a recognised, albeit rare, association between the chronic inflammatory condition, sarcoidosis, and arachnoiditis. ([85]) Sarcoidosis is a multisystem, chronic granulomatous (a specific type of chronic inflammation) disorder, which involves an abnormal immune response. The exact source of this reaction is as yet unknown. A study by Sharma ([86]) showed 24% of neurosarcoidosis cases had meningeal involvement.

Marinac ([87]) noted that there appears to be an association between the occurrence of hypersensitivity-type reactions in drug and chemical induced meningitis (an acute reaction) and underlying collagen vascular disease (known to be autoimmune).

It has been seen in conditions such as Rheumatoid Arthritis that there may be anti-plasminogen antibodies (plasminogen is part of the fibrinolytic pathway).

It may therefore be possible that arachnoiditis involves an autoimmune process that affects fibrinolysis.

A recent paper ([88]) suggests that in arachnoiditis there is a similar process of inflammation to that seen in serous membranes such as the peritoneum, with “a negligible inflammatory cellular exudate and a prominent fibrinous exudate”. It is worth noting that the condition retroperitoneal fibrosis may be seen in association with rheumatoid arthritis.

Table of Contents

Introduction
THE SCALE OF THE PROBLEM
ARACHNOIDITIS OR EPIDURAL FIBROSIS?
NOMENCLATURE
THE INFLAMMATORY NATURE OF ADHESIVE ARACHNOIDITIS
PATHOLOGY
CLASSIFICATION
CAUSES
THE IATROGENIC ASPECT OF ADHESIVE ARACHNOIDITIS
PRESERVATIVES IN SPINAL INJECTIONS
PROGNOSIS
THE SYNDROMIC NATURE OF SYMPTOMS IN ADHESIVE ARACHNOIDITIS (Warning: LONG)
COMPLICATIONS OF ADHESIVE ARACHNOIDITIS
DIFFERENTIAL DIAGNOSIS
CLINICAL ASSESSMENT
DIAGNOSTIC TESTS
TREATMENT OPTIONS (Warning: LONG)
MULTIPLE CHEMICAL SENSITIVITY
LOOKING TO THE FUTURE
APPENDIX I: AUTOIMMUNE ASPECTS
NEXT: APPENDIX II: SYRINGOMYELIA
ADDENDUM - May 2000
REFERENCES