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Arachnoiditis: by L.O. Simpson & M.G. Anderson DISCUSSION: PART I - Documentation of the experience of New Zealanders with symptomatic arachnoiditis for comparison with two other reported series. Gender. The survey results showed that the Male : Female ratio of 1/3 : 2/3 is the same for the 1998 NZ and the 1999 Global surveys, but the reverse ratio applied to D.M. Long’s survey during the period 1967 –1992. The reasons for this change in ratio are not apparent and would make an interesting subject for further study. Worth noting is the difference in data collection; Long’s review was based on records of patients under his care while the other two surveys were based on voluntary responses and it may be that females are more likely to respond positively to such data collection. Age. In the New Zealand study 91% of respondents were aged 40 – 70 years and in the global study 94% were aged 40 – 80 years. This wider age range may indicate a later start in the management procedures that resulted in arachnoiditis in New Zealand. Alternatively there are possibly individuals in the older age group in New Zealand who have not been diagnosed with this condition and carry the label of Failed Back Surgery. Chronic Tiredness. This symptom is common to many chronic diseases. In the New Zealand survey it was reported by 87% and in the Global survey by 76%. This aspect is addressed in greater detail in the discussion on the second part of the study. Pain. This was a universal complaint in all three surveys. Most individuals with symptomatic adhesive arachnoiditis experience a number of different types of pain and over time develop symptoms characteristic of Fibromyalgia (in Long’s review this may have been the equivalent of pain described as ‘diffuse – apparently non-radicular’, which occurred in 41% of his series of 321 cases.) In the New Zealand study painful trigger spots are possibly indicative of diffuse soft tissue pain and occurred in 55%. In Smith’s Global survey 48% were recorded with symptoms of FM/FMS. It is notable that chronic tiredness is also a feature of FM. Some people with arachnoiditis are given a primary diagnosis of Fibromyalgia, or a dual diagnosis of arachnoiditis and FM. In this regard Dr. R. Wigley in a personal communication commented that “Fibromyalgia frequently complicates any painful condition or chronic pain syndrome of this nature and can be generated by anything in which there is sustained pain.” PART II - (a) Red blood cell shape analysis. This study showed that a significant number of the respondents had increased levels of flat cells in their blood. The subjects match the criteria used for a previously reported red cell shape analysis, viz chronic disease associated with tiredness exacerbated by exertion. (1) If the preponderance of flat cells indicates a response to a change in the red cell environment, then the following factors could be considered as causative in symptomatic arachnoiditis:- Chemical – foreign substances introduced into the subarachnoid space; Mechanical – spinal stenosis, degenerative conditions, trauma, surgery; Infective – viral and bacterial meningitis, and the pathophysiological response to these stimuli. For example, events which stimulate persistent immunoglobulin formation, as in graft rejection, or after vaccination, give rise to changed red cell shape population; Autoimmune – may account for the development of symptoms in some people with scarring in the subarachnoid space and surroundings and not others who have the same type of chronic inflammation. (Smith’s survey recorded 27% with associated autoimmune conditions.) (9) Reduced oxygen delivery to the tissues of specific body organs will impair function and will be evident from the presenting symptoms, a typical example being that of a myocardial infarction. Impaired blood flow in intraneurial capillaries could be the cause of pain in diabetic and other neuropathies. Experimental studies on rats (11, 12) showed that in an induced diabetic state motor nerve conduction was impaired, probably as a result of endoneurial hypoxia, leading to neurological deficits and pain. Burton refers to neurological tissue anoxia as an important factor in the disabling pain and neurological impairment experienced by individuals with adhesive arachnoiditis. (13). Smith noted that similar symptoms occur in spinal stenosis and symptomatic arachnoiditis. (14). In both conditions pain is brought on, or exacerbated by, prolonged walking or standing ( and in arachnoiditis by prolonged sitting also). In both the pain “tends to be burning, gripping or cramping in nature and radiates from the buttocks down the leg. There may also be dull aching and fatigue in the thighs and lower legs. Other common symptoms may include tingling and numbness, as well as a degree of weakness”. And in both there is compression of neural structures and blood vessels resulting in ischaemia to the nerve roots. While the wide range of symptoms in arachnoiditis is likely to be the result of several mechanisms it is probable that most if not all could be accounted for, in whole or in part, by tissue dysfunction due to oxygen deprivation. Symptoms are triggered or exacerbated by situations in which increased metabolism occurs with an associated requirement for increased oxygen delivery. Long reported that back pain was aggravated by activity in 94% of the cases reviewed. (10). Trigger factors identified in the New Zealand survey included physical activity, increased ambient temperature, mental and emotional stress, and for some, therapies such as physio, hydro and osteopathic. “Flare up” is the term generally used when manifestations of a systemic, flu-like illness occur. The onset may be immediate or delayed up to 24-36 hours, and it may take from a few hours to several weeks to settle.
(b) Dietary Supplementation with EPO. If oxygen deprivation due to impaired capillary blood flow is a factor in the symptomatology of chronic diseases then an appropriate treatment would be the administration of agents known to improve capillary blood flow in the tissues. These include Evening Primrose Oil (EPO), fish oil rich on Omega 3 fatty acids, bioflavenoids in Gingko extract, Trental. Such agents have been beneficial in MS, Lupus, and Diabetes. EPO contains gammalinolenic acid which is converted in the body to Prostaglandin E-1 (PGE-1) and it is this product which acts on the red blood cells, increasing the fluidity of their cell membranes. Flexibility is restored and capillary blood flow improves, allowing for better oxygenation of the tissues. Fish oil and Gingko improve blood flow by other means which are not yet understood. (15) In the studies on diabetic induced rats EPO improved blood flow and oxygen delivery to the nerve tissues, resulting in prevention or attenuation of nerve conduction deficits. (11,12). In a Japanese study (16) Lipoprostaglandin (Lipo PGE-1) was used intravenously to treat the pain of spinal stenosis. Symptomatic improvement followed and was maintained for a limited period. It appeared that the effectiveness of the drug was due to an increase in the circulation of blood in the nerve roots and cauda equina. The beneficial effects of PGE-1 on blood flow have been well demonstrated in Raynaud’s phenomenon, where spasm of small blood vessels in hands and feet results in poor circulation with cold, painful fingers and toes. Martin and Tooke (17) showed that an effect of infused PGE-1 was to increase the rate of capillary blood flow. After showing that comparable infusions of saline produced no benefits, Pardy et al (18) found that infused PGE-1 caused an increase in finger temperature and significantly improved Doppler-detectable arterial blood flow. They noted that the mechanism of action was unclear as 85% of PGE-1 was removed during passage through the pulmonary circulation. That observation was made also by Kyle and Hazelmanm (19) who reported that the infusion of PGE-1 abolished or reduced attacks for up to 12 weeks. A surprising aspect of these reports is that they were unaware of the effects of PGE-1 on red blood cell deformability which had been reported in 1974 (5) and 1975 (6). Based upon experimental work (20) the recommended daily dose of EPO for effective relief of symptoms is 4,000mg, with the beneficial effects becoming more apparent over time. There is individual variability in responsiveness so lower doses may be satisfactory for some people. There is strong anecdotal evidence for the effectiveness of EPO in relieving the symptoms experienced in many chronic conditions where such symptoms appear to be related to oxygen deprivation. Further studies are warranted to confirm this form of treatment. |
