The term 'peripheral neurop-athy' is used to describe damage to the peripheral nervous system, usually causing pain and numbness in the hands and feet. Neurological exam-ination reveals dulled perception of vibration, pain and temperature, especially in the lower limbs. Other symptoms include weakness, paraes-thesia (a burning or prickling sensation), diminished reflexes, fever and, in some cases, flaccid paralysis (loss of muscle tone).
The disorder may be caused by exposure to toxic substances (such as organophosphates, nitrobenzol, anti-mony, carbon monoxide, thallium, arsenic, mercury, lead, copper, N-hexane, acrylamide and triortho-cresyl phosphate) or certain drugs (such as vincristine, isoniazid, diphenylhydantoin, nitrofurantoin, thalidomide, metronidazole, clio-quinol, tricyclic antidepressants, griseofulvin, amiodarone and pheny-toin).
Peripheral nerve damage may also be seen in people with diabetes, alcoholism, chronic gastrointestinal disease, systemic lupus erythema-tosus, malignancies, infectious diseases, AIDS, vitamin deficiencies (such as thiamine or niacin) or por-phyria, or be inherited, as occurs in Charcot-Marie-Tooth disease.
Therapy consists of the identifica-tion and removal of the toxic agent, supplementation with the deficient vitamin or treatment of the asso-ciated disorder. In all cases of this disorder, rest and alleviation of any pain should be part of the treatment.
Natural medicine offers a number of therapeutic approaches.
Aranea ixobola 8DH is particularly helpful in alcoholic polyneuritis, as proven in a series of patho-genetic experiments from the Robert Bosch Hospital in Stutt-gart, Germany (Cahiers d'Hom'eo-pathie et de Th'erapeutique Compar'ee, 1958: 279-84).
- Aranea diadema 3DH may be helpful for toxic or viral poly-neuritis in a number of provings (Deutsche Hom"oopath Monatsschr, 1958: 161), and Abelmoschus 3DH was found to produce the symp-tomatology of polyneuritis and multiple neuromyositis in controlled pathogenetic experi-ments carried out in two Mexican hospitals (De Legarreta L. Mati`ere M'edicale Hom'eopathique des Plantes Mexicaines. Mexico City, 1961).
Traditional Oriental medicine teaches that this condition is caused by Dampness moving to the limbs, where it obstructs the channels and coagulates the Qi (energy) and Blood within them.
This can occur only when the Spleen's transportive and transfor-mative functions are impaired, as the Spleen provides nourishment and, thus, controls the movement of the limbs. First, there is pain followed by numbness and, finally, debility-these mark the stages of its pathological development.
Treatment is directed towards opening the channels to boost circulation of both Qi and Blood. The principal points used are: upper limb: LI-11 (Quchi); LI-15 (Jianyu); TB-5 (Waiguan); and LI-4 (Hegu); lower limb: GB-30 (Huantiao); GB-34 (Yangling-quan); GB-39 (Xuanzhong); and Sp-6 (Sanyingjiao). These should be needled once a day with moder-ate stimulation for 2 to 4 weeks (Shanghai College of Traditional Medicine. Acupuncture: A Comprehensive Text. Seattle, WA: Eastland Press, 1984: 613).
- Nutritional therapy
As there may be a deficiency of l-carnitine, supplementing with this amino acid may have beneficial effects (Circulation, 1996; 93: 1685-9).
Charcot-Marie-Tooth disease is an hereditary neuropathy charac-terized by abnormal peripheral myelination such that the muscles of the feet deteriorate. A three-month blinded trial of 20 patients given vitamin E (81.6 IU/day) vs paraffin oil (placebo), followed by a year of 3 g/day of EFA and vitamin E, brought about signif-icant improvements in strength, sensation and scores of total disability. It was thought that vitamin E worked by improving membrane stabilization (Neurology, 1986, 36: 1200-5).
A multicentre randomized, double-blind, controlled trial of topical 0.075-per-cent capsaicin (Zostrix HP, an extract of Cap-sicum frutescens, or cayenne pepper) cream involved 252 patients, diagnosed with diabetic neuropathy, who applied the cream to painful areas four times a day for 8 weeks.
At the end of the study, the cream had resulted in statistically significant improvements in the patients' overall pain scores and pain intensity/relief compared with a placebo (the vehicle without the active ingredient). It was concluded that capsaicin-containing cream was both effective and safe for the treatment of painful diabetic neuropathy (Arch Intern Med, 1991; 151: 2225-9).
Finally, a 12-month placebo-controlled trial of oil of evening primrose (EPO; OEnothera bien-nis), involving 84 patients with mild diabetic neuropathy, noted significant improvements in the tendon reflexes in both the arms and legs, in the muscle strength of the arms, sensation in the arms and legs, cold threshold on the wrists and heat threshold on the ankles in those in the treatment group. The effective dose was 480 mg/day of EPO taken as capsules (Diabetes Care, 1993; 16: 8-15).
Harald Gaier, a registered naturopath, osteopath, homeopath and herbalist, practises at The Allergy and Nutrition Clinic, 22 Harley Street, London, and the Irish Centre of Integrated Medicine, Co. Kildare ( www.drgaier.com ).