Abstract
Carpal tunnel syndrome (CTS) is a condition characterised by a collection of signs and symptoms indicative of focal median nerve dysfunction within the anatomical confines of the carpal tunnel at the wrist. The syndrome appears to be multifactorial in its aetiology. It has been asociated with certain systemic disorders, (e. g. Diabetes Mellitus, Acromegaly), factors related specifically to the movements and actions of the wrists and hands, (e.g., repetitive manual work, prolonged pinching and grasping and the use of vibratory hand held tools) and other conditions or characteristics which are systemic in nature but do not necessarily represent diseases (e. g. pregnancy, side effects to certain drugs). Recent reports suggest that vitamin B6 deficiency might play a role in the development of CTS. A review of the literature has shown there to be a paucity of analytical epidemiological data concerning these hypothesized risk factors. A study was therefore undertaken to investigate the association between a set of risk factors identified in the literature, (including low vitamin B6 status) and CTS. The study design selected was that of a pair matched case-control study. In this way, associations between aspects of CTS, aspects of vitamin B6 status and other hypothesized risk factors were examined. Thirty four cases were identified (electrophysiologically) and these were matched (for sex and age +/-3 years) with controls attending physiotherapy departments for accidental injuries involving the lower half of the body. Data were collected at interview, examination, and using a self administered questionnaire. Venous blood samples were also obtained from 32 cases and 20 controls. Vitamin B6 status was assessed using an enzyme stimulation assay, (Erythrocyte Glutamate Oxaloacetic Transaminase or EGOT). No statistically significant differences between the cases and controls regarding any aspects of vitamin B6 status were evident. These findings were confirmed by comparison with a group of fifty healthy volunteer subjects, (university staff). The need for further elucidation regarding the possible role of vitamin B6 in the treatment is highlighted. Cases statistically outnumbered controls with respect to the performance of repetitive manual work (p=0.019; exposure odds ratio = 5.0) and participation in leisure pursuits (p=0.03; exposure odds ratio = 2.75) involving the use of the hands. This supports the findings of other studies reported in the literature. The cases reported significantly more oedema (p=0.04; exposure odds ratio 3.0) and stiffness, (p=0.001) than the controls. A significant impairment in the range of movement of the index finger was noted. Certain of these symptoms have been reported to occur in groups of CTS sufferers and improve upon vitamin B6 therapy. The implications of these and other findings are discussed in the light of the current knowledge of the many hypothesized risk factors.