The Diagnosis and Treatment of Pain and Paraesthesiae in the Arm.

PAIN and parasthesiae in the arm are common symptoms. Four-fifths of the sufferers are women usually of middle age and the majority experience their discomfort at night. Because of sleep disturbance the morbidity of the condition is considerable. The syndrome of 'acroparaosthesia' has been recognized for many years, and the term was coined by Schultze (I893). After a number of identifiable causes had been eliminated, there remained a substantial group of patients with stereotyped symptoms but no diagnosis. Such vague terms as 'sleep tetany' and 'sleep rheumatism' were applied to them. Wartenberg (I944) suggested that compression of the brachial plexus by a normal first rib during sleep was the cause. Walshe (I945), who saw chiefly women with such symptoms in wartime conditions in Britain, attributed the compression to drooping of the shoulder girdle because of muscular fatigue. He called it the 'axillary outlet' or 'costo-clavicular compression' syndrome. A significant contribution to the problem of aetiology was made by Brain, Wright and Wilkinson (I947) when they described a patient with bilateral spontaneous compression of the median nerves in the carpal tunnels. Since that time the 'carpal tunnel syndrome' has been diagnosed with increasing frequency, but in certain circles there has been a tendency to group all patients with painful arms under the label 'brachial neuropathy' (Lishman and Russell, I96I). Effective therapy demands precise diagnosis and the need for precision is enhanced by the effectiveness of surgical division of the anterior carpal ligament in relieving the symptoms of the carpal tunnel syndrome (Garland, Sumner and Clark, I963; Garland, Langworth, Taverner and Clark, I964). A valuable aid to such precision was demonstrated by Simpson (I956). He showed that slowing of nerve impulse conduction occurred in the compressed segment of the median nerve producing an increase in the latency of the action potential recorded from the abductor pollicis brevis muscle when the median nerve was stimulated above the wrist. This paper records our experience using this technique in the investigation of 40I patients referred to us with pain or parresthesix in the arm.