In 15 patients who underwent open exploration of the brachial plexus, the somatosensory evoked potentials and nerve action potentials recorded at the time of operation were useful as guides to the most appropriate surgical procedure, and also in predicting the outcome in certain lesions. In three patients the apparent normality of the upper trunk of the plexus was concealing a more proximal lesion which was irrecoverable. The presence of a somatosensory evoked potential showed functional continuity in three patients in whom the C7 root was clinically involved and who recovered after operation. In five patients proximal stumps ofruptured CS roots showed functional central continuity; this indicated their sultabifity for grafting. These patients recovered except one who suffered from co-existing disease.

Fig 1 Superficial anddeep sensation. Scale ofgrading:.~-j Superficial: 0, ancesthetic; 1, hypowsthetic; 2, hyperasthetic; 3, normal. Deep: 0, no aware-10 ness; 1,partial; 2,full unaware of movement; 1, aware at extremes only; 2, aware of gross movement (>60°); 3, aware of coarse movement (>300); 4, aware of fine movements; 5, normal. Superficial and deep sensation: Each side of the body is divided into 10 areas (see Fig 1), and is tested by working from the proximal to the distal end. Superficial sensation is tested using light touch (cotton wool) and deep sensation by firm pressure from a blunt object such as the cap of a pen. These very simple tests were chosen to allow assessment of patients with severe word finding difficulty or other problems of communication. Localization: This is tested in the palm, finger, and thumb of each hand and is done using light touch and is scored as follows: 0, unaware; 1, aware but out of area; 2, aware and in area; 3, aware to within 1 square inch (6.5 cm2); 4, aware to within i square inch (0.4 cm2); 5,

Too little attention has been paid to the hand in the past. It was common practice for severed tendons and nerves to be dealt with by inexperienced junior staff, often late at night, under unsatisfactory conditions. Small wonder that results of severe hand injuries were bad, and without the interest and encouragement of senior staff rehabilitation was insufficient or even non-existent. However, in recent years, pioneer surgeons in this country, in France, Switzerland and America, have aroused great interest in the problems of tendon and nerve surgery, and in the overall organization of rehabilitation services to ensure the best functional results.

No abstract

The papers presented here, stimulated by a symposium held in January 1983, were co-ordinated by Rolfe Birch, who has also written the opening section. The symposium is not intended to provide a comprehensive guide to injuries of peripheral nerves but aims to acquaint the reader with today's thinking on certain theoretical and practical aspects and, of equal importance, to warn him of the dangers of iatrogenic injury.