C. B. Wynn Parry

Pain in avulsion lesions of the brachial plexus.

&NA; Traction lesions of the brachial plexus are becoming more frequent. Many of the lesions involve avulsion of nerve roots from the spinal cord. This very often results in severe pain which is associated with deafferentation. Although reference to this pain and the difficulty in its management has been made is several reports in the literature, there has been no long‐term study of the natural history of this pain and the effects of various attempts to mitigate it. This series reports on a long‐term follow‐up of 275 patients of which 108 had evidence of avulsion lesions. Of these 108, 98 suffered significant pain. There is a remarkably constant description of the pain and the various activities that may affect it. Drugs are of very limited use and the most valuable method of treatment found in this series was transcutaneous electrical stimulation — although, only one‐third responded dramatically to this treatment. The single most effective manoeuvre that reduces pain is absorption by the patient in work. There remains a significant number of young men with severe pain who may expect to suffer such pain indefinitely. There is urgent need for new methods to be developed to control this pain.

Sensory Re-Education after Median Nerve Lesions

Technique for re-educating sensory function after median nerve lesions at the wrist is described. Results of re-education of Twenty-three patients are presented. The functional results are good and belie the traditional view of sensory function after nerve suture. Recent advances in sensory neuro-physiology are discussed which may explain the successes of this technique.

Free microvascular and microneural transfer of the extensor digitorum brevis muscle for the treatment of unilateral facial palsy.

The operation of transfer of the extensor digitorum brevis muscle to the face in the treatment of unilateral facial palsy (Thompson and Gustavson, 1976) has been further modified by immediate anastomosis of its vascular pedicle to the superficial temporal vessels. Six of our ten patients showed some new movement but in only three did this approach symmetry with the other side. Long term follow-up showed that improvement can be expected for up to two years after transfer. Our technique is assessed critically and suggestions are made for further improvement.

Clinical trial of propranolol in post-traumatic neuralgia

Abstract In view of several case reports of relief of various neuralgias by propranolol, a double‐blind cross‐over trial using this drug was conducted in 10 patients with severe persistent pain and paraesthesiae following upper limb peripheral nerve injuries. The patients received up to 240 mg of propranolol per day. Only one patient reported pain relief, but this patient withdrew from the trial. An open trial of propranolol was conducted in 6 other patients with a variety of peripheral nerve lesions. Of these, neuroma tenderness was transiently reduced in one patient and the hyperaesthesia of a painful scar was relieved in another. Routine use of propranolol in such patients cannot be recommended.

The Musician’s Hand:

Care of the painful or injured hand or arm in a musician requires time, great patience, sophisticated knowledge and analysis of both the musician and their instrument, and in most cases a non-surgical approach. This is a tall order for the busy hand surgeon. Close collaboration between interested specialized physicians and the hand surgeon facilitates care of these patients. Additional help from music teachers, specialized instrumentalists, psychologists, arts therapists and family may be vital. Nevertheless, nothing short of a comprehensive approach will be successful and a limited approach may be functionally damaging if not disastrous. If an operation is necessary, provided surgery is performed with careful planning and skill, the results need not be as unsatisfactory as previously believed and indeed can in certain circumstances salvage a musician’s career.

Diagnosis of brachial plexus traction lesions by sensory nerve action potentials and somatosensory evoked potentials.

Forty-two patients with unilateral brachial plexus traction lesions were investigated by recording sensory nerve action potentials (SNAPs) from the lower arm and somatosensory evoked potentials (SEPs) from the clavicle, the cervical spine and the scalp overlying the contralateral somatosensory cortex, in response to electrical stimulation of peripheral nerves. The median and radial nerves were assumed to derive principally from the C6 and C7 roots, and the ulnar nerve from the C8 and T1 roots. Combination of SEP and SNAP findings suggested a location for the lesion (preganglionic, postganglionic or combining pre-and postganglionic elements) which was found to be accurate in 10 out of 16 operated cases, and substantially accurate in another 3. There was a poor correlation, however, between the presence of absence of SNAPs in the musculocutaneous nerve and the location of the lesion to the C5 root.

The management of painful peripheral nerve disorders

At the Royal National Orthopaedic Hospital, a special clinic has been established for painful peripheral nerve disorders. During the last seven years a variety of problems have been seen including painful neuromas following division of the median nerve at the wrist, causalgia from partial nerve lesions, painful amputation stumps and phantom limb pain following amputation, Sudeck’s atrophy, painful,digital nerve lesions and the deafferentation pain that follows avulsion lesions of the Brachial Plexus. It is only a few years since patients with painful peripheral nerve disorders resisted all attempts at treatment. Little was understood of the pathophysiology, and apart from temporary relief from analgesics, treatment was disappointing. However, in recent years there have been some exciting advances in our understandingof pain mechanisms, these are discussed in detail in the section by Professor Wall. The clinical pictures fall into the following major categories:

Management of causalgia after peripheral nerve injury

The authors report on a series of patients with severely painful disorders of peripheral nerves--they review the modern theories on the nature of causalgia and reflex sympathetic dystrophy. Peripheral causes include spontaneous discharges from neuroma sprouts, their sensitivity to adrenergic compounds, ectopic generator activity in abnormally myelinated fires and increased firing in dorsal root ganglia. Central causes include spontaneous activity of deafferented nerves in the dorsal horn and development of response to new receptive fields. The natural history of such disorders is poor--many patients suffering pain for 10 years or more--the clinical picture is characterized by spontaneous burning pain and allodynia and hyperpathia, chronicity, osteoporosis, skin and nail changes and deformities. The basis of treatment is sympathetic blockade using intravenous guanethedine on alternate days. At least 6 blocks are given as the majority of patients do not respond until the 5th or 6th block. Each block is followed by desensitization and intensive rehabilitation. The authors emphasize that sympathetic blockade is only one, albeit the most important, modality in a multi-faceted treatment programme. Surgical attempts to relieve pain almost uniformly failed--causing as they do further neuronal changes peripherally and centrally. Recurrences depend on the degree of initial response. Those who obtained virtually complete relief of pain had a lower recurrence rate but a high proportion needed repeated sessions of treatment at yearly intervals. Follow-ups must therefore be indefinite.

Mechanical back pain and the facet joint syndrome

Mechanical back pain is a common disability often associated with the facet joint syndrome. Treatment is based on early, adequate pain relief with simple techniques of regional analgesia. In a few cases this is not enough and more sophisticated methods, such as radiofrequency denervation, cryo-analgesia and possibly intrathecal midazolam, are necessary. However, the main thrust of our approach is to treat the underlying structural disorder with strengthening of the back muscles and correction of postural abnormalities responsible for the mechanical back pain. Our report is based on an analysis of 83 patients who failed to respond to long periods of rest, suitable analgesic and allied drugs and other non-invasive measures. There had been no overriding indication for major surgery. A large number of these patients have been improved by our methods, but further work is in progress to extend the proportion of satisfactory results.

Successful repair of a complete brachial plexus lesion.

A case of a complete brachial plexus lesion and partial axillary artery division is described, which was satisfactorily treated by operation.