60
Injury,
8, 60 62
Injection C. M. Ling
injury of the radial nerve
Senior Lecturer, University Department Singapore General Hospital
of Orthopaedic
Surgery,
S. C. Loong Consultant Neurologist, Department Tan Tack Seng Hospital ’
of Neurosurgery and Neurology,
Summary
Four cases of radial nerve palsy following intramuscular injections into the arm are reported. Recovery occurred in all 4 cases-l after neurolysis and 3 spontaneously. The mechanism of nerve damage and its treatment are discussed. INTRAMUSCULAR injections of therapeutic and prophylactic agents into buttock, thigh and arm occasionally damage the peripheral nerves. This usually results from ignorance of the anatomy of the nerves and failure to exercise adequate care during the injection. Injection injuries of the sciatic nerve are not rare (Woodson, 1943; Combes and Clark, 1960; Curtiss and Tucker, 1960) but only isolated cases of radial nerve injuries have been reported (Seshachalam, 1929; Broadbent et al., 1949; Holbrook and Pilcher, 1950). The aim of this paper is to report 4 cases of radial nerve paralysis from injections into the arm, and to serve as a reminder that such injury can occur.
CASE
REPORTS
Case 1
A 47-year-old Chinese male was given an injection of tetanus toxoid into his left arm. At the time of injection he experienced severe pain at the injection site with radiation down the back of his forearm. The limb became swollen and 2 weeks later a complete palsy of the left radial nerve was noted. Electromyography 6 months after the injury showed no evidence of recovery. Jones’s tendon transfer was carried out. When last seen 4 years later there was
good extension of the wrist and fingers but hardly any palmar flexion. Further electromyography still showed absent sensory action potential* but voluntary activity was recorded in the extensor digitorum. Case 2 A 9-year-old Chinese boy was given an injection (solution not known) into the left arm for hyperpyrexia. Almost immediately after the injection he could not extend his wrist and fingers and developed
*The technique employed was essentially that described by Downie and Scott (1967). Surface electrodes were used for stimulation and recording and each of these consisted of a pair of silver discs of 1 cm diameter and mounted 4 cm apart on a plastic base and covered with gauze soaked in saline. The sites for stimulation and recording were: along the course of the cephalic vein in the lower third of the forearm; and at the wrist or just distally where the superficial branches of the nerve normally cross the tendon of the extensor pollicis brevis. Both antidromic and orthodromic stimulation of sensory fibres at both sites were attempted. The stimulus, with a duration of 0.1-0.4 ms and an amplitude of 200 V was delivered by 2 isolated devices stimulators. Evoked sensory potentials, if any, were amplified by a Tektronix Type 122 preamplifier and displayed for Polaroid photography on a Tektronix Type 564B storage oscilloscope, as for recording of median and ulnar sensory potentials (Loong and Seah, 1971). The sensitivity was 6 uV/cm. Radial sensory nerve potentials were tested in the normal upper limb when none could be evoked in the clinically affected limb; they were noted to be present in all the patients studied but were not photographed for permanent record.
Ling and Loong
: Injection
numbness over the dorsum of the first interosseous space. When seen 2 months later there was a complete left radial nerve palsy. Electromyography showed fibrillation potentials in the left extensor digitorum with no sign of voluntary activity. Stimulation of the radial nerve in the upper part of the arm evoked a motor response of abnormally low amplitude with a latency period of 3.5 ms. The sensory action potential was absent. The first sign of recovery was detected after 5 months. Three years after the injury, the wrist and finger extensors had completely recovered but the extensor pollicis longus was still weak. Electromyography confirmed normal activity in the extensor digitorum but the sensory action potential was still absent. Case 3 A 54-year-old Chinese male had an injection of metamizol (Bonpyrin) into the left arm. At the time of injection, he experienced severe pain along the dorsum of the forearm with immediate onset of wrist drop and loss of finger extension. Clinical examination and electromyography a month later showed a complete paralysis of the radial nerve. Exploration of the nerve 3 months after the injury revealed 1 cm of thickening of the nerve in the musculospiral groove. Neurolysis was performed and recovery began within 5 months. When seen a year later, the affected muscles had fully recovered but a mild hypoaesthesia in the radial nerve’s distribution was still detectable. Electromyography showed no fibrillation but slight reduction of motor unit potentials. The sensory action potential was still absent. Case 4 A 21-year-old Chinese female was given an injection of oxytetracycline hydrochloride into her right arm. There was immediate onset of severe pain at the injection site with radiation to the dorsum of the forearm. There was also wrist and finger drop. When seen 3 months later, there was a complete palsy of the right radial nerve confirmed by electromyography. Evidence of recovery was noted 4 months after the onset. Two years later, except for slight weakness of extensor pollicis longus, the other muscles had fully recovered. Mild hypoaesthesia was still present over the anatomical snuff-box. Electromyography 5 and 10 months after onset showed normal findings in the extensor digitorum but no sensory action potential could be evoked. DISCUSSION Injury of a peripheral
61
Injury
nerve by intramuscular injection can result from the needle, or the solution used being injected into the nerve (Scheinberg and Allensworth, 1957). Nerve damage may also result from chemical irritation and toxic action of the injected solution (Combes and Clark, 1960; Sunderland, 1968), or neuritis from progressive inflammatory and fibrotic changes (Tarlov et al., 1951). If the injury results
from progressive inflammatory and fibrotic changes, there is usually a latent period before the onset of paralysis (as in Case 1). The severity of the neural damage is determined by the internal structure of the nerve at the site of injury and the amount and toxicity of the injected material (Sunderland, 1968). The known agents injected into the arm in the present series were tetanus toxoid, metamizol, and oxytetracycline hydrochloride. There is no report in the English literature of nerve injury from tetanus toxoid or metamizol injections. Other causative agents reported include sulphonamides, tetracycline, penicillin, streptomycin, erythromycin, sulphapyridine, alcohol, bismuth, arsenical compounds, typhoid vaccine, colchicine and quinine (Sunderland, 1968). It is obvious that most of the therapeutic and prophylactic agents in use can cause paralysis if injected into the wrong site. All 4 patients in the present series recovered, though in Case 1 it was difficult to determine the extent of the recovery. This confirms the observations of previous authors (Seshachalam, 1929; Kolb and Gray, 1946; Matson, 1950; Curtiss and Tucker, 1960). As the majority of cases go on to useful recovery, tendon transfers must be delayed until adequate time has elapsed for natural recovery to occur. Treatment of the injured peripheral nerve is controversial. Although early exploration and neurolysis is recommended to enhance the recovery of the nerve (Matson, 1950), others (Scheinberg and Allensworth, 1957) favour delaying neurolysis. In the present series only 1 patient underwent neurolysis but all showed recovery, 3 of them within 4-5 months. It seems reasonable to delay exploration and neurolysis for the first 6 months and to explore if there is no sign of recovery after this period. Injection injury of the radial nerve is an avoidable complication if the relationship of the nerve to the site of intramuscular injection is kept in mind. The nerve is very superficial in the middle third of the arm and an injection at the junction of the uppermost and middle thirds of the posterolateral aspect or in the middle third of the lateral aspect of the arm may damage the radial nerve. The best way to avoid damage to the radial nerve is by selecting the site of injection midway between the acromion and the deltoid tuberosity. Acknowledgements
We wish to thank Associate Professor P. B. Chacha and Mr V. K. Pillay for their helpful criticisms in the preparation of this paper. We are
Injury: the British Journal
62
grateful to Mr N. Balachandran for permission to study his case. We are grateful also to Mr E. W. Kong and Mrs Patricia Koh for the secretarial help.
REFERENCES Broadbent T. R., Odom G. L. and Woodhall B. (1949) Peripheral nerve injuries from administration of penicillin. Report of 4 clinical cases. JAM.4 140, 1008. Combes M. A. and Clark W. K. (1960) Sciatic nerve injury following intragluteal injections. Pathogenesis and prevention. Am. J. Dis. Child. 100. 579. Curtiss P. H. and Tucker H. J. (1960) Sciatic paisy in premature infant. JAMA 174, 1586. Downie A. W. and Scott T. R. (1967) An improved technique for radial nerve conduction studies. J. Neural. Neurosurg. Psychiatry 30, 332. Holbrook T. J. and Pilcher C. (1950) The effects of injection of penicillin, peanut oil and beeswax, separately and in combination, upon nerve and muscle. An experimental study. Surg. Gynrcol. Obstet. 90, 39.
Requests Singapore
or reprints should be addressed General Hospital, Singapore
3.
to:
C.
M.
Ling,
FRCS,
Kolb L. C. and Gray
a complication 323.
of Accident
Surgery
S. J. (1946) Peripheral
Vol. ~/NO. 1 neuritis
as
of penicillin therapy. JAMA 132,
Loong S. C. and Seah C. S. (1971) Comparison of median and ulnar sensory nerve action potentials in the diagnosis of the carpal tunnel syndrome. .I. Neural. Neurosurg. Psychiatry 34, 750. Matson D. D. (1950) Early neurolysis in the treatment of injury of the peripheral nerves due to faulty injection of antibiotics. New .Grgl. J. Med. 242, 973. Scheinberg L. and Allensworth M. (1957) Sciatic neuropathy in infants related to antibiotics injections. Pediatrics 19. 261. Seshachalam T. (1929) Musculospiral nerve paralysis following intramuscular injection of quinine. Indian Med. Gaz. 64, 86. Sunderland S. (I 968) Nervrs and Nerve Injuries, I st ed. London, Livingstcne, p. 168. Tarlov I. M., Perlmutter I. and Berman A. J. (1951) Paralysis caused by penicillin injection : mechanism of complication-a warning. J. Neuroputhol. Exp. Nrurol. 10, 158. Woodson F. G. (1943) Sciatic nerve injury due to the intra-muscular injection of paraldehyde. JAMA 121, 1343.
Senior
Lecturer,
University
Department
of Orthopaedic
Surgery,