Peripheral Nerve Injuries: a Retrospective Survey of 456 Cases
Total Page:16
File Type:pdf, Size:1020Kb
SHORT REPORT ABSTRACT: This 16-year retrospective study reports the data on 456 consecutive patients with 557 peripheral nerve injuries (PNIs) between 1989 and 2004. Most patients were men (74%) and the mean age was 32.4 years. In 83% of cases the PNIs were isolated; combined lesions most commonly involved the ulnar and median nerves. Upper-limb PNIs occurred in 73.5% of cases; the ulnar nerve was most often injured, either singly or in combi- nation. Vehicle accidents affecting the brachial plexus or radial, sciatic, facial, and peroneal nerves were the most common cause of injury. Pene- trating trauma commonly affected the ulnar and median nerves; falls and gunshot wounds frequently affected the ulnar, radial, and median nerves; and sports injuries, particularly soccer, affected mainly the peroneal and tibial nerves. More than half of the brachial plexus lesions after vehicular accidents were from motorcycle crashes. Muscle Nerve 34: 785–788, 2006 PERIPHERAL NERVE INJURIES: A RETROSPECTIVE SURVEY OF 456 CASES JOA˜ O ARIS KOUYOUMDJIAN, MD, PhD Department of Neurological Sciences, State Medical School (FAMERP), Sa˜o Jose´ do Rio Preto, Sa˜o Paulo, Brazil Accepted 31 May 2006 Peripheral nerve injuries (PNIs) are a major medi- after a PNI, not so early that severe axonal degener- cal problem caused mainly by motor vehicle acci- ation is missed or too late when possible surgical dents, penetrating trauma after stabbing incidents, benefits are minimal.12 Clinical and electrophysio- gun-shots, and stretching or crushing after falls. logical changes should be carefully followed on a Fractures of adjacent bones are commonly associ- monthly basis to evaluate possible early reinnerva- ated with PNIs, such as humeral fractures with radial tion. Patients frequently have multiple injuries and neuropathy.11 In addition to penetrating injury caus- various medical specialties may be involved in their ing sharp or blunt transections/lacerations, nerves care. Thus, clinical–electrophysiological correla- may be displaced, contused, stretched, or even par- tions may be missed or misinterpreted. The purpose tially divided, leading to neuromas or lesions in con- of this study was to analyze data from 456 patients tinuity.6 The incidence of PNIs is frequently under- referred for EMG after symptomatic PNI. estimated and, surprisingly, few large general series have been published worldwide. METHODS Electromyography (EMG) is the most appropri- From January 1989 to December 2004, 456 consec- ate diagnostic method in the evaluation of the to- utive subjects were referred for electrodiagnostic pography and severity of PNIs. Magnetic resonance consultation due to PNIs; only the first EMG re- imaging also provides useful additional information quested after trauma was considered in this study. All about root avulsion after traction injury to the bra- subjects were symptomatic, reporting either motor chial plexus. Patients should be referred for electro- (weakness) or sensory (positive or negative) symp- diagnostic consultations within a 6-month period toms. Trauma to the spine with consequent acute, subacute, or chronic radiculopathy, myelopathy, or cauda equina syndrome was not evaluated in this Abbreviations: CMAP, compound muscular action potential; CNS, central study. From the total of 456 cases included in the nervous system; EMG, electromyography; MUAP, motor unit action potential; PNI, peripheral nerve injury; PSW, positive sharp wave; SNAP, sensory nerve study, 557 nerve lesions were identified in the face action potential and limbs. Data on age, gender, referring specialty, Key words: electromyography; nerve conduction studies; nerve injury; pe- ripheral neuropathy; trauma and interval between injury and first EMG were ob- Correspondence to: J. A. Kouyoumdjian, R. Luiz Antoˆ nio Silveira 1661, tained. 15025-020 Sa˜ o Jose´ do Rio Preto, SP, Brazil; e-mail: [email protected] All patients underwent EMG performed by the © 2006 Wiley Periodicals, Inc. Published online 31 July 2006 in Wiley InterScience (www.interscience.wiley. author and the results were analyzed retrospectively. com). DOI 10.1002/mus.20624 Electrophysiological involvement was graded using Short Reports MUSCLE & NERVE December 2006 785 Table 1. Injury categories to peripheral nerves in 437 cases involving 534 nerve trunks. Cases Nerves Category (n) Percentage (n) Percentage A Vehicle accidents 192 43.9 237 44.4 B Penetrating traumas 90 20.6 105 19.7 C Falls 58 13.3 68 12.7 D Gun-shot wounds 37 8.5 48 9.0 E Car accidents involving pedestrian 17 3.9 23 4.3 F Sports 12 2.7 16 3.0 G Miscellaneous 31 7.1 37 6.9 Total 437 534 the Seddon classification.13 Neurotmesis was diag- the upper limbs represented 73.5% of instances; to nosed on the basis of absence of sensory nerve action lower limbs, 21.5%; and to the face, 5%. In 2 lower- potential (SNAP) or compound muscular action po- limb cases and in another 2 involving the facial tential (CMAP) after distal stimulation of the af- nerve, nerve injuries were bilateral. fected nerve, profuse fibrillation potentials and pos- PNI categories were identified in 437 of 456 cases itive sharp wave potentials (PSWs), and absence of (95.8%), or 534 nerves (Table 1). There were 377 any volitionally recruited motor unit action poten- (83%) cases with single and 79 (17%) with multiple tials (MUAPs). In axonotmesis, mild to profuse fi- PNIs. Multiple nerve lesions involved two nerves in brillation potentials and PSWs were present and 62 cases, three nerves in 13 cases, four nerves in 3 MUAP recruitment was reduced. Neurapraxia con- cases, and five nerves in 1 case. The most frequent sisted of absent or rare fibrillation potentials and isolated nerve injuries, in descending order, were to PSWs, normal MUAP morphology with reduced re- the ulnar, brachial plexus, radial, median, peroneal, cruitment, and normal or reduced/absent SNAP or and sciatic nerves. The most common two-nerve in- CMAP amplitude, depending on whether stimulation juries were the ulnar plus median (37.1%), peroneal was distal or proximal to the conduction block. MUAP plus tibial (14.5%), sciatic plus femoral (6.5%), and morphology from reinnervation was also evaluated. radial plus axillary (4.8%). The most common three- The brachial plexus (and lumbar and lumbosa- nerve combination was ulnar, median, and radial. cral plexus) was considered one nerve regardless of The frequencies of the most common PNIs in any associated root avulsion. All terminal hand each trauma category are given in Table 2. branches of the median or ulnar nerves were also Neurotmesis occurred in 41% cases, axonotmesis considered together as median or ulnar lesions. Sen- in 45%, and neurapraxia in 14%. There were more sory nerve injuries were considered as neurotmesis cases of complete denervation with peroneal nerves when there was no SNAP response. Patients were (65%), followed by brachial plexus (51%), supras- classified as having single or multiple PNIs; the max- capular (50%), sciatic (49%), facial (48%), and pos- imum number was five affected nerves in one pa- terior interosseous (47%) nerves. tient. Descriptive statistics used included means and DISCUSSION frequencies. The protocol for the retrospective study was approved by the institutional ethics committee. The limitations of this work are that the data came from a private practice in which EMG consultation occurred at a variable interval after trauma, lead- RESULTS ing to underestimates of severity. The series also The 456 PNI patients constituted 3.7% of all cases includes many patients without central nervous referred for electrodiagnostic consultations. There system (CNS) lesions at the time of EMG consul- were 337 men (74%) and 119 women (26%). The tation. Because patients with severe CNS involve- mean age of patients was 32.4 years, ranging from 4 ment go to rehabilitation centers, their PNIs may to 79 years; the women were slightly older than the well be misdiagnosed as secondary medical prob- men (36.0 vs. 31.1 years). EMG was performed lems.3,4,14,15 within the first 180 days after PNI in 67% of cases, Young and male patients are more likely to between 6 and 24 months in 23.5%, and at more suffer PNIs. In fact, 95% of motorcycle accidents than 2 years after injury in 9.5%. Injuries to nerves of involved men and more than half of brachial 786 Short Reports MUSCLE & NERVE December 2006 Table 2. Percentage of individual nerve injuries in the different injury categories. Trauma ABCDEFG Total number 237 105 68 48 23 16 37 Axillary 6.8 0.0 8.8 4.2 4.3 18.8 0.0 Brachial plexus 19.8 1.9 8.8 10.4 13.0 0.0 8.1 Facial 9.3 0.0 1.5 0.0 4.3 0.0 2.7 Femoral 2.1 0.0 1.5 2.1 4.3 0.0 0.0 Inferior gluteal 0.8 0.0 0.0 0.0 0.0 0.0 0.0 Interosseous anterior 0.0 1.0 0.0 0.0 0.0 0.0 0.0 Interosseous posterior 2.1 1.9 4.4 2.1 0.0 6.3 13.5 Lumbar plexus 0.0 0.0 0.0 2.1 0.0 0.0 0.0 Lumbosacral plexus 0.4 0.0 0.0 0.0 0.0 0.0 0.0 Median 5.1 35.2 16.2 16.7 4.3 0.0 27.0 Musculocutaneous 3.0 1.0 1.5 0.0 0.0 6.3 0.0 Peroneal 9.3 1.9 2.9 8.3 21.7 37.5 10.8 Radial 16.5 2.9 19.1 14.6 8.7 6.3 16.2 Radial superficial 1.3 1.0 1.5 2.1 0.0 0.0 0.0 Sciatic 11.4 5.7 4.4 10.4 4.3 6.3 0.0 Superior gluteal 0.8 0.0 0.0 0.0 0.0 0.0 0.0 Suprascapular 1.3 1.0 1.5 2.1 4.3 6.3 0.0 Sural 0.4 0.0 0.0 0.0 8.7 0.0 0.0 Tibial 1.7 0.0 0.0 4.2 0.0 12.5 5.4 Ulnar 8.0 45.7 27.9 20.8 21.7 0.0 16.2 Ulnar, cutaneous dorsal 0.0 1.0 0.0 0.0 0.0 0.0 0.0 Data expressed in percent.