Traumatic Brachial Plexus Injuries Represents Serious Peripheral Nerve Palsies

Czech version

Authors: P. Vaško ¹; A. A. Leis ²; V. Boček ¹; L. Mencl ³; P. Haninec ³; I. Štětkářová ¹
Authors‘ workplace: Neurologická klinika 3. LF UK a FN Královské Vinohrady, Praha ¹; Methodist Rehabilitation Center, Jackson, Mississippi, USA ²; Neurochirurgická klinika 3. LF UK a FN Královské Vinohrady, Praha ³
Published in: Cesk Slov Neurol N 2016; 79/112(5): 595-599
Category: Short Communication

Overview

Objectives:
Traumatic lesions of brachial plexus are serious periferal nerve injuries. Neurological examination and CT myelography or MRI are the basic examination methods that can confirm spinal root avulsion. To specify severity of the injury – electromyography and evoked potentials are used. The objective of this study was to determine whether implementation of cutaneous silent period that asseses function of small diameter A-delta fibers, is useful as a diagnostic tool in cervical root avulsion and brachial plexus injury.

Material and methods:
Clinical examination, imaging studies (CT myelography or MRI) and neurophysiological examination were performed in 23 patients with traumatic brachial plexus injury (16 males, age 18–62 years). Needle EMG was obtained from muscles supplied by C5–T1 myotomes. CSP was recorded after painful stimuli were delivered to the thumb (C6 dermatome), middle (C7) and little (C8) fingers while subjects maintained voluntary contraction of intrinsic hand muscles.

Results:
Electrodiagnostic and CT/MRI studies confirmed brachial plexopathy involving mainly the upper trunk or corresponding C5, C6 roots in all patients. However, well defined CSP was still present in 16 subjects. CSP was absent in at least one of the dermatomes in the remaining seven patients. All these patients had severe plurisegmental sensitive lesion.

Conclusion:
CSP was still present, although not absolutely normal, in the majority of patients with severe brachial plexus injury. This suggests there are plurisegmental innervations with residual function of A-delta fibers and the presence of spinal inhibitory reflexes. Resistance of A-delta fibers seems to be higher compared to motor fibers despite of severe traumatic lesion.

Key words:
plexus brachialis injury – CT myelography – magnetic resonance imaging – neurophysiology – EMG – cutaneous silent period

The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.

The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers.

Sources

1. O’Shea K, Feinberg JH, Wolfe SW. Imaging and electrodiagnostic work-up of acute adult brachial plexus injuries. J Hand Surg Eur Vol 2011; 36 (9): 747–59. doi: 10.1177/1753193411422313.

2. Chanlalit C, Vipulakorn K, Jiraruttanapochai K, et al. Value of clinical findings, electrodiagnosis and magnetic resonance imaging in the diagnosis of root lesions in traumatic brachial plexus injuries. J Med Assoc Thai 2005; 88 (1): 66–70.

3. Roger B, Travers V, Laval-Jeantet M. Imaging of posttraumatic brachial plexus injury. Clin Orthop Relat Res 1988; 237: 57–61.

4. Ochi M, Ikuta Y, Watanabe M, et al. The diagnostic value of MRI in traumatic brachial plexus injury. J Hand Surg Br 1994; 19 (1): 55–9.

5. Tsai PY, Chuang TY, Cheng H, et al. Concordance and discrepancy between electrodiagnosis and magnetic resonance imaging in cervical root avulsion injuries. J Neurotrauma 2006; 23 (8): 1274–81.

6. Trojaborg W. Clinical, electrophysiological, and myelographic studies of 9 patients with cervical spinal root avulsions: discrepancies between EMG and X-ray findings. Muscle Nerve 1994; 17 (8): 913–22.

7. Haninec P, Mencl L, Kaiser R. End-to-side neurorrhaphy in brachial plexus reconstruction. J Neurosurg 2013; 119 (3): 689–94. doi: 10.3171/2013.6.JNS122211.

8. Floeter MK. Cutaneous silent periods. Muscle Nerve 2003; 28 (4): 391–401.

9. Svilpauskaite J, Truffert A, Vaiciene, et al. Electrophysiology of small peripheral nerve fibers in man. A study using the cutaneous silent period. Medicina (Kaunas) 2006; 42 (4): 300–13.

10. Puri V, Chaudhry N, Jain KK, et al. Brachial plexopathy: a clinical and electrophysiological study. Electromyogr Clin Neurophysiol 2004; 44 (4): 229–35.

11. Parry GJ. Electrodiagnostic studies in the evaluation of peripheral nerve and brachial plexus injuries. Neurol Clin 1992; 10 (4): 921–34.

12. Vredeveld JW, Slooff BC, Blaauw G, et al. Validation of an electromyography and nerve conduction study protocol for the analysis of brachial plexus lesions in 184 consecutive patients with traumatic lesions. J Clin Neuromuscul Dis 2001; 2 (3): 123–8.

13. Oberle J, Antoniadis G, Kast E, et al. Evaluation of traumatic cervical nerve root injuries by intraoperative evoked potentials. Neurosurgery 2002; 51 (5): 1182–8.

14. Burkholder LM, Houlden DA, Midha R, et al. Neurogenic motor evoked potentials: role in brachial plexus surgery. Case report. J Neurosurg 2003; 98 (3): 607–10.

15. Leis AA. Conduction abnormalities detected by silent period testing. Electropenceph Clin Neurophysiol 1994; 93 (6): 444–9.

16. Kofler M, Valls-Solé J, Vasko P, et al. Influence of limb temperature on cutaneous silent periods. Clin Neurophysiol 2014; 125 (9): 1826–33. doi: 10.1016/j.clinph.2014.01.018.

17. Kofler M. Functional organization of exteroceptive inhibition following nociceptive electrical fingertip stimulation in humans. Clin Neurophysiol 2003; 114 (6): 973–80.

18. Kofler M, Stetkarova I, Wissel J. Nociceptive EMG suppression in triceps brachii muscle in humans. Clin Neurophysiol 2004; 115 (5): 1052–6.

19. Kofler M, Kumru H, Stetkarova I, et al. Muscle force up to 50% of maximum does not affect cutaneous silent periods in thenar muscles. Clin Neurophysiol 2007; 118 (9): 2025–30.

20. Rodi Z, Springer C. Influence of muscle contraction and intensity of stimulation on the cutaneous silent period. Muscle Nerve 2011; 43 (3): 324–8. doi: 10.1002/mus.21868.

21. Svilpauskaite J, Truffert A, Vaiciene N, et al. Cutaneous silent period in carpal tunnel syndrome. Muscle Nerve 2006; 33 (4): 487–93.

22. Aurora SK, Ahmad BK, Aurora TK. Silent period abnormalities in carpal tunnel syndrome. Muscle Nerve 1998; 21 (9): 1213–5.

23. Leis AA, Kofler M, Ross MA. The silent period in pure sensory neuronopathy. Muscle Nerve 1992; 15 (12): 1345–8.

24. Lo YL, Tan YE, Fook-Chong S, et al. Role of spinal inhibitory mechanisms in whiplash injuries. J Neurotrauma 2007; 24 (6): 1055–67.

25. Štětkářová I, Chrobok J. Elektrofyziologická diagnostika míšních dysfunkcí u syringomyelie. Cesk Slov Neurol N 2002; 65/98 (4): 379–85.

26. Štětkářová I, Kofler M, Leis AA. Cutaneous and mixed nerve silent periods in cervical syringomyelia. Clin Neurophysiol 2001; 112 (1): 78–85.

27. Kofler M, Kronenberg MF, Brenneis C, et al. Cutaneous silent periods in intramedullary spinal cord lesions. J Neurol Sci 2003; 216 (1): 67–79.

28. Stetkarova I, Kofler M. Cutaneous silent periods in the assessment of mild cervical spondylotic myelopathy. Spine 2009; 34 (1): 34–42. doi: 10.1097/BRS.0b013e31818f8be3.

29. Leis AA, Kofler M, Stetkarova I, et al. The cutaneous silent period is preserved in cervical radiculopathy: significance for the diagnosis of cervical myelopathy. Eur Spine J 2011; 20 (2): 236–9. doi: 10.1007/s00586-010-1627-z.