Evaluation of Neurologic Injury Following Regional Anesthesia
Neurologic injury associated with regional blockade is rare but does occur. Upon suspicion or discovery of a neurologic injury following a nerve block, factors including preexisting conditions, surgical or anesthetic events, and development/course of the injury should be investigated.
Physical examination of neurologic, cognitive, motor, sensory, and reflex function, as well as electrodiagnostic studies, can yield clues as to the source and site of nerve injury following regional anesthesia.
Examination of nerve conduction can help evaluate the degree of the injury but can be limited by factors including accessibility and size of the nerve, technical difficulties of electrode placement and response measurement, nature of the injury, and presence of preexisting neuronal damage.
Electromyography (EMG) can help determine the location and type of neuronal injury, be it neuropraxia, axonotmesis, or neurotmesis, and prognosis for nerve regeneration or reinnervation. The value of EMG findings is dependent on the skill of the examiner.
Imaging technologies, including conventional radiography, computed tomography, magnetic resonance imaging, magnetic resonance neurography, angiography, and ultrasonography, can be used to identify and evaluate neurologic injury.
KeywordsNeurologic injury Electrodiagnostic studies Nerve conduction Electromyography Neuropraxia Axonotmesis Neurotmesis Reinnervation
We thank Dr. Paul Barkhaus M.D. for his valuable input in writing this chapter.
- 12.O’Brien M. Aids to the examination of the peripheral nervous system. 5th ed: Saunders; 2010.Google Scholar
- 17.Burke RE. Motor units in mammalian muscle. Sumner AJ, ed. The physiology of peripheral nerve disease. Philadelphia, PA: WB Saunders Co; 1980. 133-194.Google Scholar
- 18.Dumitru D, Amato A, Zwarts M. Electrodiagnostic medicine, 2nd edition. 2001Google Scholar