Electromyography in craniomaxillofacial trauma.
OBJECTIVE
Electromyography is used in conjunction with clinical diagnosis to determine the presence and extent of craniofacial injuries; it is also an aid in prognosis of recovery. This article reviews the neural pathophysiology following trauma and the basic principles of electrodiagnostic testing; such understanding helps to determine indications for electrodiagnostic testing.


METHODS
Electrodiagnostic techniques can detect and differentiate the degree of injury. There are three major categories of nerve injury--neurapraxia, axonotmesis, and neurotmesis. In neuropraxic injuries, stimulation distal to the lesion will continue to elicit a response indefinitely; in more severe injuries, axonal degeneration begins within 3 to 5 days postinjury.


CONCLUSIONS
Electromyography may be used as a valuable adjunct to traditional forms of diagnosis and prognosis. The accuracy of electrodiagnostic data reported in the literature ranges from 50% to 67% in some studies and 77% to 90% in others. Studies with larger patient populations and longer follow-up periods are required.
Stitik
T P
TP
Department of Physical Medicine and Rehabilitation, UMDNJ (University of Medicine and Dentistry of New Jersey), Newark, New Jersey, USA.
Foye
P M
PM
Nadler
S F
SF
D000200:Action Potentials / Q000502:physiology; D020209:Cranial Nerve Injuries / Q000145:classification / Q000175:diagnosis*; D004567:Electrodes, Implanted; D004576:Electromyography / Q000295:instrumentation / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology; D020220:Facial Nerve Injuries / Q000175:diagnosis; D006801:Humans; D061228:Hypoglossal Nerve Injuries; D008446:Maxillofacial Injuries / Q000145:classification / Q000175:diagnosis*; D009046:Motor Neurons / Q000502:physiology; D009410:Nerve Degeneration / Q000175:diagnosis; D009431:Neural Conduction / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D009915:Orbit / Q000294:innervation; D011930:Reaction Time / Q000502:physiology; D011999:Recruitment, Neurophysiological / Q000502:physiology; D012183:Retrograde Degeneration / Q000175:diagnosis; D012886:Skull / Q000293:injuries*; D061221:Trigeminal Nerve Injuries