Intraoperative nerve action potential recordings: technical considerations, problems, and pitfalls.
OBJECTIVE
The purpose of this article is to provide our experience with intraoperative nerve action potential (NAP) recordings. In particular, we focus on a discussion of the technical considerations of intraoperative NAP with emphasis on identifying and remedying problems and pitfalls.


METHODS
We report, perhaps, the largest operative series of peripheral nerve lesions in continuity with intraoperative NAP recording derived from 1736 patients with 3459 lesions in continuity with operative outcomes. We pay special attention to patients for whom we felt that NAP recordings were either difficult or misleading.


RESULTS
A positive NAP across a lesion resulting in neurolysis gave grade 3 or better function using the Louisiana State University Health Science Center grading system in 94.7% of neural elements. Differential fascicular recordings resulted in split repair in 62 nerves with recovery in 58. The absence of an NAP correlated histologically with a neurotmetic lesion. With resultant repair, 1111 of 1975 nerves recovered to grade 3 or better.


CONCLUSIONS
Visual inspection of a nerve lesion in continuity can be misleading. Although there is no "head-to-head" comparison of our data with data obtained without the use of intraoperative NAP recordings, we feel strongly that with experience and knowledge of the problems and pitfalls regarding intraoperative recording techniques, one may take advantage of the great benefits of this very useful and informative surgical tool.
Robert
Everett G
EG
Department of Neurosurgery, Louisiana State University Health Science Center, New Orleans, Louisiana 70112, USA. erobert@lsuhsc.edu
Happel
Leo T
LT
Kline
David G
DG
D000200:Action Potentials / Q000502:physiology*; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods*; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D009416:Nerve Regeneration / Q000502:physiology; D010525:Peripheral Nerves / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control; D011237:Predictive Value of Tests; D020127:Recovery of Function / Q000502:physiology