Abstract
Objective
To assess factors affecting electrophysiological changes in the peripheral nervous
system below the neurologic level of injury (NLI) in patients with subacute spinal
cord injury (SCI).
Design
Retrospective observational study.
Setting
An inpatient rehabilitation center of a university hospital.
Participants
Through reviewing the medical records of 151 subjects with SCI, 42 without any other
disease inducing peripheral neurologic abnormalities were included. They were classified
into 2 groups, with or without denervation potentials in electromyography (EMG) below
NLI.
Intervention
Not applicable.
Main Outcome Measures
Demographics and clinical characteristics including NLI, American Spinal Injury Association
Impairment Scale (AIS), and Lower Extremity Motor Score were compared. Results of
electrophysiological study including nerve conduction study, somatosensory-evoked
potential (SSEP), and motor-evoked potential (MEP) were compared.
Results
Denervation potentials in EMG below NLI were observed in 20 subjects, and 10 of them
were AIS A or B, but there was none in subjects without denervation potentials (P<.001). The lower extremity motor score was 4.35±7.74 in the group with denervation
potentials, lower than 33.64±13.60 of the opposite group (P<.001). In the analysis of electrophysiological study, patients with denervation potentials
showed a higher proportion of no response than patients without denervation potentials
(60.0% vs 11.4% in peroneal nerve conduction study, 35.0% vs 2.3% in tibial nerve
conduction study, 80.0% vs 18.2% in SSEP, 87.5% vs 22.7% in MEP; P<.001, respectively). Additionally, greater axonal loss, based on decrease of amplitude
without delayed latency on nerve conduction study, was observed in the group with
denervation potentials than the opposite group (P<.001).
Conclusion
Among subjects with subacute SCI, cases of peripheral nervous dysfunction below the
injury site occur, possibly associated with the severity of SCI.
Keyword
List of abbreviations:
AIS (American Spinal Injury Association Impairment Scale), CMAP (compound muscle action potential), EMG (electromyography), MEP (motor-evoked potential), NLI (neurologic level of injury), SA (spontaneous activity), SCI (spinal cord injury), SNAP (sensory nerve action potential), SSEP (somatosensory-evoked potential)To read this article in full you will need to make a payment
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Article Info
Publication History
Published online: February 05, 2020
Footnotes
Disclosures: none
Identification
Copyright
© 2020 by the American Congress of Rehabilitation Medicine
