Disclosures: Miran Yoo, n/a: No financial relationships or conflicts of interest
Objective: Considering other studies in which the SNAP amplitude ratio of the affected side in the foraminal L5 nerve root entrapment was lower than that of the unaffected side, the aim of the study is to check the latency and amplitude of SNAP in patients with cervical foraminal stenosis as comparing patients without cervical foraminal stenosis.
Design: Retrospective study Setting : Outpatient nerve conduction study (NCS) clinic of single center Participants : Patients who visited our nerve conduction study (NCS) clinic from January 2016 to December 2017.
Interventions: Not applicable
Main Outcome Measures: According to MRI finding, we divided patients into 2 groups. Group A (46 patients) included patients whose lesion was located at C6-7, C7-T1 foraminal stenosis. Group B (75 patients) had no lesion at above site. The amplitude and latency of SNAPs on the affected side were compared to that on the unaffected side between group A and B. Also the abnormal SNAP responses were compared between two groups.
Results: The amplitudes of median and ulnar nerve of group A were lower than that in group B (p = < 0.001, 0.001, respectively). The latency of median nerve for group A was longer than that in group B (p = 0.003). The latency of ulnar nerve for group A was longer than group B, but no statistical difference between two groups (p = 0.448). The amplitude of median nerve was found to be abnormal in 33.3% of group A, 4.0% of group B. The amplitude of ulnar nerve was found to be abnormal in 25.0% of group A, 4.1% of group B. Conclusions: Patients with foraminal stenosis had significantly longer latency of median nerve and lower amplitude of median and ulnar nerve than those without foraminal stenosis. Abnormal SNAP amplitudes were more frequent in patients with foraminal stenosis. The SNAP could be used as predictors of cervical foraminal stenosis.
Level of Evidence: Level III
To cite this abstract in AMA style:
Yoo M, Kim DY. Electrodiagnosis Using Sensory Nerve Action Potential for the C7,8 Nerve Root Entrapment Due to Foraminal Stenosis [abstract]. PM R. 2020; 12(S1)(suppl 1). https://pmrjabstracts.org/abstract/electrodiagnosis-using-sensory-nerve-action-potential-for-the-c78-nerve-root-entrapment-due-to-foraminal-stenosis/. Accessed May 31, 2025.« Back to AAPM&R Annual Assembly 2020
PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/electrodiagnosis-using-sensory-nerve-action-potential-for-the-c78-nerve-root-entrapment-due-to-foraminal-stenosis/