Cutaneous silent periods of the vastus medialis evoked by the stimulation of lateral femoral cutaneous nerve.
OBJECTIVE
Cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is transient suppression of the electromyographic activity. In this study, our aim is to investigate CSPs of vastus medialis muscle (vm-CSP) evoked by the stimulation of the lateral femoral cutaneous nerve (LFCN) in healthy controls and in patients with meralgia paresthetica (MP).


METHODS
Twenty-one patients with MP (17 unilateral, 4 bilateral) and 27 healthy controls were included. Nerve conduction studies of LFCN and vm-CSP were analyzed in all subjects. A stimulus train consisting of five electrical shocks was applied to the skin at the anterolateral side of the thigh for recording of the vm-CSP.


RESULTS
Nerve conduction abnormalities of LFCN were observed in all patients with MP. Mean duration of vm-CSP was 69.7+/-9.2ms, and mean onset latency was 44.7+/-6.9 in healthy controls. Onset latency of vm-CSP was significantly prolonged and the duration of vm-CSP was significantly shortened in patients with MP. Vm-CSP abnormalities were observed in 20/25 extremities with MP.


CONCLUSIONS
Dysfunction of A-delta afferents may cause these findings in patients with MP. Additionally, spinal modulation of pain may also play a role in the explanation of our findings.


CONCLUSIONS
The present study demonstrates the CSP alterations in the patients with entrapment neuropathy of a cutaneous nerve.
Tataroglu
Cengiz
C
Department of Neurology, Medical Faculty, Adnan Menderes University, Aydin 09100, Turkey. ctataroglu@adu.edu.tr
Uludag
Burhanettin
B
Karapinar
Nevin
N
Bademkiran
Fikret
F
Ertekin
Cumhur
C
D000328:Adult; D000704:Analysis of Variance; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods*; D004576:Electromyography / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation*; D009413:Nerve Fibers, Myelinated / Q000502:physiology / Q000528:radiation effects*; D009431:Neural Conduction / Q000502:physiology / Q000528:radiation effects; D009433:Neural Inhibition / Q000502:physiology* / Q000528:radiation effects; D010292:Paresthesia / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D012016:Reference Values