Sciatic Nerve In Thigh Research Articles

Sciatic nerve excursion during neural mobilization with ankle movement using dynamic ultrasound imaging: a cross-sectional study.

Ankle movement is used as a sensitizing maneuver for sciatica during neurodynamic techniques. In vivo studies on the sciatic nerve biomechanics associated with ankle movement during different positions of neighboring joints are scarce. The aim of this study was to investigate sciatic nerve excursion during ankle dorsiflexion in different positions in a healthy population. This is a cross-sectional study. High-resolution dynamic ultrasound imaging was used to measure longitudinal excursion of the sciatic nerve in the posterior thigh of 27 healthy participants during ankle dorsiflexion in six positions of the neck, hip, and knee. Both the long and short distance of the nerve excursion were measured. Wilcoxon signed-rank tests were used for data analysis, and Eta squared (r) was used to quantify the effect size. Ankle dorsiflexion resulted in distal sciatic nerve excursion that was significantly higher in positions in which the knee was extended (median 0.7-1.6mm) than in positions in which the knee was flexed (median 0.5-1.4mm) (P ≤ 0.049, r ≥ 0.379). There were no significant differences in nerve excursion between positions where the neck was neutral compared with positions where the neck was flexed (P ≥ 0.710, r ≤ 0.072) or between positions where the hip was neutral compared with positions where the hip was flexed (P ≥ 0.456, r ≤ 0.143). The positions of adjacent joints, particularly the knee, had an impact on the excursion of the sciatic nerve in the thigh during ankle movement.

Siyatik sinirin varyasyon anatomisi ve klinik yansımaları

Aim: The aim of present study was to demonstrate the variations of piriformis muscle, sciatic nerve and its branches and discuss their clinical importance.Materials and Methods: Fifty-two gluteal and lower limb regions of 26 formalin fixed male cadavers were evaluated in Ege University Faculty of Medicine, Department of Anatomy. The anatomical relationship between the sciatic nerve and the piriformis muscle, and division level of sciatic nerve in thigh was recorded. Results: The sciatic nerve exited the pelvis as a single branch through the infrapiriform foramen with no variation in 84.62% of the lower limbs. The division variations of sciatic nerve were determined in 23.08%. In 8 of 12 high divisions were observed in gluteal regions (15.38%). The common peroneal nerve and the tibial nerve entered deep gluteal region via the greater sciatic foramen below piriformis muscle separately in four lower limbs (7.69%). Two separate nerve divisions passed above and through (or below) the piriformis muscle and then combined together to form common peroneal nerve while tibial nerve passing below the piriformis muscle in 4 lower limbs (7.69%). In 2 of 12, high division occurred in the 1/3 upper portion of the thigh unilaterally (3.85%). The division of sciatic nerve in the popliteal fossa was seen in two lower limbs (3.85%). Conclusion: The clinical importance of the sciatic nerve around the piriformis muscle or in the thigh was discussed for piriformis syndrome, palsy after total hip arthroplasty, intramuscular injections in gluteal region and failed popliteal nerve block.

Effects of repeated injection of local anesthetic on sciatic nerve blocks response.

In order to examine whether repeated sciatic nerve blocks showed tachyphylaxis and continuity of sciatic nerve with spinal cord affected development of tachyphylaxis when assayed in vivo by duration of depression compound action potentials (CAP), rats were anesthetized with halothane, ventilated, monitored and supported with stable hemodynamics and temperature. Posterior tibial nerve distally and sciatic nerve in thigh were exposed, placed on bipolar silver electrodes for stimulation and recording respectively. Three sequential sciatic nerve blocks were performed between these electrodes using 0.15 ml of 3% chloroprocaine. Nine rats were chosen to observe the effects of repeated sciatic nerve blocks on CAP. In another 18 rats, a second investigator exposed the sciatic nerve near its origin at spinal cord and randomly performed nerve cut and sham (n=9), and closed the incision blinding the electrophysiologic investigator. The results showed that electrical stimulated tibial nerve induced sciatic nerve Aalpha/beta, Adelta, C fiber mediated CAP waves. CAP amplitudes were remained stable during whole experimental procedure. CAP amplitudes were decreased completely with 3% chloroprocaine blocked sciatic nerve and recovered fully. The duration of CAP depression were reduced with repeated blocks. There were no selective blocked effects on Aalpha/beta, Adelta, C fiber mediated CAP. With sciatic nerve cut proximally, there was no statistical significant tachyphylaxis with 3% chloroprocaine repeated blocked sciatic nerve, and the duration of first and third blocked Adelta fiber mediated CAP was 108+/-20 and 92+/-14 min respectively (P>0.05). In normal rats the duration of first and third blocked Adelta fiber mediated CAP was 110+/-20 and 75+/-16 min respectively (P<0.05). It was suggested that tachyphylaxis to local anesthetics can occur in rats repeated blocked sciatic nerve when assayed in vivo by duration of depression CAP. The continuity of sciatic nerve with spinal cord is one of the important factors affecting the development of tachyphylaxis.