H بررسي در مورد تخمين تعداد سيناپس نخاعي رفلكس

Study on H- Reflex: Estimated Number of Synapses at Si Cord Level

Introduction: The main clinical application of the H-reflex is: evaluation of Si nerve root such as radiculopathy. An attempt has been made to reduce the pathway over which H-reflex can be obtained in the hope for localizing a lesion to the SI nerve root; So SI central loop has been suggested. Objective: The main goal of this investigation is to estimate H-reflex number of synapses. Materials and Methods: 40 healthy adult volunteers (26 males, 14 females) with mean age of (37.7) years participated in this study. They were positioned comfortably in the prone, with the feet off the edge of the plinth. Recording electrodes were positioned at mid point of a line connecting the mid popliteal crease to the proximal flare of the medial malleolus. Stimulation was applied at tibial nerve in popliteal fossa and H& F& M waves were recorded. Without any change in location of recording electrodes, a monopolar needle was inserted as cathode at a point 1cm medial to the posterior superior iliac spine, perpendicular to the frontal plane. The anode electrode was placed over the anterior superior iliac spine, then M & H waves of central loop were recorded. After processing the data, sacral cord conduction delay was determined by this formula: * Sacral cord conduction delay = central loop of H-reflex - delays of the proximal motor & sensory fibers in central Ioop. Results: Central loop of H- reflex was: (6.77 ± 0.28) ms and sacral cord conduction delay was: (1/09 ± 0.06) ms. Conclusion: This study is in accord with previous investigations indicative of 1 synapse at SI cord level for H-reflex.