Correlation Between High-frequency Ultrasound Findings And Pathological Changes Of Chronic Compression Of Sciatic Nerve In Rabbits

Background Limbs pain,numbness and dysfunction,which are common symptoms in clinic,are usually associated with peripheral nerve damage caused by chronic compression or pression,and many kinds of syndromes can cause these symptoms,such as carpal tunnel syndrome,cubital tunnel syndrome and piriformis muscle syndrome,etc.In general,call these syndromes peripheral nerve entrapment syndrome(PNES).The diagnosis and treatment of chronic peripheral nerve compression damage are the focus of relative research projects, because the early diagnosis and accurate localization will provide valuable information for treatment and prognosis.the diagnosis of PNES mainly depends on symptom,medical examination,Electrophysiology,electromyogram and so on, but these methods can not early diagnosis and accurate localization.To provide more information for treatment and prognosis,finding new radiographic diagnosis methods becomes focus at present.Objective To discuss the relation between the sonographic characteristics and pathological changes at different time after the chronic compression of sciatic nerve in rabbits in order to evaluate the potential value of high-frequency ultrasonography on the diagnosis of peripheral nerve compression.Methods 20 rabbits were randomly divided into control group(4 rabbits)and model groups(16 rabbits).A Machinnonic's method was used to create the chronic nerve compression models using the sciatic nerve of rabbits.The sonographic characteristics was observed and the nerve diameter was measured by high-frequency ultrasonography.Sensory/motor nerve conduction velocity (SNCV,MNCV)and evoked potential amplitude of sciatic nerves were assessed by evoked potential instrument.The pathological examination was performed subsequently.Results There was no obvious change in the ulstrasonographic characteristics and the pathology of the control group.The diameters,internal echo,the continuity of internal linear echo and epineurium changed correpondingly with time of compression in different model groups.Pathological examination showed the obvious edema in myelin sheath,axons and perineurium in 2 w group,and disintegrated myelin sheath,degenerated axons and hyperplastic fibrous connective tissues in the other model groups.The results of MNCV and SNCV in all compression groups decreased with time of compression.Conclusions High-frequency ultrasonography can accurately reflect the morphological changes of the compressed nerve.It may provide a new diagnostic approach to detect peripheral nerve compression.