Doppler sonography for intraneural vascularization of ulnar neuropathy at the elbow – Before and after surgery

Abstract

The finding of intraneural blood flow (IBF) signal by doppler sonography was interpreted in several ways at entrapment neuropathy. There is no report of IBF after surgery of ulnar neuropathy at the elbow (UNE). We investigated IBF in UNE before and after surgery. Case series study. Subject: nine arms (only men) diagnosed and confirmed as UNE by surgery. All arms were performed grey scale sonography (GS) using an ultrasound machine (AprioXV; Toshiba) with 12 MHz linear-array transducer and electrodiagnostic study (EDX) before and after surgery. We performed Doppler sonography (DS): 5 arms before surgery, 6 arms after surgery and 2 arms both. In EDX, diagnosis of UNE as follows: absolute motor CV from above elbow to below elbow of less than 50 m/s and (1) or (2) (1) differential slowing (10 m/s across elbow). (2) conduction block across elbow. In GS, diagnosis of UNE as follows: cut-off value was the largest cross-sectional area from 2 cm distal to 2 cm proximal to the medial epicondyle > 11 mm 2 . General findings before surgery: EDX diagnosed 8 arms as UNE but one. Seven arms were diagnosed as UNE by GS. General findings after surgery: All 9 arms were improved in clinical signs. EDX did not change. Eight were diagnosed as UNE by GS. DS findings before surgery: IBF signal was not detected in 3 arms and detected in 2 arms but absent pulse. DS findings of after surgery: six arms were detected IBF signal and pulsatility. These findings may suggest that releasing entrapment site might decrease endoneurial fluid pressure and increase IBF. About recovery from UNE after surgery, it may be useful to evaluate intraneural vascularity at the affected site with DS.