Darryl B Sneag1,2, Eliana B Saltzman3,4, David W Meister3, Joseph H Feinberg2,3, Steve K Lee2,3, Scott W Wolfe2,3. 1. Department of Radiology and Imaging, Hospital for Special Surgery, 535 East 70th Street, New York, New York, USA, 10021. 2. Weill Medical College of Cornell University, New York, New York, USA. 3. Center for Brachial Plexus and Traumatic Nerve Injury, Hospital for Special Surgery, New York, New York, USA. 4. Department of Medical Education, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Abstract
INTRODUCTION: The role of MRI in identifying hourglass constrictions (HGCs) of nerves in Parsonage-Turner syndrome (PTS) is largely unknown. METHODS: Six patients with PTS and absent or minimal recovery underwent MRI. Surgical exploration was performed at identified pathologic sites. RESULTS: The time between symptom onset and surgery was 12.4 ± 6.9 months; the time between MRI and surgery was 1.3 ± 0.6 months. Involved nerves included suprascapular, axillary, radial, and median nerve anterior interosseous and pronator teres fascicles. Twenty-three constriction sites in 10 nerves were identified on MRI. A "bullseye sign" of the nerve, identified immediately proximal to 21 of 23 sites, manifested as peripheral signal hyperintensity and central hypointensity orthogonal to the long axis of the nerve. All constrictions were confirmed operatively. CONCLUSIONS: In PTS, a bullseye sign on MRI can accurately localize HGCs, a previously unreported finding. Causes of HGCs and the bullseye sign are unknown. Muscle Nerve 56: 99-106, 2017.
INTRODUCTION: The role of MRI in identifying hourglass constrictions (HGCs) of nerves in Parsonage-Turner syndrome (PTS) is largely unknown. METHODS: Six patients with PTS and absent or minimal recovery underwent MRI. Surgical exploration was performed at identified pathologic sites. RESULTS: The time between symptom onset and surgery was 12.4 ± 6.9 months; the time between MRI and surgery was 1.3 ± 0.6 months. Involved nerves included suprascapular, axillary, radial, and median nerve anterior interosseous and pronator teres fascicles. Twenty-three constriction sites in 10 nerves were identified on MRI. A "bullseye sign" of the nerve, identified immediately proximal to 21 of 23 sites, manifested as peripheral signal hyperintensity and central hypointensity orthogonal to the long axis of the nerve. All constrictions were confirmed operatively. CONCLUSIONS: In PTS, a bullseye sign on MRI can accurately localize HGCs, a previously unreported finding. Causes of HGCs and the bullseye sign are unknown. Muscle Nerve 56: 99-106, 2017.
Authors: Darryl B Sneag; Susan C Lee; Joseph H Feinberg; Darius P Melisaratus; Ian Amber Journal: Skeletal Radiol Date: 2017-07-28 Impact factor: 2.199
Authors: Claire E Fernandez; Colin K Franz; Jason H Ko; James M Walter; Igor J Koralnik; Shivani Ahlawat; Swati Deshmukh Journal: Radiology Date: 2020-12-01 Impact factor: 11.105