title: Ultrasonographic swelling ratio in the diagnosis of ulnar neuropathy at the elbow.
abstract: High-resolution ultrasound can demonstrate focal nerve enlargement in entrapment neuropathies. We hypothesized that a ratio between the nerve cross-sectional area at the site of maximal enlargement and at an unaffected site may improve diagnostic accuracy in ulnar neuropathy at the elbow (UNE), when compared to a single measurement at the site of maximal enlargement. Ultrasound was used to measure the cross-sectional area of the ulnar nerve at three sites in 30 normal, healthy controls and 26 individuals with UNE. In individuals with UNE, the ratio was 2.9:1 when the site of maximal swelling was compared with a distal ulnar nerve site and 2.8:1 when compared with a proximal site. This represented a significant increase compared with the ratio of 1.1:1 for both comparisons in controls (P < 0.0001). This type of ratio may be particularly useful for assessing entrapment in those with polyneuropathy or obesity, both of which can cause diffuse nerve enlargement.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University College of Medicine, Seoul, South Korea.
authors.forename: Joon Shik
authors.initials: JS
authors.lastname: Yoon
authors.forename: Francis O
authors.initials: FO
authors.lastname: Walker
authors.forename: Michael S
authors.initials: MS
authors.lastname: Cartwright
mesh_terms: D000328:Adult; D000367:Age Factors; D015984:Causality; D020430:Cubital Tunnel Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D004487:Edema / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D004550:Elbow / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D011115:Polyneuropathies / Q000150:complications; D012720:Severity of Illness Index; D014459:Ulnar Nerve / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D014463:Ultrasonography / Q000379:methods*