@article{103049,
  keywords = {Ulnar neuropathy at the elbow, Hansen’s ulnar neuropathy, Ultrasonography, nerve cross-sectional area, humero-cubital nerve ratio},
  author = {Muralidhar Reddy Y and Pidaparthi L and Murthy JMK},
  title = {Nerve enlargement on ultrasound can differentiate ulnar neuropathy at the elbow and Hansen’s ulnar neuropathy: an observational study from a tertiary care centre},
  abstract = {<p><strong>Introduction</strong></p>

<p>Hansen’s ulnar neuropathy (HUN) and entrapment ulnar neuropathy, commonly referred to as ulnar neuropathy at the elbow (UNE), are the most common causes of focal ulnar neuropathies. Differentiating between the two can be challenging. We examined the utility of ultrasound (US) in distinguishing them.</p>

<p><strong>Methods</strong></p>

<p>We retrospectively gathered data from 26 nerves of 22 HUN patients and 36 nerves of 28 UNE patients who underwent US examination. The ulnar nerve cross-sectional area (CSA) was measured at the elbow, behind the medial epicondyle, 5 cm proximal and distal to the elbow. The length of the enlarged nerve and the humero-cubital nerve ratio (HCR) were calculated. All these parameters were compared between UNE and HUN cases.</p>

<p><strong>Results</strong></p>

<p>The CSA of the ulnar nerve was significantly higher in the HUN at all three measurement sites than in the UNE (P&nbsp;&lt;&nbsp;0.001). The maximum CSA was noted above the elbow in the HUN and at the elbow in the UNE (P&nbsp;&lt;&nbsp;0.001). A lengthy enlarged segment was characteristic of HUN (P&nbsp;&lt;&nbsp;0.001). HCR was also significantly different between the two groups (P&nbsp;&lt;&nbsp;0.001). The optimum cut-off of HCR (for HUN) was 0.87 (sensitivity 88%, specificity 100%, AUC&nbsp;0.95).</p>

<p><strong>Conclusion</strong></p>

<p>The HCR is a useful sonographic indicator for distinguishing HUN and UNE. Other variables favouring HUN are extensive and maximal nerve enlargement above the elbow. UNE is characterised by focal nerve enlargement at the elbow.</p>
},
  year = {2025},
  journal = {Leprosy Review},
  volume = {96},
  pages = {1-6},
  publisher = {Lepra},
  issn = {2162-8807},
  url = {https://leprosyreview.org/article/96/4/20-25063},
  doi = {10.47276/lr.96.4.2025063},
  language = {ENG},
}