The scratch collapse test: a systematic review

Publication date: Available online 4 October 2018

Source: Journal of Plastic, Reconstructive & Aesthetic Surgery

Author(s): Urška Čebron, Catherine M Curtin

Abstract

The diagnosis of nerve compression relies on collecting diagnostic clues from the history, physical exam, imaging, and diagnostic testing. There are several provocative tests to aide in the diagnosis of nerve compression. The 'Scratch Collapse Test' (SCT) has emerged as a new provocative test to assist in the localization of peripheral nerve compression. This study aims to perform a systematic review of the literature to assess the data on the reliability of the SCT as a diagnostic test for entrapment neuropathy. Ten articles were reviewed. Five had sufficient numerical data for analysis, in these 5 the positive predictive values and specificity were high: between 0.71 and 0.99 and 0.6 and 0.99 respectively, while other values were very variable: individual Negative Predictive Values ranged from 0.15 to 0.92 and the sensitivity values ranged from 0.24 to 0.77. Another main finding was the versatility of the test, in that it can be used for various nerve entrapments, and localise the exact level of compression. The literature suggests that SCT has potential as a clinical diagnostic tool for of entrapment neuropathy. However wide variations in the early literature suggest SCT should not be used as a sole diagnostic tool but as an adjunct to a surgeon's diagnostic repertoire.