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Scratch Collapse Test: a new clinical test for peripheral nerve compression

Scratch Collapse Test: um novo teste clínico para nervos periféricos comprimidos

A 70-year-old woman presented left hand neuropathic pain and nocturnal paresthetic brachialgia. The neurological examination was unremarkable except for positive Scratch Collapse Test (SCT) suggesting left Carpal Tunnel Syndrome (CTS) (Figure). Subsequent electromyographic evaluation was consistent with left CTS. The SCT is a new clinical maneuver for peripheral nerve compression diagnosis11. Cheng CJ, Mackinnon-Patterson B, Beck JL, Mackinnon SE. Scratch collapse test for evaluation of carpal and cubital tunnel syndrome. J Hand Surg Am. 2008;33(9):1518-24. http://dx.doi.org/10.1016/j.jhsa.2008.05.022
https://doi.org/10.1016/j.jhsa.2008.05.0...
that has greater sensitivity than both Tinel’s test and the flexion/nerve compression test for the median and ulnar nerves, respectively. It is believed that a silent period following cutaneous stimuli over the compressed nerve briefly inhibits external shoulder rotation, thus producing the sign which can be indefinitely repeated22. Logigian EL, Plotkin GM, Shefner JM. The cutaneous silent period is mediated by spinal inhibitory reflex. Muscle Nerve. 1999;22:467-72. http://dx.doi.org/10.1002/(SICI)1097-4598(199904)22:43.0.CO;2-Y
https://doi.org/10.1002/(SICI)1097-4598(...
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Figure
(A) The patient faces the examiner, elbows flexed and hands neutral. The examiner pushes the patient’s forearms, asking them to resist, (B) then “scratches” the skin over the carpal tunnel, and repeats the first step; (C) A positive response is a temporary loss of external resistance with arm “collapse”; and (D) Immediate repetition will show strength recovery.

References

Publication Dates

  • Publication in this collection
    Jan 2015

History

  • Received
    01 Aug 2014
  • Reviewed
    23 Aug 2014
  • Accepted
    11 Sept 2014
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