Mateusz Gładysz FESSH prep

FESSH prep Physical examination Threshold versus innervation density tests, Semmes–Weinstein monofilaments and two point discrimination in carpal tunnel syndrome, immersion wrinkle test, responsiveness of tests after nerve repair

Sensibility testing in nerve compression and after nerve repair

Last reviewed v1.0

FESSH-067Physical examination●●● advanced

Regarding clinical tests of sensibility in nerve compression and after nerve repair:

  1. 1.In experimental median nerve compression, threshold tests (Semmes–Weinstein monofilaments and vibration) become abnormal before innervation-density tests such as static and moving two-point discrimination.

  2. 2.In systematic-review data on carpal tunnel syndrome, two-point discrimination is among the most specific sensory or motor tests.

  3. 3.Skin wrinkling after immersion in warm water depends on intact sympathetic innervation, so a digit with a recent complete nerve division does not wrinkle.

  4. 4.Loss of immersion wrinkling is a reliable sign of sensory loss in compressive neuropathy.

  5. 5.After median nerve repair, static two-point discrimination is the most responsive test for tracking sensory recovery.

FESSH marking: +1 per correct statement, 0 for blank, −1 for incorrect. Click the same TRUE/FALSE button twice to clear it.

Question ID
FESSH-067
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. In experimental median nerve compression, threshold tests (Semmes–Weinstein monofilaments and vibration) become abnormal before innervation-density tests such as static and moving two-point discrimination.

    True

    In Gelberman's volunteer study of controlled carpal tunnel compression, the threshold tests tracked the gradual decline in nerve function, whereas static and moving two-point discrimination stayed normal until nearly all sensory conduction had ceased. Szabo's companion study found the vibratory threshold to be the earliest indicator of declining nerve function in every subject.

    • Gelberman RH, Szabo RM, Williamson RV, Dimick MP. Sensibility testing in peripheral-nerve compression syndromes. An experimental study in humans. J Bone Joint Surg Am. 1983;65(5):632-8. PMID 6853569
    • Szabo RM, Gelberman RH, Williamson RV, Dellon AL, Yaru NC, Dimick MP. Vibratory sensory testing in acute peripheral nerve compression. J Hand Surg Am. 1984;9A(1):104-9. PMID 6693727

  2. 2. In systematic-review data on carpal tunnel syndrome, two-point discrimination is among the most specific sensory or motor tests.

    True

    In Dabbagh's systematic review of 16 diagnostic studies, two-point discrimination was among the most specific tests (specificity 0.81–0.98), together with thenar atrophy and grip and pinch strength, whereas the Semmes–Weinstein monofilament test was the most sensitive (sensitivity 0.49–0.96). The authors advise against relying on any single sensory or motor test.

    • Dabbagh A, MacDermid JC, Yong J, Packham TL, Macedo LG, Ghodrati M. Diagnostic accuracy of sensory and motor tests for the diagnosis of carpal tunnel syndrome: a systematic review. BMC Musculoskelet Disord. 2021;22(1):337. PMID 33827512

  3. 3. Skin wrinkling after immersion in warm water depends on intact sympathetic innervation, so a digit with a recent complete nerve division does not wrinkle.

    True

    Braham showed that immersion wrinkling is abolished by lesions of central or peripheral sympathetic pathways, and in Phelps's series all 24 patients with recent complete nerve injuries lacked wrinkling over the territory of the divided nerve. Tsai found that higher tonicity slows wrinkling, so plain water should be used for the bedside test.

    • Braham J, Sadeh M, Sarova-Pinhas I. Skin wrinkling on immersion of hands: a test of sympathetic function. Arch Neurol. 1979;36(2):113-4. PMID 420620
    • Phelps PE, Walker E. Comparison of the finger wrinkling test results to established sensory tests in peripheral nerve injury. Am J Occup Ther. 1977;31(9):565-72. PMID 907018
    • Tsai N, Kirkham S. Fingertip skin wrinkling - the effect of varying tonicity. J Hand Surg Br. 2005;30(3):273-5. PMID 15862367

  4. 4. Loss of immersion wrinkling is a reliable sign of sensory loss in compressive neuropathy.

    False

    In Phelps's study, patients with nerve compression continued to wrinkle and sweat even when two-point discrimination was reduced or absent. Absent wrinkling corresponded consistently with loss of other sensory modalities only after a recent complete nerve lesion.

    • Phelps PE, Walker E. Comparison of the finger wrinkling test results to established sensory tests in peripheral nerve injury. Am J Occup Ther. 1977;31(9):565-72. PMID 907018

  5. 5. After median nerve repair, static two-point discrimination is the most responsive test for tracking sensory recovery.

    False

    In Jerosch-Herold's cohort, two-point discrimination was hardly measurable at any time point and showed strong floor effects, whereas monofilament touch threshold, locognosia, the Moberg pick-up test and object recognition captured change well. Fonseca's systematic review likewise found Semmes–Weinstein monofilament testing the most responsive and two-point discrimination the least responsive sensory measure (effect sizes 1.2 and 0.1).

    • Jerosch-Herold C. A study of the relative responsiveness of five sensibility tests for assessment of recovery after median nerve injury and repair. J Hand Surg Br. 2003;28(3):255-60. PMID 12809660
    • Fonseca MCR, Elui VMC, Lalone E, da Silva NC, Barbosa RI, Marcolino AM, et al.. Functional, motor, and sensory assessment instruments upon nerve repair in adult hands: systematic review of psychometric properties. Syst Rev. 2018;7(1):175. PMID 30368253