Practice Parameter and Literature Review of the Usefulness of ...

Practice Parameter: Carpal Tunnel SyndromeTable 19.Comparison of Median and Ulnar SensoryConduction Between Wrist and Ring Finger in CTS.Author Jackson and Clifford 110 Uncini and colleagues 254Year 1989 1993Number of Normal Hands (subjects) 38 (38) 72 (47)Normal Subject’s Age: Mean (range) 42 (21 to 69) 45 (18 to 78)Number of CTS Hands (patients) 131 (123) 95 (70)CTS Subject’s Age: Mean (range) 53 (21 to 85) 49 (26 to 78)Technique: Conduction Distance 14 cmIdentical for each subjectRange: 12 cm to 14 cmStimulation Site Wrist Ring fingerRecording Site Ring finger WristMinimum Hand Temperature 31°C 32°CDifference Median and Ulnar OnsetLatency ± SD0.13 ± 0.15 ms 0.14 ± 0.13 msDifference Median and Ulnar PeakLatency ± SD0.09 ± 0.13 ms Not reportedCriteria for Abnormal Value Mean + 2 SD Mean + 2 SDAbnormal ValueOnset >0.43 msPeak >0.35 msOnset >0.4 msPeak (not reported)Specificity of Abnormal Value 95% (actual) 97.5% (estimate)Sensitivity of Abnormal Value 82% 77% (89%)*Nerve conduction of the branches of the median and ulnar nerves to the ring finger can be measured by securing surface ring electrodes on the ringfinger and surface disc electrodes over both the median and ulnar nerves proximal to the wrist crease with identical conduction distances (14 cm).The conduction time (ms) from the stimulus artifact to the onset (onset latency) or peak (peak latency) of the SNAP is determined and the medianulnarlatency difference calculated.* In the Uncini and colleagues paper, 254 comparison of orthodromic median and ulnar sensory conduction from D4 along an identical distance to thewrist (range 12-14 cm for all tests) was done only in the CTS patients with (1) normal median sensory conduction from D2 to wrist (SCV >45 ms)and (2) normal median motor conduction (MDL