Boston Carpal Tunnel Syndrome Questionnaire (BCTQ)
BCTQ, the most commonly used measurement of CTS symptoms, contains two
multi-item scales with a summary score of 0 to 5 for each item; a higher
score indicates greater severity. A total of 11 items in the Symptom
Severity Scale (SSS) and the 8 questions in the Functional Status Scale
(FSS) were used to evaluate the severity of symptoms and functional
status, respectively.23The minimal clinically important difference (MCID) for SSS and FSS were
8.8 and 4 points, respectively, and the proportion of participants
meeting the MCID value was
recorded.24
Secondary outcome
Cross-sectional area of nerve: The same physician used
an electronic caliper to evaluate the cross-sectional area (CSA) of
the MN. For reliable results, the patients held their wrists in a
neutral position with the palm facing upwards and the fingers in a
semi-extended position. The examinations were performed at the
proximal inlet of carpal tunnel with the short-axis scan
(scaphoid-pisiform level) and where the largest swelling of the MN was
identified, as described
previously.6;
19 The ultrasonographic evaluation of
the CSA of the MN performed at this level has high sensitivity (89%)
and specificity (83%) for the diagnosis of
CTS.25;
26 Measurements were repeated three
times and averaged for further analysis.
Electrophysiological study: The same physician
performed the examinations to compare the antidromic SNCV and DML of
the MN.6;
7; 27 To
survey the SNCV, a stimulator was placed 14 cm proximal to the active
electrode where the 2nd interphalangeal joint was
recorded. To assess the DML, the active electrode was placed on the
abductor pollicis brevis with a stimulator at 8 cm proximal to the
active electrode. The cutoff
values for MN’s SNCV and DML for the diagnosis of CTS using
electrophysiological assessment were <3.6 ms and
<4.3 ms,
respectively.20-22 We
performed each measurement three times overall and averaged these
values for a mean SNCV and DML for statistical
analysis.28