Introduction:
Carpal tunnel syndrome (CTS) is the most prevalent peripheral nerve entrapment of upper limb.
Typical symptoms comprise pain, numbness or tingling of the thumb and index, middle or ring
fingers. Thumb weakness and decreased grip strength can occur in the later stage. Currently
treatments included physical modalities (low power laser, transcutaneous electrical nerve
stimulation, ultrasound), medication, splinting, injection and surgery. Ultrasound guided
intracarpal hydro-dissection of median nerve had been proposed based on its accurate
localization, while the injectates were diverse. Corticosteroid has been widely used for CTS
for decades. However, growing evidences suggested that 5% dextrose, normal saline, platelet
rich plasma injection also have therapeutic effects on alleviating CTS symptoms. Among the
injectates, a single 5% dextrose injection could be considered as a substitute of
corticosteroid based on its long term effect up to six months. However, the clinical efficacy
of 5% dextrose injection has not validated by the further study. Whether repeated injection
could expand the treatment effect was undetermined. The investigators aim to compare the
therapeutic effect repeated 5% dextrose injection with corticosteroid injection in patients
with CTS, up to 12 weeks follow up.
Material and methods:
Participants: 60 adult patients (>20 year olds) with carpal tunnel syndrome, recruited from
outpatient clinic.
Inclusion criteria: Presenting with CTS symptoms, including nocturnal, postural, or
motion-associated paresthesias +/- pain of the median nerve distribution area in the
subjective hand. Confirmed Electrophysiological confirmed median neuropathy at the wrist with
mild to moderate degree. Persistent symptoms for more than 3 months
Exclusion Criteria: Patients cervical radiculopathy, polyneuropathy, brachial plexopathy,
thoracic outlet syndrome. Recent corticosteroid injection to the carpal tunnel within 6
months.
Thenar muscle atrophy. Previous history of carpal tunnel surgical release. History of wrist
trauma. Regular use of systemic nonsteroidal anti-inflammatory drugs, corticosteroids or
diuretics. Pregnancy. Cognitive impairment.
Objective:
The aim of this study is to compare the treatment effect of repeated 5 mL 5% dextrose with
5mL triamcinolone acetonide injection in patients with CTS.
Detail of the intervention The study is designated as randomized, double blinded, and
parallel experiment. The randomization was decided by random table in block of 4.
Repeated ultrasound guided injection intracarpal median nerve hydro-dissection with 5 mL 5%
dextrose (Group B) or 5mL triamcinolone acetonide injection (Group A) in patients with CTS.
The regimen was shown as below:
Group A: 1st injection (0 week): 40mg triamcinolone acetonide (40mg/mL) with 4mL normal
saline, 2nd injection (6 week): 5 mL normal saline Group B: 1st injection (0 week): 5 mL 5%
dextrose, 2nd injection (6 week): 5 mL 5% dextrose
Skin infiltration with local anesthetic (lidocaine cream) at the needle insertion site was
performed before the injection. Then injection was performed after sterilization. The
equipment for ultrasound-guided injection will be high-resolution ultrasound machine with the
linear probe.
Outcome measurement:
Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and Visual analogue scale (VAS) before 1st
injection, before 2nd injection (6-week) and 12-week after first injection.
Electrophysiological evaluation (amplitude and distal latency of median nerve compound motor
action potential and sensory nerve action potential); cross-sectional area of median nerve at
carpal tunnel inlet, were evaluated before and 12-week after 1st injection.
Global assessment of treatment was evaluated at before 2nd injection (6-week) and 12-week
after first injection.
Statistical analysis:
Continuous variables Student's t test: fit assumption of normal distribution Mann-Whitney
test: does not fit the assumption of normal distribution Categorical variables (1) Chi-square
test (2) Fisher exact test: sparse data (3)Repeated-measures analysis of variance (ANOVA) was
used to evaluate the effect of injection with post-hoc Bonferroni test to evaluate
intra-group data at different time-frame
Keywords: Hydro-dissection, corticosteroid, dextrose, carpal tunnel syndrome