Neural plasticity secondary to carpal tunnel syndrome: a pseudo-continuous arterial spin labeling study.

Conventional neuroimaging techniques cannot truly reflect the change of regional cerebral blood flow in patients with carpal tunnel syndrome. Pseudo-continuous arterial spinning labeling (pCASL) as an efficient non-invasive neuroimaging technique can be applied to directly quantify the neuronal activities of individual brain regions that show the persistent symptoms owing to its better spatial resolution and increased signal-to-noise ratio. Therefore, this prospective observational study was conducted in 27 eligible female carpal tunnel syndrome, aged 57.7 ± 6.51 years. Psychometric tests, nerve conduction studies and pCASL neuroimaging assessment were performed. The results showed that the relevant activated brain regions in the cortical, subcrotical, and cerebral regions were correlated with numbness, pain, functionality, median nerve status and motor amplitude of median nerve (K = 21-2849, r = -0.77-0.76, P < 0.05). There was a tendency of pain processing which shifted from the nociceptive circuitry to the emotional and cognitive one during the process of chronic pain caused by carpal tunnel syndrome. It suggests the necessity of addressing the ignored cognitive or emotional state when managing patients with carpal tunnel syndrome. Approval for this study was obtained from the Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West, China (HKU/HA HKW IRB, approval No. UW17-129) on April 11, 2017. This study was registered in Clinical Trial Registry of The University of Hong Kong, China (registration number: HKUCTR-2220) on April 24, 2017.

Diagnostic Use of Ultrasonography in Carpal Tunnel Syndrome and Its Correlation with the Chinese Version of Boston Carpal Tunnel Questionnaire.

INTRODUCTION: There were yet no correlation studies performed between ultrasound and the Chinese version of Boston Carpal Tunnel Questionnaire (C-BCTQ). Besides, controversies still remain regarding the correlation between ultrasound and different language versions of BCTQ. PURPOSE OF THE STUDY: To examine whether ultrasound can (i) reflect symptom severity and/or functional status, (ii) differentiate primary/secondary symptom, and (iii) correlate with subscale items in C-BCTQ. METHODS: Forty-two Chinese female individuals (aged 58.84 ± 9.02 years) with 73 hands were enrolled in the study. Factor analysis was used to identify the hidden factors of C-BCTQ. Correlations were examined between hidden factors, relevant subscale items of C-BCTQ, and ultrasound. RESULTS: Three factors were identified as Factor One (functional status, 36.534%), Two (sensory symptoms, 15.057%) and Three (pain, 11.867%), with 63.458% of total variance explained in C-BCTQ. All the ultrasound parameters were positively correlated with Factor One (r = 0.29-0.411, P < 0.05), while no correlations were found with Factor Two and Three. Meanwhile, correlation between wrist cross-sectional area and functional status scale (FSS) was also found (W-CSA, r = 0.266, P = 0.023), whereas no correlation was found with symptom severity scale (SSS), subscales of primary symptom (Paresthesia) and secondary symptom (pain) related items in C-BCTQ. CONCLUSION: Morphological information via ultrasound can reflect the impact on functionality that carpal tunnel syndrome (CTS) exerted. However, it can be used neither to describe symptom severity nor differentiate primary/secondary symptom of CTS.

Prognostic Value of Ultrasonography in Predicting Therapeutic Outcome for Carpal Tunnel Syndrome after Conservative Treatment: A Retrospective Long-term Follow-up Study.

PURPOSE: This study aimed at investigating prognostic values of different ultrasound variables in predicting therapeutic outcome of the patients with carpal tunnel syndrome (CTS) after conservative treatment in a long-term follow-up data. MATERIALS AND METHODS: One hundred and three participants with 162 affected hands were enrolled in this retrospective study. Records of baseline clinical information, nerve conduction studies (NCSs), and ultrasound assessment were retrieved. A structured telephone interview was conducted for acquiring patients' response to recovery after treatment. Multinomial logistic regression analysis was used to estimate the odds ratio and 95% confidence interval of individual ultrasound variable, adjusted for age, gender, and other confounding factors. RESULTS: Perimeter at wrist (W-P), ratio of cross-sectional area of wrist over one-third distal forearm (R-CSA), changes of CSA from wrist to the one-third distal forearm (△CSA), and changes of perimeter from wrist to one-third distal forearm (△P) were negatively and significantly associated with "improved" and "no change" categories relative to reference category ("deteriorated" category). After adjustment for age, gender, affected hand side, surgical history, and comorbidity, for one unit increase of W-P/△CSA/△P, the odds of "improved" category versus "deteriorated" category decreased by 89.1%/56%/95.2%, whereas the odds of "no change" relative to "deteriorated" category decreased by 77.8%/54.6%/84.9% should one unit increase in the correspondent individual ultrasound variable. CONCLUSION: Ultrasound variables can significantly predict therapeutic outcome in CTS after conservative management in a long-term follow-up. Further studies may be required to assess whether a combination of clinical, NCS, and ultrasound variables can better predict the therapeutic outcome.

Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies.

Axonal degeneration, indicative of surgical decompression, may coexist in carpal tunnel syndrome (CTS) as the disease progresses. However, the current diagnostic and severity gradation system cannot clearly indicate its coexistence, resulting in confusion of appropriate treatment prescription. There are also constraints in conventional methods for differentiation as well. This study aims at introducing an innovative, efficient, and quick screening protocol to differentiate axonal degeneration associated with CTS, using ultrasound and nerve conduction studies (NCS). It starts by using NCS to perform orthodromic stimulation at the wrist, to obtain the sensory conduction of the median and the ulnar nerves respectively. Meanwhile, the motor conduction of the median nerve is collected by stimulating the palm, wrist, and elbow, followed by the stimulation of the ulnar nerve at the wrist, below and above the elbow. Then, an ultrasound assessment is performed, using a linear array transducer, with cross-sectional area (CSA) and perimeter (P) at the wrist and at the one-third distal forearm calipered. Ratios (R-CSA, R-P) and changes from wrist to one-third distal forearm (ΔCSA and ΔP) are calculated according to a standard format. Potential axonal degeneration coexisting in CTS will be screened according to the criteria of NCS and cut-off values of ultrasound measurements established in a previous study. In terms of its noninvasiveness, low cost, convenience, and efficiency, it is easy to apply ultrasound complimentarily in clinical practice to prescreen patients with potential coexisting axonal degeneration. Nevertheless, the ultrasonographic imaging cannot directly reflect axonal degeneration. It still relies on conventional but invasive methods such as electromyography (EMG) and biopsy for confirmation if needed.

Exploratory use of ultrasound to determine whether demyelination following carpal tunnel syndrome co-exists with axonal degeneration.

Carpal tunnel syndrome (CTS) accompanied by secondary axonal degeneration cannot be clearly discriminated using the current cross-validated ultrasound severity classification system. This study aimed at exploring cut-off values of ultrasound parameters, including wrist cross-sectional area (W-CSA), wrist perimeter (W-P), ratio of cross-sectional area (R-CSA) and perimeter (R-P), changes of CSA and P from wrist to one third distal forearm (ΔCSA&ΔP) for differentiation. Seventy-three patients (13 male and 60 female) were assigned into group A (demyelination only, n = 40) and group B (demyelination with secondary axonal degeneration, n = 33) based on the outcomes of nerve conduction studies (NCS). Receiver Operative Characteristics (ROC) curves were plotted to obtain sensitivity, specificity, and accuracy of cut-off values for all the ultrasound parameters. The overall identified cut-off values (W-CSA 12.0 mm2, W-P 16.27 mm, R-CSA 1.85, R-P 1.48, ΔCSA 6.98 mm2, ΔP 5.77 mm) had good sensitivity (77.1-88.6%), fair specificity (40-62.2%) and fair-to-good accuracy (0.676-0.758). There were also significant differences in demographics (age and severity gradation, P < 0.001), NCS findings (wrist motor latency and conduction velocity, P < 0.0001; wrist motor amplitude, P < 0.05; distal sensory latency, P < 0.05; sensory amplitude, P < 0.001) and ultrasound measurements (W-CSA, W-P, R-CSA, R-P, ΔCSA&ΔP, P < 0.05) between groups. These findings suggest that ultrasound can be potentially used to differentiate demyelinating CTS with secondary axonal degeneration and provide better treatment guidance.

Long-term clinical outcomes after deployment of femoral vascular closure devices in coronary angiography and percutaneous coronary intervention: an observational single-centre registry follow-up.

OBJECTIVES: There are few data evaluating the long-term effect of femoral vascular closure devices (FCDs) on patients' clinical outcome. We aim to evaluate the incidence of peripheral vascular disease (PVD) in patients who received FCD following its deployment in coronary angiography and percutaneous coronary intervention (PCI) procedures. DESIGN AND SETTING: Observational study of a single-centre registry. PARTICIPANTS: From June 2000 to September 2004, 265 patients who received FCD after coronary angiography and PCIs were enrolled on the study. OUTCOME MEASURES: Clinical follow-up (using Rutherford's categories of claudication), ankle brachial index (ABI) and duplex ultrasound of femoral arteries (using the non-accessed side as control) were performed to evaluate the presence of PVD. RESULTS: The mean follow-up interval was 3320±628 days. 1 patient (0.4%) suffered from grade 2 claudication and another (0.4%) suffered from grade 1 claudication. The mean ABIs of the accessed side and non-accessed side were 1.06±0.13 and 1.08±0.11, respectively (p=0.17). For duplex ultrasound, the mean common femoral artery peak systolic velocities of the accessed side and non-accessed side were 87.4±22.3 and 87.7±22.1 cm/s, respectively (p=0.73); the mean superficial femoral artery peak systolic velocities of the accessed side and non-accessed side were 81.4±20.1 and 81.31±17.8 cm/s, respectively (p=0.19). CONCLUSIONS: The use of FCD after a coronary angiogram and PCI is safe and does not increase the long-term risk of PVD.