Dynamic ultrasound for evaluating the adequacy of median nerve decompression following minimally invasive carpal tunnel release: technical innovation and case study.

Background: Minimally invasive carpal tunnel release has recently emerged as the primary surgical approach for recalcitrant carpal tunnel syndrome. A major concern related to surgical failure with this technique is the incomplete release of the flexor retinaculum. Case presentation: We developed a technique using dynamic ultrasound for evaluating the adequacy of median nerve decompression following minimally invasive carpal tunnel release. This novel imaging method was applied to two patients who showed significant symptom relief after the intervention. This case study also provides details of the dynamic ultrasound protocol and highlights the advantages of this technique. Conclusion: Dynamic ultrasound imaging can be used to confirm the completeness of carpal tunnel decompression. A large-scale prospective trial should be conducted to validate whether additional dynamic ultrasound examination can improve the outcome of minimally invasive carpal tunnel release.

Two Decades of Cardiac Amyloidosis: A Danish Nationwide Study.

BACKGROUND: Cardiac amyloidosis (CA) has been associated with poor outcomes. Screening studies suggest that CA is overlooked-especially in the elderly. Recent advances in treatment have brought attention to the disease, but data on temporal changes in CA epidemiology are sparse. OBJECTIVES: The aim of this work was to describe all patients with CA in Denmark, examining changes in patient characteristics from 1998 to 2017. METHODS: All patients with any form of amyloidosis diagnosed from 1998 to 2017, as well as their comorbidities and pharmacotherapy, were identified in Danish nationwide registries. CA was defined as any diagnosis code for amyloidosis combined with a diagnosis code for heart failure, cardiomyopathy, or atrial fibrillation or a procedural code for pacemaker implantation, regardless of the order. The index date was defined as the date of meeting those criteria. Patients were divided into 5-year periods by index date. For comparison, we also included control subjects (1:4 ratio) from the general population. RESULTS: CA criteria were met by 619 patients. Comparing 1998-2002 vs 2013-2017, the median age at baseline increased from 67.4 years (interquartile range [IQR]: 53.9-75.2 years) to 72.3 years (IQR: 66.0-79.3 years). The frequency of male patients increased from 62.1% to 66.2%. The incidence of CA rose from 0.88 to 3.56 per 100,000 person-years in the Danish population aged ≥65 years, and the 2-year mortality decreased from 82.6% (IQR: 69.9%-90.5%) to 50.2% (IQR: 43.1%-56.9%). Compared with control subjects, the mortality among CA patients was significantly higher (log-rank test: P < 0.0001). CONCLUSIONS: CA, as defined in this study, was increasingly diagnosed on a national scale. The increasing frequency of male patients and median age suggest that wild-type transthyretin amyloidosis is driving this increase. Greater recognition of earlier, less advanced cases might explain decreasing mortality.

Reduction in median nerve cross-sectional area at the forearm correlates with axon loss in carpal tunnel syndrome.

OBJECTIVE: To explore the relationship between axon loss and measured cross-sectional areas of the median nerve (MN) in severe carpal tunnel syndrome (CTS). METHODS: In this retrospective study of 158 examined wrists, we compared axon loss to the ultrasound parameters MN cross-sectional area at the wrist (wCSA), MN cross-sectional area at the forearm (fCSA) and wrist-to-forearm ratio (WFR), in patients with moderate to extreme CTS. Axon loss was evaluated by needle electromyography (EMG) of the abductor pollicis brevis muscle (spontaneous activity and reduction of interference pattern). RESULTS: Both the spontaneous activity and interference pattern reduction correlated negatively to fCSA (r = -0.189, p = 0.035; r = -0.210, p = 0.019; respectively). In moderate CTS, both the spontaneous activity and interference pattern reduction correlated positively to WFR (r = 0.231, p = 0.048; r = 0.232, p = 0.047; respectively). The WFR was highest when slight spontaneous activity was detected. Neither wCSA nor WFR correlated with axon loss in severe and extreme CTS. CONCLUSIONS: The fCSA is smaller when axon loss in CTS is more prominent. The WFR is highest when CTS is associated with slight axon loss of the MN. SIGNIFICANCE: CTS might cause retrograde axonal atrophy detected as small fCSA. Prominent axon loss in CTS may reduce the diagnostic value of WFR.

Impact of technical variations on the ring-finger test for carpal tunnel syndrome.

OBJECTIVE: To assess if recording the sensory latencies of the median and ulnar nerves one-by-one (consecutive) or at the same time (simultaneous) in the ring-finger test for carpal tunnel syndrome (CTS) will show equivalent results or if it will lead to a different clinical classification of patients. METHODS: We assessed the limits of agreement between the simultaneous and the consecutive method based on the median- ulnar sensory latency difference derived by both methods in 80 subjects and compared the number of minimal CTS cases identified by the two methods. RESULTS: Limits of agreement ranged from -0.23 to 0.29 ms. A significantly higher proportion of subjects with minimal CTS (only detectable by using the comparison test) was found using the simultaneous method (n = 8 and 2, respectively; p = 0.03). CONCLUSION: The two methods have a poor to moderate agreement as indicated by the range of the limits of agreement (0.5 ms). SIGNIFICANCE: Even small methodological changes to the ring-finger test can lead to results with different clinical meaning in the same individual and one should be aware of which method was used when interpreting results.

Standard median nerve ultrasound in carpal tunnel syndrome: A retrospective review of 1,021 cases.

OBJECTIVE: Carpal tunnel syndrome (CTS) is diagnosed with electrodiagnostic (EDx) studies. Investigations have examined US cross sectional-area (CSA) and wrist to forearm ratio (WFR) cut-offs for screening EDx abnormalities in patients with suspected CTS. The objective of this study is to determine if these US parameters are effective in a real world population. METHODS: This is a retrospective review of patients presenting to the Duke Electromyography (EMG) Laboratory during 2013-2014 with a final diagnosis of CTS. US diagnosis of CTS was based upon median nerve cross-sectional area of >9 mm2 and/or wrist-to-forearm ratio of >1.4. EDx studies were the gold standard for diagnosis. RESULTS: A total of 670 patients and 1,021 extremities were studied. US was positive in 97.6% of EDx confirmed CTS. CONCLUSION: Median nerve US is nearly as sensitive as the gold standard for EDx testing for the diagnosis of CTS. SIGNIFICANCE: The data here suggest that US may have use as a screening tool prior to performing EDx testing for CTS.

Pulsed magnetic field versus ultrasound in the treatment of postnatal carpal tunnel syndrome: A randomized controlled trial in the women of an Egyptian population.

The aim of this study was to compare the effects of pulsed electromagnetic field versus pulsed ultrasound in treating patients with postnatal carpal tunnel syndrome. The study was a randomized, double-blinded trial. Forty postnatal female patients with idiopathic carpal tunnel syndrome were divided randomly into two equal groups. One group received pulsed electromagnetic field, with nerve and tendon gliding exercises for the wrist, three times per week for four weeks. The other group received pulsed ultrasound and the same wrist exercises. Pain level, sensory and motor distal latencies and conduction velocities of the median nerve, functional status scale and hand grip strength were assessed pre- and post-treatment. There was a significant decrease (P < 0.05) in pain level, sensory and motor distal latencies of the median nerve, and significant increase (P < 0.05) in sensory and motor conduction velocities of the median nerve and hand grip strength in both groups, with a significant difference between the two groups in favour of pulsed electromagnetic field treatment. However, the functional status scale showed intergroup no significant difference (P > 0.05). In conclusion, while the symptoms were alleviated in both groups, pulsed electromagnetic field was more effective than pulsed ultrasound in treating postnatal carpal tunnel syndrome.