MRI analysis of carpal tunnel syndrome in hemodialysis patients versus non-hemodialysis patients: a multicenter case-control study

Magnetic Resonance Imaging and Sonographic Features before and after Surgery in Carpal Tunnel Syndrome: Association with Clinical Findings

BACKGROUND

The interest in ultrasonography (US) and magnetic resonance imaging (MRI) assessment of the patients with carpal tunnel syndrome (CTS) is growing. This paper aimed to find the correlation of postoperative changes in these modalities' parameters with clinical outcomes.

METHODS

Boston CTS questionnaire-symptom severity (BQ-SS), Boston CTS questionnaire-functional status (BQ-FS), and visual analog scale (VAS) questionnaires (for pain, paresthesia, and grip weakness assessment) were used to evaluate clinical outcomes. Various imaging parameters of the median nerve and carpal tunnel were evaluated using US and MRI at two levels of the hook of the hamate (distal) and the pisiform (proximal) once preoperatively and then 3 months postoperatively. Corresponding US and MRI parameter measures were compared, and correlational analysis was performed between alteration of imaging findings and changes in clinical parameters postoperatively.

RESULTS

Patients' functional status (BQ-FS score) was positively correlated with the nerve width both in US and MRI at the proximal level (r = 0.457 and r = 0.453, respectively) and also with the MRI nerve circumference at the distal level (r = -0.482). Correlation between paresthesia and the nerve width was notable in MRI at the distal hook of the hamate level (r = -0.403). Grip weakness VAS score was correlated with the nerve width-to-height ratio (WHR) in US at the distal level (r = 0.432).

CONCLUSIONS

Changes in US and MRI parameters of the median nerve width, circumference, and WHR were associated with clinical changes in patients with CTS after surgery.

Evaluation of the Existing Electrophysiological Severity Classifications in Carpal Tunnel Syndrome

Electrophysiological examination is important for the diagnosis and evaluation of nerve function in carpal tunnel syndrome (CTS). Electrophysiological severity classifications of CTS using a nerve conduction study (NCS) have been reported, and there are many reports on the relationship between severity classifications and clinical symptoms. The existing electrophysiological severity classifications have several problems, such as cases that do not fit into a classification and unclear reasons for the boundary value. The purpose of this study was to clarify the relationship between sensory nerve conduction velocity (SCV) and distal motor latency (DML) and to evaluate whether the existing severity classification method is appropriate. We created a scatter diagram between SCV and DML for our NCSs and found a negative correlation between SCV and DML (correlation coefficient, −0.786). When we applied our NCSs to the existing classifications (Padua and Bland classifications), there were many unclassifiable cases (15.2%; Padua classification), and the number of Grade 3 cases was significantly higher than that of Grade 2 or 4 cases (Bland classification). Our large dataset revealed a strong negative correlation between SCV and DML, indicating that the existing severity classifications do not always accurately reflect the severity of the disease.

Prediction of carpal tunnel syndrome using the thenar muscle cross-sectional area by magnetic resonance imaging

Carpal tunnel syndrome (CTS) is a common neuropathy. Although CTS progression is known to be associated with thenar muscle (TM) atrophy, the diagnostic value of TM atrophy for CTS has not been established. In this research, the thenar muscle cross-sectional area (TMCSA) was evaluated to analyze the relationship between the TMCSA and CTS. We assumed that TMCSA is a major diagnostic parameter in the CTS.Both TMCSA and thenar muscle thickness (TMT) samples were acquired from 18 CTS patients, and from 18 control subjects who underwent wrist magnetic resonance imaging with no evidence of CTS. T2-weighted transverse magnetic resonance imaging images were obtained. We measured the TMCSA and TMT at the level of first carpometacarpal joint.The average TMCSA was 296.98 ± 49.39 mm2 in the normal group and 203.36 ± 72.13 mm2 in the CTS group. The average TMT was 8.54 ± 1.45 mm in the normal group and 7.38 ± 1.14 mm in the CTS group. CTS group had significantly lower TMCSA and TMT. Receiver operator characteristics curve analysis showed that the best cutoff point for the TMCSA was 260.18 mm2, with 77.8% sensitivity, 77.8% specificity. The best cutoff point of the TMT was 7.70 mm, with 61.1% sensitivity, 66.7% specificity.Although the TMCSA and TMT were both significantly associated with CTS, the TMCSA was a much more sensitive measurement parameter. Thus, to evaluate CTS patients, the physician should more carefully inspect the TMCSA than TMT.

Amyloidosis: Multisystem Spectrum of Disease with Pathologic Correlation

Amyloidosis is a group of conditions defined by extracellular deposition of insoluble proteins that can lead to multiorgan dysfunction and failure. The systemic form of the disease is often associated with a plasma cell dyscrasia but may also occur in the setting of chronic inflammation, long-term dialysis, malignancy, or multiple hereditary conditions. Localized forms of the disease most often involve the skin, tracheobronchial tree, and urinary tract and typically require tissue sampling for diagnosis, as they may mimic many conditions including malignancy at imaging alone. Advancements in MRI and nuclear medicine have provided greater specificity for the diagnosis of amyloidosis involving the central nervous system and heart, potentially obviating the need for biopsy of the affected organ in certain circumstances. Specifically, a combination of characteristic findings at noninvasive cardiac MRI and skeletal scintigraphy in patients without an underlying plasma cell dyscrasia is diagnostic for cardiac transthyretin amyloidosis. Histologically, the presence of amyloid is denoted by staining with Congo red and a characteristic apple green birefringence under polarized light microscopy. The imaging features of amyloid vary across each organ system but share some common patterns, such as soft-tissue infiltration and calcification, that may suggest the diagnosis in the appropriate clinical context. The availability of novel therapeutics that target amyloid protein fibrils such as transthyretin highlights the importance of early diagnosis. Online supplemental material is available for this article. ^©RSNA, 2021.

Assessment of grip-motion characteristics in carpal tunnel syndrome patients using a novel finger grip dynamometer system

Background

Grip strength measurement is widely used in daily medical practice, and it has been reported that the grip strength decreases in patients with carpal tunnel syndrome (CTS). However, conventional grip dynamometers evaluate only the maximum power of total grip strength and cannot measure the time course of grip motion. In this report, we aimed to determine the grip characteristics of CTS patients by measuring the time course of each finger’s grip motion and to analyze the relationship between finger grip strength and subjective symptoms using this new grip system.

Methods

The grip strength of each finger was measured using the new grip system that has four pressure sensors on the grip parts of each finger of the Smedley grip dynamometer. We analyzed the time course of grip motion and relationship between finger grip strength and subjective symptoms in 104 volunteer and 51 CTS hands. The Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH) and the Disability of Arm, Shoulder, and Hand questionnaire (DASH) were used as subjective evaluation scores.

Results

In the CTS group, the grip time with the index, middle, and ring fingers was longer, and the time at which strength was lost after reaching the maximum was earlier. Patients with severe subjective symptoms tended to not use the index and middle fingers during grip motion.

Conclusions

This new system that measures each finger’s grip strength at one time and record the time course of grip motion could quantify a patient’s symptoms easily and objectively, which may contribute to the evaluation of hand function.

Clinical and ultrasonographic screening for carpal tunnel syndrome in hemodialysis patients

Background

Carpal tunnel syndrome (CTS) is one of the most common complications among hemodialysis (HD) patients. This study aimed to assess the prevalence of CTS in HD patients using clinical and noninvasive ultrasound (US) criteria.

Methods

A cross-sectional, observational study was conducted on 94 HD patients to evaluate CTS manifestations and demographic, clinical, and laboratory data. The median nerve (MN) cross sectional area (CSA) (MN-CSA) was estimated by US examination at the pisiform and hamate levels. Both hands were evaluated, and the higher MN-CSA was considered.

Results

Neuropathic pain and nocturnal numbness at MN distribution were present in 40.4% and 18.1%, respectively, while Tinel’s test was positive in 25.5% of patients. A MN-CSA ≥ 11.5 mm² identified the probability of CTS with 63% sensitivity and 80% specificity. Patients with CTS had higher serum calcium (P = 0.02) and lower parathyroid hormone (PTH) (P = 0.02). CTS was frequently developed on the same side of an arteriovenous fistula. The MN-CSA had positive correlations with age, serum phosphorus, and visual analogue scale (VAS) score (P = 0.01, 0.01, and 0.03 respectively) and a negative correlation with PTH level (P = 0.007). Serum phosphorus level (P = 0.015) and VAS (P = 0.04) were the significant predictors of MN-CSA.

Conclusion

CTS appears to frequently occur in HD patients. US examination may be helpful in detection of CTS and can be an alternative to electrodiagnostic studies in HD patients.

Carpal Tunnel Syndrome Surgery: What You Should Know

Carpal tunnel release (CTR) surgery continues to evolve. Carpal tunnel syndrome remains a primarily clinical diagnosis, although ultrasound has supplemented electrodiagnostic testing as a confirmatory tool. Magnetic resonance imaging of the carpal tunnel has also showed some promise as an alternative method for the examination of the median nerve. Open CTR surgery remains the traditional, and most popular, method of CTR. Wide-Awake, with Local Anesthesia only, and No Tourniquet CTR has emerged as a means to decrease cost and improve pain control and convenience for patients. Endoscopic CTR is increasing in popularity due to its more rapid recovery. The safety profile of endoscopic CTR has improved, and recent studies show similar rates of major complications between open and endoscopic techniques. Nonsurgeon operated ultrasound-guided techniques for release of the transverse carpal ligament have emerged. While promising in early studies, the current evidence in their favor is limited in terms of patient numbers and direct comparison with other techniques. The outcomes of CTR continue to be excellent. Recent research has demonstrated that nerve conduction continues to recover postoperatively over a longer period of time than previously believed. Patient psychological factors play a significant role in outcomes after surgery but do not appear to limit the improvement provided by intervention.

[Carpal tunnel syndrome: Rare causes and associated forms behind a common and stereotyped affection]

Carpal tunnel syndrome (CTS) is too common a condition not to daily interact with the practitioner, if only because of its entanglement to other pathologies, causal or chance association. The typical symptomatology, with hand paresthesia and morning pain upon waking, is related to a median nerve injury in the confined space of the carpal tunnel, more often by local inflammation and tenosynovitis of the finger flexors (repetitive activity of the hands). SCC may be secondary to situations (pregnancy) or conditions (edema, hypothyroidism…), which exaggerate the ordinary pathophysiology or cause deposits in the channel (amyloidosis, mucopolysaccharidoses, etc.). Otherwise, SCC is favored by all neuropathies that cause nerve fragility (especially diabetes). It is sometimes the first sign of these various affections of which it can allow early diagnosis. Electroneuromyographic examination (ENMG) is a key examination to confirm the diagnosis (slowing of sensitive and motor conduction of the median nerve through the carpal tunnel, due to local demyelination), to look for a predisposing neuropathy and for signs of seriousness (amplitude reduction of electrophysiological signals) that indicate axonal loss. In SCC forms with only slowed conduction without sign of seriousness, a splint or infiltration treatment may be attempted. If this medical treatment does not bring healing, or if there are signs of seriousness or unbearable pains, a decompression surgery is indicated. Whether it is performed traditionally or endoscopically, it provides fast relief, even immediate.