Carpal tunnel syndrome--a comprehensive review

State of the art review. Complications after carpal tunnel release

Carpal tunnel release (CTR) is the most performed surgery of the upper extremity. It is effective but not without complications. This state-of-the-art review covers most common intra- and postoperative complications after CTR. As endoscopic carpal tunnel release (ECTR) has developed over time, severe complications, such as nerve lesions, have diminished. ECTR still has a higher risk on transient nerve lesions. Open CTR on the other hand has a higher incidence of wound-related problems, including scar tenderness, irrespective of incision used. Most complications, such as pillar pain and infection, are ill-defined in the literature, leaving the exact incidence unknown and proposing challenges in treatment. The same is true for failure of treatment. Optimizing the length and location of incisions has played a vital role in reducing intra- and postoperative complications in CTR. It is expected that technical advances, such as ultrasound-guided percutaneous carpal tunnel release, will continue to play a role in the future.Level of evidence: V.

Genetic screening for hereditary transthyretin amyloidosis with polyneuropathy in western Sicily: Two years of experience in a neurological clinic

BACKGROUND AND PURPOSE

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils.

METHODS

A prospective systematic genetic screening for ATTRv-PN was proposed in patients presenting with a sensory-motor idiopathic polyneuropathy and two or more "red flags" among the following: family history of polyneuropathy or cardiopathy, bilateral carpal tunnel syndrome, cardiac insufficiency, renal amyloidosis, lumbar tract stenosis, autonomic dysfunction, idiopathic gastrointestinal disease, amyloid deposits on biopsy, and vitreous opacities. The detection rate was calculated, and nonparametric analyses were carried out to underline differences among screened positive versus negative patients.

RESULTS

In the first step, 145 suspected patients underwent genetic testing, revealing a diagnosis of ATTRv-PN in 14 patients (10%). Then, cascade screening allowed early recognition of 33 additional individuals (seven symptomatic ATTRv-PN patients and 26 presymptomatic carriers) among 84 first-degree relatives. Patients with a positive genetic test presented a higher frequency of unexplained weight loss, gastrointestinal symptoms, and family history of cardiopathy.

CONCLUSIONS

A systematic screening for ATTRv-PN yielded an increased recognition of the disease in our neurological clinic. Unexplained weight loss associated with axonal polyneuropathy had the highest predictive value in the guidance of clinical suspicion. A focused approach for the screening of ATTRv-PN could lead to an earlier diagnosis and identification of asymptomatic carriers, who will be promptly treated after a strict follow-up at the clinical onset.

Machine Learning for Early Diagnosis of ATTRv Amyloidosis in Non-Endemic Areas: A Multicenter Study from Italy

BACKGROUND

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is an adult-onset multisystemic disease, affecting the peripheral nerves, heart, gastrointestinal tract, eyes, and kidneys. Nowadays, several treatment options are available; thus, avoiding misdiagnosis is crucial to starting therapy in early disease stages. However, clinical diagnosis may be difficult, as the disease may present with unspecific symptoms and signs. We hypothesize that the diagnostic process may benefit from the use of machine learning (ML).

METHODS

397 patients referring to neuromuscular clinics in 4 centers from the south of Italy with neuropathy and at least 1 more red flag, as well as undergoing genetic testing for ATTRv, were considered. Then, only probands were considered for analysis. Hence, a cohort of 184 patients, 93 with positive and 91 (age- and sex-matched) with negative genetics, was considered for the classification task. The XGBoost (XGB) algorithm was trained to classify positive and negative TTR mutation patients. The SHAP method was used as an explainable artificial intelligence algorithm to interpret the model findings.

RESULTS

diabetes, gender, unexplained weight loss, cardiomyopathy, bilateral carpal tunnel syndrome (CTS), ocular symptoms, autonomic symptoms, ataxia, renal dysfunction, lumbar canal stenosis, and history of autoimmunity were used for the model training. The XGB model showed an accuracy of 0.707 ± 0.101, a sensitivity of 0.712 ± 0.147, a specificity of 0.704 ± 0.150, and an AUC-ROC of 0.752 ± 0.107. Using the SHAP explanation, it was confirmed that unexplained weight loss, gastrointestinal symptoms, and cardiomyopathy showed a significant association with the genetic diagnosis of ATTRv, while bilateral CTS, diabetes, autoimmunity, and ocular and renal involvement were associated with a negative genetic test.

CONCLUSIONS

Our data show that ML might potentially be a useful instrument to identify patients with neuropathy that should undergo genetic testing for ATTRv. Unexplained weight loss and cardiomyopathy are relevant red flags in ATTRv in the south of Italy. Further studies are needed to confirm these findings.

The treatment effect of intramuscular stimulation on carpal tunnel syndrome: A blinded randomized trial on 75 patients

BACKGROUND

Carpal tunnel syndrome (CTS) is a disorder with a prevalence of about 5.8% for females and 0.6% for males. This study aims to determine whether intramuscular stimulation (IMS) to the pronator teres muscle subsequently reduces the severity of clinical parameters and the diameter of the median nerve.

METHODS

Seventy-five individuals with a cross-sectional diameter of the median nerve of more than 2 mm were included in this randomized clinical trial. Thirty-seven individuals received IMS to the pronator teres muscle with a depth of up to 45-50 mm. The 38 individuals in the control group received an acupuncture needle at Li11 with a depth of 4-5 mm. Both groups had 7 treatments within 7 weeks. The primary outcome was the cross-section of the median nerve in the carpal tunnel. Additionally, Phalen's test, Tinel's sign, VAS for pain intensity, and pincer grip strength were measured.

RESULTS

Both IMS subjects and controls showed significant reductions in the cross-section of the median nerve from baseline to follow-up (p < 0.001 and p = 0.002 respectively). The IMS group had the largest change, but the difference in change between the groups was not significant (p = 0.39). On all clinical tests, IMS subjects showed significant improvement from baseline compared with the control group (largest p = 0.002).

CONCLUSION

In this study we found that IMS to the pronator teres muscle significantly improved all clinical variables measured, compared with the group receiving acupuncture. Furthermore, the cross-section of the median nerve reduced over time for both groups. IMS may be a low-risk alternative while patients are waiting for surgery.

TRIAL REGISTRATION

Clinicaltrials. gov Identifier: NCT01102868. Retrospectively registered: March 29th^, 2010.

Assessing the Performance of Morphologic and Echogenic Features in Median Nerve Ultrasound for Carpal Tunnel Syndrome Diagnosis

OBJECTIVES

To assess the feasibility of using ultrasound (US) image features related to the median nerve echogenicity and shape for carpal tunnel syndrome (CTS) diagnosis.

METHODS

In 31 participants (21 healthy participants and 10 patients with CTS), US images were collected with a 30-MHz transducer from median nerves at the wrist crease in 2 configurations: a neutral position and with wrist extension. Various morphologic features, including the cross-sectional area (CSA), were calculated to assess the nerve shape. Carpal tunnel syndrome commonly results in loss of visualization of the nerve fascicular pattern on US images. To assess this phenomenon, we developed a nerve-tissue contrast index (NTI) method. The NTI is a ratio of average brightness levels of surrounding tissue and the median nerve, both calculated on the basis of a US image. The area under the curve (AUC) from a receiver operating characteristic curve analysis and t test were used to assess the usefulness of the features for differentiation of patients with CTS from control participants.

RESULTS

We obtained significant differences in the CSA and NTI parameters between the patients with CTS and control participants (P < .01), with the corresponding highest AUC values equal to 0.885 and 0.938, respectively. For the remaining investigated morphologic features, the AUC values were less than 0.685, and the differences in means between the patients and control participants were not statistically significant (P > .10). The wrist configuration had no impact on differences in average parameter values (P > .09).

CONCLUSIONS

Patients with CTS can be differentiated from healthy individuals on the basis of the median nerve CSA and echogenicity. Carpal tunnel syndrome is not manifested in a change of the median nerve shape that could be related to circularity or contour variability.

Carpal Tunnel Syndrome: A Review of Literature

Carpal tunnel syndrome (CTS) is a common medical condition that remains one of the most frequently reported forms of median nerve compression. CTS occurs when the median nerve is squeezed or compressed as it travels through the wrist. The syndrome is characterized by pain in the hand, numbness, and tingling in the distribution of the median nerve. Risk factors for CTS include obesity, monotonous wrist activity, pregnancy, genetic heredity, and rheumatoid inflammation. The diagnosis of CTS is conducted through medical assessments and electrophysiological testing, although idiopathic CTS is the most typical method of diagnosis for patients suffering from these symptoms. The pathophysiology of CTS involves a combination of mechanical trauma, increased pressure, and ischemic damage to the median nerve within the carpal tunnel. The diagnosis of CTS patients requires the respective medical professional to develop a case history associated with the characteristic signs of CTS. In addition, the doctor may question whether the patients use vibratory objects for their tasks, the parts of the arm where the sensations are felt, or if the patient may already have predisposing factors for CTS incidence. During the diagnosis of CTS, it is essential to note that other conditions may also provide similar symptoms to CTS, thus requiring vigorous diagnosis to assert the medical condition of the patients. Doctors use both non-surgical and surgical treatments when addressing CTS. Non-surgical treatments include wrist splinting, change of working position, medications, and the use of alternative non-vibrating equipment at work. On the other hand, surgical methods include open release and endoscopic surgeries. This review of literature has provided an overview of CTS with an emphasis on anatomy, epidemiology, risk factors, pathophysiology, stages of CTS, diagnosis, and management options.

Preoperative corticosteroid injections are associated with worse long-term outcome of surgical carpal tunnel release

BACKGROUND AND PURPOSE

Failed closed treatment of carpal tunnel syndrome (CTS) is often followed by surgery. We investigated whether preoperative steroid injections could have a negative effect on the long-term outcome of the operation.

PATIENTS AND METHODS

174 hands (164 patients) were operated on by a single surgeon at Tartu University Hospital in 2005. The patients were interviewed by telephone 5-6 years after the operation. Self-reported data were gathered retrospectively concerning the number of steroid injections received before the surgery and the perceived regression of symptoms (on a 100-point numeric rating scale) at the time of interview. The patients were also asked about the presence of specific symptoms of CTS if regression of their symptoms had not been complete.

RESULTS

93 of the 174 hands had complete regression of symptoms. Each additional injection was associated with an increased risk of occurrence of pain (RR = 1.1, 95% CI: 1.02-1-2), paresthesiae (RR = 1.1, CI: 1.1-1.2), and nocturnal awakenings (RR = 1.2, CI: 1.1-1.3). There was a weak association between the number of injections and the score given to regression of symptoms.

INTERPRETATION

This is the first study to indicate that patients who received a greater number of local steroid injections preoperatively were more likely to have postoperative complaints associated with CTS.

Long-term trends in carpal tunnel syndrome

OBJECTIVE

To assess temporal trends in carpal tunnel syndrome (CTS) incidence, surgical treatment, and work-related lost time.

METHODS

Incident CTS and first-time carpal tunnel release among Olmsted County, Minnesota, residents were identified using the medical records linkage system of the Rochester Epidemiology Project; 80% of a sample were confirmed by medical record review. Work-related CTS was identified from the Minnesota Department of Labor and Industry.

RESULTS

Altogether, 10,069 Olmsted County residents were initially diagnosed with CTS in 1981-2005. Overall incidence (adjusted to the 2000 US population) was 491 and 258 per 100,000 person-years for women vs men (p < 0.0001) and 376 per 100,000 for both sexes combined. Adjusted annual rates increased from 258 per 100,000 in 1981-1985 to 424 in 2000-2005 (p < 0.0001). The average annual incidence of carpal tunnel release surgery was 109 per 100,000, while that for work-related CTS was 11 per 100,000. An increase in young, working-age individuals seeking medical attention for symptoms of less severe CTS in the early to mid-1980s was followed in the 1990s by an increasing incidence in elderly people.

CONCLUSIONS

The incidence of medically diagnosed carpal tunnel syndrome (CTS) accelerated in the 1980s. The cause of the increase is unclear, but it corresponds to an epidemic of CTS cases resulting in lost work days that began in the mid-1980s and lasted through the mid-1990s. The elderly present with more severe disease and are more likely to have carpal tunnel surgery, which may have significant health policy implications given the aging population.

Reliability of hand diagrams for the epidemiologic case definition of carpal tunnel syndrome

The purpose of this study was to evaluate the inter-rater reliability of hand diagrams, which are commonly used in research case definitions of carpal tunnel syndrome (CTS). To evaluate the potential of non-random misclassification of cases, we also studied predictors of rater disagreement as a function of personal and work factors, and of hand symptoms not classic for CTS. Participants in a longitudinal study investigating the development of CTS completed repeated self-administered questionnaires. Three experienced clinicians, blind to subjects' work or personal history, independently rated all hand diagrams on an ordinal scale from 0 to 3. Disagreements between ratings were resolved by consensus. Reliability was measured by the weighted kappa statistic. Logistic regression models evaluated predictors of disagreement. Three hundred and thirty-three subjects completed 494 hand diagrams. Eighty-five percent were completed by self-administered questionnaire and 15% by telephone interview. Weighted kappa values representing agreement among the three raters, were 0.83 (95% CI: 0.78, 0.87) for right hand diagrams and 0.88 (95% CI: 0.83, 0.91) for left hand diagrams. Ratings from hand diagrams obtained by telephone interview produced better agreement. Agreement among raters was not affected by subjects' personal or work factors. Disagreement among raters was associated with the presence of hand/wrist symptoms other than classic CTS symptoms. Overall, high levels of agreement were attained by independent raters of hand diagrams. Personal factors did not affect agreement among raters, but presence of non-CTS symptoms seemed to affect results and should be considered in studies focused on diverse populations with heterogeneity of upper extremity symptoms.