The controversy of the normal values of ultrasonography in carpal tunnel syndrome: diagnostic accuracy of wrist-dependent CSA revisited.

INTRODUCTION: No consensus exists about the upper limit of normal (ULN) of the cross-sectional area (CSA) of the median nerve in diagnosing carpal tunnel syndrome (CTS). Previously, we demonstrated a strong positive correlation between wrist circumference and CSA. ULN depending on wrist circumference turned out to have a low sensitivity, which was hypothesized to be caused by an age mismatch. The aim of this study was to re-evaluate the found invariance by augmentation of the healthy control group, adding older subjects, and to determine the diagnostic accuracy of the updated normal values. METHODS: CSA and wrist circumference were measured in an additional 42 healthy controls in the ages of 40-60. Univariable and multivariable linear regression analyses were applied to determine predicting factors for CSA. Diagnostic accuracy was assessed in a prospective cohort of 253 patients. RESULTS: A strong correlation was found between wrist circumference and CSA (r = 0.61). Wrist circumference is the most important independent predictor for ULN (r2 = 0.37). We managed to simplify our newly derived regression equations, which turned out to be unrelated to age. Sensitivity of our new equations is low, but higher than a general fixed cut-off value (53.4% and 47.4%, respectively). DISCUSSION: Wrist circumference is the most important independent predicting factor of CSA. By using our updated equations and taking wrist circumference into account, one can determine a more precise ULN for each individual, which will lead to the improvement of the diagnostic accuracy of ultrasonography (US). Sensitivity for US in diagnosing CTS remains low and it can therefore not replace EDX.

Outcome after carpal tunnel release: effects of learning curve.

INTRODUCTION: In carpal tunnel release, it is yet unclear whether a learning curve exists among surgeons. The aim of our study was to investigate if outcome after carpal tunnel release is dependent on surgeon's experience and to get an impression of the learning curve for this procedure. METHODS: A total of 188 CTS patients underwent carpal tunnel release. Patients completed the Boston Carpal Tunnel Questionnaire at baseline and 6-8 months postoperatively together with a six-point scale for perceived improvement. RESULTS: Patients operated by an experienced resident or certified surgeon reported a favorable outcome more often than patients operated by an inexperienced resident (adjusted OR 3.23 and adjusted OR 3.16, respectively). In addition, a negative association was found between surgeon's years of experience and postoperative Symptom Severity Scale and Functional Status Scale scores. DISCUSSION: Outcome after carpal tunnel release seems to be dependent on surgical experience, and there is a learning curve in residents.

Long-term outcome after carpal tunnel release and identification of prognostic factors.

BACKGROUND: The effectiveness of the surgical treatment of carpal tunnel syndrome (CTS) is well known on short term. However, limited data is available about long-term outcome after carpal tunnel release (CTR). The aims of this study were to explore the long-term outcome after CTR and to identify prognostic factors for long-term outcome. METHODS: Patients with clinically defined CTS underwent CTR and completed the Boston Carpal Tunnel Questionnaire at baseline (T0), at about 8 months (T1), and after a median follow-up of 9 years (T2), as well as a 6-point scale for perceived improvement (at T1 and T2). Potentially prognostic factors were identified by logistic regression analysis and correlation. RESULTS: At long-term follow-up, 87 patients (40.3%) completed the questionnaires. Mean score on Symptom Severity Scale (2.87 to 1.54; p < 0.001) and Functional Status Scale (2.14 to 1.51; p < 0.001) improved at 8 months and did not change significantly after 8 months. A favorable outcome was reported in 81.6%. A good treatment outcome after 8 months and to a lesser extent a lower FSS score at T0 were associated with a better long-term outcome. CONCLUSIONS: CTR is a robust treatment for CTS and its effect persists after a period of 9 years. The most important factor associated with long-term outcome is treatment outcome after about 8 months and to a lesser extent functional complaints preoperatively. Outcome is independent of patient characteristics, electrodiagnostic test results, or findings at the initial neurological examination.

Wrist Circumference-Dependent Upper Limit of Normal for the Cross-Sectional Area Is Superior Over a Fixed Cut-Off Value in Confirming the Clinical Diagnosis of Carpal Tunnel Syndrome.

Introduction: In confirming the clinical diagnosis of carpal tunnel syndrome (CTS), ultrasonography (US) is the recommended first diagnostic test in The Netherlands. One of the most important parameters for an abnormal US result is an increase of the CSA of the median nerve at the carpal tunnel inlet. An earlier study showed that a wrist-circumference dependent cut-off for the upper limit of normal of this CSA might be superior to a fixed cut-off of 11 mm2. In this study we compared three ultrasonography (US) parameters in three large Dutch hospitals. Methods: Patients with a clinical suspicion of CTS and with reasonable exclusion of other causes of their symptoms were prospectively included. A total number of 175 patients were analysed. The primary goal was to compare the number of wrists with an abnormal US result while using a fixed cut-off of 11 mm2 (FC), a wrist circumference-dependent cut-off (y = 0.88 * x-4, where y = ULN and x = wrist circumference in centimetres; abbreviated as WDC), and an intraneural flow related cut-off (IFC). Results: The WDC considered more US examinations to be abnormal (55.4%) than the FC (50.3%) did, as well as the IFC (46.9%), with a statistically significant difference of p = 0.035 and p = 0.001, respectively. The WDC detected 12 abnormal median nerves while the FC did not, and 18 while the IFC did not. The wrist circumference of the patients of these subgroups turned out to be significantly smaller (p < 0.001) when compared with the rest of the group. Conclusion: According to these study results, the wrist-circumference dependent cut-off value for the CSA of the median nerve at the wrist appears to have a higher sensitivity than either a fixed cut-off value of 11 mm2 or cut-off values based on intraneural flow, and may add most value in patients with a smaller wrist circumference.

Patients' expectations of autologous hematopoietic stem cell transplantation as a treatment for MS.

BACKGROUND: Autologous hematopoietic stem cell transplantation (aHSCT) receives increasing attention as a treatment option for MS. However, as there are no randomized controlled trials comparing aHSCT to best medical treatment as yet, aHSCT is not generally advised and implemented as a treatment option for MS. Neurologists are increasingly faced with patients asking questions regarding aHSCT and seeking commercially offered aHSCT abroad. The aim of this study is to evaluate MS patients' knowledge and expectations of aHSCT and their actual and desired sources of information. METHODS: 137 MS patients visiting the Amsterdam University Medical Center MS clinic, completed a self-developed questionnaire with items on disease history, knowledge about aHSCT, expectations of aHSCT, information sources and the role they assign to their neurologists. RESULTS: Fifty-four percent is considering aHSCT either now or in the future, especially those who are dissatisfied with current treatment, have a shorter disease duration (≤ 10 years) or are more disabled (EDSS > 3.5). Only 25% report to have sufficient knowledge about aHSCT. Patients mainly use potentially unreliable information sources such as the internet and television, although they prefer information from their neurologist. Half of the patients think aHSCT to be superior to highly effective DMT. Expectations of efficacy in patients interested in aHSCT are significantly higher than in patients not wanting to undergo aHSCT. Only about one third of patients are able to mention at least one side effect. CONCLUSION: Many MS patients are considering aHSCT as a treatment option, although they think that they are not well-informed regarding aHSCT. They prefer their neurologist as a source of information. Therefore, neurologists should pro-actively inform their patients about the potential benefits and risks of aHSCT to enable them to choose the best treatment option.

Augmented Diagnostic Accuracy of Ultrasonography for Diagnosing Carpal Tunnel Syndrome Using an Optimised Wrist Circumference-Dependent Cross-Sectional Area Equation.

Introduction: In diagnosing carpal tunnel syndrome (CTS) there is no consensus about the upper limit of normal (ULN) of the cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet. A previous study showed wrist circumference is the most important independent predictor for the ULN. In this study we optimised a wrist circumference-dependent ULN equation for optimal diagnostic accuracy and compared it to the generally used fixed ULN of 11 mm2. Methods: CSA and wrist circumference were measured in a prospective cohort of 253 patients (clinically defined CTS) and 96 healthy controls. An equation for the ULN for CSA was developed by means of univariable regression analysis. We calculated z-scores for all patients and healthy controls, and analysed these scores in a ROC curve and a decision plot. Sensitivity and specificity were determined and compared to fixed ULN values. Results: We found augmented diagnostic accuracy of our newly developed equation y = 0.88 * x -4.0, where y = the ULN of the CSA and x = wrist circumference. This equation has a corresponding sensitivity and specificity of 75% compared to a sensitivity of 70% while using a fixed cut-off value of 11 mm2 (p = 0.015). Conclusion: Optimising the regression equation for wrist circumference-dependent ULN cross-sectional area of the median nerve at the wrist inlet might improve diagnostic accuracy of ultrasonography in patients with carpal tunnel syndrome and seems to be more accurate than using fixed cut-off values.

Validation of the Dutch Version of the Boston Carpal Tunnel Questionnaire.

The Boston Carpal Tunnel Questionnaire (BCTQ) is a scale that has been developed specifically for carpal tunnel syndrome (CTS). It consists of the Functional Status Scale (FSS) and the Symptom Severity Scale (SSS). It is the most widely used patient reported outcome measure in CTS and has been validated in many languages. Although already widely used, psychometric properties of the Dutch version of the BCTQ are yet unknown. The aim of this study was to assess the validity, reliability, responsiveness, and acceptability of the Dutch version. Moreover, this paper focuses the longitudinal validity (the use after an intervention) of the BCTQ, which has not been investigated before. A total of 180 patients completed the BCTQ in addition to a six-point Likert scale for perceived improvement, before and about 6-8 months after carpal tunnel release (CTR). Principal factor analysis revealed that the FSS is unidimensional, consisting of a single latent factor ("functionality") and has a high internal consistency (Cronbach's α = 0.825). However, the SSS has three dimensions, which are all highly internally consistent: "daytime symptoms" (Cronbach's α = 0.805), "nighttime symptoms" (Cronbach's α = 0.835), and "operational capacity" (Cronbach's α = 0.723). Post-treatment, the FSS still consisted of one factor, but the SSS changed in dimensionality, as it had only two factors left post-treatment. The ΔFSS and ΔSSS had good correlation with the six-point Likert scale for perceived improvement (r = 0.524; p < 0.01 and r = 0.574; p < 0.01, respectively), a moderate correlation between FSS and pinch grip (r = 0.259; p < 0.01) was found, and a weak correlation between SSS and pinch grip (r = 0.231; p < 0.01) was found. Standard Response Mean for FSS and SSS was 0.76 and 1.49, respectively. Effect size was 0.92 and 1.96, respectively, both indicating a good responsiveness. Response rate was high (82-84%). We concluded that the Dutch version of the BCTQ has a proper reliability, validity, responsiveness, and acceptability to assess the symptom severity and functional disabilities of CTS patients. Because of multidimensionality, we would recommend to create sum scores of the four different dimensions instead of two. Caution is required when interpreting the results postoperatively, due to the insufficient longitudinal validity of the SSS.

Minimal clinically important difference for the Boston Carpal Tunnel Questionnaire: new insights and review of literature.

No consensus exists about the minimal clinically important difference for the Boston Carpal Tunnel Questionnaire, which hampers its clinical application. This study assessed the minimal clinically important difference of this questionnaire. The Boston Carpal Tunnel Questionnaire was completed by 180 patients, with clinically defined carpal tunnel syndrome, preoperatively and at about 8 months follow-up after carpal tunnel release, together with a six-point scale for perceived improvement. Receiver operator characteristics curves showed that relative changes in Symptom Severity Scale and Functional Status Scale scores correspond better to a clinically relevant improvement than absolute changes. The minimal clinically important difference should be individually calculated from baseline Symptom Severity Scale and Functional Status Scale scores, as patients experiencing more symptoms require more improvement to notice a clinically important difference. By taking this into account, the Boston Carpal Tunnel Questionnaire is more meaningful as an outcome measure in research and clinical practice.

Treatment outcome in patients with clinically defined carpal tunnel syndrome but normal electrodiagnostic test results: a randomized controlled trial.

Little is known about treatment effect of carpal tunnel release in patients with clinically defined carpal tunnel syndrome (CTS), but normal electrodiagnostic test results (EDX). The aim of this study was to determine whether this category of patients will benefit from surgical treatment. 57 patients with clinically defined CTS and normal EDX were randomized for surgical treatment (n = 39) or non-surgical treatment (n = 18). A six-point scale for perceived improvement as well as the Boston Carpal Tunnel Questionnaire was completed at baseline and at follow-up after 6 months. A significant improvement of complaints was reported by 70.0% of the surgically treated patients and 39.4% reported full recovery 6 months after surgery. Furthermore, both Functional Status Score and Symptom Severity Score improved significantly more in the surgically treated group (p = 0.036 and p < 0.001, respectively). This study demonstrates that most patients with clinically defined CTS and normal EDX results will benefit from carpal tunnel release. Therefore, this group of CTS patients must not a priori be refrained from surgery.

Negative Myoclonus Induced by Ciprofloxacin.

BACKGROUND: Negative myoclonus is characterized by a brief sudden loss of muscle activity, and can be caused by a variety of acquired factors and epilepsy syndromes. PHENOMENOLOGY SHOWN: We show a clear video example of a patient with an extensive negative myoclonus that was induced by ciprofloxacin. EDUCATIONAL VALUE: Several neurotoxic effects have been associated with the use of ciprofloxacin, but negative myoclonus has not been reported previously.

Anterior opercular syndrome as a first presentation of herpes simplex encephalitis.

We report a 5-year-old girl who presented with fever, drooling, dysphagia, and anarthria. Moreover, voluntary facial movements were disturbed, but the emotional facial movements were completely normal. This clinical phenomenon is known as the anterior opercular syndrome. There was a positive polymerase chain reaction for herpes simplex in the cerebrospinal fluid. The diagnosis herpes simplex encephalitis was supported by both magnetic resonance images (MRI) as by electroencephalogram (EEG). Herpes simplex encephalitis is a rare, but severe, cause of the anterior opercular syndrome that demands treatment as soon as possible in order to prevent high morbidity or mortality. The phenomenon of autonomic-voluntary dissociation, associated with other clinical and radiologic findings related to an underlying neurologic disorder, alerts clinicians to the anterior opercular syndrome as a critical diagnostic observation with time-dependent therapeutic consequences.