Ring finger sensory latency difference in the diagnosis and treatment of carpal tunnel syndrome

Objective To explore the sensitivity of median and ulnar nerve sensory latency differences in diagnosing carpal tunnel syndrome (CTS) at different severities. Methods CTS patients were divided into three groups based on disease severity (mild, moderate, and severe). Distal latency of sensory nerve action potential (SNAP) for the median and ulnar nerves was recorded. The sensitivity of SNAP distal latency to CTS and its correlation with CTS severity were analyzed. Results Significant differences were found in the median nerve sensory action potential distal latency (MSDL) and in the median and ulnar sensory latency difference to ring finger (MUD) but not in the ulnar nerve sensory action potential distal latency (USDL) between CTS and control. The sensitivity and specificity were 92.2 and 99.4% with an MSDL cutoff value of 2.40 ms, respectively, and were both 100% with a MUD cutoff value of 0.33 ms. There was no significant difference in USDL among the CTS and control groups. Significant differences were found in MSDL and MUD among the CTS severities and between mild and moderate CTS, but not between mild and severe CTS or between moderate and severe CTS. Correlations with CTS severity were observed for MSDL and MUD but not for USDL. Conclusion The ulnar nerve of the CTS patients was not damaged. A smaller MSDL reflected median nerve damage, which can be used for the early diagnosis of CTS. MUD correlated with CTS severity with a higher sensitivity than MSDL, which can provide therapeutic insight without pain to patients.

Ring Finger Sensory Latency Difference in the Diagnosis and Treatment of Carpal Tunnel Syndrome

Objective: To explore the evaluation value of the sensitivity of the median/ulnar nerve sensory latency difference in the diagnosis of carpal tunnel syndrome and the evaluation value of severity.Methods: 122 patients with CTS and 42 normal controls were collected from the department of Neurology in Renmin Hospital of Wuhan University from July 2019 to January 2021. Electrophysiological tests were performed on the CTS patients group and the control group. The distal latency of the sensory nerve action potential (SNAP) of the median nerve and the ulnar nerve of the two groups was recorded. According to electrophysiological results，the patients were divided into three grades: mild, moderate and severe, the sensitivity of the nerve sensory action potential distal latency (SDL) to the diagnosis of CTS patients were analyzed, and the relationship with the severity of CTS was analyzed.Results: ①There were significant differences between the median nerve sensory action potential distal latency (MSDL) of 179 affected hands and the control group; And median and ulnar sensory latency difference to ring finger (MUD) was significantly different from the control group; But ulnar nerve sensory action potential distal latency （USDL） was not significantly different from the control group (P=0.182). When the cutoff value of MSDL is 2.465ms, the sensitivity is 85.5% and the specificity is 90.4%; when the cutoff value of MUD is 0.38ms, the sensitivity is 100% and the specificity is 100%. ②In the mild, moderate, severe and control group, there was no significant difference in USDL between all the groups (P=0.56)a; between the control group and the mild group, moderate group, and severe group, and between the mild and moderate, significant differences were found in the MSDL and MUD. No significant difference between mild and severe (P=0.66), moderate and severe (P=1.00). ③ MSDL and MUD are correlated with the severity of CTS. There is no correlation between USDL and CTS severity.Conclusion: The ulnar nerve is not damaged in CTS; a smaller MSDL can reflect median nerve damage, which is beneficial to the early diagnosis of CTS; MUD is more sensitive than MSDL in diagnosing CTS; MUD is correlated with severity, which is beneficial to pain for patients who are more sensitive and cannot tolerate electrical stimulation, perhaps only measuring MUD can reflect the severity, relieve the patient's pain, and can be used to evaluate the therapeutic effect.

A Prediction-Based Model for Consistent Adaptive Routing in Back-Bone Networks at Extreme Situations

To reduce congestion, numerous routing solutions have been proposed for backbone networks, but how to select paths that stay consistently optimal for a long time in extremely congested situations, avoiding the unnecessary path reroutings, has not yet been investigated much. To solve that issue, a model that can measure the consistency of path latency difference is needed. In this paper, we make a humble step towards a consistent differential path latency model and by predicting base on that model, a metric Path Swap Indicator (PSI) is proposed. By learning the history latency of all optional paths, PSI is able to predict the onset of an obvious and steady channel deterioration and make the decision to switch paths. The effect of PSI is evaluated from the following aspects: (1) the consistency of the path selected, by measuring the time interval between PSI changes; (2) the accuracy of the channel congestion situation prediction; and (3) the improvement of the congestion situation. Experiments were carried out on a testbed using real-life Abilene traffic datasets collected at different times and locations. Results show that the proposed PSI can stay consistent for over 1000 s on average, and more than 3000 s at the longest in our experiment, while at the same time achieving a congestion situation improvement of more than 300% on average, and more than 200% at the least. It is evident that the proposed PSI metric is able to provide a consistent channel congestion prediction with satisfiable channel improvement at the same time. The results also demonstrate how different parameter values impact the result, both in terms of prediction consistency and the congestion improvement.

Assessment of cervical and ocular vestibular evoked myogenic potentials in migraine patients

Background Patients suffering from vestibular migraine (VM) are known to have various vestibular test abnormalities interictally and ictally. Recently, vestibular evoked myogenic potentials (VEMPs) have become accepted as a valid method for otolith function assessment. Many studies have identified various vestibular symptoms and laboratory abnormalities in migraineurs. Since migraineurs with no accompanying vestibular symptoms might exhibit subclinical vestibular dysfunction, we investigated vestibular function using ocular and cervical VEMPs in migraine patients. The aim was to study cervical VEMP and occular VEMP in migraineurs with and without vestibular symptoms interictally. Results Migraine and VM patients showed significantly longer P13 latency of cVEMP compared to controls. A statistically significant cVEMP interaural P13 latency difference was found in VM compared to healthy controls. Cervical VEMP N23 latency, peak-to-peak amplitude, interaural N23 latency, and amplitude asymmetric ratio did not show any significant difference in migraine and VM patients compared to healthy controls as well as no significant difference across the three groups regarding oVEMP parameters. Conclusions Abnormal interictal cVEMP results in migraineurs might indicate subclinical vestibulo-collic pathway dysfunction.

Scale Invariant Contrasts of Response Latency Distributions

Individual differences in general speed lead to a positive correlation between the mean and standard deviation of mean latency. This “coarse” scaling effect causes the mean latency difference (MLD) to be spuriously correlated with general speed. Within individuals, the correlation between the mean and standard deviation of trial latencies leads contrasted distributions to increase their overlap as an MLD of fixed width is translated to the right. To address this “fine” scaling effect, contrasts based on within subject latency transformations including the logarithm, standardization, and ranking were evaluated and turned out to be distinctly superior to the MLD. Notably, the mean gaussian rank latency difference was internally consistent, eliminated fine scaling, meliorated coarse scaling, reduced correlations with general speed, increased statistical power to detect within subject and between group effects, and has the potential to increase the validity of inferences drawn from response latency data.

Clinical Evaluation and Diagnostic Utilities of Different Nerve Conduction Tests in 100 Patients with Carpal Tunnel Syndrome

ABSTRACT Background and Purpose: The purpose of the study is to determine whether the clinical profile of patients with carpal tunnel syndrome (CTS) has been same over the years with the help of routine and comparative electrodiagnostic tests. Methods: A prospective study of 100 patients with suspected CTS was conducted without controls. Three provocative maneuvers were performed. Routine and comparison nerve conduction tests were performed, i.e., second lumbrical interossei motor latency difference (2 LIMLD), digit 4 median-ulnar sensory latency difference (D4MUSLD), palm wrist distal sensory latency difference (PWDSLD), and digit 1 median-radial sensory latency difference (D1MRSLD). Data entry, analysis, and statistical evaluation were done using International Business Machines Corporation Statistical Package for the Social Sciences statistics package (IBM, SPSS). Results: A total of 195 hands of 100 patients met the criteria for CTS. Forty-three percentage of patients were homemakers. Considering the rapidly changing communication technology, we observed 84% patients had aggravation of symptoms with continuous long-term daily mobile phone use (>30 min per session per day). We noted positive Tinel's sign in only 25%. Phalen's sign was positive in 53 right hands with mean duration of 11.49s (standard deviation [SD] ± 2.54 s) and was positive in 26 left hands with mean being 10.4 s (SD ± 1.91 s). The mean motor distal latency of median was 4.67 ms (SD ± 1.71 ms) and mean sensory distal latency of median was 3.24 ms (SD ± 1 ms). On internal comparison testing, mean difference in 2 LIMLD was 0.7 ± 0.3 ms, in D4MUSLD was 0.81 ± 0.32, in PWDSLD was 0.71 ± 0.20, and in D1MRSLD was 0.76 ± 0.32. Conclusion: Further analysis of clinical profile needs to be done, and new risk or provoking factors should be analyzed in patients with CTS.