Electrodiagnosis Of Carpal Tunnel Syndrome Research Articles

How Does Nerve Mechanical Interface Treatment Impact Pre-Surgical Carpal Tunnel Syndrome Patients? A Randomized Controlled Trial

Background: Carpal tunnel syndrome (CTS) presents a high burden on the healthcare system. However, no alternative treatments are provided during the waiting period. In addition, the incidence of severe patients with comorbidities is underestimated. The aim of this study was to determine whether nerve mechanical interface treatment improves the symptoms, function, and quality of life in pre-surgical CTS patients. Methods: A randomized controlled trial and intention-to-treat analysis were carried out. Forty-two patients with an electrodiagnosis of carpal tunnel syndrome, included on the surgery waiting list of a public healthcare system, were analyzed. The intervention group (n = 20) received a 45 min session/per week of instrument-assisted manual therapy (diacutaneous fibrolysis) for 3 weeks. The Boston Carpal Tunnel Questionnaire (BCTQ) was the primary outcome. The symptoms, mechanical threshold, grip strength, mechanosensitivity of the median nerve, quality of life, and patient satisfaction were included as secondary outcomes. The control group (n = 22) remained on the waiting list. Results: The intervention seems to be beneficial for the BCTQ score (function and symptoms scale), pain, and mechanosensitivity after treatment, at the 3 and 6 months follow-up (p < 0.05). Kinesiophobia was improved at 6 months (p = 0.043; η2 = 0.10) and the mechanical threshold at the 3-month follow-up (p = 0.048; η2 = 0.10). No differences were identified for grip strength. At 6 months, the intervention group patients were satisfied (100%), as opposed to the controls, who felt that they had experienced a worsening of their condition (50.1%). Conclusions: Nerve mechanical interface treatment improved the symptoms, function, and quality of life in pre-surgical CTS patients. One hundred percent of the treated patients, characterized as moderate and severe CTS with associated comorbidities, were satisfied.

Median to ulnar nerve comparison on diagnosis of carpal tunnel syndrome in patients with diabetic polyneuropathy - A neurophysiological study.

<p style="text-align: justify;"><strong>Background and purpose </strong>&ndash; To analyze the utility of median nerve (MN) to ulnar nerve (UN) comparative parameters on the diagnosis of carpal tunnel syndrome (CTS) in diabetic patients with distal symmetrical sensorimotor polyneuropathy (DSMPNP). <br><br><strong>Methods</strong> &ndash; Patients who were referred to our electroneuromyography laboratory within the last two years were included. We compared the diagnostic accuracy values of traditional MN conduction parameters, and the MN-to-UN comparative tests on electrodiagnosis of CTS between the patients with DSMPNP involving the nerves of upper and lower extremities (UEI-positive group), and the ones without the involvement of upper extremities (UEI-negative group). <br><br><strong>Results</strong> &ndash; There were 64 upper extremities in the UEI-positive group and 70 patients in the UEI-negative group. The most accurate traditional parameter was MN distal motor latency (DML) with a diagnostic accuracy of 70.2% whereas the most accurate comparative technique was the second lumbricalinterosseous DML difference (2L-INT DMLD) with an accuracy of 81.3%. (p=0.03). In addition, when compared diagnostic accuracy values of MN parameters with their corresponding comparative parameters in the UEI-positive group which carries the major diagnostic challenges for detecting co-morbid CTS, MN to UN minimum F wave latency (mFWL) difference, SNAP amplitude ratio on the ring finger (RF), and 2L-INT DMLD had higher accuracy values than MN mFWL, MN SNAP amplitude on RF, and MN DML on lumbrical muscle, respectively (p&lt;0.05 for all comparisons). <br><br><strong>Conclusion</strong> &ndash; MN to UN comparative studies have high accuracy values in electrodiagnosis of CTS in DSMPNP. In particular, 2L-INT DMLD could be helpful to overcome the diagnostic difficulty in the presence of UEI as an additional conduction technique.</p>.

Comparison of second lumbrical interosseous median and ulnar motor conduction study in population of subjects with idiopathic carpal tunnel syndrome and non-CTS hands-a cross-sectional study

Background: Second lumbrical interosseous (2L-I) median-ulnar motor conduction study across wrist is pivotal in electrodiagnosis of carpal tunnel syndrome (CTS) in different grades of severity. 2L-I Median versus ulnar distal motor latency (DML) difference more than 0.5 milliseconds is used to diagnose median neuropathy at wrist. Other variables of study, namely, 2L DML, compound muscle action potential (CMAP) amplitude, CMAP duration, and conduction velocity (CV) remain less explored with few studies pressing for its role to substantiate CTS diagnosis. Aims and Objectives: Current cross-sectional study aimed to explore role of 2L-I DML, amplitude, duration, and CV in diagnosis of median neuropathy at wrist. Materials and Methods: Total 70, 37 clinically suspected CTS hands and 33 age, height, and weight matched non-CTS hands underwent 2L-I Median Ulnar motor conduction study. Results: Statistically significant difference (P &lt; 0.05) in 2L median DML, CMAP amplitude, duration and CV between CTS and non-CTS hands along with 2L-I Median versus Ulnar DML difference. 2L DML and 2L-I DML difference variables showed better specificity and sensitivity: 83.78 and 93.91, respectively, in diagnosing CTS. Conclusion: We concluded that apart from 2L-I DML difference other variables such as DML, amplitude, duration, and CV may also play substantial role in evaluation of CTS and may be included as part of electrodiagnostic protocol.

Automatic Electrodiagnosis of Carpal Tunnel Syndrome Using Machine Learning.

Recent literature has revealed a long discussion about the importance and necessity of nerve conduction studies in carpal tunnel syndrome management. The purpose of this study was to investigate the possibility of automatic detection, based on electrodiagnostic features, for the median nerve mononeuropathy and decision making about carpal tunnel syndrome. The study included 38 volunteers, examined prospectively. The purpose was to investigate the possibility of automatically detecting the median nerve mononeuropathy based on common electrodiagnostic criteria, used in everyday clinical practice, as well as new features selected based on physiology and mathematics. Machine learning techniques were used to combine the examined characteristics for a stable and accurate diagnosis. Automatic electrodiagnosis reached an accuracy of 95% compared to the standard neurophysiological diagnosis of the physicians with nerve conduction studies and 89% compared to the clinical diagnosis. The results show that the automatic detection of carpal tunnel syndrome is possible and can be employed in decision making, excluding human error. It is also shown that the novel features investigated can be used for the detection of the syndrome, complementary to the commonly used ones, increasing the accuracy of the method.

Quality measures in electrodiagnosis: Carpal tunnel syndrome-An AANEM Quality Measure Set.

Carpal tunnel syndrome (CTS) is a common neuromuscular condition and a major cause of work-related disability. As healthcare in the United States transitions toward a value-based system from fee-for-service, quality measures assume importance in the evaluation of care provided. This report from the American Association of Neuromuscular & Electrodiagnostic Medicine Quality Improvement Committee provides an introduction to quality measures and outlines a quality measurement set for the electrodiagnosis of CTS. The measures attempt to standardize technical requirements for electrodiagnostic (EDX) studies of CTS, the criteria for diagnosing median neuropathy at the wrist and assessing its severity, and the role of operative EDX testing. The assumption is that implementation of these measures will improve the accuracy of CTS diagnosis when EDX is performed, help exclude mimics, and, therefore, improve care of patients with CTS with the ultimate goal of improving outcomes. Postimplementation assessment of outcomes will refine these measures.

Evaluation of peak or onset latency in the median-versus-ulnar digit four sensory comparison study for diagnosing carpal tunnel syndrome

Aim: Peak or onset latency difference of the median and ulnar nerves can be used in the median-versus-ulnar digit 4 sensory comparison study (MUD4CS) for electrodiagnosis of carpal tunnel syndrome (CTS). This study aimed to investigate the differences in results while using peak or onset latency difference.Material and Methods: The hands of patients with clinical CTS diagnosis but normal median nerve conduction study (NCS) results were included retrospectively in this study. NCSs of the median and ulnar nerves with onset and peak latencies in MUD4CS were recorded. Onset and peak latency differences of the two nerves and also peak-onset latency difference of the median nerve in MUD4CS were calculated. The hands were divided into two groups according to MUD4CS findings: abnormal and normal. The hands in the abnormal group were also divided into peak and onset subgroups.Results: A total of 277 hands were included in this study. Abnormal MUD4CS results were observed in 103 hands; 77 hands based on onset latency difference, and in 76 hands based on peak latency difference. Median sensory conduction velocity was slower and amplitude was smaller in the abnormal group than in the normal group (p=0.003, p=0.027 respectively). Median peak-onset latency difference was significantly greater in the peak subgroup than in the onset subgroup (p=0.0001).Conclusion: It may be more useful to measure both peak and onset latency differences when diagnosing CTS because some cases may be overlooked by using a single latency difference.

Ring finger sensorial conduction studies in grading carpal tunnel syndrome: Part II.

Comparison of sensory conduction of median nerve (MN) with the one of ulnar nerve (UN) over writs-to-ring finger (RF) segment is useful in electrodiagnosis of carpal tunnel syndrome (CTS). However, there is not any consensus regarding the usage of this technique in grading of CTS. To determine whether the hands of CTS with elicitable MN sensory responses on index finger, but not on RF (non-respondings) compose a more severe electrophysiologic grade than the hands with elicitable responses on both fingers (respondings). The patients with bilateral moderate grade of CTS in whom one hand was responding and the contralateral hand was non-responding were included. Conduction study results of MN and UN were compared between respondings and non-respondings. A total of 19 patients were included. Mean distal sensory onset latency (DSOL) of MN over index finger was longer (4.26 ± 0.49 msec versus 3.44 ± 0.39 msec; p< 0.001), sensory conduction velocity (SCV) was slower (33.7 ± 4.3 m/sec versus 40.2 ± 3.0 m/sec; p< 0.001), SNAP amplitude was smaller (10.3 ± 3.3 μV versus 19.1 ± 7.7 μV; p< 0.001), distal motor latency was longer (5.69 ± 0.60 msec versus 4.63 ± 0.32 msec; p< 0.001), and minimum F wave latency was longer (29.3 ± 1.7 msec versus 26.8 ± 1.4 msec; p< 0.001) in non-respondings than respondings. The nonresponding hand had a longer MN DSOL and slower SCV on index finger compared with contralateral responding hand in all of 19 patients. Non-responding hands have more progressed median neuropathies, and represent a more severe electrophysiologic grade than responding hands. Further studies are warranted to determine whether the absence of MN sensory responses on ring finger is related with forthcoming NCS worsening and a preferable hallmark for deciding surgical intervention or not.

Does electrodiagnostic evidence correlate with mood and function in patients with a pre-diagnosis of carpal tunnel syndrome?

This study aims to investigate if function and mood involvement correlate in female patients who have a pre-diagnosis of carpal tunnel syndrome (CTS) and its correlation with physical examination and electrodiagnostic findings. A total of 170 patients between the ages of 18-65 who applied to Physical Medicine and Rehabilitation outpatient clinics with CTS symptoms between May 2014 and December 2015 were enrolled. The mean age of patients was 44.6±11 years. Before electrophysiological testing (electromyography; EMG), Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH), Beck Depression Inventory, Tinnel, Phalen and Durkan tests, grip and pinch strength measurement by JAMAR hand dynamometer were performed. The patients also used a Visual Analog Scale (VAS) to determine the severity of their symptoms during the day and at night. In 98 patients (57.6%) the diagnosis of CTS was confirmed by EMG, while 72 patients (42.4%) had normal electrodiagnostic findings. In patients who had normal EMG, Beck Depression Inventory and QuickDASH scores were not significantly different from the patients who had an electrodiagnosis of CTS. Pain experienced in the night was significantly higher in patients who had an electrodiagnosis of CTS, and these patients had significantly higher Beck Depression Inventory and QuickDASH scores. The lack of electrodiagnostic evidence in patients who have CTS symptoms does not show that function and mood are not affected in these patients. However, mood is significantly affected in patients with severe CTS.

Characteristics of nerve conduction studies in carpal tunnel syndrome

Nerve conduction studies are used for the electrodiagnosis of carpal tunnel syndrome (CTS), with a wide range of sensitivityand specificity reported for each tests in clinical studies. The aim of this study was to compare the diagnostic accuracy ofvarious nerve conduction tests and determine the properties of the most accurate test. Forty patients with clinically confirmedCTS and 40 healthy controls were included in the study. All patients and controls underwent various nerve conduction studyprotocols for CTS. The mean age was 53±11.6 years and the female to male ratio was 2:1. The mean duration of disease was1.25±0.61 years. The median nerve motor latency was 4.35±0.63ms while the sensory latency was 3.47±0.58ms. The mediannerve orthodromic sensory latency was found to be 2.51±0.32 ms. The conduction velocity across the palm and wrist was28.7 m/s. The sensitivity was the highest in the inching method (89.6%) and lowest for the conventional median motor andsensory latencies. Addition of a single test of median and ulnar sensory latency, the median and radial sensory latency or theinching method, in routine protocol will improve the sensitivity for the diagnosis of CTS in all patients.

Does the comparison of median-to-ulnar nerve sensory conduction add an additional value in electrodiagnosis of carpal tunnel syndrome?

Distal sensory onset latency (DSOL), conduction velocity (SCV) and nerve action potential (SNAP) amplitudes are used in electrodiagnosis of carpal tunnel syndrome (CTS) beside motor conduction data. The aim of our study is to search whether the comparison of median-to-ulnar nerve sensory conduction adds an additional diagnostic value in CTS or not. Median and ulnar nerve were stimulated on wrist, and SNAPs were recorded on second and fifth fingers, respectively. Best cut-off points for the searched parameters and their diagnostic efficiencies were determined. The cut off points were also stratified according to the age and gender, and their diagnostic efficiencies were calculated again. The study includes 415 hands belong to 344 subjects. Best cut off points for median nerve DSOL and SCV were 2.7 msec and 49.0 m/sec with the diagnostic efficiencies of 87.7% and 88.7%, respectively. Best cut off points for DSOL difference and SCV difference were 0.62 msec and 4.0 m/sec, and efficiencies were 89.6% and 84.3%, respectively. Determining the relative elongation of median nerve DSOL to the ulnar nerve one has a little additional value in electrodiagnosis of CTS, whereas any additional value is not obtained from SCV comparison.

Characteristics of nerve conduction studies in carpal tunnel syndrome.

Numerous nerve conduction tests are used for the electrodiagnosis of carpal tunnel syndrome (CTS), with a wide range of sensitivity and specificity reported for each test in clinical studies. The purpose of this study was to compare the diagnostic accuracy of various nerve conduction tests and determine the properties of the most accurate test. A prospective observational case control study. Eighty patients with clinically confirmed CTS and 80 asymptomatic healthy controls were included in the study. All patients underwent the routine hematological investigations as per the protocol. All cases and controls were subjected to various nerve conduction study protocols for CTS. Results were analyzed statistically. The two-tailed Student's t-test was used for the comparative statistical analysis. The sensitivity of each test was calculated as (the number of hands with an abnormal study result/the number of CTS hands) × 100. Comparison between percentages was performed by the McNemar test. The mean age was 38.19 ± 10.13 years and the female:male ratio was 1.5:1. The mean duration of disease was 0.89 ± 0.61 years. Hypothyroidism was present in 21 (26.25%) patients, whereas 13 (16.25%) and 4 (5%) patients had diabetes mellitus and rheumatoid arthritis, respectively. The median nerve motor latency was 4.73 ± 0.83 ms while the sensory latency was 3.44 ± 0.56 ms. The median nerve orthodomic sensory latency was found to be 2.57 ± 0.31 ms. The conduction velocity across the palm and wrist was 41.37 ± 0.67 ms. The sensitivity was the highest in the inching method (86.25%) and lowest for the conventional median motor and sensory latencies (56.25% and 45%, respectively). Addition of a single test of median and ulnar sensory latency, the median and radial sensory latency or the inching method, in routine protocol will improve the sensitivity for the diagnosis of CTS in all patients.

Value of F-wave studies on the electrodiagnosis of carpal tunnel syndrome

BackgroundF waves are late electrophysiological responses to antidromic activation of motor neurons and are used to evaluate the conduction along the whole length of peripheral nerves. We aimed to determine the diagnostic efficacies of minimum median nerve F-wave latency (FWL) and median-to-ulnar nerve F-wave latency difference (FWLD) on carpal tunnel syndrome (CTS).Materials and methodsThe electrophysiological studies consisted of sensory and motor nerve conduction and F-wave studies of the median and ulnar nerves. The best cut-off points of minimum median nerve FWL and FWLD for the diagnosis of CTS were detected for the whole study group and for different height subgroups (Group 1: 150–159 cm, Group 2: 160–169 cm, and Group 3: over 170 cm). The diagnostic efficacies of minimum median nerve FWL and FWLD were calculated for the whole CTS group and for the mild CTS group, separately.ResultsThe best cut-off point of minimum median nerve FWL on the diagnosis of CTS was determined as 24.60 ms for the whole group. It was 23.90 ms for Group 1, 24.80 ms for Group 2, and 28.40 ms for Group 3. The usage of these stratified cut-off points yielded a higher total diagnostic efficacy rate than single cut-off point usage (79.9% vs 69%, respectively; P=0.02). The best cut-off point of FWLD on the diagnosis of CTS was 0.80 ms for the whole group. It was 0.55 ms for Group 1, 0.30 ms for Group 2, and 0.85 ms for Group 3. Both the single cutoff point usage and the stratified chart usage for FWLD had equal diagnostic efficacy (85.1%). In the mild CTS group, diagnostic efficacy was 55.5% for minimum median nerve FWL and 78.8% for FWLD (P=0.0001).ConclusionMedian-to-ulnar nerve FWLD yields a higher diagnostic efficacy than minimum median nerve FWL on the diagnosis of CTS. However, the sensitivities of both parameters are not satisfactory for the extremities with mild CTS, which compose the main group having diagnostic challenge.

Low sensitivity of F-wave in the electrodiagnosis of carpal tunnel syndrome

ObjectivePrevious studies showed “F-wave inversion” (F-INV) as a sensitive method in the electrodiagnosis of early stage of carpal tunnel syndrome (CTS). This study aimed at evaluating the sensitivity and specificity of F-wave and nerve conduction velocity (NCV) testing in CTS. MethodsWe consecutively enrolled 244 cases and 108 controls. F-waves analysis included: Fwave minimum and mean latencies, F-wave persistence and chronodispersion, mean-F/CMAP amplitude ratio, F-INV. Specificity and sensitivity of F-waves parameters were calculated in the whole sample of CTS patients and by grouping the patients according to CTS severity. Multivariate logistic regression was also performed using F-INV as a dependent variable. ResultsIn the whole sample the sensitivity of F-mean-INV and of median–ulnar NCV comparative testing was 50.8% and 93.7%, respectively. F-INV sensitivity dropped to 8% in CTS early stage. F-INV could be predicted only by distal motor latency of the median nerve. The sensitivity of all F-wave parameters increased only in the most severe stages of CTS. ConclusionsThis study does not confirm the electrodiagnostic usefulness of F-INV in early stage of CTS. All F-wave parameters, including F-INV, are much less sensitive than conventional NCV in CTS electrodiagnosis. F-wave does not add further useful information specifically related to CTS.

P981: Electrodiagnosis in carpal tunnel syndrome, contribution of nerve conduction study of the first digit median nerve

P981: Electrodiagnosis in carpal tunnel syndrome, contribution of nerve conduction study of the first digit median nerve

Carpal Tunnel Syndrome’s Laboratory Testing:Current Practice in an Academic Center in Western Saudi Arabia

There is no consensus to obtain screening blood tests after carpal tunnel syndrome electro-diagnosis, nor does medical literature provide a clear cut indication. A retrospective review of 140 consecutive adult patients diagnosed with carpal tunnel syndrome between January and December 2010, at King Abdulaziz University Hospital electrophysiology laboratory, looking at screening blood tests ordered by their various practitioners to diagnose commonly associated clinical conditions with carpal tunnel syndrome, namely: Diabetes mellitus , hypothyroidism and connective tissue diseases. Around one third of patients had screening for diabetes mellitus with one or more of the following: fasting blood glucose, random blood glucose, two hours glucose testing or glycated hemoglobin. All patients who were found to have abnormal glucose values were known diabetics. Thyroid stimulating hormone was obtained in 42 (30%) patients, only 4 patients showed abnormal values, two of them were known to have hypothyroidism on treatment, the other two patients showed a normal free thyroxine values. Erythrocyte sedimentation rate, C-reactive protein, antinuclear antibodies and rheumatoid factor were requested in a negligible number of patients and were within normal limits. Screening for clinical conditions associated with carpal tunnel syndrome in this series yielded no new cases.

Electrodiagnosis of carpal tunnel syndrome in patients with diabetic polyneuropathy

Objective Diagnosis of carpal tunnel syndrome (CTS) is difficult in patients with diabetic polyneuropathy as both conditions may affect median nerve conduction in a similar manner. There is no agreement about which electrodiagnostic tests are more efficient in determining CTS accurately in these patients. In this study, we aimed to define the best electrodiagnostic test in the diagnosis of CTS in diabetic polyneuropathy patients. Methods We prospectively investigated 72 patients with CTS (140 hands), 32 patients with diabetic polyneuropathy without CTS (61 hands), 35 patients with diabetic polyneuropathy with CTS (62 hands) and 43 healthy controls (86 hands). Standard nerve conduction studies, segmental and comparative median nerve conduction tests were performed in all subjects. Cut-off values, sensitivities and specificities of each test for the diagnosis of CTS in diabetic polyneuropathy patients were determined by using receiver operating characteristic (ROC) curve. Results Distoproximal latency ratio (DPLR) with a sensitivity of 90% and specificity of 81% for the cut-off value of 1 and median and ulnar sensory latency difference to digit 4 (MUDD4) with a sensitivity of 90% and specificity of 85% for the cut-off value of 0.35 showed the highest sensitivity and specificity in the diagnosis of CTS in diabetic polyneuropathy patients among all nerve conduction tests. Wrist–palm median sensory conduction velocity (W–P SCV) and median and radial sensory latency difference to digit 1 (MRDD1) also showed high sensitivity and specificity. Conclusions Segmental median nerve conduction studies like DPLR and W–P SCV and sensory comparative tests such as MUDD4 and MRDD1 in combination with standard nerve conduction tests should result in more accurate diagnosis of CTS in diabetic polyneuropathy patients. Significance These results could be helpful to overcome the diagnostic difficulty of CTS in patients with diabetic polyneuropathy.

How to Make Electrodiagnosis of Carpal Tunnel Syndrome With Normal Distal Conductions?

The purpose of this study is to investigate which electrodiagnostic techniques are better in clinically diagnosed patients with carpal tunnel syndrome (CTS) and patients with CTS with normal distal conduction study. A total of 230 clinically diagnosed patients with CTS and 100 normal control subjects were enrolled. All subjects were evaluated by eight electrodiagnostic techniques, including conventional conduction studies: median distal sensory latency and distal motor latency; short distance conduction studies across wrist, including wrist-palm sensory conduction time and wrist-palm motor conduction velocity; comparison of median sensory conduction across the wrist with radial or ulnar nerves in the same limb (median-radial sensory latency difference [M-R] or median-ulnar sensory latency difference [M-U]); and comparison of median wrist-palm and palm-index conduction, including distoproximal conduction time difference and distoproximal conduction time ratio. Normal limits were derived by calculating the mean ± 2 standard deviations from the data of the controls. The sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve with 95% confidence interval of each test were calculated. In clinically diagnosed patients with CTS, M-R is the best diagnostic technique with significant difference in area under the receiver operating characteristic curve (0.912) compared with other tests except that of M-U. The sensitivity, specificity, positive predictive value, and negative predictive value of M-R were 84.3%, 98%, 99%, and 73.1%, respectively. Further evaluation of patients with CTS with normal distal latencies also revealed the best diagnostic value of M-R and M-U with significance to other tests in area under the receiver operating characteristic curve. In clinical practice, after conventional median distal sensory latency and distal motor latency studies, the authors suggest performing M-R or M-U studies instead of segmental conduction or comparative studies of median nerves in the patients with CTS with normal distal latencies.

P30-7 How to make electrodiagnosis of carpal tunnel syndrome with normal distal conductions?

P30-7 How to make electrodiagnosis of carpal tunnel syndrome with normal distal conductions?

S34-5 Electrodiagnosis of carpal tunnel syndrome

S34-5 Electrodiagnosis of carpal tunnel syndrome

Carpal tunnel syndrome in the elderly: nerve conduction parameters

To establish nerve conduction parameters for carpal tunnel syndrome (CTS) electrodiagnosis in the elderly. Thirty healthy subjects (65-86 years), 9 male and 21 female, were studied. Routine median and ulnar sensory and motor nerve conduction studies, median mixed palmar latency, comparative latency techniques median to ulnar (sensory, mixed and motor lumbrical-interossei), median to radial (sensory), and combined sensory index (CSI) were performed in both hands. The upper limits of normality (97.5%) were: median sensory distal latency 3.80 ms (14 cm); median motor distal latency 4.30 ms (8 cm); median palmar latency 2.45 ms (8 cm); lumbrical-interossei latency difference 0.60 ms (8 cm); comparative median to radial 0.95 ms (10 cm); comparative median to ulnar 0.95 ms (14 cm); comparative palmar median to ulnar 0.50 ms (8 cm); and CSI 2.20 ms. Sensory and mixed latencies were measured at peak. Our results establish new nerve conduction parameters for mild CTS electrodiagnosis in the elderly and will be helpful to reduce the number of false positive cases in this age.