Effectiveness of high intensity laser therapy on pain, grip strength and median nerve conductivity in pregnant women with carpal tunnel syndrome: A randomized controlled trial.

STUDY DESIGN: Single-blind randomized controlled trial. INTRODUCTION: High-intensity laser therapy (HILT) was recently introduced to the physiotherapy field as a treatment option for patients with carpal tunnel syndrome (CTS). However, evidence about its effectiveness on pregnant women with CTS is sparse. PURPOSE OF STUDY: To test the effectiveness of HILT combined with a conventional physical therapy program to reduce pain intensity, sensory and motor nerve distal latency, and increase grip strength in pregnant women with CTS compared with the physical therapy alone. METHODS: Fifty-four pregnant women with mild to moderate CTS were randomized and further allocated into two groups. The HILT group (n = 27) received both HILT and conventional physical therapy, and the control group (n = 27) received only physical therapy, including nerve and tendon gliding exercises and the use of an orthotic device. Participants received the interventions at the University Hospital (omitted for review) three times per week for 5 weeks. An 11-points numerical pain rating scale, electromyography, and a handheld dynamometer were used for data collection before and after the treatment. RESULTS: Participants from both groups presented significant improvement in the median nerve motor nerve distal latency (MNDL), sensory nerve distal latency, numerical pain rating scale, and handgrip strength after the intervention. The between-group difference showed more improvements in participants of the HILT group on reducing pain intensity, mean difference (MD) = -3.11 (-4.1 to 2.1), and sensory nerve distal latency, MD = -0.3 (-0.5 to -0.1) compared with the control group. DISCUSSION: HILT produced greater improvement in outcomes of pregnant women with mild to moderate CTS whichsuggests that adding HILT to traditional CTS physical therapy protocol is beneficial and safe. CONCLUSIONS: High-intensity laser therapy combined with a standard physical therapy program for CTS in pregnant women is better than the physical therapy program alone to improve pain intensity and median nerve sensory distal latency.

High-Resolution Manometry Thresholds and Motor Patterns Among Asymptomatic Individuals.

OBJECTIVE: High-resolution manometry (HRM) is the current standard for characterization of esophageal body and esophagogastric junction (EGJ) function. We aimed to examine the prevalence of abnormal esophageal motor patterns in health, and to determine optimal thresholds for software metrics across HRM systems. DESIGN: Manometry studies from asymptomatic adults were solicited from motility centers worldwide, and were manually analyzed using integrated relaxation pressure (IRP), distal latency (DL), and distal contractile integral (DCI) in standardized fashion. Normative thresholds were assessed using fifth and/or 95th percentile values. Chicago Classification v3.0 criteria were applied to determine motor patterns across HRM systems, study positions (upright vs supine), ages, and genders. RESULTS: Of 469 unique HRM studies (median age 28.0, range 18-79 years). 74.6% had a normal HRM pattern; none had achalasia. Ineffective esophageal motility (IEM) was the most frequent motor pattern identified (15.1% overall), followed by EGJ outflow obstruction (5.3%). Proportions with IEM were lower using stringent criteria (10.0%), especially in supine studies (7.1%-8.5%). Other motor patterns were rare (0.2%-4.1% overall) and did not vary by age or gender. DL thresholds were close to current norms across HRM systems, while IRP thresholds varied by HRM system and study position. Both fifth and 95th percentile DCI values were lower than current thresholds, both in upright and supine positions. CONCLUSIONS: Motor abnormalities are infrequent in healthy individuals and consist mainly of IEM, proportions of which are lower when using stringent criteria in the supine position. Thresholds for HRM metrics vary by HRM system and study position.

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.

Median nerve conduction studies in rabbits.

BACKGROUND: When planning nerve conduction studies using animal models, the sciatic nerve is often used and the upper extremity nerves are not preferred due to the size of laboratory animals. This study aimed to present the method and mean values of median nerve conduction studies in laboratory rabbits. Fifty-five six-month-old male New Zealand white rabbits weighing 2 to 2.5 kg were included in nerve conduction studies performed under anesthesia. The compound muscle action potential amplitude and distal latency values were recorded for the median motor nerve with the electrodes placed on the flexor digitorum superficialis muscle and tendon. RESULTS: A total of 110 median nerves were evaluated. The mean amplitude of the median nerve was 30.6 ± 6.8, mV the median nerve distal latency was 1.3 ± 0.2 ms, and the mean intensity of stimulation inducing a response was 2.5 ± 1 mA. CONCLUSIONS: The mean values obtained by the median motor nerve conduction method in this study can act as a guide for future nerve interventions undertaken in the upper extremities.

Membrane property changes in most distal motor axons in chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION: Distal nerve terminals, where the blood-nerve barrier is anatomically deficient, are preferentially affected in immune-mediated neuropathies. Excitability alterations near the motor nerve terminals may be more prominent than the nerve trunk in typical chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: In 20 patients with typical CIDP, motor nerve excitability testing was performed at the motor point and wrist of the ulnar nerve, and results were compared with those in 20 healthy persons. RESULTS: Chronic inflammatory demyelinating polyneuropathy patients showed greater threshold changes in hyperpolarizing threshold electrotonus at the motor point (P < .05) but not at the wrist. Strength-duration time constant did not show significant differences between CIDP and controls at both sites. DISCUSSION: Axonal property changes in CIDP are more prominent in distal portions of axons compared with the nerve trunk, presumably due to salient demyelination near the distal nerve terminals. Motor point excitability measurements could elucidate underlying pathophysiology in immune-mediated neuropathies.

The extrapolated reference values procedure: Theory, algorithm, and results in patients and control subjects.

INTRODUCTION: Reference values (RVs) are required to separate normal from abnormal values obtained in electrodiagnostic (EDx) testing. However, it is frequently impractical to perform studies on control subjects to obtain RVs. The Extrapolated Reference Values (E-Ref) procedure extracts RVs from data obtained during clinically indicated EDx testing. We compared the E-Ref results with established RVs in several sets of EDx data. METHODS: The mathematical basis for E-Ref was explored to develop an algorithm for the E-Ref procedure. To test the validity of this algorithm, it was applied to simulated and real jitter measurements from control subjects and patients with myasthenia gravis, and to nerve conduction studies from patients with various conditions referred for EDx studies. RESULTS: There was good concordance between E-Ref and RVs for all evaluated data sets. DISCUSSION: E-Ref is a promising method to develop RVs. Muscle Nerve 57: 90-95, 2018.

Comparison of four different nerve conduction techniques of the superficial fibular sensory nerve.

INTRODUCTION: There are many different nerve conduction study (NCS) techniques to study the superficial fibular sensory nerve (SFSN). We present reference distal latency values and comparative data regarding 4 different NCS for the SFSN. METHODS: Four different NCS techniques, Spartan technique, Izzo techniques (medial and intermediate dorsal cutaneous branches), and Daube technique, were performed on (114) healthy volunteers. A total of 108 subjects with 164 legs were included. RESULTS: The mean latency of the Spartan technique was longest (3.9 ± 0.3 ms) while the Daube technique was the shortest (3.6 ± 0.7 ms). The mean amplitude of the Daube technique displayed the highest (15.2 ± 8.2 µV) with the Spartan technique having the lowest (8.7 ± 4.2 µV). Among the absent sensory nerve action potentials (SNAPs), the Spartan technique was absent only twice (1.2%) and the Izzo Medial technique was absent more than the other techniques (2.9%). CONCLUSIONS: All 4 techniques were reliable methods for obtaining the superficial fibular nerve SNAP, present in 95% of individuals. Muscle Nerve 56: 458-462, 2017.

Identification of optimal site of G1 placement for median orthodromic palmar nerve conduction study.

INTRODUCTION: G1 electrode placement at the distal wrist crease during the median orthodromic palmar nerve conduction study (NCS) could result in a false negative study if compression is more proximal. METHODS: In this study we aimed to determine the effect of median G1 electrode placement on distal latencies and amplitudes. Methods Median orthodromic palmar NCS was performed with the G1 electrode at the wrist crease and 2 cm proximal, stimulating 8 cm distal to G1. The difference in the distal latencies and amplitudes between the 2 recording sites was calculated. RESULTS: In 26 controls and 25 carpal tunnel syndrome (CTS) patients, the mean proximal-distal latency difference and percent amplitude decrease (distal vs. proximal) was -0.085 ms/53% (controls) and -0.072 ms/45% (CTS). CONCLUSION: Distal latency is not significantly affected by G1 placement in the median orthodromic palmar NCS, but the amplitudes are nearly twice as high when G1 is placed 2 cm proximal to the wrist crease.

Effects of viscosity and volume on the patterns of esophageal motility in healthy adults using high-resolution manometry.

The purpose of this study was to determine the effects of age, sex, body mass index (BMI), viscosity, and volume on esophageal motility using high-resolution manometry (HRM). Manometric studies were performed on 60 asymptomatic volunteers (27 men and 33 women, age: 19-56 years) while in a supine position. Manometric protocol included 10 water swallows (5 cc), 10 jelly swallows (5 cc), and 1 water swallow (20 cc). Evaluation of HRM parameters including length of proximal pressure trough (PPT length), distal latency (DL), contractile front velocity (CFV), distal contractile integral (DCI), and 4-second integrated relaxation pressure (IRP) was performed using MATLAB. Significant differences were noted in median IRP between water 5 cc (median 7.2 mmHg [range 5.5-9.6]), jelly 5 cc (median 6.0 mmHg [range 3.8-8.0]), and water 20 cc {(Median 4.8 mmHg [range 3.3-7.4]), P < 0.01}. DL were significantly different between water 5 cc, jelly 5 cc, and water 20 cc (P < 0.01), and in terms of PPT, proportions of small (2 cm ≤ < 5 cm) and large (5 cm≤) break for jelly 5 cc were significantly higher than those for the water 5 cc swallow (P < 0.05). Furthermore, DCI increased with age for water 5 cc, and a significant negative correlation was noticed between proportions of small break and BMI for water 5 cc. Manometric measurements vary depending on age, BMI, viscosity, and volume. These findings need to be taken into account in the interpretation of manometry results.

Effectiveness of the muscle energy technique on postpartum meralgia paresthetica: A randomized controlled trial.

BACKGROUND: The effectiveness of the muscle energy technique (MET) on postpartum meralgia paresthetica (MP) affecting the lateral femoral cutaneous nerve is unknown. OBJECTIVE: To investigate the effectiveness of the MET on postpartum MP affecting the lateral femoral cutaneous nerve. METHODS: In this randomized controlled trial, 30 patients with postpartum MP were randomly allocated to study and control groups. The study group received the MET with conventional therapeutic exercises and the control group received the conventional exercises alone for four weeks (thrice a week, for 30-40 minutes duration). Lateral femoral cutaneous nerve distal latency, pain intensity, response to the prone knee bend (PKB) test and pelvic compression test were assessed. RESULTS: Patients allocated to the MET group had improvements compared to the controls in pain intensity (MD: -1.66, 95%CI -2.39 to -0.94), distal latency (MD: -0.66, 95%CI -0.94 to -0.36), and knee range of motion in the PKB test (MD: 19.5∘, 95%CI 13 to 26.1) with high treatment effects, Cohen's d -ES = 1.71, 1.86 and 2.24 respectively. However, there was no between-group difference for the pelvic compression test (p= 0.41). CONCLUSION: The MET can reduce pain, distal latency, and increase the prone knee range of motion in women with MP affecting the lateral femoral cutaneous nerve.

Chicago Classification Update (v4.0): Technical review on diagnostic criteria for distal esophageal spasm.

Distal esophageal spasm (DES) is defined as a manometric pattern of at least 20% of premature contractions in a context of normal esophago-gastric junction relaxation in a patient with dysphagia or non-cardiac chest pain. The definition of premature contraction requires the measurement of the distal latency and identification of the contractile deceleration point (CDP). The CDP can be difficult to localize, and alternative methods are proposed. Further, it is important to differentiate contractile activity and intrabolus pressure. Multiple rapid swallows are a useful adjunctive test to perform during high-resolution manometry to search for a lack of inhibition that is encountered in DES. The clinical relevance of the DES-manometric pattern was raised as it can be secondary to treatment with opioids or observed in patients referred for esophageal manometry before antireflux surgery in absence of dysphagia and non-cardiac chest pain. Further idiopathic DES is rare, and one can argue that when encountered, it could be part of type III achalasia spectrum. Medical treatment of DES can be challenging. Recently, endoscopic treatments with botulinum toxin and peroral endoscopic myotomy have been evaluated, with conflicting results while rigorously controlled studies are lacking. Future research is required to determine the role of contractile vigor and lower esophageal sphincter hypercontractility in the occurrence of symptoms in patients with DES. The role of impedance-combined high-resolution manometry also needs to be evaluated.

Prolonged distal latency of the median motor nerve is associated with poor prognosis in amyotrophic lateral sclerosis.

A nerve conduction study (NCS) is routinely undertaken for the differential diagnosis of amyotrophic lateral sclerosis (ALS). Prolonged median motor distal latency (MMDL) has been reported in a subset of patients with ALS. This study aimed to investigate the clinical importance of NCS characteristics in patients with ALS. A total of 75 patients who underwent NCS were enrolled in this study. The frequency of ALS patients with prolonged motor DL was higher in the median than ulnar NCS. The multivariate analysis revealed that shorter diagnostic latency, prolonged MMDL, and higher disease progression rate were significantly associated with poor prognosis. When ALS patients were divided into two groups according to the cut-off value (4.2 ms) of the MMDL, the group with prolonged MMDL had lower ALS functional rating scale and frontal assessment battery scores, upper limbs subscore, and shorter survival time than the group with shorter MMDL. In conclusion, patients with ALS that have prolonged MMDL may have upper limb dysfunction and shorter survival. MMDL can be a useful prognostic marker for patients with ALS. Abbreviations: ADM = abductor digiti minimi; APB = abductor pollicis brevis; ALS = amyotrophic lateral sclerosis; ALSFRS-R = revised ALS Functional Rating Scale; CI = confidence interval; CMAP = compound muscle action potential; CTS = carpal tunnel syndrome; DL = distal latency; ΔFS = disease progression rate; FAB = frontal assessment battery; FVC = forced vital capacity; HR = hazard ratio; MCV = motor nerve conduction velocity; MMDL = median motor distal latency; MMSE = mini-mental state examination; NCS = nerve conduction study; PaCO2 = partial pressure of arterial carbon dioxide; SBMA = spinal and bulbar muscular atrophy; SCV = sensory nerve conduction velocity; SD = standard deviation; SMA = spinal muscular atrophy; SNAP = sensory nerve action potential; SOD1 = superoxide dismutase 1; UMDL = ulnar motor distal latency.

Normative Data for Median Nerve Conduction in Healthy Young Adults from Punjab, India.

BACKGROUND: Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse neuropathies. Due to the paucity of local NCS data, electrodiagnostic laboratories in Punjab rely on values from Western and other Indian studies. AIM: This study was conducted to provide normative data for median nerve conduction parameters (motor and sensory) in Punjabi populace. MATERIALS AND METHODS: A cross-sectional study was done on 290 participants (150 males and 140 females), aged 17-21 years, as per standardized protocol. The data were analyzed separately for both genders using SPSS version 20. It consisted of distal latencies and conduction velocities of motor and sensory divisions of median nerve. Student's unpaired t-test was used for statistical analysis. RESULTS: There was no effect of gender on any of the median nerve conduction parameters. Height and weight had nonsignificant negative and positive correlation, respectively (P > 0.05), with conduction velocity in both motor and sensory median nerves. For median motor nerve, the values of distal latency and conduction velocity in males were 2.9 ± 0.16 ms and 60.25 ± 2.99 m/s, respectively, whereas, in females, they were 2.6 ± 0.43 ms and 59.83 ± 2.82 m/s. Similarly, for median sensory nerve, the latency and velocity values in males were 2.8 ± 0.56 ms and 54.81 ± 3.70 m/s, whereas, in females, they were 2.4 ± 0.33 ms and 54.56 ± 3.65 m/s, respectively. CONCLUSION: The data in this study compared favorably with already existing data. It would help the local electrodiagnostic laboratories in assessing the median nerve abnormalities with greater accuracy in this population subset.

Electrophysiological Assessment for Splinting in the Treatment of Carpal Tunnel Syndrome.

An electrophysiological study is commonly used to decide a therapeutic strategy for carpal tunnel syndrome (CTS). In this study, the electrophysiological parameter measurement as a prognostic indicator for CTS after wrist splinting was assessed to identify appropriate candidates for wrist splinting for CTS. One hundred and six hands in 78 patients with CTS were treated by wrist splinting, and three electrophysiological parameters; median distal motor latency (DML) of the abductor pollicis brevis (APB) muscle, median distal sensory latency (DSL) of the index finger, and second lumbrical-interossei latency difference (2L-INT LD); were statistically analyzed to compare with clinical results by Kelly's evaluation respectively. Clinical results were excellent in 15 hands, good in 51 hands, fair in 19 hands, and poor in 21 hands. The recordable rate in 2L-INT LD (99.1%) was higher than DML (96.2%) and DSL (79.2%). Patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT LD less than 2.5 ms had significantly excellent or good clinical results. The odds ratios of the DML, DSL, and the 2L-INT LD were 7.93, 8.81, and 12.8, respectively. This study demonstrated that CTS patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT less than 2.5 ms were good candidates for wrist splinting. Especially, the 2L-INT LD could be the most reliable indicator to predict clinical results for all grades of CTS. This electrophysiological information could be useful in further improvement of accurate diagnosis of CTS, and may help in the assessment of appropriate treatment for CTS with wrist splinting.

Electrophysiological Study of Nerves in Type-II Reaction in Leprosy.

BACKGROUND: Leprosy is a chronic granulomatous infection primarily affecting the peripheral nervous system, skin and reticuloendothelial system. Cutaneous nerves are severely affected in lepra reaction and this leads to morbidity. OBJECTIVE: To study electrophysiological pattern of different nerves involved in Type-II reactions in leprosy. METHOD: The present study was undertaken in 21 leprosy patients with Type-II reactions attending in and out-patient department of Dermatology & Venereology, B.R.D. Medical College, Gorakhpur from July 2005 to October 2006. This was a prospective case control study in which 20 healthy, age and sex matched people with no evidence of any disease (particularly nerve involvement) were included. LIMITATION: Lesser number of cases were studied. RESULT: The proximal motor conduction latency was significantly prolonged in both ulnar and common peroneal nerve and proximal motor conduction velocity was also significantly reduced. On examining the values beyond 2S.D. of the control value, distal latency was not affected and only proximal conduction was affected in ulnar nerve. CONCLUSION: In Type II lepra reaction the motor conduction abnormalities are not prominent. Abnormalities are relatively more marked in the proximal segment.

Pulsed magnetic field versus ultrasound in the treatment of postnatal carpal tunnel syndrome: A randomized controlled trial in the women of an Egyptian population.

The aim of this study was to compare the effects of pulsed electromagnetic field versus pulsed ultrasound in treating patients with postnatal carpal tunnel syndrome. The study was a randomized, double-blinded trial. Forty postnatal female patients with idiopathic carpal tunnel syndrome were divided randomly into two equal groups. One group received pulsed electromagnetic field, with nerve and tendon gliding exercises for the wrist, three times per week for four weeks. The other group received pulsed ultrasound and the same wrist exercises. Pain level, sensory and motor distal latencies and conduction velocities of the median nerve, functional status scale and hand grip strength were assessed pre- and post-treatment. There was a significant decrease (P < 0.05) in pain level, sensory and motor distal latencies of the median nerve, and significant increase (P < 0.05) in sensory and motor conduction velocities of the median nerve and hand grip strength in both groups, with a significant difference between the two groups in favour of pulsed electromagnetic field treatment. However, the functional status scale showed intergroup no significant difference (P > 0.05). In conclusion, while the symptoms were alleviated in both groups, pulsed electromagnetic field was more effective than pulsed ultrasound in treating postnatal carpal tunnel syndrome.

Distal esophageal spasm and the Chicago classification: is timing everything?

BACKGROUND: According to the Chicago classification of esophageal motility disorders, distal esophageal spasm (DES) is defined as premature esophageal contractions (distal latency [DL] <4.5 s) for ≥20% of swallows, in the presence of a normal mean integral relaxation pressure (IRP). However, some patients with symptoms of DES have rapid contractions with a normal DL. The aim of this study was to characterize these patients and compare their clinical characteristics to those of patients classified as DES. METHODS: We retrospectively compared clinical characteristics and high-resolution manometry findings of patients with rapid contractions with normal latency to those meeting the Chicago classification criteria for DES. KEY RESULTS: Over a 3-year period, nine patients were diagnosed with DES and 14 showed rapid contractions in the distal esophagus with normal latency. The latter were younger than DES patients (60 ± 4 vs 72 ± 3 years, p < 0.05). Dysphagia and retrosternal pain occurred to a similar degree in both groups. Weight loss and abnormal barium esophagogram tended to be more frequent in DES patients. There was no difference in contractile front velocity (CFV) and in distal contractile integral (DCI) between patients with DES and rapid contractions with normal latency. Lower esophageal sphincter pressures were not different between groups. However, IRP was significantly higher in DES compared to rapid contractions with normal latency (11.7 ± 0.6 mmHg vs 7.6 ± 1.2 mmHg, p < 0.05), albeit still within the normal range. CONCLUSIONS & INFERENCES: These data suggest that patients with simultaneous contractions with normal latency represent a group of patients with many features similar to DES.

Focal nerve enlargement is not the cause for increased distal motor latency in ALS: Sonographic evaluation.

OBJECTIVE: To elucidate the mechanism of focal conduction slowing in the median nerve in ALS. METHODS: The patients with ALS and CTS and normal control subjects were tested with sonography of the median and ulnar nerves. The cross-sectional areas (CSAs) and the wrist-forearm CSA ratios were compared with the parameters of nerve conduction study. RESULTS: The median motor distal latency was frequently prolonged in ALS and CTS. CSA and the wrist-forearm ratio of the median nerve were smaller in ALS than in CTS. The ulnar nerve sonography was similar in all the groups. CONCLUSIONS: Selective conduction slowing of the median nerve at the wrist in ALS is unlikely due to secondary compressive neuropathy, as seen in carpal tunnel syndrome. SIGNIFICANCE: Unique vulnerability of the median nerve in ALS may explain the selective conduction slowing.