Antidromic Sensory Nerve Conduction Study Research Articles

Elucidation of peripheral nerve myelination by bimodal waveform analysis

PurposeAs the myelin sheath of the peripheral nerves is immaturely developed in children, a bimodal waveform may be evoked when sensory nerve conduction studies are performed in them. However, there has been no study regarding the relationship between age and the frequency of appearance of the bimodal waveform or the inter-peak latency. Herein, we examined how the bimodal waveform changes with age. MethodsA total of 218 sensory nerves (109 median and 109 ulnar nerves) in 86 children (0 to 15 years old) were analyzed. The frequency of the bimodal waveform and the distance-corrected inter-peak latency were examined with antidromic sensory nerve conduction studies of the upper limbs on proximal stimulation. ResultsThe frequency of bimodal waveforms and distance-corrected inter-peak latency decreased with age. Analysis of the slope line of the scatter plot demonstrated that the bimodal waveform was present until the age of 15–16 years. ConclusionThe bimodal waveform of sensory nerves faded with growth. Given that development-associated temporal dispersion is considered to be the cause of the differences in the bimodal waveform, our findings suggest that the underlying cause of the bimodal waveform is an immature myelin sheath, which may not be fully developed until the age of 15–16 years.

Frequency of Type-1 Berrettini's Connection in a Neurophysiology Laboratory.

Objective This study aims to estimate the frequency of Berrettini's ulnar-median nerves communication in a neurophysiology laboratory. Materials and Methods A total of 358 hands belonging to patients, both sexes, median age of 58 years, was studied. Antidromic sensory nerve conduction studies of the ulnar nerves, registered in digits III and IV were performed in search of the ulnar-median communication. A Berrettini's percentage was calculated in each communication: [(amplitude SAP digit III/amplitude SAP digit IV) × 100]. Results Ulnar-median nerves communication (Berrettini's branch) was found in 37 hands (10.95%), with a female gender predominance. Bilaterality percentage was low (1.78%). Most communications encountered had a Berretini's percentage between 11 and 50%. Some of them exceeded 100%. Conclusions Electromyographers should routinely search for this nerve communication, especially in those patients undergoing carpal tunnel syndrome or Dupuytren's contracture surgeries.

Individually tailored whole-body vibration training to reduce symptoms of chemotherapy-induced peripheral neuropathy: study protocol of a randomised controlled trial—VANISH

IntroductionChemotherapy-induced peripheral neuropathy (CIPN) is a prevalent and clinically meaningful side effect of cancer treatment. CIPN is induced by neurotoxic agents, causing severe sensory and/or motor deficits, resulting in disability...

O-3-20. Peripheral sensory nerve conduction disorder in amyotrophic lateral sclerosis

Peripheral sensory nerve involvement is inconspicuous in patients with amyotrophic lateral sclerosis (ALS), while previous reports on the frequency and extent of sensory nerve involvement in ALS are not consistent. We investigated the differences in the peripheral sensory nerve conduction between 160 patients with ALS and 69 control participants. Motor and antidromic sensory nerve conduction studies were conducted for the median, ulnar and sural nerves. In ALS patients, sensory conduction velocity (SCV) was significantly lower in all examined nerves than that in controls. Amplitude of sensory nerve action potential (SNAP) of the sural nerve was significantly lower in patients than in controls. The median/ulnar ratio of SNAP amplitude was significantly lower in patients than in controls, and the median/sural ratio of SNAP amplitude was significantly higher in patients than in controls. SCV and SNAP amplitude in ALS patients showed no significant correlations with disease duration or disease severity. Our findings suggest subclinical loss of the fast conducting sensory nerve fibers or the large dorsal root ganglion cells in ALS. The sural nerve may be the most affected sensory nerve, and the median nerve may be more vulnerable than the ulnar nerve.

Electrophysiological study of the ulnar palmar cutaneous nerve in normal individuals

The electrophysiological assessment of the ulnar palmar cutaneous nerve (UPCN) is clinically essential to assess the integrity of this nerve in some clinical situations that involve compression or injury of this nerve. This study proposed to assess the electrophysiological antidromic technique of the UPCN and to obtain normal reference values for the electrophysiological parameters of this nerve. It is a single-center public hospital-based electromyography laboratory. It is a cross-sectional study of consecutive apparently healthy volunteers. The study included 70 apparently healthy volunteers. Antidromic sensory nerve conduction study of the UPCN was carried out. Quantitative data were analyzed using Student’s t-test and paired t-test. Correlation was tested using the Pearson correlation test. The present study included 119 hands of 70 healthy individuals [36 (51.43%) women]. Their mean age was 41.91±13.21 years. The UPCN was elicited in 116 (97.48%) hands. The estimated reference values (mean±2 standard deviations) for the UPCN sensory nerve action potential were determined for onset latency (≤2.1 ms), peak latency (≤2.8 ms), conduction velocity (≥46.4 m/s), amplitude (≥6.9 μV), and interside sensory nerve action potential amplitude ratio (≥0.50). This study provided a feasible electrophysiological antidromic technique and normal reference values for sensory conduction study of the UPCN.

Peripheral nerve function in patients with excessive fragmentary myoclonus during sleep

ObjectivesExcessive fragmentary myoclonus is a frequent incidental finding in patients undergoing polysomnography for other reasons. The aim of this study was to evaluate whether electrophysiological examination in patients with excessive fragmentary myoclonus during sleep according to American Academy of Sleep Medicine (AASM) criteria shows findings of peripheral nerve dysfunction. MethodsNinety-eight of 100 patients with excessive fragmentary myoclonus detected as an incidental finding during routine polysomnography underwent electrophysiological workup. Motor nerve conduction studies of the right peroneal and tibial nerves, F-wave recordings of the tibial nerve, antidromic sensory nerve conduction studies of the left sural nerve and needle electromyography of the right tibialis anterior muscle were performed and classified as normal, peripheral neuropathy, lumbar 5 (L5) nerve root lesion, or benign fasciculations. ResultsFifty percent (49 out of 98) presented with electrophysiological abnormalities, most frequently polyneuropathy (32 out of 49, 65.3%), followed by L5 nerve root lesions (13 out of 49, 26.5%) and benign fasciculations (4 out of 49, 8.2%). Patients with electrophysiological abnormalities were older than those without. ConclusionsThe high prevalence of abnormal neurophysiological findings in patients with excessive fragmentary myoclonus during polysomnography suggests that excessive fragmentary myoclonus during sleep according to AASM criteria is not primarily a sleep-related phenomenon, but only persists during sleep and points to peripheral nerve pathology at least in part of the cases. Patients with incidental EFM during polysomnography should undergo electrophysiological workup for peripheral nerve pathology.

P783: The effect of surface round electrode locations in median nerve antidromic sensory nerve conduction study – an investigation with high density surface electrode

P783: The effect of surface round electrode locations in median nerve antidromic sensory nerve conduction study – an investigation with high density surface electrode

Reliability, reference values and predictor variables of the ulnar sensory nerve in disease free adults

The purposes of this descriptive and exploratory study were to examine electrophysiological measures of ulnar sensory nerve function in disease free adults to determine reliability, determine reference values computed with appropriate statistical methods, and examine predictive ability of anthropometric variables. Antidromic sensory nerve conduction studies of the ulnar nerve using surface electrodes were performed on 100 volunteers. Reference values were computed from optimally transformed data. Reliability was computed from 30 subjects. Multiple linear regression models were constructed from four predictor variables. Reliability was greater than 0.85 for all paired measures. Responses were elicited in all subjects; reference values for sensory nerve action potential (SNAP) amplitude from above elbow stimulation are 3.3 μV and decrement across-elbow less than 46%. No single predictor variable accounted for more than 15% of the variance in the response. Electrophysiologic measures of the ulnar sensory nerve are reliable. Absent SNAP responses are inconsistent with disease free individuals. Reference values recommended in this report are based on appropriate transformations of non-normally distributed data. No strong statistical model of prediction could be derived from the limited set of predictor variables. Reliability analyses combined with relatively low level of measurement error suggest that ulnar sensory reference values may be used with confidence.

Antidromic sensory nerve conduction study of the digital branches of the medial plantar nerve: A novel method to detect early diabetic sensory axonal polyneuropathy

Distal sensory neuropathy is the most common form of diabetic neuropathy. We developed a novel antidromic technique for assessment of distal nerve function for early diagnosis of diabetic neuropathy. Diabetic and control groups underwent standard and more distal sensory nerve conduction studies (NCS); sensory nerve action potentials (SNAPs) of the proper digital branches of the medial plantar nerve were recorded with our method after stimulation at the sole and recording from digits I and II. Comparison between controls and diabetics showed a statistically significant difference in mean SNAP amplitudes for all nerves tested. A higher percentage of abnormal SNAPs was obtained with our technique than with either conventional or more distal NCS in all patients. As compared with clinical evaluation and other NCS, our antidromic stimulation was the most sensitive method to detect abnormal sensory nerve conduction in symptomatic and asymptomatic diabetic patients.

A new pitfall in a sensory conduction study of the lateral antebrachial cutaneous nerve: Spread to the radial nerve

We describe a previously unreported pitfall, spread of the stimulus at the elbow to the radial nerve, in an antidromic sensory nerve conduction study of the lateral antebrachial cutaneous (LAC) nerve. Subjects consisted of 80 healthy volunteers, and both sides were examined for each subject. Besides routine recording of the LAC nerve, sensory nerve action potentials (SNAPs) of the radial nerve were recorded distally. The spread phenomenon occurred in 73 of 160 arms (46%), and the SNAP amplitude increased due to contamination of the radial SNAP up to 6.7 times the genuine LAC SNAP. In 10 arms (6%), the spread started before the LAC SNAP was saturated, and the genuine LAC SNAP was unknown due to an anatomical variation in at least 1 arm. Without monitoring distal radial SNAPs, the spread phenomenon will remain unrecognized. This pitfall undermines the reliability of the test.

Comparison of Ring Versus Disposable Disk Electrodes in Recording Antidromic Sensory Median Nerve Conduction Study for Diagnosis of Carpal Tunnel Syndrome

The authors performed a study using disposable disk electrodes, currently used to record motor nerve conduction study, for median antidromic sensory recording from the second digit with the aim of establishing efficiency by using one type of electrode throughout the entire nerve conduction study. This study aims to establish noninferiority with the use of disk electrodes rather than conventionally used nondisposable ring electrodes in the diagnosis of carpal tunnel syndrome. For median sensory response, 4 parameters were studied: (1) onset latency, (2) peak latency, (3) amplitude, and (4) conduction velocity. Ten hands with active disease and 10 control hands without disease were studied via both ring electrodes and disk electrodes. The results were compared between the ring and disk electrodes. There was no statistically significant difference between the ring electrodes and the disk electrodes in recording the four parameters of the antidromic median sensory nerve conduction study using the second digit. Our study indicates that disposable disk electrodes could replace ring electrodes to perform median sensory antidromic nerve conduction studies for the diagnosis of carpal tunnel syndrome. However, further studies need to be carried out with larger sample sizes and for other indications.

Electrodiagnostically Confirmed Posttraumatic Neuropathy and Associated Clinical Exam Findings With Lisfranc Injury

Patients with a Lisfranc injury often complain of persistent pain radiating from the Lisfranc joint up or down the first dorsal web space, accompanied by decreased sensation. We hypothesized that these symptoms were related to a posttraumatic neuropathy of the terminal medial branch of deep fibular (peroneal) nerve (MBDFN) and that by recognizing this symptom an earlier diagnosis of Lisfranc injury may be possible. Twelve patients with diagnosis of subtle unilateral Lisfranc injury, confirmed by standing X-ray, CT, or bone scan, were enrolled. Standardized antidromic sensory nerve conduction studies of MBDFN were performed bilaterally within 2 months postinjury and prior to surgical intervention. The contralateral, normal side was used as a control. All patients were tested for decreased 2-point discrimination in the first dorsal web space on both lower extremities. Sensory nerve action potential of the MBDFN was absent, with decreased 2-point discrimination on the injured side in all patients. Lisfranc injuries were associated with a posttraumatic neuropathy of the MBDFN and decreased 2-point discrimination in the first dorsal web space. The finding of altered sensation in the first dorsal web space may help the practitioner to earlier diagnosis of a Lisfranc injury. Level III, case control study.

Comparison in placement location of disposable surface electrode in antidromic sensory nerve conduction study

Comparison in placement location of disposable surface electrode in antidromic sensory nerve conduction study

Spread to the dorsal ulnar cutaneous branch: A pitfall during the routine antidromic sensory nerve conduction study of the ulnar nerve

ObjectiveTo document the incidence and effects of a previously unreported pitfall during routine antidromic sensory nerve conduction study (SCS) of the ulnar nerve: the spread of the wrist stimulation to the dorsal ulnar cutaneous (DUC) branch. MethodsThe subjects consisted of 20 healthy volunteers. An antidromic sensory nerve action potential (SNAP) was recorded over the proximal interphalangeal joint of the little finger, and the DUC response was monitored over the dorsum of hand to check for the occurrence of this spread. ResultsThe spread occurred in all subjects, which caused a 4–87% increase in the SNAP amplitude. The likelihood that this spread may occur during routine SCS varied among the subjects, and also within an individual subject depending on minute shifts of the stimulating site. Selective stimulation of the ulnar main trunk up to maximal intensity without spread to the DUC was not achieved despite every effort in two subjects. ConclusionsThis spread phenomenon may occur frequently during routine antidromic SCS, but would not be recognized without monitoring the DUC response. SignificanceThis pitfall may interfere with the reproducibility of the SNAP amplitude, and also with the diagnosis of ulnar neuropathy at the wrist.

Utility of ultrasound‐guided surface electrode placement in lateral femoral cutaneous nerve conduction studies

Meralgia paresthetica is a common clinical complaint for which some patients ultimately undergo surgical treatment. The lateral femoral cutaneous nerve (LFCN) has been difficult to reliably test electrophysiologically, likely due to anatomic variability and lack of responses in asymptomatic obese subjects. We compared a novel ultrasound-guided antidromic sensory nerve conduction study (NCS) with a technique described previously in a population of normal subjects, of whom 50% had body mass indices within the obese range (>27.5). Responses were obtained in at least 92% of subjects using either technique, and 92% of normal subjects had <60% interside variability using the ultrasound-guided technique. LFCN sensory nerve action potentials can be obtained in the vast majority of normal subjects, even in an obese population and can provide a useful sensory NCS for evaluation of mid-lumbar radiculopathy, plexopathy, or meralgia paresthetica.

2. Compound nerve action potential (CNAP) study is a useful examination for evaluating muscle afferent Ia fibers

s of the 40th Annual Meeting of Japanese Society of Clinical Neurophysiology, Kobe, Japan, November 1–2, 2010 Ryuji Kaji , Koichi Hirata b,⇑ a Secretariat: Koishikawa Building 4F, 5-3-13 Otsuka, Bunkyo-ku, Tokyo 112-0012, Japan, Department of Neurology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi 321-0293, Japan 1. Traumatic injury of the digital nerve by snow shoveling—Rie Haga, Chieko Murakami, Masayuki Baba (Aomori Prefectual Central Hospital, Aomori, Japan) We presented a case with traumatic injury of the median palmar digital nerve by snow shoveling. A woman aged 74 visited us for three month-history of numbness and dysesthetic pain in the left index finger and thumb after snow shoveling. On examination, there was hypoesthesia on the palm side of the left index finger and thumb. Tinel sign was positive by percussion to the upper edge of the thenar eminence. The left median motor conduction to the abductor pollicis brevis muscle was normal. Compound sensory action potentials recorded from the left thumb and the index finger were around 5 lV, both distinctively reduced compared with those from the left middle and ring fingers, 27 and 18 lV, respectively. Inching records of the sensory potential from the index finger by electric stimulation with successive decrement by one cm from the wrist demonstrated prolonged conduction time more than 0.7 ms at the particular segment including the Tinel sign point: all other segments had normal conduction time of around 0.3 ms. These findings indicated the focal demyelination and Wallerian degeneration at the site of the injury. doi:10.1016/j.clinph.2011.01.013 2. Compound nerve action potential (CNAP) study is a useful examination for evaluating muscle afferent Ia fibers—Keisuke Abe, Tadashi Kanouchi, Teruhiko Sekiguchi, Hidehiro Mizusawa, Takanori Yokota (Tokyo Medical and Dental University, Tokyo, Japan) The aim of this study was to investigate whether CNAP is useful tool for evaluation of Ia fiber conduction. The conventional sensory nerve conduction study recording the sensory nerve action potential (SNAP) gives us the information of only the cutaneous afferents but not about the muscle afferents. We tried to use CNAP of the median nerve for evaluating muscle afferent. The median nerves of seven patients with sensory neuropathy and 4 normal subjects were studied. CNAPs was clearly recorded in all patients with inexcitable SNAP as well as normal subjects. The velocity of CNAP was faster than those of SNAP and CMAP (compound muscle action potential) in the same segment in all normal subjects. The CNAPs in three of 5 patients with no SNAP evoked were obviously faster than the CMAPs. In three patients whose SNAP was evoked, the CNAPs were the fastest among the three responses. Because the conduction velocity of CNAP is determined by that of Ia fiber in normal subjects, CNAP study has the potential to evaluate Ia fiber conduction. Furthermore, in patients with severe sensory neuropathy showing inexcitable SNAP, CNAP study is expected to be an only and new examination for sensory nerve function. doi:10.1016/j.clinph.2011.01.014 3. Comparison in placement location of disposable surface electrode in antidromic sensory nerve conduction study—Kenji Sekiguchi, Toko Miyawaki, Mariko Takata, Akihiro Nomura, Ichiro Yokota, Yoshihisa Otsuka, Naoko Yasui, Horotoshi Hamaguchi, Hisatomo Kowa, Fumio Kanda, Tatsushi Toda (Department of Neurology, Kobe University, Kobe, Japan) Although the ring electrodes generally used in antidromic sensory nerve conduction study of hand, disposable surface electrode is frequently used in recent years and there are many advantages in terms of infection control and usability. However, there are no reports of investigation in optimal location of electrode placement. Antidromic median nerve sensory conduction study was performed in 20 hands of 10 healthy subjects. We made comparison with each measurement of disposable surface electrodes placed at various locations and ring electrodes. The latency and the amplitude delivered by disposable surface electrode placed on midline volar aspect of index finger showed no significant difference compared to using a ring electrodes. In case of surface electrode placement on the radial aspect of index finger, lower amplitude and shorter latency were doi:10.1016/j.clinph.2011.01.012 ⇑ Corresponding author. Tel.: +81 282 87 2152; fax: +81 282 86 5884. E-mail address: hirata@dokkyomed.ac.jp (K. Hirata). Clinical Neurophysiology 122 (2011) e9–e14

3. Comparison in placement location of disposable surface electrode in antidromic sensory nerve conduction study

3. Comparison in placement location of disposable surface electrode in antidromic sensory nerve conduction study

Sural and Saphenous 14-cm Antidromic Sensory Nerve Conduction Studies

To create a large database of normal values for the sural and saphenous nerve conduction studies and to compare the results for the two nerves. Using a 14-cm antidromic technique, data were collected for onset latency, peak latency, onset-to-peak amplitude, peak-to-peak amplitude, area, duration, side-to-side variability, and between-nerve variability. A total of 230 subjects were included in the study. For the sural nerve, the upper limits of normal, defined as the 97th percentile of observed values, for onset latency, peak latency, and duration were 3.6, 4.5, and 2.1 msec, respectively. The comparable values for the saphenous nerve were 3.8, 4.4, and 1.9 msec, respectively. The lower limits of normal (third percentile) for sural onset-to-peak amplitude and peak-to-peak amplitude were 4 and 4 microV. The comparable values for the saphenous study were 2 and 1 microV. The upper limit of normal difference in onset latency between the two nerves was: saphenous 0.7 msec longer than sural or sural 0.3 msec longer than saphenous. The corresponding values for peak latency were: 0.6 and 0.5 msec. Normal ranges are presented for a large database of subjects for the sural and saphenous nerve conduction studies.

The lateral femoral cutaneous nerve: nerve conduction technique.

In 58 subjects without signs or symptoms of peripheral nerve disorders, an antidromic sensory nerve conduction study was performed on the lateral femoral cutaneous nerve. Anatomic dissections were performed on two cadavers to reveal the course of the nerve and to localize the optimal stimulation and recording sites. Mean sensory nerve action potential latency was measured at 1.7 msec (SD = 0.23) with a mean amplitude of 10.5 microV (SD = 4.0). The optimal localization of recording and stimulating surface electrodes and nerve conduction technique procedures are discussed. Reliable electrophysiologic criteria, according to age and body mass index, are obtained.

Effects of clinical infrared laser on superficial radial nerve conduction.

The purposes of this study were to demonstrate the effects of infrared laser radiation on the sensory nerve conduction of a specified peripheral nerve in man and determine temperature changes in the tissue surrounding the treated nerve. Twenty healthy adults were divided into three groups: control (n = 5); experimental (n = 10), infrared laser radiation at 20 sec/cm2; and experimental (n = 5), infrared laser radiation treatment at 120 sec/cm2. Antidromic sensory nerve conduction studies were performed on the superficial radial nerve of each subject's right forearm. The infrared laser radiation was applied at a fixed intensity for five 1-cm2 segments. Latency, amplitude, and temperature measurements were recorded pretest; posttest; and posttest intervals of 1, 3, 5, 10, and 15 minutes. An analysis of variance with repeated measures was used to examine the data. No significant change was noted in the distal sensory latency or amplitude of the evoked sensory potential in either experimental or control groups as a result of the applications of the infrared laser radiation treatment. This study demonstrates that infrared laser used at clinically applied intensities does not alter conduction of sensory nerves nor does it elevate the subcutaneous temperature.