Ulnar Motor Research Articles

Electrodiagnosis of ulnar neuropathy at the elbow (Une): A bayesian approach

In ulnar neuropathy at the elbow (UNE), we determined how electrodiagnostic cutoffs [across-elbow ulnar motor conduction velocity slowing (AECV-slowing), drop in across-elbow vs. forearm CV (AECV-drop)] depend on pretest probability (PreTP). Fifty clinically defined UNE patients and 50 controls underwent ulnar conduction testing recording abductor digiti minimi (ADM) and first dorsal interosseous (FDI), stimulating wrist, below-elbow, and 6-, 8-, and 10-cm more proximally. For various PreTPs of UNE, the cutoffs required to confirm UNE (defined as posttest probability = 95%) were determined with receiver operator characteristic (ROC) curves and Bayes Theorem. On ROC and Bayesian analyses, the ADM 10-cm montage was optimal. For PreTP = 0.25, the confirmatory cutoffs were >23 m/s (AECV-drop), and <38 m/s (AECV-slowing); for PreTP = 0.75, they were much less conservative: >14 m/s, and <47 m/s, respectively. (1) In UNE, electrodiagnostic cutoffs are critically dependent on PreTP; rigid cutoffs are problematic. (2) AE distances should be standardized and at least 10 cm.

Application of ultrasound to the median sensory and ulnar motor nerve conduction studies

Application of ultrasound to the median sensory and ulnar motor nerve conduction studies

Ulnar nerve lesion at the wrist related to pisotriquetral joint arthropathy

Ulnar nerve lesions at the wrist (UNLW) are always difficult to localize clinically and sometimes electrophysiologically. Finding conduction block when studying ulnar motor nerve conduction (CB) across the wrist is sometimes the only way to demonstrate that the ulnar deep motor branch (UDMB) is entrapped. An elderly woman who had bilateral carpal tunnel syndrome (CTS) and thumb osteoarthritis for many years experienced worsening of left hand impairment recently. Electrodiagnostic and ultrasound examinations revealed an acute and severe UDMB lesion related to pisotriquetral joint effusion. The patient received a local injection of a corticosteroid that provided rapid recovery. The diagnosis of UDMB lesion is especially difficult when CTS coexists, but CTS may allow for early diagnosis, if CB at the wrist is not overlooked. Chondrocalcinosis was responsible for the systemic inflammation, the CTS, the pisotriquetral joint effusion, and the UDBM compression, which has not been reported previously.

The effects of working hours on nerve conduction test in computer operators.

Long hours of work at a computer can result in potential adverse effects such as pain, paraesthesia, and subjective weakness of upper extremities with associated decreased nerve conduction velocities of peripheral nerves (median and ulnar). To determine whether repetitive tasks performed for long hours by computer operators can lead to peripheral neuropathy as measured by nerve conduction studies of upper extremities. We performed nerve conduction tests on 50 computer operators in two study groups. Group I consisted of computer operators who worked a minimum of 6 hours per day at the computer while Group II worked a maximum of 2 hours per day. Significant differences were observed between groups for most physical signs. In addition, there were significant differences between the groups for nerve conduction velocities of the medial (motor & sensory) and ulnar (motor & sensory) nerves. We found symptoms of pain, paraesthesia and subjective weaknesses as well as decreased conduction velocities of peripheral nerves in computer operators who work long hours. Further nerve conduction studies are needed to confirm predictive value for the development of carpal tunnel syndrome. computer operator, long work hours, nerve conduction studies.

Ultrasonographic cross‐sectional area normal values of the ulnar nerve along its course in the arm with electrophysiological correlations in 100 asian subjects

Normative cross-sectional areas (CSAs) have been obtained for the Western population. We obtained CSAs of normal ulnar nerves at predetermined sites and correlate them with electrophysiological variables in Asian subjects. One hundred healthy volunteers, mean age 39 ± 14 years (range, 18-75 years), were recruited for the study after obtaining informed consent. The ulnar nerve was examined ultrasonographically from wrist to axilla, and CSA was measured at predetermined sites. All subjects underwent a simultaneous standardized nerve conduction study. Men had larger CSAs, and CSAs increased with advancing age. There was a statistically significant correlation between CSA at the wrist and distal ulnar motor latency (P = 0.005). Ulnar CSA correlated with age, gender, and distal motor latency. No correlations were observed with height, weight, or body mass index.

Influence of Age, Gender, and Sidedness on Ulnar Nerve Conduction

Anatomic variation and susceptibility for injuries depending on gender were described for the ulnar nerve. The aim of this study was to investigate the association between gender and ulnar never motor conductance and the influence of sidedness for this association. Study was conducted as a retrospective study using nerve conduction study data of ulnar nerve of 2,526 patients. Influences of age, gender, and sidedness on ulnar never motor conduction velocity (UMV) were investigated. Regression analysis was conducted to compare the relationship between UMV and age. Regression was significantly higher in males (-0.253 vs. -0.113), suggesting higher influence of age on UMV in males than in females. When analyzing right and left sides separately, influence of age on UMV is higher in males (-0.286 vs. -0.109) only in right side. Multiple regression analysis was done comparing the influence of age, gender, and sidedness on UMV, and it found that the order of influence is gender, age, and sidedness (Beta values 0.153, -0.140, and 0.029). Ulnar nerve motor conductance depends on gender, age, and sidedness. Males are having lower UMV than females. Age-dependant change of UMV is more prominent in males than in females and is more prominent in right hand than in left hand in males.

Long term follow up results of a pediatric brachial plexus laceration

A rare case of pediatric brachial plexus laceration is presented. A five-year-old boy who sustained a sharp laceration on his right axillary region was immediately operated. The axillary artery, radial, ulnar and musculocutaneous nerve branches of the brachial plexus, and the lateral root of the median nerve were totally lacerated. The medial root of the median nerve was partially transected. All of the lacerated brachial plexus elements and axillary artery were immediately repaired. Significant functional recovery was determined even six months after the repair. Motor and sensory functions of the affected extremity were almost totally restored at the postoperative 21st month, except for the ulnar nerve motor functions. There was no cold intolerance or trophic change at the injured extremity. Primary repair of a brachial plexus laceration injury in the pediatric population can be expected to produce successful functional recovery results, even in a relatively short period after the repair.

Electrophysiological pattern of 53 cases of ulnar nerve lesion at the wrist

We aimed to evaluate the relative diagnostic sensitivity and specificity of different motor and sensory conduction electrodiagnostic (EDX) tests used to demonstrate ulnar neuropathy at the wrist (UNW). We also reported some data on associated nerve lesions and unusual causes of UNW. A prospective case series was conducted in 53 cases of UNW and 100 cases of ulnar neuropathy at elbow (UNE). All cases underwent the same EDX examination according to a protocol defined in 1997. A few cases required additional conduction tests with coaxial needle recording. The diagnostic sensitivity of the distal motor latency (DML) to adductor digiti minimi (ADM) and sensory conduction was 42% and 19% respectively. The diagnostic sensitivity of the DML to first dorsal interosseous (FDI) was 66% and studying conduction across the wrist to search for conduction block (CB) improved the diagnostic sensitivity up to 90%. In 10% of cases, no EDX test of this protocol allowed locating the site of the UNL. The specificity of each test was 100% for controls, and varied from 100% for conduction block (CB), to 95% (DML to FDI) for UNE. CB at the wrist in UNW was 2.7times more frequent than at the elbow in UNE (57% vs. 22%; P<0.0001). Finally, we found three cases of isolated sensory UNW, 16 of sensory and motor UNW, and 34 of pure motor lesions. A median nerve lesion at the wrist coexisted in 22 cases. Improving UNW diagnosis requires systematic study of the ulnar motor conduction to FDI across the wrist, and in a few cases conduction tests with a coaxial needle recording.

Ulnar Motor Nerve Conduction Study for Lesion Localization in Ulnar Neuropathy at Elbow

Ulnar Motor Nerve Conduction Study for Lesion Localization in Ulnar Neuropathy at Elbow

Plasma total homocysteine is not associated with peripheral neuropathy in a groups Bangladeshi type 2 diabetic subjects

Aims: The present study was undertaken to explore the relationship of plasma homocysteine in the pathogenesis of neuropathy in diabetic patients.Subjects and Methods: Forty two type 2 diabetic patients [22 with neuropathy (DN group) and 20 without neuropathy (DNN group)], age range between 35-70 years had relatively controlled glycemia and duration of diabetes 7-15 years, were studied. Motor and sensory nerve conduction velocities and action potential amplitudes of peripheral nerves were determined by following standard protocol. HbA1c was estimated by modified HPLC (BIO-RAD Variant, USA). Serum C-peptide was measured by enzyme linked immunosorbentassay (ELISA), plasma total homocysteine by Fluorescent Polarization Immunoassay (FPIA). Results: Age, BMI and blood pressure of the study subjects were. Duration of diabetes between DN and DNN groups was comparable. DN group had significantly higher fasting glucose levels (9.8±3.8, mmol/l) compared to the DNN group (6.9±1.8, p=0.004). This trend was also reflected in the HbA1c level: 8.7± 2.1 vs 7.2±1.6 in DN group and DNN group respectively (p=0.009). The two diabetic groups had relatively higher absolute C-peptide level compared to the controls (p=ns). DN and DNN groups had significantly higher plasma homocysteine level compared to the Controls. But between the two diabetic groups no significant difference was observed. Ulnar and peroneal motor nerve conduction velocities and compound muscle action potentials in the diabetic neuropathy group significantly lower compared to diabetic counterpart and the controls. Ulnar and sural sensory nerve conduction velocities and action potentials were significantly lower in the diabetic neuropathy group compared to the diabetic counterpart and the controls. Plasma homocysteine did not show any correlation with nerve conduction velocities and action potential amplitudes.Conclusions: The data concluded that (i) Diabetic neuropathy may not be related to hyperhomocysteinemia in type 2 diabetic patients of Bangladeshi origin; (ii) Hyperglycemia, even at milder level, is related to neuronal dysfunction in these subjects; and (ii) Hyperinsulinemia don't seem to be prerequisite for neuropathy in these subjects. DOI: http://dx.doi.org/10.3329/bjms.v11i4.12607 Bangladesh Journal of Medical Science Vol. 11 No. 04 Oct’12

Application of Ultrasound in an Ulnar Motor Nerve Conduction Study after Anterior Ulnar Nerve Transposition

Ulnar nerve entrapment at the elbow (cubital tunnel syndrome) is one of the most common peripheral nerve entrapments. Surgical management of cubital tunnel syndrome often involves anterior transposition of the ulnar nerve. After surgical treatment of ulnar neuropathy, patients will often be referred for a repeat nerve conduction study (NCS) to assess for changes in conduction velocity. However, in a patient with a transposed ulnar nerve, it is technically difficult to localize the proper NCS stimulation sites, requiring nerve mapping by multiple submaximal stimulations. We present a case report utilizing ultrasound to localize and map the transposed ulnar nerve for the ulnar motor NCS test across the elbow. As a result, the need for nerve mapping through repeated stimulation is eliminated.

HAND WEAKNESS IN CHARCOT-MARIE-TOOTH DISEASE 1X

There have been suggestions from previous studies that patients with Charcot-Marie-Tooth disease (CMT) have weaker dominant hand muscles. Since all studies to date have included a heterogeneous group of CMT...

Poster 139 A Novel Technique for Electrodiagnostic Testing of the Ulnar Motor Nerve

Poster 139 A Novel Technique for Electrodiagnostic Testing of the Ulnar Motor Nerve

Supercharged End-to-Side Anterior Interosseous to Ulnar Motor Nerve Transfer for Intrinsic Musculature Reinnervation

Functional motor recovery after peripheral nerve injury is predominantly determined by the time to motor end plate reinnervation and the absolute number of regenerated motor axons that reach target. Experimental models have shown that axonal regeneration occurs across a supercharged end-to-side (SETS) nerve coaptation. In patients with a recovering proximal ulnar nerve injury, a SETS nerve transfer conceptually is useful to protect and preserve distal motor end plates until the native axons fully regenerate. In addition, for nerve injuries in which incomplete regeneration is anticipated, a SETS nerve transfer may be useful to augment the regenerating nerve with additional axons and to more quickly reinnervate target muscle. We describe our technique for a SETS nerve transfer of the terminal anterior interosseous nerve (AIN) to the pronator quadratus muscle (PQ) end-to-side to the deep motor fascicle of the ulnar nerve in the distal forearm. In addition, we describe our postoperative therapy regimen for these transfers and an evaluation tool for monitoring progressive muscle reinnervation. Although the AIN-to-ulnar motor group SETS nerve transfer was specifically designed for ulnar nerve injuries, we believe that the SETS procedure might have broad clinical utility for second- and third-degree axonotmetic nerve injuries, to augment partial recovery and/or "babysit" motor end plates until the native parent axons regenerate to target. We would consider all donor nerves currently utilized in end-to-end nerve transfers for neurotmetic injuries as candidates for this SETS technique.

Chondroitinase ABC promotes plasticity of spinal reflexes following peripheral nerve injury

Peripheral nerve transection, even with optimal repair, can result in an extensive disruption of central connectivity, which can lead to long-lasting impairments in motor and sensory function. We hypothesised that removal of spinal cord chondroitin sulphate proteoglycans (CSPGs) would promote plasticity in the spinal cord, allowing compensation for inaccurate peripheral reinnervation. In adult rats, the median and radial nerves were cut and repaired, either correctly (median to median and radial to radial), or incorrectly (median to radial and vice versa). This produced two levels of inaccuracy of peripheral reinnervation. Whole nerve recordings from a third brachial plexus nerve, the ulnar, were made during median or radial nerve stimulation. Low and high threshold reflexes were characterised in uninjured animals and a clear difference in the pattern of ulnar response to flexor (median) or extensor (radial) stimulation was established. This included the phenomenon of wind-up, where repetitive median nerve stimulation at supramaximal C-fibre threshold leads to a progressive increase in the number of spikes recorded. To achieve digestion of CSPGs a lentiviral vector expressing ChABC was delivered to the spinal cord via intraspinal injection. Following ChABC treatment, we found several indicators of reorganisation of central connections. Firstly, we found that the amplitude of a low threshold, polysynaptic reflex could be increased after nerve injury, only following treatment with ChABC. Secondly, wind-up of motor responses in the ulnar nerve to supramaximal stimulation of afferents in the median nerve, which collapses after nerve injury (to ~25% of uninjured value), could be restored by ChABC after correct repair (to ~90% of uninjured value). Thirdly, wind-up in ulnar motor axons to stimulation of radial nerve afferents, which is minimal in the uninjured state, becomes significantly stronger after nerve injury and ChABC treatment (a 10 fold increase). We propose that application of a plasticity-promoting treatment to the spinal cord allows the amplification of adaptive changes in response to inaccurate wiring in the periphery.

32. Contribution of far-field potentials on motor unit number estimation (MUNE)

and chronic inflammatory demyelinating polyneuropathy (CIDP). Case report: A 78-year-old man presented with a 2-week history of ataxia, progressive weakness, and numbness of both hands and feet. His weakness was such that he was unable to ambulate. He has a history of well-controlled diabetes and refractory Crohn’s disease treated with infliximab for 1 year. He had marked distal muscles and mild proximal muscles weakness. He was areflexic throughout and had loss of proprioception below his wrists and knees with preservation of pain sensation. Initial nerve conduction studies (NCSs) of the median, ulnar, peroneal, and tibial motor nerves showed markedly prolonged distal latencies, decreased amplitudes, temporal dispersion, and absent F waves. His sensory NCSs were unresponsive. It was concluded that his CIDP was secondary to infliximab after ruling out other causes. He received intravenous (IV) Solu-Medrol 1 g daily for 3 days and IV immunoglobulin (IVIg) for 5 days with marked improvement. NCSs 6 weeks later showed shortened latencies, shortened F waves, and increased amplitudes. Conclusion: Infliximab is a TNF-alpha inhibitor used in the treatment of Crohn’s disease. It has been rarely linked to MS and CIDP. In this report the patient achieved significant clinical and electrodiagnostic improvement with a combination of IVIg and Solu-Medrol treatment.

Posterior Interosseous and Ulnar Nerve Motor Palsies After a Minimally Displaced Radial Neck Fracture

Peripheral nerve injury is a serious potential complication following an upper extremity fracture. A rare case of acute posterior interosseous nerve and ulnar nerve palsy following a minimally displaced radial neck fracture is reported. With nonsurgical management, both nerves demonstrated excellent functional recovery. Although rare, nerve palsies can occur during a variety of upper extremity clinical situations, including minimally displaced fractures, and the importance of a detailed neurologic examination cannot be overstated.

Nerve Conduction study in healthy individuals, a preliminary age based study

Nerve conduction study assesses peripheral nerve functions and has clinical implication. To study the effect of age on nerve conduction study variables in healthy adults. Cross sectional study was done from Jan 2006 to Dec 2006 in department of Physiology, BP Koirala Institute of Health Sciences, Dharan, Nepal. The study was done in 34 (younger, n= 18, 17 to 29 years; older, n= 16, 30 to 57 years) consenting healthy adults of either sex. The compound muscle action potential and sensory nerve action potential were recorded using standard technique. Due to the non-normal distribution of data, the effect of age on nerve conduction study variables was analyzed using Mann Whitney U test. Younger vs. older individuals: older had lower Compound Muscle action potential amplitude (mV) in all motor nerves except radial and left ulnar nerves. Compound Muscle action potential duration (ms) was shorter in older (p less than 0.05) in ulnar, tibial, right median and left common peroneal motor nerves than the younger: right median (6.92±1.3 vs. 8.5±1.88), right ulnar (7.09±1.54vs. 8.2±1.31), left ulnar (10.56±1.44 vs. 12.06±1.5), right tibial (6.28±0.81vs. 7.28±1.12), and left tibial (9.58±1.52vs.10.78±1.71). Sensory nerve actional potential amplitude (μV) was smaller in older as compared to younger: right median (19.01±7.83 vs. 26.97±10.63), right ulnar (10.9±3.44 vs.16.09±5.85) and right radial (14.31±4.34 vs.19.72±6.47). SNAP duration (ms) was longer in older: right ulnar (1.34±0.17 vs.1.26± 0.18), left ulnar (1.46±0.14 vs. 1.29±0.26), and left median (1.11± 0.14 vs. 1± 0.14). Age has definite effects on amplitude and duration of motor and sensory nerves. Different nerves have different timing of aging. Without adjustment for age, the sensitivity and specificity of nerve conduction study will decrease whenusing the same reference data in patients with different age.

The Second Lumbrical–Interosseous Latency Comparison in Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. Electromyogram (EMG) is beneficial in supporting the diagnosis of CTS. We compared standard nerve conduction studies of EMG with median and ulnar motor nerve conduction studies from recordings of second lumbrical and interosseal muscles in supporting the diagnosis of CTS. In this study, a total of 242 patients were included, and a total of 375 hands were involved. Electrophysiologic CTSs were diagnosed in 283 hands of 161 patients. A significant association between second lumbrical-interosseal distal motor latency difference (2LI-MDLD) and CTS was found in this study. Statistically, every 0.1 increment in the 2LI-MDLD value was observed to increase the risk of disease by 1.74. When a cut-off of ≥ 0.5 for 2LI-MDLD is taken for predicting CTS, the sensitivity of the test is found to be 89.4% and specificity 84.4%. When the cut-off value for motor distal latency of second lumbrical of the median nerve (2L-MDL) was taken as ≥ 3.15 milliseconds in the diagnosis of CTS, the sensitivity of the test was 87.3%, and specificity 70.7%. Previous reports and our findings suggest that in CTS diagnosis, not only 2LI-MDLD value but also 2L-MDL value are easy and rapidly obtainable and offer additional information in very severe cases where compound muscle action potentials (CMAP) cannot be recorded from the abductor pollicis brevis (APB) muscle.

New Clinical Motor Test for Cubital Tunnel Syndrome

When suspecting proximal injury to the ulnar nerve, it is common to assess the integrity of the small finger flexor digitorum profundus muscle via methods such as isolated blocking exercises, active exercises, and applied resistance. This author describes another method of assessing the integrity of proximal ulnar nerve motor function.