Ulnar Nerve Cross-sectional Area Research Articles

Extensive sonographic ulnar nerve enlargement above the medial epicondyle is a characteristic sign in Hansen's neuropathy.

ObjectiveEarlier studies have shown sonographic enlargement of the ulnar nerve in patients with Hansen’s neuropathy. The present study was performed to determine whether sonography or electrophysiological studies can detect the specific site of ulnar nerve pathology in leprosy.MethodsEighteen patients (thirty arms) with Hansen’s disease and an ulnar neuropathy of whom 66% had borderline tuberculoid (BT), 27% lepromatous leprosy (LL) and 7% mid-borderline (BB) leprosy were included in the study. Cross-sectional area (CSA) of ulnar nerve was measured every two centimeters from wrist to medial epicondyle and from there to axilla. All patients underwent standard motor and sensory nerve conduction studies of the ulnar nerve. Thirty age and sex matched controls underwent similar ulnar nerve CSA measurements and conduction studies.ResultsUlnar nerve was clinically palpable in 19 of the 30 arms of patients. Motor and sensory nerve conduction studies of the ulnar nerve showed a reduced compound motor action potential and sensory nerve action potential amplitude in all patients. Motor Conduction Velocity (MCV) in patients were slower in comparison to controls, especially at the elbow and upper arm, but unable to exactly locate the site of the lesion. In comparison to controls the ulnar nerveCSA was larger in the whole arm in patients and quite specific the maximum enlargement was seen between nulnar sulcus and axilla, peaking at four centimeters above the sulcus.ConclusionsA unique sonographic pattern of nerve enlargement is noted in patients with ulnar neuropathy due to Hansen’s disease, while this was not the case for the technique used until now, the electrodiagnostic testing. The enlargement starts at ulnar sulcus and is maximum four centimeters above the medial epicondyle and starts reducing further along the tract. This characteristic finding can help especially in diagnosing pure neuritic type of Hansen’s disease, in which skin lesions are absent, and alsoto differentiate leprosy from other neuropathies in which nerve enlargement can occur.

Nerve conduction velocity and cross-sectional area in ulnar neuropathy at the elbow.

In the precise localization of ulnar neuropathy at the elbow (UNE) we have noted discrepancies between electrodiagnostic (EDx) and ultrasonographic (US) findings. We aimed to explore the relationship between the 2 techniques. Four study-blind examiners took a history and performed neurologic, EDx, and US examinations of a group of prospectively recruited patients with UNE. They assessed the relationship between ulnar nerve cross-sectional area (CSA) and motor nerve conduction velocity (MNCV). In 106 patients with UNE at the retrocondylar (RTC) groove, the highest CSA and lowest MNCV were noted in the same short segment. In 54 patients with UNE at the humeroulnar aponeurosis (HUA), the highest CSA and lowest MNCV were noted proximal to the HUA. MNCV and CSA were highly correlated in UNE. Ulnar nerve slowing proximal to the entrapment at the HUA was surprising, but consistent with previous studies done on carpal tunnel syndrome. Muscle Nerve 56: E65-E72, 2017.

Estimation of ultrasound reference values for the ulnar nerve fascicular number and cross-sectional area in young males: A cross-sectional study.

The objective of this study is to estimate the reference values for the number of fascicles and cross-sectional area (CSA) of the ulnar nerve at a single predetermined site by ultrasound in healthy young adult males.The demographic and physical characteristics of 50 adult male volunteers were evaluated and recorded. The subjects were positioned supine with the elbow flexed at 90° and the palm of the hand placed on a hard surface. The ulnar nerve was scanned bilaterally 1 cm proximal to the medial epicondyle in projection of the cubital tunnel. The number of fascicles and mean CSA of the ulnar nerve were identified. In addition, the side-to-side differences of the estimated reference values and their correlations with the age, weight, height, and body mass index (BMI) were evaluated.The mean fascicular number was 5.66 ± 1.48, the mean ultrasound-estimated CSA of the ulnar nerve was 6.54 ± 1.67 mm2 and both sides were comparable in the mean CSA and fascicular number (6.43 ± 1.80 mm2 and 5.88 vs 6.64 ± 1.55 mm2 and 5.44, for right and left side, respectively). No significant correlations were observed between CSA and fascicles number and age, weight, height, or BMI of study subjects.The reference values for the number of fascicles number and the CSA of the ulnar nerve at a single predetermined site were identified. These values could be used for the sonographic diagnosis and follow-up of the ulnar nerve lesions.

Ultrasonographic and Electrophysiological Evaluation of the Ulnar Nerve in Patients Diagnosed With Carpal Tunnel Syndrome

In this study, we evaluated the ulnar nerve of patients diagnosed with carpal tunnel syndrome (CTS) using electrophysiology and ultrasonography. The study included 86 patients (136 hands) and 39 controls (78 hands) with normal electrophysiological assessment. According to Bland's classification, patients were divided into group 1 (grades 1-3 CTS) or group 2 (grades 4-6 CTS). The ulnar nerve was evaluated at the wrist using nerve conduction studies and ultrasonography. The sensory velocity was slower in group 2 than in group 1 (P < 0.001), slower in group 2 than in controls (P < 0.001), and slower in group 1 than in controls (P < 0.005). Although the ultrasonography results showed a reduction in the ulnar nerve cross-sectional area in group 1 compared with controls, the difference was not statistically significant. However, the reduction was significant in group 2 compared with group 1 and controls (P < 0.001). Based on our study results, the ulnar nerve is affected electrophysiologically and morphologically in patients with CTS, especially those with advanced-stage CTS.

Quantifying disease progression in amyotrophic lateral sclerosis using peripheral nerve sonography.

In this study we investigated whether peripheral nerve sonography could be used as a biomarker to monitor disease progression in amyotrophic lateral sclerosis (ALS). In 37 patients, ulnar and median nerve cross-sectional area (CSA) was determined in at least 2 ultrasound sessions; mean follow-up was 14.5 months. Linear mixed-effects models were conducted to analyze time effects on CSA. Ulnar nerve CSA declined significantly at a monthly rate of -0.04 mm(2) (forearm) and -0.05 mm(2) (wrist); the decrease was more pronounced when baseline CSA was greater. To detect a 50% treatment effect on ulnar nerve CSA, 332 patients would need to be entered in a hypothetical randomized, controlled clinical trial. Time had no significant impact on median nerve CSA. Distal ulnar nerve ultrasound may be a useful biomarker to monitor disease progression in ALS, especially as hypothetical treatment effects on CSA seem to be detectable in manageable cohort sizes. Muscle Nerve 54: 391-397, 2016.

ID 184 – Effect of carpal tunnel syndrome on the ulnar nerve at the wrist: Electrophysiologic and ultrasonographic studies

Objectives The aim of this study is to compare the ulnar nerve by electrophysiologic and ultrasonographic study between patients with carpal tunnel syndrome (CTS) and controls. We also compare the cross sectional area (CSA) of ulnar nerve before and after carpal tunnel release in CTS. Methods We recruited 41 hands with CTS and 37 hands of controls. Electrophysiologic study of ulnar nerve was done in all participants. CSA of median and ulnar nerve at the wrist was evaluated by ultrasonography. Fifteen hands with CTS who underwent carpal tunnel release were evaluated with ultrasound after the operation. Results The ulnar nerve CSA of the patients of CTS (5.16 ± 1.04) was statistically significant larger than control (3.56 ± 0.52). After transverse carpal ligament release operation, the CSA of ulnar nerve after operation (4.20 ± 0.84) was statistically significant smaller compared with that of prior to surgery (5.23 ± 1.02). The CSA of median nerve was significant correlation with the CSA of ulnar nerve. Conclusions CSA of ulnar nerve as well as medan nerve increased in patients with CTS. Ulnar nerve is affected by carpal tunnel syndrome.

Is ultrasonography useful in the diagnosis of the polyneuropathy in diabetic patients?

[Purpose] The aim of this study was to investigate the usefulness of ultrasonography for the diagnosis of polyneuropathy in diabetic patients by examination of the median and ulnar nerves. [Subjects and Methods] Sixty-three diabetic patients and fourteen controls were enrolled in the study. Nerve conduction studies were performed on both upper and lower limbs. Median and ulnar nerve cross-sectional areas were measured at the wrist and forearm levels in 140 hands by ultrasound. [Results] The median nerve cross-sectional area was increased at the hook of hamatum, pisiform bone, and radioulnar joint levels in patients with carpal tunnel syndrome. The ulnar nerve area at the medial epicondyle was significantly increased in the diabetic polyneuropathy (9.2 ± 1.6), diabetic polyneuropathy plus carpal tunnel syndrome (9.3 ± 1.4), and carpal tunnel syndrome (9.2 ± 1.9) groups compared with the control group (7.7 ± 1.1). In receiver operating characteristics analysis, the cutoff value of the ulnar nerve was 8.5 mm2 at ulnar epicondyle with 71.4% specificity and 70.4% sensitivity, corresponding to the highest diagnostic accuracy for diabetic polyneuropathy. [Conclusion] Ultrasonographic examination of the median and ulnar nerves can be an alternative or additional diagnostic modality for the evaluation of neuropathies in diabetic patients.

Pre- and Postseason Dynamic Ultrasound Evaluation of the Pitching Elbow

To use ultrasound imaging to document changes over time (i.e., preseason v postseason) in the pitching elbow of high school baseball pitchers. Twenty-two high school pitchers were prospectively followed. Pitchers were evaluated after a 2-month period of relative arm rest via preseason physical exams, dynamic ultrasound imaging of their throwing elbow, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) assessment. Players were reevaluated within 1 week of their last game. Dynamic ultrasound images were then randomized, blinded to testing time point, and evaluated by 2 fellowship-trained musculoskeletal radiologists. Average pitcher age was 16.9 years. Average pitches thrown was 456.5, maximum velocity 77.7 mph, games pitched 7.3, and days off between starts 6.6. From preseason to postseason, there were significant increases in ulnar collateral ligament (UCL) thickness (P = .02), ulnar nerve cross-sectional area (P = .001), UCL substance heterogeneity (P = .001), and QuickDASH scores (P = .03). In addition, there was a nonsignificant increase in loaded ulnohumeral joint space (P = .10). No pitchers had loose bodies on preseason exam, while 3 demonstrated loose bodies postseason. The increase in UCL thickness was significantly associated with the number of bullpen sessions per week (P = .01). The increase in ulnar nerve cross-sectional area was significantly associated with the number of pitches (P = .04), innings pitched (P = .01), and games pitched (P = .04). The stresses placed on the elbow during only one season of pitching create adaptive changes to multiple structures about the elbow including UCL heterogeneity and thickening, increased ulnohumeral joint space laxity, and enlarged ulnar nerve cross-sectional area. Level II prospective observational study.

V14. Complementary use of central and peripheral non-invasive imaging to distinguish between subtypes in amyotrophic lateral sclerosis

Background Diffusion tensor imaging (DTI) has successfully been used to investigate ALS-related changes in the central nervous system (CNS). Many studies reported, for example, decreased white matter integrity in the cortico-spinal tract (CST). Consequently, DTI has been proposed as a potential biomarker to support clinical diagnosis. While recent results look promising in principle, the reliability of DTI-based diagnosis seems currently insufficient for practical use. To enhance discriminative performance, one would ideally integrate information from complementary diagnostic modalities during classifier construction. Objective In a recent study, we observed ALS-related thinning of different peripheral nerves based on cross-sectional area (CSA) measurements using high-resolution ultrasound ( Schreiber et al., 2014 ). Here, we combined DTI-based measures of the CST with CSA of the upper limb peripheral nerves to improve imaging-based discrimination between different ALS subtypes and healthy controls. Methods 51 patients with ALS (14 classic, 10 upper motor neuron dominant (UMND), 14 lower motor neuron dominant (LMND), 8 bulbar, and 5 primary lateral sclerosis (PLS)) and 18 healthy controls underwent diffusion-weighted MRI at 3T and peripheral nerve ultrasound in order to determine the fractional anisotropy (FA) in the white matter underneath the motor cortex, posterior limb of the internal capsule, cerebral peduncle, pons and medulla oblongata as well as the CSA of the N. medianus and the N. ulnaris. Statistical comparisons were conducted using analysis of variance (ANOVA). Classifier construction was carried using linear discriminants after dimensionality reduction based on principal component analysis. Separate classifiers were constructed using FA, CSA, and both FA and CSA data, respectively. Results Compared to controls, ALS patients exhibited significant, distally pronounced reductions of the ulnar nerve CSA across all subtypes with the exception of PLS. In addition, DTI data revealed significant differences between ALS subtypes with pronounced impairment of the CST in UMND and PLS and modest impairment in LMND patients, while bulbar ALS is intermediately located within this spectrum. Classification performance was considerably higher exploiting both central and peripheral data compared to using either modality alone. Most notably, UMND and PLS patients could be accurately separated. Conclusion Combining central and peripheral data acquired through DTI and ultrasound, respectively, leads to improved discrimination not only between ALS and healthy controls, but also between ALS subtypes. This speaks to the complementary role of both methods regarding their contribution to classification performance. The potential of combining both imaging methods is particularly evident in the reliable separation of UMND and PLS patients, since early differentiation of these subtypes remains a difficult problem in clinical practice.

Diagnostic cutoff value for ultrasonography in the ulnar neuropathy at the elbow.

ObjectiveTo determine the diagnostic cutoff values of ultrasonographic measurements in ulnar neuropathy at the elbow (UNE).MethodsTwenty-five elbows of 23 patients (9 females, 16 males) diagnosed with UNE and 30 elbows of 30 healthy controls (15 females, 15 males) were included in our study. The ulnar nerve cross-sectional area (CSA) was measured at the Guyon canal, midforearm, and maximal swelling point (MS) around the elbow (the cubital tunnel inlet in healthy controls). CSA measurements of the ulnar nerve at each point, the Guyon canal-to-MS ulnar nerve area ratio (MS/G), and the midforearm-to-MS ulnar nerve ratio (MS/F) were calculated.ResultsAmong the variables, only CSA at MS, MS/G, and MS/F displayed significant differences between the control and patient groups. The cutoff value for diagnosing UNE was 8.95 mm2 for the CSA at MS (sensitivity 93.8%, specificity 88.3%), 1.99 for the MS/G (sensitivity 75.0%, specificity 73.3%), and 1.48 for the MS/F (sensitivity 93.8%, specificity 95.0%).ConclusionThese findings may be helpful to diagnose UNE.

G.P.291: Peripheral nerve and spinal root ultrasonography in amyotrophic lateral sclerosis

High-resolution ultrasound has been used to evaluate several neuromuscular conditions. We can find some reports of muscle ultrasonography. Previous reports have documented muscle ultrasonography can clearly visualize fasciculation, one of characteristic features of amyotrophic lateral sclerosis (ALS), and can contribute to the diagnosis of ALS. But there are few reports of nerve ultrasonography in ALS. The aim of this study was to evaluate if ultrasonography can detect any characteristic findings of peripheral nerves and ventral spinal roots in ALS. Four patients with ALS (2 men and 2 women, mean age 67.0 years) underwent nerve ultrasonography to measure the cross-sectional area (CSA) of median and ulnar nerves at 4 levels, and the CSA and the diameter of C5, C6, C7 ventral spinal roots. They were also examined nerve conduction study (NCS). We investigated the correlations between findings of ultrasonography and physiological parameters. The CSA of median nerve was larger in the wrist than in the forearm, and the CSA of ulnar nerve was larger in the elbow than in the other levels. There was no difference between the CSA in the ALS patients and that in controls in reported. But the diameter and the CSA of ventral spinal roots were smaller in the ALS patients than those in the controls. On the other hand, the distal motor latency (DL) of median nerve was prolonged in all patients, the DL of ulnar nerve was prolonged in 2. The compound muscle action potential (CMAP) amplitude of median nerve was reduced in 2 patients. The latency of F wave and sensory NCS were normal in all patients. Nerve ultrasound demonstrates distal nerve and ventral spinal root atrophy in ALS and should be further explored as a disease biomarker.

Contribution of static and dynamic ultrasound in cubital tunnel syndrome

IntroductionElectroneuromyography (ENMG) is the gold standard examination in cubital tunnel syndrome (CuTS), but sheds no light on etiology. High-resolution ultrasound (HRU) analyzes the anatomic abnormalities and physical properties of the ulnar nerve (UN) and enables dynamic study. The present non-randomized prospective study compared HRU with clinical, ENMG and intraoperative findings. Material and methodsSixty patients were included. The McGowan clinical classification as modified by Goldberg was employed, and ENMG lesions were ranked for severity. HRU screened for morphologic abnormalities of the ulnar nerve and cubital tunnel, measuring UN cross-sectional area (UNCSA) and flattening index (FI) in the cubital tunnel, in extension and flexion. UN stability was assessed. ResultsUltrasound found 2 stenoses, 29 pseudoneuromas 25 dedifferentiations. There were 16 morphologic abnormalities. Mean cubital tunnel UNCSA (in cm2) and FI were respectively 0.112 and 1.549 in extension and 0.117 and 1.827 in flexion. Nineteen cases of UN instability were found on HRU, versus 17 intraoperatively. Only 8 patients showed no abnormality on HRU. Pseudoneuroma or dedifferentiation on HRU correlated with clinical stage (P=0.2579 and 0.2615, respectively). Dedifferentiation was associated with severe abnormality on ENMG (P<0.5). Thirty-two stenoses, 18 pseudoneuromas and 10 epitrochlearis anconeus muscles were found intraoperatively, matching HRU abnormalities. DiscussionThe present findings were comparable to those of the literature. Cubital tunnel UNCSA was elevated in case of CuTS, with cut-off at 0.112cm2. FI was elevated in flexion (P=0.0063). The rate of UN instability was 32%, compared to 21–60% in the literature. HRU findings matched the clinical and ENMG classifications. HRU proved to be an effective diagnostic tool for CuTS and its etiologies. Level of evidenceIV.

5. Segmental changes in ulnar nerve ultrasound across the elbow and their pathophysiological significance in ulnar neuropathy

To characterise changes in the ulnar nerve by ultrasound of different segments across the elbow, to help determine the optimum site of quantitative nerve measurements, and to correlate ultrasound measurements with electrodiagnostic findings. Ultrasound studies were performed on 17 limbs with clinically and electrophysiologically confirmed UNE and 52 control subjects at four standardised sites proximal and distal to the medial epicondyle (P2, P1, D1 and D2), corresponding to segments of ulnar nerve inching studies. In patients with UNE, ulnar nerve cross sectional area (CSA) and hypoechoic fraction (HEF) were significantly increased at D1 ( p < 0.05) and P1 ( p = 0.02). UNE patients had significantly greater Maximum CSA ( p = 0.002) and HEF ( p < 0.001). Receiver Operating Characteristics (ROC) analysis identified the optimum area under the curve (AUC) for measurement of CSA max (0.80) and HEF max (0.82). In individual segments, measurement of CSA and HEF was most discriminative of patients from controls at D1 (AUC 0.78 and 0.76 respectively). Motor nerve conduction velocity across the elbow significantly correlated with CSA max and HEF max ( R = 0.6, p < 0.05). CSA and HEF in individual segments did not correlate with corresponding latencies on inching studies, but CSA did correlate with latencies of adjacent segments. UNE is best diagnosed on ultrasound using CSA max and HEF max . Nerve changes detected on ultrasound may not exactly localise the site of compression but reflect secondary changes in the nerve.

Ultrasound of inherited vs. acquired demyelinating polyneuropathies

We compared features of nerve enlargement in inherited and acquired demyelinating neuropathies using ultrasound. We measured median and ulnar nerve cross-sectional areas in proximal and distal regions in 128 children and adults with inherited [Charcot-Marie-Tooth-1 (CMT-1) (n = 35)] and acquired [chronic inflammatory demyelinating polyneuropathy (CIDP) (n = 55), Guillaine-Barre syndrome (GBS) (n = 21) and multifocal motor neuropathy (MMN) (n = 17)] demyelinating neuropathies. We classified nerve enlargement by degree and number of regions affected. We defined patterns of nerve enlargement as: none, no enlargement; mild, nerves enlarged but never more than twice normal; regional, nerves normal in at least one region and enlarged more than twice normal in at least one region; diffuse, nerves enlarged at all four regions with at least one region more than twice normal size. Nerve enlargement was commonly diffuse (89 %) and generally more than twice normal size in CMT-1, but not (p < 0.001) in acquired disorders which mostly had either no, mild or regional nerve enlargement [CIDP (64 %), GBS (95 %), and MMN (100 %)]. In CIDP, subjects treated within 3 months of disease onset had less nerve enlargement than those treated later. Ultrasound identified patterns of diffuse nerve enlargement can be used to screen patients suspected of having CMT-1. Normal, mildly, or regionally enlarged nerves in demyelinating polyneuropathy suggests an acquired etiology. Early treatment in CIDP may impede nerve enlargement.

Ultrasound assessment of sural nerve in Charcot–Marie-Tooth 1A neuropathy

ObjectiveNerve ultrasound (US) has been used to study peripheral nerve disease, and increase of the cross-sectional area (CSA) has been described in demyelinating polyneuropathy. The objective of the current study is to characterise the US features of the sural nerve in a sample of Charcot–Marie-Tooth (CMT) 1A patients. MethodsA total of 20 CMT1A patients were enrolled. As control group we studied 37 age- and sex-matched subjects. All patients underwent clinical examination, neurophysiology and US evaluation of the bilateral sural nerve and right ulnar nerve. US results were correlated with neurophysiology and clinical data. ResultsSural nerve CSA was not increased in the majority of patients (70%), whereas an increased ulnar nerve CSA was present in the whole sample. Inverse relations were found between CSA of the ulnar nerve and body mass index (BMI) (p<0.0002, R=−0.8) and CSA of the sural nerve and age (right 0.006, R=−0.6, left 0.002, R=−0.6 and left and right p=0.00003, R=−0.4). ConclusionsUS showed ulnar CSA enlargement and normal sural nerve CSA. SignificanceThe significance of normal sural nerve CSA in CMT1A patients need to be further investigated, possibly through longitudinal studies.

Ulnar nerve measurements in healthy individuals to obtain reference values

The aim of this study was to obtain the ultrasonographical reference values of ulnar nerve cross-sectional areas at the common areas of nerve entrapment as well as any differences related to age, sex, weight, height, dominant arm. Cross-sectional areas of the ulnar nerves of 72 healthy volunteers were measured bilaterally at the level of the epicondyle, 2 cm proximal to and 2 cm distal to the epicondyle, just at the entrance of cubital tunnel, at arterial split, at Guyon's canal. Age, sex, body weight, height, body mass index, and dominant extremity were recorded. The mean ulnar nerve cross-sectional area was 5.8 ± 1.1 mm(2) at 2 cm proximal to medial epicondyle, 6.2 ± 1.1 mm(2) at the medial epicondyle, 5.6 ± 0.9 mm(2) at the entrance of the cubital tunnel, 5.6 ± 1.0 mm(2) at 2 cm distal to medial epicondyle (inside the flexor carpi ulnaris), 5.0 ± 0.6 mm(2) at arterial split, and 4.9 ± 0.6 mm(2) at Guyon's canal. There was statistically no difference between the dominant and nondominant sides (p > 0.05). Females had statistically smaller nerves than males (p < 0.05). There was a significant correlation with height at all levels; also, weight was significantly correlated with cross-sectional areas except at two levels: tip of medial epicondyle and 2 cm distal. This study provides normative data of ulnar nerve ultrasonography and as well as any differences related to age, sex, height, weight, and dominant arm.

Diagnostic value of ultrasonography and magnetic resonance imaging in ulnar neuropathy at the elbow.

Aim. To evaluate the diagnostic value of ultrasonography and magnetic resonance imaging (MRI) in patients with ulnar neuropathy at the elbow (UNE). Methods. We prospectively performed electrodiagnostic, ultrasonographic, and MRI studies in UNE patients and healthy controls. Three cross-sectional area (CSA) measurements of the ulnar nerve at multiple levels along the arm and maximum CSA(-max) were recorded. Results. The ulnar nerve CSA measurements were different between the UNE severity grades (P < 0.05). CSA-max had the greatest sensitivity (93%) and specificity (68%). Moreover, CSA-max ≥10 mm2 defined the severe UNE cases (sensitivity/specificity: 82%/72%). In MRI, ulnar nerve hyperintensity had the greatest sensitivity (90%) and specificity (80%). Conclusion. Ultrasonography using CSA-max is sensitive and specific in UNE diagnosis and discriminating the severe UNE cases. Furthermore, MRI particularly targeting at increased signal of the ulnar nerve can be a useful diagnostic test of UNE.

Ulnar Neuropathy in Hansen Disease

To assess the relationship between the cross-sectional area (CSA) of the ulnar nerve by ultrasound (US) with clinical and electrophysiologic findings in Hansen ulnar neuropathy. Twenty-one patients (42 arms) with Hansen disease (mean age 30.0 ± 12.97, range 13-61 years, borderline tuberculoid 29%, borderline lepromatous, 19% lepromatous leprosy 42%, and pure neuritic type 10%) were examined clinically for ulnar sensory and motor weakness. The ulnar nerve was ultrasonographically examined from the wrist to the axilla, and CSA was measured at the level of maximum enlargement. Ulnar sensory nerve conduction was recorded orthodromically with ring electrodes placed at the fifth digit and amplitude of sensory nerve action potential (SNAP) recorded 3 cm proximal to the distal wrist crease. Motor conduction velocity (MCV) was recorded at the wrist-below the elbow, below the elbow-above the elbow, and above the elbow-axilla segments. Out of the 42 arms with Hansen disease, 76% had clinically motor weakness, and 43% had sensory loss in the upper limbs innervated by the ulnar nerve. As compared with healthy subjects, the patients with Hansen ulnar neuropathy had a statistically significant reduction in SNAP (P ≤ 0.0001) and MCV (P ≤ 0.0001). It was observed that the maximum enlargement of the ulnar nerve in all the patients was a few centimeters above the elbow segment. The mean CSA of ulnar nerve above the medial epicondyle was 18 ± 15 mm as compared with controls 4.83 ± 1.12 mm (P < 0.0001). In addition to nerve thickening, US depicted abnormality in morphology. In 55%, the nerve was hypoechoic, and in 7.1%, the nerve pattern was oligofascicular. Color Doppler (CD) flow signals were observed in all the nerves with loss of fascicular pattern and in 40% of the nerves that were hypoechoic. A statistically significant correlation was found between CSA of ulnar nerve above the medial epicondyle vs. MCV at BE-AE and compound muscle action potentials (CMAP) above the elbow in the patients with clinical motor weakness (r = -0.55, P < 0.001) and (r = -0.57, P < 0.001), respectively. There was no statistical significant correlation between CSA and SNAP in the patients with (r = -0.52, P = 0.23) and without (r = -0.07, P = 0.83) sensory loss. In leprosy patients, a positive correlation exits between the presence of motor weaknesses of the ulnar nerve innervated muscles, sonographically thickening of the ulnar nerve, and motor conduction slowing of the ulnar nerve at the BE-AE segment. In addition, US provided information on nerve morphologic alterations regarding the echo texture and location of nerve enlargement.

Peripheral nerve size in normals and patients with polyneuropathy: An ultrasound study

Ultrasound has been used for visualizing peripheral nerve pathology. Our goal was to use ultrasound to quantitate the sizes of upper extremity nerves along their length in control subjects and patients with neuropathy. We measured median and ulnar nerve cross-sectional areas (NCSA) in the arms of 190 subjects, including 100 with neuropathies and 90 controls. We found that NCSAs in healthy child and adult controls were greater with increasing height, at proximal sites, and at sites of entrapment. Nerves were enlarged in all Charcot-Marie-Tooth 1A (CMT-1A) (11 of 11; 100%), most chronic inflammatory demyelinating polyneuropathy (CIDP) (31 of 36; 86%), half of Guillain-Barré syndrome (GBS) (8 of 17; 47%), but few axonal neuropathy (7 of 36, 19%) subjects. In GBS, nerve enlargement occurred early and with minimal electrodiagnostic abnormalities in some patients. We conclude that NCSA measured by ultrasound is a quantifiable marker of nerve features that should be corrected for patient characteristics and nerve site. NCSA is generally larger in demyelinating than it is in axonal polyneuropathies.

Ultrasound of peripheral nerves in acromegaly: changes at 1‐year follow‐up

We have previously demonstrated peripheral nerve enlargement in acromegaly. The aim of this study was to use ultrasound (US) to assess any changes in the peripheral nerves of patients with acromegaly 1 year after the first evaluation. We prospectively examined the median and ulnar nerve cross-sectional area (CSA) in 34 non-diabetic, patients with acromegaly (18 females and 16 males; 18-79 years) and 34 age-, sex-, BMI-matched controls, using a 17-5 MHz US probe. The median nerve was examined at the mid-forearm (MN-f) and at the carpal tunnel (MN-Ct) levels; the ulnar nerve at mid-forearm (UN-f) and at distal arm (UN-a). Patients were grouped according to the clinical control of the disease: 'improved'; 'always controlled'; 'always uncontrolled'; and 'worsened'. The median nerve at mid-forearm (MN-f), the ulnar nerve at mid-forearm (UN-f) and at distal arm (UN-a) were significantly reduced after 1-year follow-up in all patients (P < 0.001, P < 0.008, P < 0.012, respectively). In the 'improved' group, there was a significant reduction of median nerve CSA examined at mid-forearm (MN-f) (P = 0.02), and distal arm ulnar nerve CSA (UN-a) (P = 0.002). In the other groups no statistically significant differences in ultrasound parameters were recorded. However, UN-a, UN-f, MN-f, MN-ct were still significantly higher in all groups compared with controls (P < 0.001). These data demonstrate that median and ulnar nerves CSA are reduced after 1 year follow-up, in line with the reduction of GH/IGF-I levels. However, as the control of the disease incompletely reverts nerve enlargement, this phenomenon could be only partially reversible.