Correlation of nerve ultrasound, electrophysiological, and clinical findings in post Guillain-Barré syndrome

Neuromuscular Ultrasound in Polyneuropathies

Neuromuscular ultrasound is a painless, radiation-free, high-resolution imaging technique for assessing the peripheral nervous system. It can accurately depict changes in the nerves and muscles of individuals with neuromuscular conditions, and it is therefore a robust diagnostic tool for the assessment of individuals with polyneuropathies. This review will outline the typical ultrasonographic changes found in a wide variety of polyneuropathies. In general, demyelinating conditions result in greater nerve enlargement than axonal conditions, and acquired conditions result in more patchy nerve enlargement compared to diffuse nerve enlargement in hereditary conditions. This review is data-driven, but more nuanced anecdotal findings are also described. The overall goal of this paper is to provide clinicians with an accessible review of the ultrasonographic approaches and findings in a wide variety of polyneuropathies.

Emerging biomarkers to predict clinical outcomes in Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is an immune-mediated poly(radiculo)neuropathy with a variable clinical outcome. Identifying patients who are at risk of suffering from long-term disabilities is a great challenge. Biomarkers are useful to confirm diagnosis, monitor disease progression, and predict outcome.

AREAS COVERED

The authors provide an overview of the diagnostic and prognostic biomarkers for GBS, which are useful for establishing early treatment strategies and follow-up care plans.

EXPERT OPINION

Detecting patients at risk of developing a severe outcome may improve management of disease progression and limit potential complications. Several clinical factors are associated with poor prognosis: higher age, presence of diarrhea within 4 weeks of symptom onset, rapid and severe weakness progression, dysautonomia, decreased vital capacity and facial, bulbar, and neck weakness. Biological, neurophysiological and imaging measures of unfavorable outcome include multiple anti-ganglioside antibodies elevation, increased serum and CSF neurofilaments light (NfL) and heavy chain, decreased NfL CSF/serum ratio, hypoalbuminemia, nerve conduction study with early signs of demyelination or axonal loss and enlargement of nerve cross-sectional area on ultrasound. Depicting prognostic biomarkers aims at predicting short-term mortality and need for cardio-pulmonary support, long-term patient functional outcome, guiding treatment decisions and monitoring therapeutic responses in future clinical trials.

Moderner Ultraschall in der Diagnostik Neuromuskulärer Erkrankungen

Der neuromuskuläre Ultraschall hat sich in den letzten Jahren zu einem festen Bestandteil in der neurologischen Diagnostik entwickelt. Dazu tragen auch die fortwährende technische Weiterentwicklung der Methode und ihr unkomplizierter und nebenwirkungsfreier Einsatz direkt am Patienten bei. Im klinischen Alltag wird der Ultraschall in der Diagnostik und Differentialdiagnostik sowie in der Verlaufskontrolle traumatischer Nervenläsionen, sekundärer und dynamischer nervaler Kompressionssyndrome, hereditärer und akuter sowie chronisch autoimmuner Polyneuropathien, Motoneuron- und Muskelerkrankungen verwendet. Dabei spielt die Ultraschalldiagnostik auch zunehmend eine Rolle für Therapieentscheidungen, v.a. im Hinblick auf die operative Versorgung und den Einsatz oder die Fortführung immunmodulatorischer Medikamente. In den nächsten Jahren ist eine weitere interdisziplinäre Verbreitung und fortwährend zunehmende Standardisierung der Methode zu erwarten.

Nerve ultrasound evaluation of Guillain-Barré syndrome subtypes in northern China

INTRODUCTION/AIMS

Ultrasound (US) studies have demonstrated patchy enlargement of spinal and peripheral nerves in Guillain-Barré syndrome (GBS). However, whether ultrasound yields useful information for early classification of GBS has not been established. We aimed to evaluate nerve ultrasound in patients with GBS in northern China and compare the sonographic characteristics between demyelinating and axonal subtypes.

METHODS

Between November 2018 and October 2019, 38 hospitalized GBS patients within 3 wk of disease onset and 40 healthy controls were enrolled. Ultrasonographic cross-sectional areas (CSA) of the peripheral nerves, vagus nerve, and cervical nerve roots were prospectively recorded in GBS subtypes and controls.

RESULTS

Ultrasonographic CSA exhibited significant enlargement in most patients' nerves compared with healthy controls, most prominent in cervical nerves. The CSA tended to be larger in acute inflammatory demyelinating polyneuropathy (AIDP) than in acute motor axonal neuropathy (AMAN)/acute motor and sensory axonal neuropathy (AMSAN), especially in cervical nerves (C5: 5.9 ± 1.6 mm² vs. 7.0 ± 1.7 mm² , p = .042; C6: 10.5 ± 1.8 mm² vs. 12.0 ± 2.1 mm² , p = .033). The chi-squared test revealed significant differences in nerve enlargement in C5 (p < .001), C6 (p < .001), the proximal median nerve (p < .001), and the vagus nerve (p = .003) between GBS and controls. The vagus nerve was larger in patients with autonomic dysfunction than in patients without it (2.3 ± 1.0 mm² vs. 1.4 ± 0.5 mm² , p = .003).

DISCUSSION

The demyelinating subtype presented with more significant cervical nerve enlargement in GBS. Vagus nerve enlargement may be a useful marker for autonomic dysfunction.

Nerve Ultrasound as Helpful Tool in Polyneuropathies

Background: Polyneuropathies (PNP) are a broad field of diseases affecting millions of people. While the symptoms presented are mostly similar, underlying causes are abundant. Thus, early identification of treatable causes is often difficult. Besides clinical data and basic laboratory findings, nerve conduction studies are crucial for etiological classification, yet limited. Besides Magnetic Resonance Imaging (MRI), high-resolution nerve ultrasound (HRUS) has become a noninvasive, fast, economic and available tool to help distinguish different types of nerve alterations in neuropathies. Methods: We aim to describe typical ultrasound findings in PNP and patterns of morphological changes in hereditary, immune-mediated, diabetic, metabolic and neurodegenerative PNP. Literature research was performed in PubMed using the terms ‘nerve ultrasound’, neuromuscular ultrasound, high-resolution nerve ultrasound, peripheral nerves, nerve enlargement, demyelinating, hereditary, polyneuropathies, hypertrophy’. Results: Plenty of studies over the past 20 years investigated the value of nerve ultrasound in different neuropathies. Next to nerve enlargement, patterns of nerve enlargement, echointensity, vascularization and elastography have been evaluated for diagnostic terms. Furthermore, different scores have been developed to distinguish different etiologies of PNP. Conclusions: Where morphological alterations of the nerves reflect underlying pathologies, early nerve ultrasound might enable a timely start of available treatment and also facilitate follow up of therapy success.

Current and future applications of ultrasound imaging in peripheral nerve disorders

Neuromuscular ultrasound (NMUS) is a rapidly evolving technique used in neuromuscular medicine to provide complimentary information to standard electrodiagnostic studies. NMUS provides a dynamic, real time assessment of anatomy which can alter both diagnostic and management pathways in peripheral nerve disorders. This review describes the current and future techniques used in NMUS and details the applications and developments in the diagnosis and monitoring of compressive, hereditary, immune-mediated and axonal peripheral nerve disorders, and motor neuron diseases. Technological advances have allowed the increased utilisation of ultrasound for management of peripheral nerve disorders; however, several practical considerations need to be taken into account to facilitate the widespread uptake of this technique.

Clinical, Sonographic, and Electrophysiologic Longitudinal Features of Chronic Inflammatory Demyelinating Polyneuropathy

BACKGROUND AND PURPOSE

Several studies have aimed to find potential biomarkers to simplify the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) and to monitor and predict the disease course. However, reliable markers are still lacking. We aimed to investigate whether high-resolution nerve ultrasound (HRUS) is suitable for monitoring the long-term clinical course of CIDP.

METHODS

Twenty patients fulfilling the definite diagnostic criteria of CIDP received clinical examination, evaluation of the INCAT (inflammatory neuropathy cause and treatment) overall disability sum score (ODSS) as well as nerve conduction studies, and HRUS every 6 months over a median follow-up time of 34 months. Patients were divided into clinically stable/regressive disease course or progressive disease course according to the development of the ODSS.

RESULTS

The intranerve cross-sectional-area (CSA) variability of the nerves of the lower extremity increased with disease progression, whereas it remained unchanged in patients with a stable or remitting disease course.

CONCLUSION

Nerve ultrasound can be used as a method to objectify the long-term disease course in CIDP patients. The intranerve CSA variability is suitable for monitoring the clinical course of patients with CIDP.

Treatment of an acute motor and sensory axonal neuropathy with propionate in a 33-year-old male

Background

The aim of this work was to report a case of an acute motor and sensory axonal neuropathy (AMSAN) treated with propionate to evaluate its therapeutic potential in AMSAN.

Materials and methods

The patient was investigated by clinical examination, electroneurography, high-resolution nerve ultrasound and confocal corneal microscopy at baseline and the 2 month follow up. We compared the outcome with those of five other patients with acute motor axonal neuropathy (AMAN) and AMSAN of who were referred to our neurology department in the past 5 years.

Results

Considering the poor prognosis of patients with acute axonal neuropathies and in comparison with the previously treated patients with AMAN or AMSAN in our clinic, the regression of our patient's symptoms and the improvement in the additional examinations under propionate seemed exceptionally good.

Conclusion

Propionate may have an additional therapeutic effect in autoimmune inflammatory neuropathies.

Nerve ultrasound in polyneuropathies

Ultrasound can be used to visualize pathology in the peripheral nerves of patients with polyneuropathy. Nerve enlargement is the most frequent pathology, but other abnormalities, including abnormal nerve echogenicity and vascularity, are also encountered. This monograph presents an overview of the role of nerve ultrasound in the evaluation and management of both inherited and acquired polyneuropathies. A description of the sonographic techniques and common abnormalities is provided, followed by a presentation of typical findings in different neuropathies. Scoring systems for characterizing the presence and pattern of nerve abnormalities as they relate to different polyneuropathies are presented. Muscle Nerve 57: 716-728, 2018.

Neuromuscular Ultrasound in the Assessment of Polyneuropathies and Motor Neuron Disease

Neuromuscular ultrasound is an emerging technology for the evaluation of conditions affecting nerve and muscle, with most of the research focusing on focal neuropathies. Despite this focus, researchers have also investigated the ultrasonographic changes that occur in the nerves and muscles of those with more diffuse polyneuropathies and motor neuron diseases, and this review will detail the findings in these conditions. Specific findings are discussed in this article, but general themes will also be presented and include the following: hereditary polyneuropathies show diffuse nerve enlargement, whereas immune-mediated polyneuropathies show more patchy involvement; nerve enlargement is more profound in demyelinating than axonal polyneuropathies; and muscle changes in motor neuron diseases include heterogeneous increases in echogenicity, atrophy, readily detectable fasciculations, and increased subcutaneous tissue thickness.

Testing nerves: an overview of investigations for neuropathy

This article reviews the main investigations available to assess and diagnose patients with neuropathy. It details the most commonly used as well as investigations now becoming routine in neuromuscular centres, and those which are less widely available. Current practice and recent developments are discussed.

Sonographic evaluation of peripheral nerves in subtypes of Guillain-Barré syndrome

BACKGROUND

Sonography of peripheral nerves can depict alteration of nerve sizes that could reflect inflammation and edema in inflammatory and demyelinating neuropathies. Guillain-Barré syndrome (GBS). Information on sonographic comparison of an axonal subtype (acute motor [and sensory] axonal neuropathy [AMAN and AMSAN]) and a demyelinating subtype (acute inflammatory demyelinating polyneuropathy [AIDP]) has been sparse.

MATERIAL AND METHODS

Sonography of peripheral nerves and cervical nerve roots were prospectively recorded in patients with GBS who were within three weeks of disease onset.

RESULTS

Five patients with AIDP and nine with AMAN (n=6)/AMSAN (n=3) were enrolled. The patients with AIDP showed evidence of greater degrees of demyelination (e.g., slower conduction velocities and increased distal latencies) than those with AMAN/AMSAN. The patients with AIDP tended to show enlarged nerves in the proximal segments and in the cervical roots, whereas the patients with AMAN/AMSAN had greater enlargement in the distal neve segment, especially in the median nerve (P = 0.03; Wrist-axilla cross-sectional ratio).

CONCLUSION

In this small study, two subtypes of GBS showed different patterns of involvement that might reflect different pathomechanisms.

Ultrasonography of the peripheral nervous system in the early stage of Guillain-Barré syndrome

Ultrasonography can be used to visualize peripheral nerve abnormalities in immune-mediated neuropathies. The objective of this study was to prove the role of ultrasonography (US) in acute phase of Guillain-Barré syndrome (GBS). Systematic ultrasonic measurements of several peripheral nerves including the vagal nerve as well as the sixth cervical nerve root were performed in 18 patients with GBS at days 1-3 after symptom onset and compared to 21 healthy controls. Nerve conduction studies (NCS) of corresponding nerves were undertaken. Consequently, significant differences between the groups were found in compound muscle action potential amplitudes, F-wave latency, and persistency. Ultrasonic cross-sectional areas (CSAs) showed significant enlargement in all nerves except of the ulnar nerve (upper arm) and the sural nerve compared to healthy controls, most prominent in proximal and middle median nerve (p < 0.01). The vagal nerve also showed enlargement compared to controls (p < 0.05), which was most pronounced in patients with autonomic dysfunction compared to patients without (p < 0.05). C6 root diameter showed a significant correlation to the amount of cerebrospinal fluid (CSF)-protein (Pearson correlation, p < 0.05). US shows nerve enlargement in several peripheral nerves including vagal nerve and C6 root in acute phase of GBS and could be an additional diagnostic tool for example, in GBS of atypical onset and autonomic dysfunction.

Ultrasound in the diagnosis of peripheral neuropathy: structure meets function in the neuromuscular clinic

Peripheral nerve ultrasound (US) has emerged as a promising technique for the diagnosis of peripheral nerve disorders. While most experience with US has been reported in the context of nerve entrapment syndromes, the role of US in the diagnosis of peripheral neuropathy (PN) has recently been explored. Distinctive US findings have been reported in patients with hereditary, immune-mediated, infectious and axonal PN; US may add complementary information to neurophysiological studies in the diagnostic work-up of PN. This review describes the characteristic US findings in PN reported to date and a classification of abnormal nerve US patterns in PN is proposed. Closer scrutiny of nerve abnormalities beyond assessment of nerve calibre may allow for more accurate diagnostic classification of PN, as well as contribute to the understanding of the intersection of structure and function in PN.

Nerve ultrasound in Miller Fisher variant of Guillain-Barré syndrome

INTRODUCTION

Focal enlargement of the peripheral and spinal nerves, visualized using high-resolution ultrasound (HRUS), has been reported in early Guillain-Barré syndrome, but not in the Miller Fisher variant. We report the use of HRUS in 2 patients who presented with acute ataxic neuropathy, areflexia, and ophthalmoparesis.

METHODS

Ultrasound and/or nerve conduction studies (NCS) of peripheral nerves, the vagus, and spinal nerves C5/6 were performed at onset and 2 weeks after immunoglobulin therapy.

RESULTS

Both patients fulfilled criteria for diagnosis of Miller Fisher syndrome (MFS). Laboratory findings revealed elevated ganglioside Q1b antibodies in both and an albuminolocytologic dissociation in 1 patient. In addition, 1 patient had NCS evidence for demyelinating neuropathy. However, ultrasound showed focal enlargement in the vagus, the spinal nerves, and/or in the peripheral nerves in both patients. After therapy, nerve enlargement decreased in parallel with clinical improvement.

CONCLUSION

Spinal and/or peripheral nerve enlargement supports the diagnosis of MFS in early phases of the disease.

Ultrasound and electrophysiologic findings in patients with Guillain-Barré syndrome at disease onset and over a period of six months

OBJECTIVE

To investigate cross-sectional areas (CSAs) of several peripheral nerves including the vagus nerve and the diameter of spinal nerves as measured by nerve ultrasound (NUS) and nerve conduction studies (NCS) in Guillain-Barré syndrome (GBS) patients over at least six months compared to healthy controls.

METHODS

NUS and/or NCS of several nerves, the vagus nerve, and the 5th/6th cervical spinal nerves were performed in patients with GBS at days 2-3 after symptom onset, at days 10-14 after immunoglobulin therapy and after six months compared to healthy controls.

RESULTS

27 GBS-patients and 31 controls were included. Using NUS significant enlargement was found in all measured nerves (P<0.001), except the sural nerve (P=0.086) compared to the controls at onset. The vagus (median 3.0 mm(2) vs. 2.0 mm(2), P<0.0001) and the cervical spinal nerves were significantly enlarged (median 3.5/4.0 mm vs. 2.6/3.2 mm, p<0.0001), the vagus most obviously in patients with autonomic dysregulation (AD, 4.0 mm(2)). Six months later, NCS showed persisting pathology in CMAP-amplitudes with amelioration of F-wave pathology. NUS showed restitution in the spinal nerves (median 2.6/3.2 mm) and the vagus (median 2.0 mm(2)) in all patients excluding the vagus in those with persistent AD (median 4.0 mm(2)). The peripheral nerves did not change significantly (P>0.05).

CONCLUSION

Ultrasonographic detection of cervical spinal nerve enlargement supports the diagnosis of GBS in the early phase. Its regression may be a good parameter for the clinical restitution over time. Vagus enlargement may be a risk marker for development of AD.

SIGNIFICANCE

Ultrasound is a reliable diagnostic follow-up tool in early GBS.

Multifocal motor neuropathy: correlation of nerve ultrasound, electrophysiological, and clinical findings

We present nerve ultrasound findings in multifocal motor neuropathy (MMN) and examine their correlation with electrophysiology and functional disability. Eighty healthy controls and 12 MMN patients underwent clinical, sonographic, and electrophysiological evaluation a mean of 3.5 years (standard deviation [SD] ± 2.1) after disease onset. Nerve ultrasound revealed significantly higher cross-sectional area (CSA) values of the median (forearm, p < 0.001), ulnar (p < 0.001), and tibial nerve (ankle, p < 0.001) when compared with controls. Electroneurography documented signs of significantly lower values of the motor conduction velocity and compound muscle action potentials (cMAPs) in the upper arm nerves (median, ulnar, radial, p < 0.001). A significant correlation between sonographic and electrophysiological findings in the MMN group was found only between cMAP and CSA of the median nerve at the upper arm (r = 0.851, p < 0.001). Neither nerve sonography nor electrophysiology correlated with functional disability. MMN seems to show inhomogeneous CSA enlargement in various peripheral nerves, with weak correlation to electrophysiological findings. Neither nerve sonography nor electrophysiology correlated with functional disability. Multicentre, prospective studies are required to prove the applicability and diagnostic values of these findings.

Nerve Ultrasound in Peripheral Neuropathies: A Review

Peripheral neuropathies are one of the most common reasons for seeking neurological care in everyday practice. Electrophysiological studies remain fundamental for the diagnosis and etiological classification of peripheral nerve impairment. The recent technological development though of high resolution ultrasound has allowed the clinician to obtain detailed structural images of peripheral nerves. Nerve ultrasound mainly focuses on the evaluation of the cross sectional area, cross sectional area variability along the anatomical course, echogenity, vascularity and mobility of the peripheral nerves. An increase of the cross sectional area, hypervascularity, disturbed fascicular echostructure and reduced nerve mobility are some of the most common findings of entrapments neuropathies, such as the carpal or cubital tunnel syndrome. Both the cross-sectional area increase and the hypervascularity detected with the Doppler technique seem to correlate significantly with the clinical and electrophysiological severity of the later mononeuropathies. Significantly greater cross sectional area values of the clinically affected cervical nerve root are often detected in cases of cervical radiculopathy. In such cases, the ultrasound findings seem also to correlate significantly with disease duration. On the other hand, multifocal cross sectional area enlargement of cervical roots and/or peripheral nerves is often documented in cases of immune-mediated neuropathies. None of the later pathological ultrasound findings seem to correlate significantly with the electrophysiological parameters or the functional disability. The aim of this review is to provide a timely update on the role of neuromuscular ultrasound in the diagnostic of the most common entrapment and immune-mediated peripheral neuropathies in clinical practice.

Bochum ultrasound score versus clinical and electrophysiological parameters in distinguishing acute-onset chronic from acute inflammatory demyelinating polyneuropathy

INTRODUCTION

The aim of this study was to evaluate whether a nerve ultrasound score (Bochum ultrasound score, BUS), clinical, and electrophysiological parameters could distinguish subacute chronic (CIDP) from acute inflammatory demyelinating polyneuropathy (AIDP).

METHODS

Phase 1: The charts of 35 patients with polyradiculoneuropathy were evaluated retrospectively regarding BUS, clinical, and electrophysiological parameters (A-waves, sural nerve sparing pattern, sensory ratio>1). Phase 2: All parameters were evaluated prospectively in 10 patients with subacute polyradiculoneuropathy.

RESULTS

Phase 1: A sum score of ≥2 points in BUS and the presence of sensory symptoms were significantly more frequent in the subacute CIDP group than in the AIDP group (P<0.001).The electrophysiological parameters showed no significant changes between the 2 groups. Phase 2: BUS (83.3%; 100%;), sensory symptoms (100%; 75%), absence of autonomic nervous system dysfunction (83.3%; 75%), or bulbar palsy (83.3%; 50%) showed the best sensitivity and specificity in distinguishing subacute CIDP from AIDP.

CONCLUSIONS

BUS is a useful diagnostic tool for distinguishing subacute CIDP from AIDP.

Recording and assessment of evoked potentials with electrode arrays

In order to optimize procedure for the assessment of evoked potentials and to provide visualization of the flow of action potentials along the motor systems, we introduced array electrodes for stimulation and recording and developed software for the analysis of the recordings. The system uses a stimulator connected to an electrode array for the generation of evoked potentials, an electrode array connected to the amplifier, A/D converter and computer for the recording of evoked potentials, and a dedicated software application. The method has been tested for the assessment of the H-reflex on the triceps surae muscle in six healthy humans. The electrode array with 16 pads was positioned over the posterior aspect of the thigh, while the recording electrode array with 16 pads was positioned over the triceps surae muscle. The stimulator activated all the pads of the stimulation electrode array asynchronously, while the signals were recorded continuously at all the recording sites. The results are topography maps (spatial distribution of evoked potentials) and matrices (spatial visualization of nerve excitability). The software allows the automatic selection of the lowest stimulation intensity to achieve maximal H-reflex amplitude and selection of the recording/stimulation pads according to predefined criteria. The analysis of results shows that the method provides rich information compared with the conventional recording of the H-reflex with regard the spatial distribution.

The Ultrasound pattern sum score - UPSS. A new method to differentiate acute and subacute neuropathies using ultrasound of the peripheral nerves

OBJECTIVE

Ultrasound differentiation of neuropathies is a great challenge. We, therefore, suggest a standardized score to operationalize differentiation between several acute and subacute onset neuropathies.

METHOD

We retrospectively analyzed the ultrasound data of 61 patients with acute or subacute neuropathies, e.g. chronic immune-mediated neuropathies, Guillain-Barré syndrome (GBS), and axonal/vasculitic neuropathies. We compared these data to 28 healthy controls. Based on these results an ultrasound pattern sum score (UPSS) with three sub-scores (UPS-A for the sensorimotor nerves, UPS-B for the cervical roots and the vagal nerve and UPS-C for the sural nerve) was developed. Afterwards, the applicability of the score was prospectively validated in 10 patients with chronic neuropathies and in 14 patients with unknown acute and subacute PNP before performing additional tests.

RESULTS

UPS-A and UPSS were significantly higher in CIDP than in other neuropathies and controls (p<0.001). UPS-B was significantly more often pathologic in GBS than in CIDP and other neuropathies (p<0.001). Using receiver operation characteristics curve analysis boundary values for each score were defined. Positive predictive value (PPV) of these scores for CIDP and GBS was >85%. Vasculitic neuropathies showed an intermediate type of UPSS compared to other axonal neuropathies (p<0.001). In the prospective application the pattern score could be used with good accuracy in several types of neuropathy.

CONCLUSION

UPS-A and UPSS operationalize to diagnose acute and subacute-onset CIDP and its variants with high sensitivity, specificity, and PPV. An increased UPS-B with normal UPSS and other sub scores may point to the diagnosis of GBS with high PPV and enables the differentiation from CIDP.

SIGNIFICANCE

Using the UPSS and its sub-scores gives a new diagnostic power to the method of the peripheral nerve ultrasound.

Nerve ultrasound for differentiation between amyotrophic lateral sclerosis and multifocal motor neuropathy

Ultrasound is useful for non-invasive visualization of focal nerve pathologies probably resulting from demyelination, remyelination, edema or inflammation. In patients with progressive muscle weakness, differentiation between multifocal motor neuropathy (MMN) and amyotrophic lateral sclerosis (ALS) is essential regarding therapy and prognosis. Therefore, the objective of this study was to investigate whether nerve ultrasound can differentiate between ALS and MMN. Systematic ultrasound measurements of peripheral nerves and the 6th cervical nerve root (C6) were performed in 17 patients with ALS, in 8 patients with MMN and in 28 healthy controls. Nerve conduction studies of corresponding nerves were undertaken in MMN and ALS patients. Electromyography was performed in ALS patients according to revised El-Escorial criteria. ANOVA and unpaired t test with Bonferroni correction revealed significant differences in cross-sectional areas (CSA) of different nerves and C6 diameter between the groups. Nerve enlargement was found significantly more frequently in MMN than in other groups (p < 0.001). Receiver operating characteristics analysis revealed detection of enlarged nerves/roots in at least four measurement points to serve as a good marker to differentiate MMN from ALS with a sensitivity of 87.5% and a specificity of 94.1%. Ultrasonic focal nerve enlargement in MMN was often not colocalized with areas of conduction blocks found in nerve conduction studies. Systematic ultrasound measurements in different nerves and nerve roots are valuable for detecting focal nerve enlargement in MMN, generally not found in ALS and thus could serve as a diagnostic marker to differentiate between both entities in addition to electrodiagnostic studies.

Ultrasound differentiation of axonal and demyelinating neuropathies

INTRODUCTION

Ultrasound can be used to visualize peripheral nerve abnormality. Our objective in this study was to prove whether nerve ultrasound can differentiate between axonal and demyelinating polyneuropathies (PNPs).

METHODS

Systematic ultrasound measurements of peripheral nerves were performed in 53 patients (25 with demyelinating, 20 with axonal, 8 with mixed neuropathy) and 8 healthy controls. Nerve conduction studies of corresponding nerves were undertaken.

RESULTS

Analysis of variance revealed significant differences between the groups with regard to motor conduction velocity, compound muscle action potential amplitude, and cross-sectional area (CSA) of different nerves at different locations. Receiver operating characteristic curve analysis revealed CSA measurements to be well suited for detection of demyelinating neuropathies, and boundary values of peripheral nerve CSA could be defined.

CONCLUSIONS

Systematic ultrasound CSA measurement in different nerves helped detect demyelination, which is an additional cue in the etiological diagnosis of PNP, along with nerve conduction studies and nerve biopsy.

Ultrasound of the peripheral nerves in systemic vasculitic neuropathies

INTRODUCTION

Ultrasound of the peripheral nerves (PNUS) can be used to visualize nerve pathologies in polyneuropathies (PNP). The aim of this study was to investigate, whether PNUS provides additional information in patients with proven systemic vasculitic neuropathies (VN).

MATERIAL AND METHODS

Systematic ultrasound measurements of several peripheral nerves, the vagal nerve and the 6th cervical nerve root were performed in 14 patients and 22 healthy controls. Nerve conduction studies of the corresponding nerves were undertaken. Finally, the measured results were compared to a study population of demyelinating immune-mediated and axonal neuropathies.

RESULTS

Patients with VN displayed significant smaller amplitudes of compound muscle action potentials (CMAP) (p<0.05) and sensory nerve action potentials (SNAP) compared to healthy controls, while conduction velocity did not differ between groups. The mean nerve cross-sectional areas (CSA) were increased in several peripheral nerves compared to the controls, most prominent in tibial and fibular nerve (p<0.01). PNUS revealed nerve enlargement in most of the clinically and electrophysiologically affected nerves (22 out of 31) in VN. Nerve enlargement was more often seen in vasculitic neuropathies than in other axonal neuropathies, but significantly rarer than in demyelinating neuropathies.

CONCLUSION

Focal CSA enlargement in one or more nerves in electrophysiologically axonal neuropathies can be a hint for VN and thus facilitate diagnostic and therapeutic procedures.

Nerve size in chronic inflammatory demyelinating neuropathy varies with disease activity and therapy response over time: a retrospective ultrasound study

INTRODUCTION

Nerves are often enlarged in chronic inflammatory demyelinating polyneuropathy (CIDP). In this investigation we studied changes with treatment over time.

METHODS

We retrospectively compared serial ultrasound measurements of median and ulnar nerve size with clinical and electrodiagnostic evaluations in 23 CIDP subjects. We defined remission as stable clinical improvement on low or decreasing amounts of medication.

RESULTS

Nerves were normal at last follow-up more often in subjects who achieved remission than in those who did not (10 of 13 vs. 0 of 10, P = 0.0001). Nerves were normal or smaller (>30% reduction) more often in subjects whose grip strength improved or remained strong compared those whose grip strength weakened (12 of 16 vs. 0 of 3, P = 0.04), and in subjects whose demyelinating electrodiagnostic features resolved compared with those whose demyelination persisted (7 of 7 vs. 6 of 12, P = 0.04). Over time, nerve size decreased more in subjects with baseline nerve enlargement who achieved remission than in those who did not (-41% vs. 7%, P = 0.04).

CONCLUSION

In CIDP, enlarged nerves normalized or decreased with remission.