Antonios Kerasnoudis

Cross sectional area reference values for sonography of peripheral nerves and brachial plexus.

OBJECTIVE Ultrasound measurements of the cross sectional area (CSA) variability have been recently introduced to quantify pathological changes in peripheral nerves (PN). METHODS Reference values from 75 healthy subjects and their correlation to age, height, weight and sex are reported. RESULTS The mean values in PN were: (1) intranerve CSA-variability: median 1.05 (SD ± 0.13), ulnar 1.53 (SD ± 0.51), fibular 1.33 (SD ± 0.37), tibial 1.39 (SD ± 0.39), (2) internerve CSA-variability 1.76 (SD ± 0.37), (3) intraplexus CSA-variability 1.52 (SD ± 0.37), (4) side-to-side difference ratio of the CSA-variability: median 1.21 (SD ± 0.04), ulnar 1.2 (SD ± 0.25), fibular 1.19 (SD ± 0.23), tibial 1.28 (SD ± 0.24) and brachial plexus 1.19 (SD ± 0.23). CSA did not correlate with height in PN, but correlated with weight in the ulnar nerve [Guyons canal, r = 0.411, p = 0.0237, elbow r = 0.409, p = 0.0248]. Significant changes between sex were found only in the ulnar (Guyons canal, p = 0.0265), fibular (popliteal fossa, p = 0.0336) and sural nerve (p = 0.048). CSA decreased with age in the median (axilla, p = 0.0236), and radial nerve (spiral groove, p = 0.0037) and increased in the tibial nerve (ankle, p < 0.0001). CONCLUSIONS The CSA reference values reported seem to correlate at certain sites with age, weight and sex but not with height. SIGNIFICANCE The new CSA variability measures may be helpful in investigating pathologies of the PN.

Correlation of Nerve Ultrasound, Electrophysiological and Clinical Findings in Chronic Inflammatory Demyelinating Polyneuropathy

We present the nerve ultrasound findings in chronic inflammatory demyelinating polyneuropathy (CIDP) and examine their correlation with electrophysiology and functional disability.

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

We aimed to correlate functional disability, electrophysiology, and nerve ultrasound in patients after Guillain‐Barré syndrome (GBS). Seventy‐five healthy controls and 41 post‐GBS patients (mean 3.4 years, SD ± 2.91 years after onset) underwent clinical, sonographic, and electrophysiological evaluation. Compared to healthy controls, the post‐GBS patients showed: (1) a mean Rasch‐built Overall Disability Scale score of 31.8 (SD ± 11.6), modified Rasch‐built fatigue severity scale score of 15.6 (SD ± 3.2), Medical Research Council sum score of 22 (SD ± 5.6); (2) electrophysiological signs of permanent axonal loss in the majority of the peripheral nerves; (3) sonographical evidence of higher cross‐sectional area values (CSA) of the ulnar (elbow, p < 0.001), radial (spiral groove, p < 0.001), tibial nerve (popliteal fossa, p < 0.001) and brachial plexus (supraclavicular space, p < 0.001). No correlation between sonographic and electrophysiological findings was found. Neither nerve ultrasound nor electrophysiology correlated with muscle strength, overall disability, and fatigue scale. Compared to healthy controls, post‐GBS patients had significant functional disability. Despite significant abnormalities in both electrophysiology and ultrasound compared to healthy controls, neither electrophysiology nor nerve ultrasound correlated with functional disability of these patients.

Ultrasonographic assessment of longitudinal median nerve and hand flexor tendon dynamics in carpal tunnel syndrome

I read with great interest the article by Korstanje and colleagues focusing on ultrasonographic assessment of longitudinal median nerve and hand flexor tendon dynamics in carpal tunnel syndrome (CTS). Based on the altered hand dynamics in CTS the authors suggested a new, non-invasive method that could be helpful in supporting the diagnosis of CTS, especially in patients with clinical suspicion but with normal electromyographic findings. The results confirm previous findings by Ettema et al. and Hough et al. The method presented seems to have better sensitivity and accuracy than other diagnostic approaches, such as color Doppler imaging, speckle tracking, and the invasive video camera approach, as mentioned by Korstanje et al. Here I would like to draw attention to a subgroup of patients with persistent clinical and electrophysiological signs of CTS after unsuccessful operative decompression of the median nerve. A common reason for persisting or new complaints after carpal tunnel surgery is incomplete release of the flexor retinaculum. Traction neuropathy, a real and recurrent carpal tunnel syndrome, and iatrogenic nerve lesions occur less frequently. Electrodiagnostic testing can only support the indication for a reoperation if the patient has had a preoperative study, but it cannot demonstrate the exact cause of a failed carpal tunnel surgery. Several ultrasonography studies after carpal tunnel release have been reported, and all have concluded that the functional outcome and crosssectional area (CSA) ratio may provide clinicians with a tool to estimate the response of patients to surgery. It remains unknown whether ultrasound evaluation of hand dynamics could be an additional diagnostic tool in such cases. We recently examined in our neurophysiologic and ultrasound laboratory a 55-year-old man with persistent clinical and electrophysiological signs of CTS after unsuccessful operative decompression (distal motor latency of the median nerve was 11.2 ms preoperatively and 10.5 ms postoperatively). High-frequency ultrasonography (18 MHZ) revealed signs of an increased CSA of the nerve in the carpal tunnel and pathological wrist-toforearm ratio (Fig. 1). Ultrasound video sequences of the median nerve and the tendons of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) muscles showed akinesia of the nerve in comparison to the tendons during finger flexion as a possible sign of severe entrapment, as shown in Video 1 (Supporting Material). We considered this finding to be the result of altered hand dynamics, possibly due to severe fibrosis of the subsynovial connective tissue. On this matter, however, no systematic data are available for either reproducibility or clinical relevance. I would like to ask the authors about their experience regarding ultrasonographic assessment of longitudinal median nerve and hand flexor tendon dynamics in patients with persistent signs of CTS after unsuccessful operative decompression. The method may serve as an additional tool for providing an indication for reoperation. I would also appreciate the authors’ comments pertaining to my concerns. I believe further work is needed to understand the complexity of hand dynamics in CTS.

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

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).

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.

Intra- and internerve cross-sectional area variability: new ultrasound measures.

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Nerve ultrasound protocol in differentiating chronic immune-mediated neuropathies

Introduction: In this study we evaluated a new neuropathy ultrasound protocol (NUP) for differentiating chronic immune‐mediated neuropathies. Methods: The NUP was evaluated in 110 patients with clinical presentations of chronic immune‐mediated neuropathy. All patients were first evaluated clinically and electrophysiologically and divided into 4 polyneuropathy groups: (a) symmetric demyelinating; (b) symmetric axonal; (c) asymmetric demyelinating; and (d) asymmetric axonal. During step 2, the NUP was evaluated prospectively for all 4 study groups. Results: Overall, the NUP led to correct classification in 42 of 49 (85.7%) patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 13 of 15 (86.9%) with multifocal motor neuropathy (MMN), and 5 of 5 (100%) with multifocal‐acquired demyelinating sensory and motor neuropathy (MADSAM). The NUP had >80% sensitivity and specificity in distinguishing CIDP, MMN, and MADSAM in all 4 study groups. Conclusions: The NUP is a useful addition in the differential diagnosis of chronic immune‐mediated neuropathies in everyday practice. Muscle Nerve 54: 864–871, 2016

Nerve Ultrasound and Electrophysiology for Therapy Monitoring in Chronic Inflammatory Demyelinating Polyneuropathy.

We evaluated prospectively nerve ultrasound and electrophysiology as monitoring methods of intravenous immunoglobulin (IVIG) therapy in chronic inflammatory demyelinating polyneuropathy (CIDP).