ArticlePDF Available

Role of Ultrasound in the EMG Lab

Authors:
Vasudeva Iyer at Neurodiagnostic Center of Louisville
Vasudeva Iyer
  • Neurodiagnostic Center of Louisville
Download full-text PDF
Read full-text
Download citation

Figures

Figures - uploaded by Vasudeva Iyer
Author content
All figure content in this area was uploaded by Vasudeva Iyer
Content may be subject to copyright.
Content uploaded by Vasudeva Iyer
Author content
All content in this area was uploaded by Vasudeva Iyer on Jun 22, 2021
Content may be subject to copyright.
Review Article
Volume 15 Issue 2 - May 2021
DOI: 10.19080/OAJNN.2021.15.555910
Open Access J Neurol Neurosurg
Copyright © All rights are reserved by Jonathan Wong Kee Chi
Role of Ultrasound in the EMG Lab
Vasudeva G Iyer*
Neurodiagnostic Center, Louisville, KY, USA
Submission: April 14, 2021; Published: May 20, 2021
*Corresponding author: Vasudeva G Iyer, Neurodiagnostic Center, Louisville, KY, USA
Open Access J Neurol Neurosurg 15(2): OAJNN.MS.ID.555910 (2021) 001
Review
During the past 10-15 years the use of ultrasound (US)
       
accelerated. Traditional Electrodiagnostic Tests (EDX) provide
insight into the location and pathophysiology of neuromuscular
disorders. However, EDX may not provide clues to the underlying
structural cause, which is more readily uncovered by imaging
studies like ultrasound and MR neurography. The advantages of
US are low cost, being painless and readily available at the point
of care. There have been suggestions that US can replace EDX
        
tunnel syndrome [1]. However, currently available US technology
cannot provide adequate information regarding the underlying
pathophysiology: demyelination, axon loss or both. EDX and US
complement each other effectively in providing comprehensive
data to respond to the practical question: Is the problem surgical
or non-surgical?.
While it is desirable to do US in every patient undergoing
EDX, in a busy clinical EDX facility, the amount of time the
electromyographer can devote to any given patient is not
unlimited; hence it may not be feasible to do US in every patient
undergoing EDX. This brings up the question as to how to identify
situations where EDX has to be complemented with US. We have
        
plays a crucial role in providing valuable information for diagnosis
and management. We will not be discussing the role of US in
nerve block, locating nerve/muscle for biopsy, and therapeutic
procedures like botulinum toxin injections in this review, but
concentrate upon the role of US in complementing EDX for more
precise diagnosis.
Situations where EDX fail to provide accurate
localization:
a. 
action potential (CMAP) and Sensory Nerve Action Potentials
(SNAP) Typical examples are severe entrapment of median nerve
at the carpal tunnel and ulnar nerve at the elbow. Documentation
of increased Cross-Sectional Area (CSA) of median nerve at the
carpal tunnel inlet/outlet and normal CSA at the forearm serve
as reliable criteria to localize median neuropathy to the carpal
tunnel [2]. A typical feature is the hour glass appearance in long
axis views (Figures 1 A, 1 B). Similarly, severe ulnar neuropathies
     
increased CSA proximal to the site of entrapment (Figure 2 A, 2 B).
 
Extensor Digitorum Brevis (EDB) and tibialis anterior / peroneus
longus pose a similar challenge and US may provide the answer.
Figure 1 A: Right thenar atrophy (Arrow). No CMAP over APB or 2nd Lumbrical. No SNAP.
How to cite this article: Iyer VG. Role of Ultrasound in the EMG Lab. Open Access J Neurol Neurosurg 2021; 15(2): 555910.
DOI: 10.19080/OAJNN.2021.15.555910
002
Open Access Journal of Neurology & Neurosurgery
b. In cases of longstanding entrapment, in addition to
focal demyelination, there may be retrograde [4] and anterograde
demyelination leading to diffuse slowing of conduction; precise
localization may not be possible in such cases with EDX alone.
US is of great value in these situations by providing accurate
localization.
c. In cases of demyelinating polyneuropathy with diffuse
       

typical of entrapment can be helpful. Most common situation
is patients with diabetic polyneuropathy in whom additional
presence of carpal/cubital tunnel syndrome is suspected.
Figure 1B: Long axis view of R. Median nerve across the carpal tunnel showing hour glass constriction.
Figure 2 A: Short axis view at the elbow showing increase in CSA (29 mm2) of the R Ulnar nerve. No CMAP over FDI or ADM; no SNAP.
Figure 2 B: Short axis view at the elbow showing enlarged ulnar nerve (single arrow) and an adjacent cyst (double arrow). No CMAP over
FDI or ADM; no SNAP.
How to cite this article: Iyer VG. Role of Ultrasound in the EMG Lab. Open Access J Neurol Neurosurg 2021; 15(2): 555910.
DOI: 10.19080/OAJNN.2021.15.555910
003
Open Access Journal of Neurology & Neurosurgery
Figure 3: Long axis view mid forearm showing neurotmesis of ulnar nerve. The hypoechoic area is neuroma at the proximal stump of the
nerve. There is no fascicular continuity; the hyperechoic areas represent scar tissue. Laceration injury resulting in clawing of ngers; no
CMAP over the FDI or ADM with denervation of both muscles.
Negative EDX in patients with typical clinical picture of
carpal/cubital tunnel syndrome:
a. Patients with symptoms of carpal tunnel syndrome
rarely show normal nerve conduction studies. There are a number
of publications which suggest that high frequency ultrasonography
may show abnormalities in such patients [5,6].
b. US has also been reported to be positive in patients with
ulnar neuropathy at the elbow, when EDX is negative [7].
Nerve injuries: EDX does not distinguish neurotmesis
from axonotmesis
Distinction between axonotmesis and neurotmesis is a crucial
piece of information for planning the ideal time for surgical
       
intervention is indicated. US can provide such information by
revealing area of discontinuity of the nerve in neurotmesis (Figure
3).

polyneuropathy (CIDP) from other polyneuropathies
This is highly important for prompt initiation of treatment
with intravenous immunoglobulin in patients with CIDP. Recent
studies have shown that sonographic enlargement of proximal
median nerve segments in the arms and brachial plexus is a
differentiating feature of CIDP [8]. In Charcot Marie Tooth (CMT)
disease, the nerve enlargement is more diffuse along the entire

Differentiation of multifocal motor neuropathy (MMN)
from amyotrophic lateral sclerosis with predominant
lower motor neuron disease (ALS/LMND)
This distinction is important from prognostic and therapeutic
points of view; US can be more sensitive than EDX [10]. showing
multifocal ulnar and median nerve enlargement. There is also
a recent report of US detecting treatment-responsive chronic
neuropathies without EDX features of demyelination [11].
Role in neuralgic amyotrophy
       
        
(Parsonage Turner syndrome), MR neurography and US have
shown enlargement of peripheral nerve/fascicles and features of
nerve torsion or fascicular entwinement. In one study nerves with
complete constriction and rotational phenomena failed to show

an indication for surgical intervention [12].
Detection fasciculations
The needle electrode can pick up fasciculations from only
a limitedl area around it; also, it can be painful to have needle
inserted into structures like the tongue. US has the advantage
of visualizing fasciculations from a much wider area without
the pain involved in multiple needle insertions. Recent studies
have documented that US is much superior to EDX in detecting
fasciculations in patients with ALS [13].
Lesions in the proximity of nerves
The main question for preoperative planning are whether the
lesion is actually arising from the nerve and if not, anatomically
how close is it to the nerve. US provides immediate answers; it can

and also alert the surgeon to the potential for perioperative nerve
injury while removing lesions in close proximity to the nerve.
Muscle disorders
a. Distinction between muscular dystrophies and
        
substantiated using US [14].
How to cite this article: Iyer VG. Role of Ultrasound in the EMG Lab. Open Access J Neurol Neurosurg 2021; 15(2): 555910.
DOI: 10.19080/OAJNN.2021.15.555910
004
Open Access Journal of Neurology & Neurosurgery
b. While EDX suggests a myopathic disorder, US can point
to a more precise diagnosis, based on the topography of muscle
involvement. The classical example is sporadic inclusion body
   

There are many more situations where US can
contribute substantially to diagnosis
a. Dynamic US is useful to document mobility of median
nerve within the carpal tunnel and to document subluxation of the
ulnar nerve at the elbow.
b. Another major use is imaging of diaphragm for diagnosis
of phrenic nerve palsy; measurement of diaphragm thickness is
being used increasingly in ALS and myopathies [17].
c. Rarely the patient may not be able to tolerate electric
stimulation and needle study. This may particularly apply to
pediatric patients. US may provide an alternate route to reach the
diagnosis.
While it is ideal to perform ultrasound evaluation in every
patient referred for EDX studies, it may not be feasible in a busy
clinical EDX lab due to time constraints. It is important to have
guidelines that identify situations where additional use of US
can provide vital information that will help in the diagnosis and
management of patients. It is likely that in the future an increasing
percentage of patients seen for EDX will also undergo US, as the
   
disorders increase and as US technology advances with more
automated measurements.
References
1. Drakapoulos D, Mitsiokapa E, Karamanis E, Vasilios K, Andreas FM
(2019) Ultrasonography provides a diagnosis similar to that of nerve
conduction studies for carpal tunnel syndrome. Orthopedics 42(5):
e460-e464.
2. Iyer V (2019) Role of ultrasonography in severe distal median nerve
neuropathy. J Clin Neurophysiol 36(4): 312-315.
3. Iyer V (2021) Ultrasonography in distal ulnar nerve neuropathy:
Findings in 33 patients. J Clin Neurophysiol 38(2): 156-159.
4. Uchida Y, Sugioka Y (1992) Electrodiagnosis of retrograde changes
in carpal tunnel syndrome. Electromyography and Clinical
Neurophysiology 33(1): 55-58.
5. Williams J, Cartwright M (2016) Neuromuscular ultrasound in carpal
tunnel syndrome with normal nerve conduction studies P4.081.
Neurology 86 (16).
6. Roghani RS, Holisaz MT, Norouzi AAS, Ahmad Delbari, Faeze Gohari, et
al. (2018) Sensitivity of high-resolution ultrasonography in clinically
diagnosed carpal tunnel syndrome patients with hand pain and normal
nerve conduction studies. J Pain Res 11: 1319-1325.
7. Yoon JS, Walker FO, Cartwright M (2010) Ulnar neuropathy with
normal electrodiagnosis and abnormal nerve ultrasound. Arch Phys
Med Rehabil 91(2): 318-320.
8. Goede HS, Pol WL, Asseldonk JH, Franssen H, Nicolette CN, et al.
(2017) Diagnostic value of sonography in treatment-naïve chronic

9. Zanette G, Fabrizi GM, Taioli F, Matteo FL, Andrea B, et al. (2018) Nerve
  
1A from other demyelinating CMTs. Clin Neurophysiol 129(11): 2259-
2267.
10. Loewenbruck KF, Liesenberg J, Dittrich M, Jochen Schäfer, Beate
Patzner, et al. (2016) Nerve ultrasound in the differentiation of
multifocal motor neuropathy (MMN) and amyotrophic lateral sclerosis
with predominant lower motor neuron disease (ALS/LMND). J Neurol
263(1): 35-44.
11. Goedee HS, HerraetsIJT, Visser LH, Hessel Franssen, Jan-Thies HA, et
al. (2019) Nerve ultrasound can identify treatment-responsive chronic
neuropathies without electrodiagnostic features of demyelination.
Muscle Nerve 60(4): 415-419.
12. ArAnyi Z, Csillik A, DeVay K, Maja Rosero, PéTer Barsi, etal. (2017)
Ultrasonography in neuralgic amyotrophy: Sensitivity, spectrum of

13. Duarte ML, Lared W, Oliveria ASB, Lucas Ribeiro Dos Santos, Maria
Stella Peccin, et al. (2020) Ultrasound versus electromyography for the
detection of fasciculation in amyotrophic lateral sclerosis: systematic
review and meta-analysis. Radiol Bras 53(2):116-121.
14. Albayda J, van Alfen N (2020) Diagnostic value of muscle ultrasound
for myopathies and myositis. Curr Rheumatol Rep 22(11): 82.
15. Noto Y, Shiga K, Tsuji Y, Masaki Kondo, Takahiko Tokuda, et al. (2014)
      
ulnaris: a diagnostic ultrasound pattern in sporadic inclusion body
myositis. Muscle Nerve 49(5): 745-748.
16. Leeuwenberg KE, van Alfen N, Stine LC, Julie J Paik, Eleni Tiniakou, et
al. (2020) Ultrasound can differentiate inclusion body myositis from
disease mimics. Muscle Nerve 61(6): 783-788.
17. Fayssoil A, Behin A, Ogna A, Dominique Mompoint, Helge Amthor, et
al. (2018) Diaphragm: Pathophysiology and ultrasound imaging in
neuromuscular disorders. J Neuromuscular Dis 5(1): 1-10.
How to cite this article: Iyer VG. Role of Ultrasound in the EMG Lab. Open Access J Neurol Neurosurg 2021; 15(2): 555910.
DOI: 10.19080/OAJNN.2021.15.555910
005
Open Access Journal of Neurology & Neurosurgery
Your next submission with Juniper Publishers
will reach you the below assets
• Quality Editorial service
• Swift Peer Review
• Reprints availability
• E-prints Service
• Manuscript Podcast for convenient understanding
• Global attainment for your research
• Manuscript accessibility in different formats
( Pdf, E-pub, Full Text, Audio)
• Unceasing customer service
Track the below URL for one-step submission
https://juniperpublishers.com/online-submission.php
This work is licensed under Creative
Commons Attribution 4.0 Licens
DOI: 10.19080/OAJNN.2021.15.555910
... Thrombosis of the PMA leading to ACTS is exceedingly rare. When an obvious cause of ACTS is not determined, US imaging, including the use of color Doppler, may shed light on the etiology such as PMA occlusion [7]. ...
... Several abnormalities (increase in CSA at the CT inlet, limited mobility of the nerve within the CT, decrease in diameter of the nerve within the CT, and altered echogenicity) are detected by US. More importantly, it can reveal the specific cause of median nerve compression, such as tendosynovitis at the wrist, ganglion cysts, excessive amount of fat tissue in the CT, synovial hypertrophy, soft tissue tumors, and aberrant vascular structures [1,3,7,11,13]. Furthermore, US may complement electrodiagnostic tests when the latter fail to provide accurate localization or are negative in patients with a typical clinical picture of CTS [7]. ...
... More importantly, it can reveal the specific cause of median nerve compression, such as tendosynovitis at the wrist, ganglion cysts, excessive amount of fat tissue in the CT, synovial hypertrophy, soft tissue tumors, and aberrant vascular structures [1,3,7,11,13]. Furthermore, US may complement electrodiagnostic tests when the latter fail to provide accurate localization or are negative in patients with a typical clinical picture of CTS [7]. Detection of PMA by US provides not only a clue to the possible etiology but also helps in preoperative planning, especially when the vessel is large and is in the line of incision for CTR [21]. ...
Acute Carpal Tunnel Syndrome: Clinical, Electromyographic, and Ultrasound Features in 25 Patients
Article
  • Oct 2021
  • CLIN NEUROL NEUROSUR
Background The acute presentation of carpal tunnel syndrome (CTS) is rare. When symptoms start acutely with no obvious causes, ultrasound (US) imaging may provide clues to the etiology. Objective This study describes the clinical, electromyographic, and US findings in 25 patients presenting with acute CTS (ACTS). Methods In this analysis, of the patients referred for electrodiagnostic confirmation of CTS over the past decade, 25 had an acute onset of symptoms. All patients underwent EMG/NCV and US of the median nerve at the carpal tunnel and forearm. Results Of the 25 cases with ACTS, 5 (20%) had bilateral involvement leading to the total hands studied to 30. In 14 (56%) patients, an inciting event was identified as a possible cause of ACTS. In 11 (44%) patients without an antecedent event, 7 (64%) had a persistent median artery (PMA) detected by US. Electrodiagnostic studies showed prolonged distal motor latency with normal motor conduction velocity proximal to the carpal tunnel in 24 (80%) of 30 hands, 6 (20%) hands showed absent compound muscle action potentials over the abductor pollicis brevis (APB), and 22 (73%) hands had absent sensory potentials. Denervation changes were seen in the APB in 13 (43%) hands, and motor unit potentials were absent in 6 (20%) hands. Sixteen (64%) patients underwent a carpal tunnel release for severe symptoms. Conclusion CTS may present acutely without a clinically identifiable cause. US complements electrodiagnostic studies and is particularly useful when electrodiagnostic tests are non-diagnostic (due to absent compound muscle and sensory action potentials). US may also provide clues to the underlying cause.
View
... Clinical examination alone cannot differentiate between neuropraxia, axonotmesis, and neurotmesis (7). EDX can differentiate between neuropraxia and axonotmesis 1-2 weeks after the injury but cannot distinguish neurotmesis from axonotmesis; US evaluation can make that distinction (13). Combining EDX and US can provide critical information in planning management of patients with nerve injuries. ...
Gunshot-related nerve injuries of the upper extremities: clinical, electromyographic, and ultrasound features in 22 patients
Article
Full-text available
  • Jan 2024
Objectives Gunshot wounds of the upper extremities may cause permanent neurovascular injuries, leading to significant morbidity, chronic pain, functional loss, and disability. While there are many reports on the incidence and intraoperative findings in gunshot-related nerve injuries (GSNI) sustained during wars, there is a paucity of details pertaining to GSNI of the upper extremities in civilians. The goal of this paper is to provide the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in 22 patients with GSNI of the upper extremities. Methods This is a retrospective study of patients referred for EDX studies to evaluate the presence of nerve injury after sustaining GSWs to the upper extremities. All patients underwent EDX studies, and 16 patients had US evaluations. Numerous metrics were documented including presenting symptoms, neurological abnormalities, EDX findings, and US features. Results The forearm was the most frequent location of injury (8 [36%] patients). The ulnar nerve was the most common injured nerve (10 [45%] patients), followed by the brachial plexus (7 [32%] patients). All patients complained of muscle weakness; the most frequently affected muscles were the first dorsal interosseous (FDI) (14 [64%] patients) and abductor pollicis brevis (APB) (11 [50%] patients). Muscle atrophy was noted in 19 (86%) patients, 15 of whom had atrophy of the FDI. Axonotmesis was the type of nerve injury in all patients based on EDX studies. Of the 16 patients who underwent US studies, a neuroma in continuity was noted in 4 (25%) patients and neurotmesis in 1 (6.2%) patient. Eleven (69%) patients had enlarged and/or hypoechoic nerves. Conclusions Axonotmesis of the ulnar nerve was the most common finding among patients sustaining gunshot injuries to the upper extremities. EDX and US studies provide valuable insight into the underlying pathophysiology and guidance for management of patients with GSNI of the upper extremities.
View
... Needle EMG is helpful to narrow down the location of the median nerve neuropathy, but still proves to be imprecise as in this case. Under these circumstances HRUS is a handy tool for localizing the median nerve neuropathy more accurately and it may also provide clue to the underlying cause 3,10 . MR neurography can also be quite helpful 11 but the advantage of HRUS is its instant availability at the point of care and the minimal cost. ...
Clinical Reasoning: A Septuagenarian With Painless Ulceration on the Fingertip
Article
  • Jul 2023
A 78-year-old non-diabetic non-smoker male presented with painless non-healing ulceration on the middle fingertip of the left hand. Similar episodes have occurred in the past involving the left middle and index fingers resulting in amputation of the tip of index finger. Diagnosis was arrived at by clinical reasoning and confirmed by additional investigations. The readers are presented with a rational step by step diagnostic paradigm in a very rare presentation of a common neurological disorder.
View
... 11,18 Unlike EDX, US has the potential to differentiate neurotmeses (nerve transection) from axonotmesis. 20 An US performed soon after the CTR may reveal a lacerated or transected nerve requiring urgent surgery, whereas a later US image may show a neuroma. Of the 11 patients who had an US in our study, imaging was done at varied intervals, depending on when the referrals for EMG study occurred, leading to varied findings. ...
Iatrogenic median and ulnar nerve injuries during carpal tunnel release: clinical, electrodiagnostic, and ultrasound features in 12 patients. Patient series
Article
Full-text available
  • Mar 2023
  • J NEUROSURG
Background: Nerve injuries during carpal tunnel release (CTR) are rare. Electrodiagnostic (EDX) and ultrasound (US) studies may be helpful in evaluating iatrogenic nerve injuries during CTR. Observations: Nine patients sustained a median nerve injury, and 3 patients experienced ulnar nerve damage. Decreased sensation occurred in 11 patients and dysesthesia in 1 patient. Abductor pollicis brevis (APB) weakness occurred in all patients with median nerve injury. Of the 9 patients with median nerve injury, the compound muscle action potentials (CMAP) of the APB and sensory nerve action potentials (SNAP) of the 2nd or 3rd digit were not recordable in 6 and 5 patients, respectively. Of the 3 patients sustaining ulnar nerve injuries, the CMAP of the ADM and SNAP of the 5th digit were not recordable in 1 patient; 2 patients showed prolonged latency and decreased amplitude of CMAP/SNAP. US studies of 8 patients with a median nerve injury showed a neuroma within the carpal tunnel. One patient underwent surgical repair urgently and 6 after variable intervals. Lessons: Surgeons should be cognizant of nerve injuries during CTR. EDX studies and US are useful in evaluating iatrogenic nerve injuries during CTR.
View
... High-resolution US is valuable in identifying structural lesions such as an intraneural ganglion or inflammatory changes and to confirm the lesion site when electrodiagnostic testing is inconclusive. 22,23 Although US has not been reported in the diagnostic evaluation of double crush lumbar and common fibular injury, it has been described as being valuable in diagnosing double crush ulnar nerve injury by showing enlargement of the ulnar nerve at the cubital tunnel and 13 Golovchinsky, 1998 15 Zheng et al., 2016 20 Lumbosacral radiculopathy and tarsal tunnel syndrome Augustijn & Vanneste, 1992 12 Posterior tibial nerve compressed under flexor retinaculum (tarsal tunnel syndrome) Kanamoto et al., 2016 16 Lumbar nerve is compressed both medially and laterally in the spinal canal Ang & Foo, 2014 8 Lumbar radiculopathy and superficial peroneal nerve entrapments at two separate locations Reife & Coulis, 2013 10 Lumbar radiculopathy and peroneal nerve Crotti et al., 2005 9 Lumbar radiculopathy and peroneal nerve crural branches Wu et al., 2020 18 Simultaneous lumbar foraminal and/or extraforaminal stenosis Yamada et al., 2011 19 Fifth lumbar spinal nerve (compression at two or more sites from intraspinal to extraforaminal zone; failed back surgery) Nishimura et al., 2020 17 Lumbosacral epidermoid tumor and sacral Tarlov cyst at S2 within the flexor carpi ulnaris muscle. 24 Knee MRI is useful in visualizing the fibular nerve by detecting lesions caused by trauma, ganglia, peripheral nerve sheath tumors, and osteochondroma. ...
Role of electromyography and ultrasonography in the diagnosis of double crush lumbar radiculopathy and common fibular injury: illustrative cases
Article
Full-text available
  • Apr 2022
  • J NEUROSURG
Background: Double crush syndrome consists of 2 compression sites along a peripheral nerve and is rare in the lower extremities. Electrodiagnostic and ultrasound (US) studies may be helpful in evaluating drop foot involving overlapping pathologies. Observations: Case #1: a man presented with left dorsiflexor weakness and left foot numbness. EMG revealed a left common fibular nerve entrapment neuropathy and left L5 radiculopathy. US and MRI revealed a large cystic lesion of the left common fibular nerve treated by cyst removal. The left foot drop persisted postoperatively. Lumbar CT-myelogram revealed severe left foraminal stenosis at L5-S1. Multilevel lumbar laminectomies and facetectomies with a L5-S1 fusion was performed. Within 1 month postoperatively, the left foot drop had improved. Case #2: a man developed a right foot drop caused by right lumbar foraminal stenosis at L4-5 and L5-S1. EMG and US of the right common fibular neuropathy demonstrated large fascicles involving the right common fibular nerve. MRI revealed a hyperintense signal of the right common fibular nerve. Spontaneous improvement occurred within 6 months without surgery. Lessons: Spine surgeons should recognize double crush in the lower extremities. EMG and US are valuable in detecting peripheral nerve abnormalities, especially in cases with overlapping lumbar pathology.
View
... US has been found to be a valuable complement to EDX in situations where EDX fail to provide accurate localization and to differentiate chronic inflammatory demyelinating polyneuropathies from hereditary polyneuropathies. In CMT1A, the CSA often appears diffusely increased along the entire course of the median nerve [5]. Disproportionate enlargement of the median nerve at the CTI and/or carpal tunnel outlet suggests the additional presence of entrapment at the carpal tunnel, which is further substantiated by a drop in diameter within the carpal tunnel as in this patient. ...
Nerve Ultrasound Findings before and after Surgery in a Patient with Charcot-Marie-Tooth Disease Type 1A and Comorbid Carpal Tunnel Syndrome
Article
Full-text available
  • Mar 2022
The diagnosis of comorbid carpal tunnel syndrome (CTS) in patients with Charcot-Marie-Tooth (CMT) disease is challenging due to the overlapping symptoms and inconclusive electrodiagnostic studies (EDX). This case report is aimed at illustrating the value of ultraso-nography (US) in a patient with CMT1 disease and comorbid CTS. A 28-year-old woman presented with symptoms of painful paresthesia and weakness of both hands. EDX demonstrated a demyelinating sensory-motor polyneuropathy in the upper and lower extremities, consistent with CMT1 disease. US showed an increased cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet (CTI) with a significant drop in the diameter within the carpal tunnel, confirming concurrent CTS. Genetic testing confirmed PMP22 duplication consistent with CMT1A. Bilateral carpal tunnel releases were performed with partial symptom resolution within 3 weeks. Postoperative EDX demonstrated improved motor conduction across the wrist, but the sensory potentials continued to be unrecordable. US showed a significant reversal of the diameter-drop of the median nerve within the carpal tunnel and decrease in CSA at the CTI. US imaging is a valuable technique for identifying comorbid CTS in patients with CMT and directing appropriate treatment.
View
Diagnostic Value of Muscle Ultrasound for Myopathies and Myositis
Article
Full-text available
  • Sep 2020
  • Curr Rheumatol Rep
Purpose of review: The purpose of this review is to critically discuss the use of ultrasound in the evaluation of muscle disorders with a particular focus on the emerging use in inflammatory myopathies. Recent findings: In myopathies, pathologic muscle shows an increase in echogenicity. Muscle echogenicity can be assessed visually, semi-quantitatively, or quantitatively using grayscale analysis. The involvement of specific muscle groups and the pattern of increase in echogenicity can further point to specific diseases. In pediatric neuromuscular disorders, the value of muscle ultrasound for screening and diagnosis is well-established. It has also been found to be a responsive measure of disease change in muscular dystrophies. In chronic forms of myositis like inclusion body myositis, ultrasound is very suitable for detecting markedly increased echogenicity and atrophy in affected muscles. Acute cases of muscle edema show only a mild increase in echogenicity, which can also reverse with successful treatment. Muscle ultrasound is an important imaging modality that is highly adaptable to study various muscle conditions. Although its diagnostic value for neuromuscular disorders is high, the evidence in myositis has only begun to accrue in earnest. Further systematic studies are needed, especially in its role for detecting muscle edema.
View
Ultrasound versus electromyography for the detection of fasciculation in amyotrophic lateral sclerosis: systematic review and meta-analysis
Article
Full-text available
  • Apr 2020
  • Radiol Bras
The objective of this study was to determine the diagnostic accuracy of ultrasound and electromyography for the detection of fasciculation in patients with amyotrophic lateral sclerosis and to compare detection rates between the two methods. By searching the Cochrane Library, MEDLINE, Excerpta Medica, and Latin-American and Caribbean Health Sciences Literature databases, we identified studies evaluating the diagnostic accuracy and fasciculation detection rates of ultrasound and electromyography. The Quality Assessment of Diagnostic Accuracy Studies, version 2, and RTI item bank tools were used for the evaluation of methodological quality. Ultrasound, for 10 s or 30 s, had a higher detection rate than did electromyography in all muscles evaluated. The overall detection rate (in patients) did not differ significantly between ultrasound for 10 s and ultrasound for 30 s. The accuracy of ultrasound for 10 s was 70% in muscles and 85% in patients. The accuracy of ultrasound for 30 s was 82% in patients. Ultrasound provided detection rates superior to those achieved with electromyography, independent of the examination time and muscles evaluated.
View
Ultrasound can differentiate inclusion body myositis from disease mimics
Article
Full-text available
  • Apr 2020
Introduction: The diagnosis of inclusion body myositis (IBM) can be challenging, and its presentation can be confused with other forms of myositis or neuromuscular disorders. In this study we evaluate the ability of quantitative muscle ultrasound to differentiate between IBM and mimicking diseases. Methods: Patients 50 years of age and older were included from two specialty centers. Muscle echogenicity and muscle thickness of four characteristically involved muscles in IBM were measured and compared with polymyositis (PM)/dermatomyositis (DM), other neuromuscular disorders, and healthy controls. Results: Echogenicity was higher and muscle thickness generally lower in all four muscles in IBM compared with PM/DM and normal controls. When comparing IBM with the comparator groups, the flexor digitorum profundus was the most discriminative muscle. Discussion: Ultrasound appears to be a good test to differentiate established IBM from PM/DM and neuromuscular controls, with value as a diagnostic tool for IBM.
View
Sensitivity of high-resolution ultrasonography in clinically diagnosed carpal tunnel syndrome patients with hand pain and normal nerve conduction studies
Article
Full-text available
  • Jul 2018
Background Suspecting carpal tunnel syndrome (CTS) in patients with hand pain is usual. Considering the variable rate of false-negative results in nerve conduction study (NCS), as a frequent reference confirmatory standard test, we aimed to evaluate the diagnostic accuracy of neuromuscular ultrasound in patients with clinical evidence of CTS and normal NCS. Methods It was a diagnostic accuracy study conducted in the outpatient clinic of Rofaydeh Hospital, Tehran, Iran, between July 2012 and December 2016; it recruited clinically diagnosed CTS patients and a control group. All participants underwent comprehensive clinical examination, NCS, and high-resolution ultrasonography of the median nerve. Results Two hundred and fifty patients with clinical evidence of CTS met the inclusion criteria, of whom 103 (27.1%) had normal NCS and underwent an ultrasound examination. A cutoff point of 9.4 mm² (mean + 2 standard deviation) for median nerve cross-sectional area at the carpal tunnel inlet from the control group was set to detect 73% abnormality in the case group. Conclusion Ultrasonography had a sensitivity rate of 73% in patients with clinical CTS and negative NCS, increasing the overall diagnostic sensitivity for clinically suspected CTS in the electrodiagnostic lab setting to 92%. The study highlights the complementary role of ultraso-nography in diagnosing CTS in conjunction with NCS.
View
Diaphragm: Pathophysiology and Ultrasound Imaging in Neuromuscular Disorders
Article
Full-text available
  • Nov 2017
Respiratory muscles are classically involved in neuromuscular disorders, leading to a restrictive respiratory pattern. The diaphragm is the main respiratory muscle involved during inspiration. Ultrasound imaging is a noninvasive, radiation-free, accurate and safe technique allowing assessment of diaphragm anatomy and function. The authors review the pathophysiology of diaphragm in neuromuscular disorders, the methodology and indications of diaphragm ultrasound imaging as well as possible pitfalls in the interpretation of results.
View
Ultrasonography in Distal Ulnar Nerve Neuropathy: Findings in 33 Patients
Article
  • Dec 2019
Purpose: Although there are many case reports on the role of ultrasonography (US) in distal ulnar nerve neuropathy (Guyon canal syndrome), there is a paucity of large series in the literature because of its rarity. During an 8-year period, 33 instances of electrodiagnostically confirmed cases underwent US imaging. These cases were analyzed to determine the role of US in uncovering the cause of distal ulnar nerve neuropathy and its contribution to further management. Methods: This was a retrospective study of patients diagnosed with distal ulnar nerve neuropathy based on electrodiagnostic criteria, who also had undergone US (measurement of the cross-sectional area and documentation of causes such as cysts and neuromas). Results: US showed normal ulnar nerve in 5, cysts in 10, neuromas in 2, and nonspecific enlargement in 16 patients. Surgery was performed in 15 patients, and the US findings were corroborated in those with cysts and neuromas; 1 patient had an aberrant muscle, and two had fibrous bands constricting the ulnar nerve in the Guyon canal (not detected preoperatively by US imaging). Conclusions: US imaging detected the underlying cause of distal ulnar nerve neuropathy in a significant percentage of patients, potentially contributing to effective treatment.
View
Ultrasonography Provides a Diagnosis Similar to That of Nerve Conduction Studies for Carpal Tunnel Syndrome
Article
  • Jun 2019
Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Its diagnosis is based on clinical symptoms and neurophysiological evaluation. Recently, ultrasonography has been introduced as a promising noninvasive diagnostic alternative. In this study, the authors compared ultrasonography with neurophysiological findings for the diagnosis of CTS in 96 patients/hands with clinical symptoms of CTS. The latency, amplitude, distance, and velocity of the median and ulnar nerves were measured. Needle electromyography was performed in the abductor pollicis brevis, in addition to muscles of the arm and forearm, to exclude proximal median nerve, brachial plexus, or radicular abnormalities. Ultrasonography was based on the morphologic/anatomic changes of the median nerve cross-sectional area in the sagittal plane of the wrist at the level of the pisiform bone, the changes of its regional echogenicity, and the identification of coexisting pathologies, such as tenosynovitis, space-occupying lesions, supplementary muscles, and vessels, that may provoke indirectly an increase of the pressure in the carpal tunnel. Eighty-seven (90%) of the 96 patients/hands with clinical symptoms of CTS showed positive findings in both ultrasonography and nerve conduction studies. Six (6%) patients showed positive findings only in nerve conduction studies, and 3 (3%) patients showed positive findings only in ultrasonography; the difference was not statistically significant. The sensitivity and the specificity of nerve conduction studies compared with ultrasonography was 97% and 89% compared with 94% and 55%, respectively. A positive correlation and proportional increase of the ultrasonography measurements compared with the increase of the nerve conduction studies severity was observed. [Orthopedics. 201x; xx(x):xx-xx.].
View
Role of Ultrasonography in Severe Distal Median Nerve Neuropathy
Article
  • Apr 2019
  • J CLIN NEUROPHYSIOL
Purpose: Electrodiagnostic studies do not differentiate severe lesions of the median nerve in the distal forearm from those within the carpal tunnel when compound muscle action potential over the abductor pollicis brevis and sensory nerve action potential are absent; needle electromyography showing denervation confined to the abductor pollicis brevis is presumed to suggest localization to the carpal tunnel, although the lesion may be in the forearm. Under these circumstances, the patient may undergo carpal tunnel release without benefit. This retrospective study looked at patients with clinical picture of severe carpal tunnel syndrome who had no compound muscle action potential or sensory nerve action potential on median nerve stimulation; the goal was to determine how often ultrasonic imaging pointed to a location other than the carpal tunnel. Methods: Patients with clinical picture of severe carpal tunnel syndrome with no sensory nerve action potential and no compound muscle action potential over the abductor pollicis brevis and second lumbrical underwent ultrasonic imaging; criteria for localization to the carpal tunnel included significant increase in the cross-sectional area of the median nerve at the carpal tunnel inlet and increase in the wrist/forearm cross-sectional area ratio. Results: In 42 of 46 cases, entrapment at the carpal tunnel was confirmed by ultrasonography; in four patients, other causes were located proximal to the carpal tunnel. Conclusions: Ultrasonic imaging is useful not only for confirming entrapment of the median nerve at the carpal tunnel in patients with nonlocalizing electrodiagnostic studies but also in detecting pathology in the forearm, which may mimic severe carpal tunnel syndrome.
View
Nerve ultrasound findings differentiate Charcot-Marie-Tooth disease (CMT) 1A from other demyelinating CMTs
Article
  • Sep 2018
  • CLIN NEUROPHYSIOL
Objective: Ulnar/median motor nerve conduction velocity (MNCV) is ≤38 m/s in demyelinating Charcot-Marie-Tooth disease (CMT). Previous nerve high resolution ultrasound (HRUS) studies explored demyelinating CMT assuming it as a homogeneous genetic/pathological entity or focused on CMT1A. Methods: To explore the spectrum of nerve HRUS findings in demyelinating CMTs, we recruited patients with CMT1A (N = 44), CMT1B (N = 9), CMTX (N = 8) and CMT4C (N = 4). They underwent nerve conduction study (NCS) and HRUS of the median, ulnar, peroneal nerve, and the brachial plexus. Results: Median, ulnar and peroneal MNCV significantly differed across CMT subtypes. Cross sectional area (CSA) was markedly and diffusely enlarged at all sites, except entrapment ones, in CMT1A, while it was slightly enlarged or within normal range in the other CMTs. No significant right-to-left difference was found. Age had limited effect on CSA. CSAs of some CMT1A patients largely overlapped with those of other demyelinating CMTs. A combination of three median CSA measures could separate CMT1A from other demyelinating CMTs. Conclusions: Nerve HRUS findings are heterogeneous in demyelinating CMTs. Significance: Nerve HRUS may separate CMT1A from other demyelinating CMTs. The large demyelinating CMTs HRUS spectrum may be related to its pathophysiological variability.
View
Ultrasonography in neuralgic amyotrophy: Sensitivity, spectrum of findings and clinical correlations
Article
  • May 2017
  • MUSCLE NERVE
Introduction: The aim of this study was to assess the value of ultrasonography in neuralgic amyotrophy. Methods: Fifty-three patients with 70 affected nerves were examined with high resolution ultrasound. Results: The most commonly affected nerve was the anterior interosseous (23%). Ultrasonographic abnormalities in the affected nerves, rather than in the brachial plexus, were observed with an overall sensitivity of 74%. Findings included the swelling of the nerve/fascicle with or without incomplete/complete constriction and rotational phenomena (nerve torsion and fascicular entwinement). A significant difference was found among the categories of ultrasonographic findings with respect to clinical outcome (p=0.01). In nerves with complete constriction and rotational phenomena, reinnervation was absent or negligible, indicating surgery was warranted. Discussion: Ultrasonography may be used as a diagnostic aid in neuralgic amyotrophy, which was hitherto a clinical and electrophysiological diagnosis, and may also help in identifying potential surgical candidates. This article is protected by copyright. All rights reserved.
View