0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Research Letters |

High-Resolution Ultrasound as a Diagnostic Adjunct in Common Peroneal Neuropathy FREE

Y. L. Lo, MD; S. Fook-Chong, MSc; T. H. Leoh; Y. F. Dan; Y. E. Tan; W. H. Lau; L. L. Chan, MD
Arch Neurol. 2007;64(12):1798-1800. doi:10.1001/archneur.64.12.1798.
Text Size: A A A
Published online

Entrapment neuropathy of the common peroneal nerve is caused mostly by compression at the fibula head region.1 In cases of severe axon loss, demonstration of conduction block or reduction of conduction velocity would be difficult. Apart from demyelination, mechanical factors and ischemic mechanisms may play a role.2 Differing degrees of damage to individual nerve fascicles may occur within the common peroneal nerve,3 rendering interpretation of needle electromyography (EMG) difficult. High sciatic nerve lesions are also known to mimic peroneal neuropathy at the fibular head if electrodiagnostic examination is not performed adequately.1 High-resolution ultrasonography (US) may be a potential diagnostic tool in these technically challenging circumstances.

Over a 1-year period, we studied 32 healthy controls and 8 otherwise well patients who presented with footdrop. All controls and patients underwent US of the peroneal nerve as well as electrodiagnostic studies. Peroneal sensory and motor nerve conduction studies (NCS) were performed with standard techniques.

Blinded US examination was conducted with a General Electric Logiq 7 Pro machine (GE Healthcare, Chalfont St Giles, England), using a 5- to 10-MHz linear array transducer. Transverse scans of the peroneal nerves were obtained at the level of the fibula head bilaterally with the subject's legs supported and slightly flexed (20° to 30°) at the knees in the lateral position (Figure 1). We measured the maximum transverse length, maximum transverse breadth (perpendicular to transverse length), ratio of these 2 parameters (breadth/length), and cross-sectional area (Figure 2). The upper limit of normality was 2 SDs above the mean. P < .05 was considered statistically significant.

Place holder to copy figure label and caption
Figure 1.

Photographic depicting ultrasonography probe in a transverse orientation at the fibular neck of a subject undergoing the procedure. The asterisk demarcates the surface anatomy of the fibular head.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.

Diagrammatic representation of ultrasonography measurements. Ratio is obtained from breadth/ length.

Graphic Jump Location

The peroneal nerve was identified without difficulty with US in controls (Table 1) and patients, using the fibula head as a prominent landmark. Of the 8 patients, 3 (patients 3, 5, and 8) with normal US findings were eventually diagnosed as having causes other than peroneal neuropathy, resulting in footdrop. The remaining 5 patients with peroneal neuropathy all had 1 or more abnormal US parameters. Of these, 4 had etiology related to local pressure and leg crossing. In terms of US parameters (Table 2 and Table 3), all 6 limbs with peroneal neuropathy had abnormal area and transverse breadth. In addition, 5 limbs showed abnormal transverse length, but only 2 had abnormal ratios. In comparison, apart from patient 7 (Figure 3) with motor conduction block, none of the other patients' NCS results had localizing value. Peroneal neuropathy was supported by EMG examination findings showing denervation in the tibialis anterior and sparing of the other muscles sampled in our protocol.

Place holder to copy figure label and caption
Figure 3.

Ultrasonography scans for patient 7. Transverse sections through the right (normal) and left (abnormal) peroneal nerves. The normal right peroneal nerve was identified by its spherical shape and echogenic rim (arrows). The left peroneal nerve was markedly swollen and had mild loss of echogenicity. Each tick mark represents 1 cm in the scans.

Graphic Jump Location
Table Graphic Jump LocationTable 1. Ultrasonography Parameter Results in Normal Controlsa,b
Table Graphic Jump LocationTable 2. Summary of Clinical and Ultrasonography Data for All Patients
Table Graphic Jump LocationTable 3. Summary of Electrophysiological Data for All Patients

We found significant negative correlation of peroneal motor amplitude with transverse length (Pearson correlation coefficient, r = −0.66, P = .04) and area (r = −0.63, P = .04). However, no significant correlation was found between superficial peroneal sensory amplitude and all 4 US parameters (P > .05 for all).

The present study demonstrated high sensitivity and specificity of US in relation to electrophysiological techniques. In particular, the area, transverse breadth, and transverse length were particularly useful, consistent with previously observed pathological changes of diffuse or focal nerve thickening.4

As with previous investigators, it was technically difficult to image the peroneal nerve proximal to the fibular head5 and longitudinally in the popliteal fossa. Hence, we used transverse US scans at the fibula head level, the most common site of abnormality.

Our findings of negative correlation of motor amplitude with transverse length and area supports a relation between morphological nerve swelling in keeping with axon loss (patients 1, 2, and 4) over focal demyelination (patient 7), although both processes may coexist. This was also the experience reported in a study of ulnar elbow neuropathy.6 In conclusion, we have demonstrated the value of US as a diagnostic adjunct to electrophysiological testing for the localization of peroneal nerve entrapment.

ARTICLE INFORMATION

Correspondence: Dr Lo, Department of Neurology, Singapore General Hospital, Outram Rd, Singapore 169608 (lo.yew.long@sgh.com.sg).

Author Contributions:Study concept and design: Lo, Fook-Chong, Dan, Tan, Lau, and Chan. Acquisition of data: Lo, Fook-Chong, Leoh, Dan, Tan, and Lau. Analysis and interpretation of data: Lo, Fook-Chong, Leoh, Dan, and Chan. Drafting of the manuscript: Lo, Leoh, Tan, Lau, and Chan. Critical revision of the manuscript for important intellectual content: Lo, Fook-Chong, Leoh, Dan, Lau, and Chan. Statistical analysis: Lo, Fook-Chong, Leoh, Dan, Tan, and Lau. Obtained funding: Lo and Chan. Administrative, technical, and material support: Lo, Dan, Tan, Lau, and Chan. Study supervision: Lo, Leoh, Dan, Tan, Lau, and Chan.

Financial Disclosure: None reported.

Additional Contributions: M. P. Lee and H. Y. Gan assisted with data analysis.

Additional Information: Dr Lo is with the Department of Neurology and the National Neuroscience Institute, Singapore General Hospital, Singapore. Dr Fook-Chong is with the Department of Clinical Research, Singapore General Hospital. Messrs Leoh, Dan, Tan, and Lau are with the Department of Neurology, Singapore General Hospital. Dr Chan is with the Department of Diagnostic Radiology, Singapore General Hospital.

Katirji  BWilbourn  AJ High sciatic lesion mimicking peroneal neuropathy at the fibular head. J Neurol Sci 1994;121 (2) 172- 175
PubMed Link to Article
Uncini  ADi Muzio  AAwad  JGambi  D Compressive bilateral peroneal neuropathy: serial electrophysiological and pathophysiological remarks. Acta Neurol Scand 1992;85 (1) 66- 70
PubMed Link to Article
Sourkes  MStewart  JD Common peroneal neuropathy: a study of selective motor and sensory involvement. Neurology 1991;41 (7) 1029- 1033
PubMed Link to Article
Beekman  RVisser  LH High-resolution sonography of the peripheral nervous system: a review of the literature. Eur J Neurol 2004;11 (5) 305- 314
PubMed Link to Article
Heinemeyer  OReimers  CD Ultrasound of radial, ulnar, median, and sciatic nerves in healthy subjects and patients with hereditary motor and sensory neuropathies. Ultrasound Med Biol 1999;25 (3) 481- 485
PubMed Link to Article
Beekman  Rvan der Plas  JPLUitdehaag  BMJSchellens  RLLAVisser  LH Clinical, electrodiagnostic, and sonographic studies in ulnar neuropathy at the elbow. Muscle Nerve 2004;30 (2) 202- 208
PubMed Link to Article

Figures

Place holder to copy figure label and caption
Figure 1.

Photographic depicting ultrasonography probe in a transverse orientation at the fibular neck of a subject undergoing the procedure. The asterisk demarcates the surface anatomy of the fibular head.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.

Diagrammatic representation of ultrasonography measurements. Ratio is obtained from breadth/ length.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 3.

Ultrasonography scans for patient 7. Transverse sections through the right (normal) and left (abnormal) peroneal nerves. The normal right peroneal nerve was identified by its spherical shape and echogenic rim (arrows). The left peroneal nerve was markedly swollen and had mild loss of echogenicity. Each tick mark represents 1 cm in the scans.

Graphic Jump Location

Tables

Table Graphic Jump LocationTable 1. Ultrasonography Parameter Results in Normal Controlsa,b
Table Graphic Jump LocationTable 2. Summary of Clinical and Ultrasonography Data for All Patients
Table Graphic Jump LocationTable 3. Summary of Electrophysiological Data for All Patients

References

Katirji  BWilbourn  AJ High sciatic lesion mimicking peroneal neuropathy at the fibular head. J Neurol Sci 1994;121 (2) 172- 175
PubMed Link to Article
Uncini  ADi Muzio  AAwad  JGambi  D Compressive bilateral peroneal neuropathy: serial electrophysiological and pathophysiological remarks. Acta Neurol Scand 1992;85 (1) 66- 70
PubMed Link to Article
Sourkes  MStewart  JD Common peroneal neuropathy: a study of selective motor and sensory involvement. Neurology 1991;41 (7) 1029- 1033
PubMed Link to Article
Beekman  RVisser  LH High-resolution sonography of the peripheral nervous system: a review of the literature. Eur J Neurol 2004;11 (5) 305- 314
PubMed Link to Article
Heinemeyer  OReimers  CD Ultrasound of radial, ulnar, median, and sciatic nerves in healthy subjects and patients with hereditary motor and sensory neuropathies. Ultrasound Med Biol 1999;25 (3) 481- 485
PubMed Link to Article
Beekman  Rvan der Plas  JPLUitdehaag  BMJSchellens  RLLAVisser  LH Clinical, electrodiagnostic, and sonographic studies in ulnar neuropathy at the elbow. Muscle Nerve 2004;30 (2) 202- 208
PubMed Link to Article

Correspondence

CME
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

1,742 Views
8 Citations
×

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Collections
PubMed Articles
Jobs
JAMAevidence.com

NYSORA Textbook of Regional Anesthesia and Acute Pain Management
Fig. 43-10

The Rational Clinical Examination: Evidence-Based Clinical Diagnosis
Original Article: Does This Patient Have Abdominal Aortic Aneurysm?