Role of nerve ultrasound versus electrophysiological studies in the evaluation of nerve injuries

Abstract

Background: High-resolution ultrasonography (US) is a non-invasive, readily applicable imaging modality capable of depicting real-time static and dynamic information concerning the peripheral nerves and their surrounding tissues. Although electrophysiological studies are the gold standard in the evaluation of nerve injuries, US can be used also to evaluate the morphological changes of nerve injuries. Objectives: To evaluate the role of the high-resolution US in the assessment of nerve injuries and to compare it to the role of electrodiagnostic studies. Subjects and methods: A total of 30 nerves from 22 consecutive patients with clinically definite nerve injury were considered. Two independent and blinded clinicians perform electrodiagnosis and US. The clinical, neurophysiological, and US findings were collected, and the contribution of US was then classified as " contributive" or "non-contributive", according to whether US confirmed the clinical and neurophysiological diagnosis or not. Results: US was "contributive" (confirming the electrophysiological diagnosis) in 66.67% of cases (n = 20), providing information about continuity of the nerve, morphological changes after injury as swelling, scar tissue formation, or neuroma formation with sensitivity of 75% compared to the electrodiagnostic studies and accuracy of 66.67%. Conclusion: Ultrasound can be used, when available, as a complementary tool for electrodiagnostic studies to provide anatomical information about the injured nerves in case of complete axonal lesion.

Evaluation of Traumatic Injuries of Median and Ulnar Nerves at the Wrist after Surgical Repair: Ultrasound and Electrophysiological Correlation

“…We found a statistically significant difference between diagnosis of the severity of nerve injury by EDX and continuity of the nerve by US at one and three months after repair. This agreed with the study done by Elfayoumy N, et al, (2020) [21] in which they studied 12 nerves diagnosed as complete nerve injuries with the use of EDX, but using US, only three nerves showed fascicular continuity. Lauretti L, et al, [22] found that complete anatomical nerve interruption is easily recognized by the US, while internal nerve damage with the epineurium in continuity is more difficult to interpret.…”

Value of ultrasound assessment for traumatic nerve injury of the upper limb

“…In addition, 48 patients had associated fibrosis. These findings almost paralleled those of the study by Elfayoumy [ 14 ], who divided high-resolution US findings into three groups: fusiform in shape (increased CSA) (36.7%), fibrosis (36.7%), and neuroma (26.6%).…”

“…In the current study, the most common cause of PNI was crush injury and cut wounds in 54 of 69 cases, followed by the other types of injuries. In contrast, Uzun [ 8 ] and Elfayoumy [ 14 ] reported that cut injury by sharp objects was the most common cause of PNI. The site of laterality of the injured nerves in our study was more often on the left side (71.9%).…”

Sonographic Evaluation of Peripheral Sciatic Nerve Injury: A Case Study

“…Another disadvantage of electrodiagnostic studies is that, although accurate in their assessment of specific nerve involvement, they are often unable to distinguish axonotmesis from neurotmesis and they are unable to precisely localize a lesion which can be especially problematic in cases of multiple injury sites, entry points, ballistics, and shrapnel. 5,13 Furthermore, relying on electrodiagnostic testing can make for a conservative and lengthy management plan. Conservative management is not uncommon in PNI as injured nerves undergo a complex physiologic process known as Wallerian degeneration before regrowth begins.…”

“…Sonography is limited in its ability to visualize individual axons, myelin, and endoneurium. 11,12 However, advances in resolution have allowed for visualization of individual fascicles, perineurium, and epineurium (see Figure 4). Changes in echogenicity of nerve connective tissue, disruption of normal shape and cross-section areas of the nerve, interruption, and discontinuity of fascicles and/or the epineurium, swelling of retracted ends, and presence of intraneural bleeding can all indicate PNI and help to determine injury classification.…”