The cross-sectional area is enlarged but the fascicular structure of the nerve is preserved. In patients with traumatic nerve lesions, adding ultrasonography to electrodiagnosis may provide a lot of important complementary information about the localization and the cause of impaired nerve function, both being essential for deciding upon surgical treatment. Ultrasonography not only allows one to precisely localize the site of nerve injury, it also indicates whether a nerve is completely transected or partially dissected or whether the nerve is displaced or even encased by surrounding scar formation or by a fibrous or bony callus after bone fracture [29], [30],

[31] and [32]. find more Furthermore, ultrasonography may identify fracture fragments compressing nerves in close vicinity to bone fractures or may quantify the amount of nerve retraction after complete nerve transection (Fig. 5). Traumatic neuroma can occur at the site of either partial or complete dissection of the nerve. Neuroma appears as a bulbous concentric enlargement at the terminal end of a transected nerve with homogeneous

texture and hypoechoic echogenicity. In case of only partial dissection, the continuity of the nerve is preserved and neuroma appears as nodular shaped broadening of the nerve contour (Supplementary Fig. 3; to view the figure, please visit the online supplementary file in ScienceDirect). Intraoperative ultrasonography is a promising new field enabling morphological examination of nerve lesions in continuity in order to assess the extent learn more of nerve fibrosis and to discriminate between intraneural or perineural fibrosis. [33]. Both information are valuable to estimate the regenerative potential of a nerve lesion. Supplementary Fig. 3.  Longitudinal view of the median nerve

(arrows) at the Benzatropine wrist. The median nerve is partially dissected with scar formation within the continuity of the nerve and nodular thickening of the nerve contour. Schwannomas (neurilemmomas) and solitary neurofibromas are the most common benign nerve sheath tumors. Sonographically, they appear as well-defined hypoechoic masses with a fusiform shape and a normal-appearing nerve that enters and exits the tumor (Supplementary Fig. 4; to view the figure, please visit the online supplementary file in ScienceDirect) [34] and [35]. Because of their capsule, schwannoma are located more excentric, while not encapsuled neurofibroma are located more centrally compared to the course of the nerve. Since many nerve fascicles remain intact, benign nerve sheath tumors may be missed with electrodiagnostic studies alone. In contrast to benign tumors, malignant nerve sheath tumors are characterized by rapid growth and progressive neurological symptoms. Their shape is ill-defined and their echotexture is more heterogeneous [35]. Supplementary Fig. 4.