Ultrasonic diagnosis of cosmetic injectable-induced neuropathy: Clinical cases

Background. Facial nerve injury, filler-induced compression or soft tissue infiltrations are among the neuropathic complications of aesthetic injection procedures. The prospects of ultrasound imaging in neuropathy diagnosis are understudied. National and foreign literature does not describe facial soft tissues ultrasound in patients with cosmetic injectable-induced clinical neuropathy.

Clinical Cases Description. Two clinical cases are presented of high resolution ultrasound (HRU)-empowered verification of injectable cosmetic procedures-induced neuropathy. Ultrasound imaging was proved necessary for differential neuropathic causes diagnosis via the clinical assessment of facial soft tissues, filler and thread depth, as well as topography relative to blood vessels and nerves. In the first case, threads were visualised at a 4.6 and 5.8 mm depth from epidermis, which can coincide in location with large facial nerve branches usually running along vessels in deeper subcutaneous fat. Vessels were not detected in immediate proximity to threads along the entire trajectory from implantation to fixation sites by colour Doppler imaging (CDI). The ultrasound pattern corresponded to dermal and soft tissue infiltration. In the second case, ultrasound was applied to differentially diagnose a iatrogenic cause of neuropathy, considering a 3-year-past history of filler injection at temporal muscle projection. A filler bolus was revealed adjacent to a vessel in subaponeurotic fat of right temporal region, with infiltrative signs of perifocal oedema around a piece of hyaluronic acid. Temporal soft tissue of the opposite facial half remained unchanged. According to HRU evidence, neuropathy developed due to nerve compression by facial soft tissue infiltrative distortions after thread implantation in the first case and by filler directly in the second. The HRU examination facilitated a correct diagnosis and choice of patient management.

Conclusion. Ultrasonography is indicated in patients with cosmetic procedures-induced neuropathy for differential diagnosis of complication causes and current therapy monitoring.