Neurapraxia, characterized by the transient loss of nerve function, is a recognized complication of thread-lifting procedures, with an incidence ranging from 0.02%–3.30% [1-3]. This article reports on an unusual complication following a thread-lift procedure in a 40-year-old woman who experienced concurrent unilateral weakness and numbness on the right side of her neck, including loss of the platysmal band and paresthesia behind the earlobe. Clinical evaluation revealed compression or minor injury to the greater auricular nerve (GAN), leading to neurapraxia (grade 1) and loss of sensation behind the right ear. In addition, the cervical branch of the facial nerve (CBFN) has been implicated in muscle weakness and platysma band loss.

The objective of this case report was to highlight the importance of understanding the intricate anatomy of the neck and submental region to avoid injury to critical structures such as the GAN and CBFN. Despite the rarity of nerve injuries during submental thread lifting, they can result in persistent symptoms that may not fully resolve. It is essential to inform practitioners and patients about these potential risks to ensure informed decision-making and optimal patient care.

The patient presented to our clinic three months after a thread-lift procedure at another facility, reporting persistent unilateral weakness, numbness on the right side of her neck, loss of the platysma band, and paresthesia behind the earlobe. After being fully informed about the nature, purpose, potential risks, and benefits of the case report, the patient provided informed consent for the use and disclosure of her health information for research and publication. All identifiable information was de-identified to protect privacy, and she was assured of confidentiality. The patient was informed that participation was voluntary and that she could withdraw consent at any time without affecting her medical care. She was given the opportunity to review the case report before its submission. The consent process followed the Institutional Review Board guidelines.

Clinical details of the case

A 40-year-old female with no significant medical history presented to our plastic surgery clinic for assessment three months after undergoing a thread-lift procedure at another facility. She had no known allergies, not taken any medications that could affect coagulation, and no relevant family or psychosocial history. The patient initially sought a minimally invasive procedure to address the mild facial laxity, particularly in the midface and jawline, to achieve a youthful appearance.

The patient’s account of the procedure and her experience

The thread-lift procedure was performed using polycaprolactone/polylactic acid threads under local anesthesia. The patient recalled that two small stab incisions were made at the hairline and along the jawline for thread insertion using the needle technique. The procedure lasted approximately one hour, during which the patient was monitored for immediate complications. She reported that three days postoperatively, she reported numbness and tingling in her right cheek and jawline, along with weakness in her right platysmal band muscle, which impaired her ability to turn her head to the right. These symptoms persisted, prompting her to undergo further evaluation at our clinic.

Clinical findings

Physical examination revealed hypoesthesia in areas innervated by the buccal and marginal mandibular branches of the facial nerves. There were no motor deficits in the facial muscles. However, weakness in the right platysmal band muscle was noted, consistent with the symptoms of neurapraxia caused by mechanical compression or direct injury during the procedure.

The patient reported that she had undergone a preoperative evaluation at another facility, which involved a detailed review of her medical history and a discussion on the potential risks of the procedure. Follow-up visits were scheduled at two weeks, one month, and three months postoperatively. At one month, there was a noticeable improvement in hypoesthesia; however, weakness in the platysmal band persisted. By three months, while facial hypoesthesia had resolved completely, the neurapraxia affecting the platysmal band had not improved.

Diagnosis was based on a thorough clinical examination. Although a referral for detailed nerve assessment via electromyography (EMG) and nerve conduction studies was offered, the patient declined. Differentiating neurapraxia from other potential causes of facial hypoesthesia and muscle weakness, such as infection or hematoma, was challenging because of the lack of specific procedural details regarding the previous treatment of the patient.

Conservative management was implemented as the standard treatment for neurapraxia, involving nonsteroidal anti-inflammatory drugs for pain relief and physical therapy focused on gentle massage and range-of-motion exercises to promote healing. Regular follow-ups to monitor recovery were conducted. During these follow-ups, no adverse reactions were observed, and no changes in therapeutic interventions were required.

Three months postoperatively, clinician-assessed outcomes indicated complete resolution of hypoesthesia. However, weakness in the right platysmal band persisted without recovery from neurapraxia. The patient opted for further neurological assessment while continuing the conservative treatment.

Our report discusses an atypical complication that occurred after a thread-lift procedure in a 40-year-old woman who experienced unilateral weakness and numbness on the right side of her neck, including loss of the platysmal band and paresthesia behind the earlobe. Thread-lift procedures carry inherent risks, particularly concerning the buccal and mandibular branches of the facial nerve, which are highly susceptible to injury due to their superficial location and proximity to the procedural fields.

The GAN is a sensory nerve that provides sensation to various areas, including the parotid gland and outer ear and runs across the mid-transverse belly of the sternocleidomastoid muscle approximately 6.5 cm below the lower edge of the bony external auditory meatus (Fig. 1) [4]. The GAN is particularly vulnerable during thread-lift procedures due to its superficial position; the reported incidence of GAN injury is approximately 6% [5,6]. Additionally, the CBFN within a 1 cm radius is susceptible to injury during these procedures, extending along an imaginary line from the mandibular angle to the chin-mastoid juncture.

Figure 1. Anatomy of greater auricular nerve. Data from the Complete Anatomy [4].

Nerve injuries resulting from thread-lifts can manifest as sensory or motor disturbances classified by Seddon’s (neurapraxia, axonotmesis, and neurotmesis) or Sunderland’s grading systems (grade 1–5). Neurapraxia (grade 1) involves mild traction or compression, resulting in temporary dysfunction, with an excellent prognosis of recovery within days to weeks. Transient nerve injuries often resolve spontaneously as injured fibers regenerate; however, permanent damage can lead to long-lasting impairments that require extended rehabilitation or surgical intervention [7,8]. Electrodiagnostic studies such as EMG can help localize lesions for prognostication [8,9].

Adopting safer techniques, such as working within the sub-platysma plane and using up to 0.4 mm diameter threads with blunt cannulas, may help mitigate the risk of nerve damage. Our report highlights the need for meticulous surgical practice and ongoing professional development to ensure the safety and efficacy of thread-lift procedures. Meticulous procedural planning, including a detailed understanding of anatomical landmarks and careful execution of the procedure, can significantly reduce the risk of nerve injury.

Patient-specific factors, such as pre-existing conditions such as diabetes mellitus or peripheral neuropathy, can increase the susceptibility to nerve injury [10]. The type of thread used, whether absorbable or non-absorbable, can also influence the risk of neurapraxia. Absorbable threads, such as polydioxanone and polylactic acid, are commonly used and have a lower risk of long-term complications. Non-absorbable threads, such as polypropylene, can cause significant and prolonged mechanical effects, potentially increasing the risk of neurapraxia [11].

The technique employed, including the depth and direction of the thread insertion, is another critical factor. Excessive tension, sharp dissection, and improper placement of the threads can cause nerve damage. A prolonged procedure duration can increase the risk of nerve compression and ischemia, further contributing to the development of neurapraxia. Postoperative complications, such as hematoma formation, can also compress the nerves, exacerbating the condition [10]. Therefore, meticulous procedural planning and execution and careful postoperative monitoring are essential for preventing neurapraxia.

Our case report underscores the importance of meticulous procedural planning and thread-lifting to prevent neurapraxia. Although facial hypoesthesia was resolved, the neurapraxia affecting the platysmal band muscle did not recover, highlighting the potential for long-term complications. The primary takeaway is the need for a thorough understanding of the facial and cervical anatomy and careful technique to minimize the risk of nerve injury during thread-lifting procedures.

Special thanks to Dr. Luk Wang Lung, Dr. Oleg Pedan and Dr. Jacqueline Luk for their support and contribution to the article.

None.

The author has nothing to disclose.