OBJECTIVE: To review the research progress on silk fibroin (SF)-nerve guidance conduits (NGCs) for peripheral nerve injury (PNI) repair. METHODS: To review the recent literature on PNI and SF-NGCs, expound the concepts and treatment strategies of PNI, and summarize the construction of SF-NGCs and its application in PNI repair. RESULTS: Autologous nerve transplantation remains the "gold standard" for treating severe PNI. However, it's clinical applications are constrained by the limitations of limited donors and donor area damage. Natural SF exhibits good biocompatibility, low immunogenicity, and excellent physicochemical properties, making it an ideal candidate for the construction of NGCs. SF-NGCs constructed using different technologies have been found to have better biocompatibility and bioactivity. Their configurations can facilitate nerve regeneration by enhancing regenerative guidance and axonal extension. Besides, the adhesion, proliferation and differentiation of neurons and Schwann cells related to PNI repair can be effectively promote by NGCs. This accelerates the speed of nerve regeneration and improves the efficiency of repair. In addition, SF-NGCs can be used as regenerative scaffolds to provide biological templates for nerve repair. CONCLUSION The biodegradable natural SF has been extensively studied and demonstrated promising application prospects in the field of NGCs. It might be an effective and viable alternative to the "gold standard" for PNI treatment.
Fibroins/chemistry* ; Peripheral Nerve Injuries/therapy* ; Nerve Regeneration ; Tissue Scaffolds/chemistry* ; Humans ; Guided Tissue Regeneration/methods* ; Biocompatible Materials ; Animals ; Tissue Engineering/methods* ; Schwann Cells/cytology* ; Peripheral Nerves ; Neurons/cytology*

OBJECTIVE: To review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. METHODS: An extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. RESULTS: By incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. CONCLUSION While nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
Peripheral Nerve Injuries/surgery* ; Nerve Regeneration ; Humans ; Tissue Scaffolds ; Animals ; Guided Tissue Regeneration/methods* ; Tissue Engineering/methods* ; Biocompatible Materials ; Peripheral Nerves ; Drug Delivery Systems

Skin wound repair is critically regulated by peripheral nerves. Injury or dysfunction of these nerves represents a key factor impairing the healing of pathological wounds, such as diabetic ulcers and deep burns. The mechanisms by which peripheral nerves participate in cutaneous wound healing primarily involve modulation of immune responses, construction of stem cell niches, and promotion of angiogenesis. Sensory neurons initiate and mediate essential local immune responses, contribute to the epidermal stem cell microenvironment, and support regenerative potential. Sympathetic nerves bidirectionally regulate immune homeostasis via the release of various neuromodulators and precisely control the activation of hair follicle stem cells as well as the homeostasis of melanocyte stem cells. Schwann cells also play pivotal roles in immune modulation, balancing repair processes and mitigating scar formation. During revascularization, sensory and autonomic nerve terminals release neurotransmitters that precisely regulate vasomotor activity and angiogenesis, while Schwann cells facilitate the reconstruction of functional vascular networks via potent paracrine signaling. This review systematically summarizes the crucial roles of peripheral nerves in skin wound repair, with emphasis on their regulatory mechanisms in immune responses, stem cell activation and homeostasis, and vascular dynamics, thereby providing insights into the development of novel therapeutic strategies targeting peripheral nerve regulation.
Humans ; Wound Healing/physiology* ; Peripheral Nerves/physiology* ; Schwann Cells/physiology* ; Skin/injuries* ; Animals

Human ; Female ; Adolescent: 13-18 Yrs Old ; Nerve Sheath Neoplasms ; Peripheral Nerves ; Neoplasms

A 57-year-old female presented with a history of a progressively enlarging palmar mass over three years, with associated numbness over the median nerve distribution and difficulty in gripping due to dimensions of the mass. Physical examination revealed a 4 x 5 cm, movable, non-tender mass over the thenar eminence and a 2 x 1 cm movable, non-tender mass over the center of the palm. Tinel’s sign was positive over the mass and the carpal tunnel.

Excision of the mass was performed under intravenous regional anesthesia. A curvilinear incision made from the thenar crease distally to the midline of the wrist overlying the carpal tunnel, proximally. Dissection was carried down to the transverse carpal ligament which was transected to allow visualization of the mass and its attachment to the median nerve.

The mass described in this present case report shares characteristics from cases in previously published literature. Its gross appearance was highly indicative of a lipoma and its close relationship with the median nerve suggested an epineural origin. Magnetic resonance imaging revealed a well-defined lesion, suggesting a mass that was more likely to be excised, potentially leading to better neurologic outcomes.

Intraneural lipomas (within the epineurium) are rare soft-tissue tumors that predominantly occur in the hand and forearm. Most cases reported involve the median nerve, followed by the radial nerve, posterior interosseus nerve and more rarely the brachial plexus. Compression of peripheral nerves by benign adipose tumors is infrequently reported in literature, with most publications restricted to case reports or series of a few patients. To the author’s knowledge, this is the first article describing an intraneural lipoma in the Filipino population.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy, characterized by late diagnosis, aggressive growth, and therapy resistance, leading to a poor overall prognosis. Emerging evidence shows that the peripheral nerve is an important non-tumor component in the tumor microenvironment that regulates tumor growth and immune escape. The crosstalk between the neuronal system and PDAC has become a hot research topic that may provide novel mechanisms underlying tumor progression and further uncover promising therapeutic targets. In this review, we highlight the mechanisms of perineural invasion and the role of various types of tumor innervation in the progression of PDAC, summarize the potential signaling pathways modulating the neuronal-cancer interaction, and discuss the current and future therapeutic possibilities for this condition.
Humans ; Carcinoma, Pancreatic Ductal/pathology* ; Pancreatic Neoplasms/therapy* ; Signal Transduction ; Peripheral Nerves/metabolism* ; Tumor Microenvironment

Our previous investigation suggested that faster seventh cervical nerve (C7) regeneration occurs in patients with cerebral injury undergoing contralateral C7 transfer. This finding needed further verification, and the mechanism remained largely unknown. Here, Tinel's test revealed faster C7 regeneration in patients with cerebral injury, which was further confirmed in mice by electrophysiological recordings and histological analysis. Furthermore, we identified an altered systemic inflammatory response that led to the transformation of macrophage polarization as a mechanism underlying the increased nerve regeneration in patients with cerebral injury. In mice, we showed that, as a contributing factor, serum amyloid protein A1 (SAA1) promoted C7 regeneration and interfered with macrophage polarization in vivo. Our results indicate that altered inflammation promotes the regenerative capacity of the C7 nerve by altering macrophage behavior. SAA1 may be a therapeutic target to improve the recovery of injured peripheral nerves.
Animals ; Brachial Plexus ; Brachial Plexus Neuropathies/surgery* ; Humans ; Mice ; Nerve Transfer ; Peripheral Nerves ; Spinal Nerves

BACKGROUND: Multifocal motor neuropathy (MMN), Lewis-Sumner syndrome (LSS), and many chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) are representative of acquired multifocal polyneuropathy and are characterized by conduction block (CB). This retrospective study aimed to investigate the demyelinating distribution and the selective vulnerability of MMN, LSS, and CIDP with CB (CIDP-CB) in nerves. METHODS: Fifteen LSS subjects (107 nerves), 24 MMN subjects (176 nerves), and 17 CIDP-CB subjects (110 nerves) were included. Their clinical information was recorded, blood and cerebrospinal fluid tests were conducted, and nerve conductions of the median, ulnar, radial, peroneal, and tibial nerves were evaluated. CB, temporal dispersion, distal motor latency (DML), and F-wave latency were recorded, and nerve conduction velocity, terminal latency index, and modified F-wave ratio were calculated. RESULTS: CB was more likely to occur around the elbow in CIDP-CB than in MMN (78.6% vs. 6.8%, P < 0.01) but less likely to occur between the wrist and the elbow than in LSS (10.7% vs. 39.3%, P < 0.05). Tibial nerve CB was most frequently observed in MMN (47.4%, P < 0.05). CIDP-CB was characterized by a prolonged DML in all nerves, and slow motor nerve velocity of the upper limb was significant when CB nerves were excluded (P < 0.05). CONCLUSIONS We report the different distributions of segmental and diffuse demyelination of the ulnar and tibial nerves in LSS, MMN, and CIDP-CB. These distinct distributions could help in differentiating among these conditions.
Humans ; Neural Conduction ; Peripheral Nerves ; Polyneuropathies ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Retrospective Studies

Malignant peripheral nerve sheath tumor (MPNST) is rare, accounting for 5-10% of all soft tissue sarcomas. MPNST is characteristically aggressive and has a poor prognosis. Fifty percent of patients with MPNST have neurofibromatosis type 1 (NF1). NF-associated MPNST occurs more often at younger ages than sporadic MPNST, but the survival difference is controversial. Superficial MPNST from a recurrent neurofibroma is extremely rare and only a limited number of cases have been reported in the literature. Herein, we report an unusual case of superficial MPNST from a recurrent neurofibroma in a patient without NF1.
Abdominal Wall ; Humans ; Nerve Sheath Neoplasms ; Neurilemmoma ; Neurofibroma ; Neurofibromatoses ; Neurofibromatosis 1 ; Neurofibrosarcoma ; Peripheral Nerves ; Prognosis ; Sarcoma

Schwannoma is a slow-growing, well-demarcated, benign soft tissue tumor of the peripheral nerve sheath. It commonly develops in the head and neck region, usually in the parapharyngeal space. In this case, a 42-year-old woman visited the outpatient department to manage a painless mass on her left cheek. She had no history of concern and no neurological symptoms were observed. In the enhanced computed tomography scan, a 2.8 × 2.8 × 1.8 cm, heterogeneously enhanced tumor was detected in the left masseter muscle. A tumor resection under general anesthesia was planned. For the resection, a facelift incision was chosen; branches of the facial nerve were identified and retrogradely dissected. A well-marginated, yellowish, solid mass was found in the left masseter muscle. The mass was excised and given a histopathological diagnosis of schwannoma. A definite diagnosis of schwannoma, originating in the masseter muscle, is difficult to arrive at with radiographic findings alone; it is often misdiagnosed as intramuscular hemangioma. Histopathological examinations, including fine-needle aspiration or histological biopsy after surgery, are necessary. Using a facelift incision with retrograde facial nerve dissection, tumor resection in an intramasseteric lesion can be performed efficiently, without nerve damage, or leaving conspicuous scars on the face.
Adult ; Anesthesia, General ; Biopsy ; Biopsy, Fine-Needle ; Cheek ; Cicatrix ; Diagnosis ; Facial Nerve ; Female ; Head ; Hemangioma ; Humans ; Masseter Muscle ; Neck ; Neurilemmoma ; Outpatients ; Peripheral Nerves ; Rhytidoplasty