This is a case of a 63-year-old female with post-COVID-19 unilateral upper lip pain and numbness. Neurologic examination did not reveal any deficits other than deficits on pinprick in the maxillary division (V2) of the left trigeminal nerve. Brain neuroimaging showed signs of acute inflammation of the left maxillary sinus. Neuropraxia of the infraorbital nerve, a branch of the trigeminal nerve, was the diagnosis considered. Reports on trigeminal neurosensory changes following acute sinusitis are few, and isolated trigeminal neuropathy is rare except in cases of dental disorders. Up to this writing, there have been no reports on post-COVID-19 unilateral upper lip numbness and pain. This study will also serve as a concise review on the correlative neuroanatomy of the trigeminal nerve.
COVID-19 ; Trigeminal Nerve

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.
Mice ; Animals ; Lip/innervation* ; Prospective Studies ; Mandibular Nerve/pathology* ; Sensation/physiology* ; Trigeminal Nerve Injuries/pathology*

Objective: To evaluate the risk factors of inferior alveolar nerve injury (IANI) after surgical removal of the mandibular third molars (M3) and present a new risk scoring system to predict the probability of IANI. Methods: Patients who underwent extraction of M3 in the Stomatology Hospital, Zhejiang University School of Medicine from April 2017 to December 2019 were involved. The investigators enrolled a sample composed of 949 mandibular third molars. Prediction model was used for univariate and multivariate analysis of gender, age, M3, inferior alveolar canal (IAC), and the contact between M3 and IAC, to assess the risk factors of IANI. Combined with the risk factors determined by the outcomes of prediction model, the risk scoring system was constructed. The diagnostic performance of each cut-off score was examined to conduct a risk stratification of IANI risk scores. The predictive ability and reliability of the model were evaluated. Results: In prediction model, twenty nine cases (4.4%, 29/664) experienced postoperative IANI. Number of root (P<0.01), depth of impaction (P<0.05), contact between M3 and IAC (P<0.01) and their contact position (P<0.05) were statistically significant as contributing risk factors of IANI. Specifically, the incidence of temporary IANI was higher in those who aged under 25 years (P<0.001), while female suffer more permanent injury (P<0.05). Based on the IANI risk scoring system, patients were stratified into low-risk, middle-risk and high-risk groups at cutoff scores of 3 and 4. The area under the receiver operator characteristic curve of the risk scoring system were 0.81 [95%CI (0.70-0.90), P=0.002] and 0.80 [95%CI (0.68-0.92), P=0.007] towards good discrimination. Conclusions: Age, gender, number of root, depth of impaction, and contact between M3 and IAC were risk factors of IANI. IANI risk scoring system might help in preoperative assessment, recognition of high-risk cases and decision-making to reduce IANI.
Aged ; Female ; Humans ; Mandible/surgery* ; Mandibular Nerve ; Molar, Third/surgery* ; Reproducibility of Results ; Risk Factors ; Tooth Extraction/adverse effects* ; Trigeminal Nerve Injuries/etiology*

Trigeminal neuralgia (TN) is a chronic disorder of the trigeminal nerve characterized by repeated electrical shock-like sensations on one side of the face. It can cause severe pain in the face and disrupt or impair quality of life in patients. Options for the management of TN consist of pharmacological and surgical treatments, including Gamma Knife radiosurgery (GKRS). GKRS has been used for TN for a long time because of its low rate of complications and high success rate. Moreover, GKRS can be of use for drug-resistant TN patients who are poor surgical candidates due to medical comorbidities, patients of older age, or patients who refuse invasive therapy. We reviewed the rationale, effects, safety, and current treatment policies of GKRS for TN in view of our institution's results and a review of the literature to date.]]>
Comorbidity ; Facial Pain ; Humans ; Quality of Life ; Radiosurgery ; Sensation ; Trigeminal Nerve ; Trigeminal Neuralgia

OBJECTIVES: Trigeminal neuralgia (TN) is undurable paroxysmal pain in the distribution of the fifth cranial nerve. Invasive treatment modalities for TN include microvascular decompression (MVD) and percutaneous procedures, such as, radiofrequency rhizotomy (RFR). Gamma Knife radiosurgery (GKRS) is a considerable option for patients with pain recurrence after an initial procedure. This study was undertaken to analyze the effects of gamma knife radiosurgery in recurrent TN after other procedures. METHODS: Eleven recurrent TN patients after other procedures underwent GKRS in our hospital from September 2004 to August 2016. Seven patients had previously undergone MVD alone, two underwent MVD with partial sensory rhizotomy (PSR), and two underwent RFR. Mean patient age was 60.5 years. We retrospectively analyzed patient's characteristics, clinical results, sites, and divisions of pain. Outcomes were evaluated using the Visual Analog Scales (VAS) score. RESULTS: Right sides were more prevalent than left sides (7:4). The most common distribution of pain was V1 + V2 division (n = 5) following V2 + V3 (n = 3), V2 (n = 2), and V1 + V2 + V3 (n = 1) division. Median GKRS dose was 80 Gy and the mean interval between the prior treatment and GKRS was 74.45 months. The final outcomes of subsequent GKRS were satisfactory in most cases, and at 12 months postoperatively ten patients (90.0%) had a VAS score of ≤ 3. CONCLUSIONS: In this study, the clinical result of GKRS was satisfactory. Invasive procedures, such as, MVD, RFR are initially effective in TN patients, but GKRS provides a safe and satisfactory treatment modality for those who recurred after prior invasive treatments.
Humans ; Microvascular Decompression Surgery ; Radiosurgery ; Recurrence ; Retrospective Studies ; Rhizotomy ; Trigeminal Nerve ; Trigeminal Neuralgia ; Visual Analog Scale

Ossification of parts of the intracranial dura mater is common and is generally accepted as an age-related finding. Additionally, duplication of the abducens nerve along its course to the lateral rectus muscle is a known, although uncommon anatomical variant. During routine cadaveric dissection, an ossified portion of dura mater traveling over the trigeminal nerve's entrance (porus trigeminus) into the middle cranial fossa was observed unilaterally. Ipsilaterally, a duplicated abducens nerve was also observed, with a unique foramen superolateral to the entrance of Dorello's canal. To our knowledge, there has been no existing report of a simultaneous ossified roof of the porus trigeminus with an ipsilateral duplicated abducens nerve. Herein, we discuss this case and the potential clinical and surgical applications. We believe this case report will be informative for the skull base surgeon in the diagnosis of neuralgic pain in the frontomaxillary, andibular, orbital, and external and middle ear regions.
Abducens Nerve ; Cadaver ; Cranial Fossa, Middle ; Diagnosis ; Dura Mater ; Ear, Middle ; Orbit ; Skull Base ; Trigeminal Neuralgia

The lingual nerve (LN) is a branch of the mandibular division of the trigeminal nerve, and its injury is one of the major complications during oral surgery. This study aims to investigate the anatomy of the LN in the lower third molar area. Twenty sides from ten fresh-frozen adult cadaveric Caucasian heads were examined to measure the diameter of the LN. The mean diameter of the LN was 2.20±0.37 mm (range, 1.61–2.95 mm). There were no statistically significant differences in the measurements between sexes, sides, or tooth status (dentulous or edentulous). Understanding the anatomical features of the LN is essential for performing any surgical procedure in the oral region.
Adult ; Cadaver ; Head ; Humans ; Lingual Nerve ; Mandibular Nerve ; Molar, Third ; Surgery, Oral ; Tooth ; Trigeminal Nerve

BACKGROUND: The trigeminocardiac reflex (TCR), which occurs after stimulation of the territory of the trigeminal nerve, is very rarely reported to be caused by stimulation of the mandibular branch. We report a case of TCR in open reduction for temporomandibular joint (TMJ) dislocation. CASE: A 74-year-old female presented for TMJ dislocation. During open reduction of TMJ under general anesthesia, severe bradycardia (15 beats/min) occurred. Immediately 0.5 mg atropine was administered intravenously, and the surgical manipulation was stopped. After 30 seconds, heart rate normalized. During surgery, severe bradycardia occurred one more time. It disappeared spontaneously as soon as surgical manipulation was stopped. The surgery was completed uneventfully. CONCLUSIONS: Because of the possibility of profound bradycardia, asystole, or even death when evoked, it is important to be aware of the trigeminocardiac reflex during manipulation of the mandibular divisions, especially during surgical stimulation of the TMJ.
Aged ; Anesthesia, General ; Atropine ; Bradycardia ; Dislocations ; Female ; Heart Arrest ; Heart Rate ; Humans ; Reflex, Trigeminocardiac ; Temporomandibular Joint ; Trigeminal Nerve

BACKGROUND: Neurosensory changes are frequently observed in the patients with mid-face fractures, and these symptoms are often caused by infraorbital nerve (ION) damage. Although ION damage is a relatively common phenomenon, there are no established and objective methods to evaluate it. The aim of this study was to test whether trigeminal somatosensory evoked potential (TSEP) could be used as a prognostic predictor of ION damage and TSEP testing was an objective method to evaluate ION injury. METHODS: In this prospective TSEP study, 48 patients with unilateral mid-face fracture (only unilateral blow out fracture and unilateral zygomaticomaxillary fracture were included) and potential ION damages were enrolled. Both sides of the face were examined with TSEP and the non-traumatized side of the face was used as control. We calculated the latency difference between the affected and the unaffected sides. RESULTS: Twenty-four patients recovered within 3 months, and 21 patients took more than 3 months to recover. The average latency difference between the affected side and unaffected side was 1.4 and 4.1 ms for the group that recovered within 3 months and the group that recovered after 3 months, respectively. CONCLUSION: Patients who suffered ION damage showed prolonged latency when examined using the TSEP test. TSEP is an effective tool for evaluation of nerve injury and predicting the recovery of patients with ION damage.
Evoked Potentials, Somatosensory ; Humans ; Methods ; Orbital Fractures ; Prospective Studies ; Trigeminal Nerve Injuries

Trigeminal nerve injury as a consequence of lower third molar surgery is a notorious complication and may affect the patient in long term. Inferior alveolar nerve (IAN) and lingual nerve (LN) injury result in different degree of neurosensory deficit and also other neurological symptoms. The long term effects may include persistent sensory loss, chronic pain and depression. It is crucial to understand the pathophysiology of the nerve injury from lower third molar surgery. Surgery remains the most promising treatment in moderate-to-severe nerve injuries. There are limitations in the current treatment methods and full recovery is not commonly achievable. It is better to prevent nerve injury than to treat with unpredictable results. Coronectomy has been proved to be effective in reducing IAN injury and carries minimal long-term morbidity. New technologies, like the roles of erythropoietin and stem cell therapy, are being investigated for neuroprotection and neural regeneration. Breakthroughs in basic and translational research are required to improve the clinical outcomes of the current treatment modalities of third molar surgery-related nerve injury.
Chronic Pain ; Depression ; Erythropoietin ; Humans ; Lingual Nerve ; Mandibular Nerve ; Molar, Third ; Neuroprotection ; Postoperative Complications ; Regeneration ; Stem Cells ; Translational Medical Research ; Trigeminal Nerve Injuries ; Trigeminal Nerve