UNASSIGNED: To determine the functional outcome after facial nerve reconstruction surgery in patients with flaccid facial paralysis.
UNASSIGNED: A systematic review and meta-analysis was performed on studies reporting outcomes after direct facial nerve suture (DFS), facial nerve interpositional graft suture (FIGS), hypoglossal-facial nerve suture (HFS), masseteric-facial nerve suture (MFS), and cross-face nerve suture (CFS). These studies were identified from PubMed/MEDLINE, Embase, and Web of Science databases. Two independent reviewers performed two-stage screening and data extraction. A favorable result was defined as a final House-Brackmann grade I-III and is presented as a ratio of all patients in percentage. Pooled proportions were calculated using random-effects models.
UNASSIGNED: From 4,932 screened records, 54 studies with 1,358 patients were included. A favorable result was achieved after DFS in 42.67% of the patients [confidence interval (CI): 26.05%-61.12%], after FIGS in 66.43% (CI: 55.99%-75.47%), after HFS in 63.89% (95% CI: 54.83%-72.05%), after MFS in 63.11% (CI: 38.53%-82.37%), and after CFS in 46.67% (CI: 24.09%-70.70%). There was no statistically significant difference between the techniques (Q = 6.56, degrees of freedom = 4, p = 0.1611).
UNASSIGNED: The established facial nerve reconstruction techniques including the single nerve cross-transfer techniques produce satisfactory results in most of the patients with permanent flaccid facial paralysis. An international consensus on standardized outcome measures would improve the comparability of facial reanimation techniques.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated neuropathy. While CIDP typically affects the peripheral nerves in the limbs, involvement of cranial nerves is atypical, and cases of muscle atrophy secondary to cranial nerve involvement are exceptionally rare. A 30-year-old female patient, who complained of numbness and weakness in her limbs, was diagnosed with CIDP after experiencing atrophy of the tongue and sternocleidomastoid muscles, along with tongue muscle fibrillation during a neurological examination. Additionally, the patient had hypothyroidism caused by Hashimoto\'s thyroiditis. Cerebrospinal fluid tests indicated albumincytological dissociation. Electrophysiological examination results confirmed the diagnosis of typical CIDP. Glucocorticoid treatment, a standard therapy for CIDP, led to a significant improvement in the patient\'s symptoms, including the regeneration of her tongue muscles. A literature review revealed only eight cases of CIDP with hypoglossal nerve involvement, and this case represents the first documentation of concurrent sternocleidomastoid muscle atrophy. Although muscle atrophy from cranial nerve involvement is infrequent in CIDP, the positive response to treatment is encouraging.

Orexin-mediated stimulation of orexin receptors 1/2 (OX[1/2]R) may stimulate the diaphragm and genioglossus muscle via activation of inspiratory neurons in the pre-Bötzinger complex, which are critical for the generation of inspiratory rhythm, and phrenic and hypoglossal motoneurons. Herein, we assessed the effects of OX2R-selective agonists TAK-925 (danavorexton) and OX-201 on respiratory function. In in vitro electrophysiologic analyses using rat medullary slices, danavorexton and OX-201 showed tendency and significant effect, respectively, in increasing the frequency of inspiratory synaptic currents of inspiratory neurons in the pre-Bötzinger complex. In rat medullary slices, both danavorexton and OX-201 significantly increased the frequency of inspiratory synaptic currents of hypoglossal motoneurons. Danavorexton and OX-201 also showed significant effect and tendency, respectively, in increasing the frequency of burst activity recorded from the cervical (C3-C5) ventral root, which contains axons of phrenic motoneurons, in in vitro electrophysiologic analyses from rat isolated brainstem-spinal cord preparations. Electromyogram recordings revealed that intravenous administration of OX-201 increased burst frequency of the diaphragm and burst amplitude of the genioglossus muscle in isoflurane- and urethane-anesthetized rats, respectively. In whole-body plethysmography analyses, oral administration of OX-201 increased respiratory activity in free-moving mice. Overall, these results suggest that OX2R-selective agonists enhance respiratory function via activation of the diaphragm and genioglossus muscle through stimulation of inspiratory neurons in the pre-Bötzinger complex, and phrenic and hypoglossal motoneurons. OX2R-selective agonists could be promising drugs for various conditions with respiratory dysfunction.

OBJECTIVE: The objective of this study was to investigate spontaneous neural regeneration and functional recovery after resection of various lengths of the hypoglossal (XII) nerve in adult rats.
METHODS: Twelve weeks after XII nerve resection at lengths ranging from 0.0-15.8 mm, the tongue deviation angle of rats was measured to evaluate the severity of paralysis; thereafter, the XII neurons in the XII nucleus were labeled with Fluoro-Gold (FG), which was injected into the tongue to visualize regenerated XII neurons re-innervating the tongue muscles.
RESULTS: In the XII nerve-resected rats, the regenerative rates, that is, the percentage of the total number of FG-positive neurons on the injured side relative to that on the uninjured side, were divided into two groups; the regenerative rates were more than 77% and less than 6%, respectively. Upon comparing the two groups, the boundary resection length was approximately 10.0 mm. Moreover, the former and latter groups demonstrated tongue deviation angles less than or greater than 15°, respectively.
CONCLUSIONS: The critical nerve gap length for spontaneous neural regeneration was approximately 10.0 mm in XII nerve-resected adult rats, and nerve regeneration occurred in both morphological and functional aspects after resection at less than the critical length.

Obstructive sleep apnea (OSA) is a chronic disorder characterized by recurrent episodes of upper airway collapse during sleep, which can lead to serious health issues like cardiovascular disease and neurocognitive impairments. While positive airway pressure serves as the standard treatment, intolerance in some individuals necessitates exploration of alternative therapies. Hypoglossal nerve stimulation (HGNS) promises to mitigate OSA morbidity by stimulating the tongue muscles to maintain airway patency. However, its effectiveness varies, prompting research for optimization. This review summarizes the effects of HGNS on upper airway obstruction from human and animal studies. It examines physiological responses including critical closing pressure, maximal airflow, nasal and upper airway resistance, compliance, stiffness, and geometry. Interactions among these parameters and discrepant findings in animal and human studies are explored. Additionally, the review summarizes the impact of HGNS on established OSA metrics, such as the apnea-hypopnea index, oxygen desaturation index, and sleep arousals. Various therapeutic modalities, including selective unilateral or bilateral HGNS, targeted unilateral HGNS, and whole unilateral or bilateral HGNS, are discussed. This review consolidates our understanding of HGNS mechanisms, fostering exploration of under-investigated outcomes and approaches to drive advancements in HGNS therapy.

Shape and size of the nasopharyngeal airway is controlled by muscles innervated facial, glossopharyngeal, vagal, and hypoglossal cranial nerves. Contrary to brainstem networks that drive facial, vagal and hypoglossal nerve activities (FNA, VNA, HNA) the discharge patterns and origins of glossopharyngeal nerve activity (GPNA) remain poorly investigated. Here, an in situ perfused brainstem preparation (n=19) was used for recordings of GPNA in relation to phrenic (PNA), FNA, VNA and HNA. Brainstem transections were performed (n=10/19) to explore the role of pontomedullary synaptic interactions in generating GPNA. GPNA generally mirrors FNA and HNA discharge patterns and displays pre-inspiratory activity relative to the PNA, followed by robust inspiratory discharge in coincidence with PNA. Postinspiratory (early expiratory) discharge was, contrary to VNA, generally absent in FNA, GPNA or HNA. As described previously FNA and HNA discharge was virtually eliminated after pontomedullary transection while an apneustic inspiratory motor discharge was maintained in PNA, VNA and GPNA. After brainstem transection GPNA displayed an increased tonic activity starting during mid-expiration and thus developed prolonged pre-inspiratory activity compared to control. In conclusion respiratory GPNA reflects FNA and HNA which implies similar function in controlling upper airway patency during breathing. That GPNA preserved its pre-inspiratory/inspiratory discharge pattern in relation PNA after pontomedullary transection suggest that GPNA premotor circuits may have a different anatomical distribution compared HNA and FNA and thus may therefore hold a unique role in preserving airway patency.

The facial nerve plays a crucial role in facial expression and sensory functions, with irreversible injuries often demanding rehabilitation therapies, with hypoglossal-facial nerve anastomosis (HFA) being one of the treatment options. This systematic review assessed different HFA techniques for facial paralysis, particularly post vestibular schwannoma resection, focusing on effectiveness and associated morbidities. Fifteen studies, comprising a case series and a retrospective cohort, were analyzed. Techniques included end-to-end, split, side-to-side, end-to-side, and jump interpositional graft hypoglossal-facial anastomosis (JIGHFA). Positive outcomes were observed with end-to-end and side-to-side techniques, while the split technique and JIGHFA showed promise. Comparative analyses favored the \'end-to-side\' approach. Shorter intervals between surgery and HFA correlated with improved outcomes. Methodological variations highlight the need for prospective studies with standardized methodologies for robust evidence and informed decision-making on optimal HFA techniques.

BACKGROUND: Schwannomas are solitary neurogenic tumors originating from the myelin sheath of peripheral nerves. Extracranial hypoglossal schwannomas comprise <5% of all head and neck schwannomas and can mimic submandibular salivary gland tumors.
METHODS: We report the diagnostic imaging, surgical treatment, and histopathological findings of a rare case of extracranial schwannoma of the hypoglossal nerve in a 73-year-old female, presented with an asymptomatic swelling in the left submandibular region that had been persisted for approximately three years.
CONCLUSIONS: Accurate diagnosis of this rare clinical entity requires comprehensive diagnostics. The optimal therapeutic strategy is nerve-sparing surgical excision, although it can be challenging.

Objective:To investigate the factors and efficacy of different surgical techniques used in facial nerve（FN） reconstruction. Methods:A retrospective analysis was conducted on 24 patients who underwent facial nerve reconstruction surgery in our department from January 2016 to January 2021. The duration of total facial nerve paralysis was less than 18 months. The study included 5 surgical techniques, including 6 cases of FN anastomosis（Group A）, 5 cases of FN grafting（sural nerve or great auricular nerve）（Group B）, 5 cases of side-to-end facial-hypoglossal nerve anastomosis（Group C）, 4 cases of side-to-end FN grafting（sural nerve or great auricular nerve） hypoglossal nerve anastomosis（Group D）, and 4 cases of dual nerve reanimation（Group E）. The postoperative follow-up period was ≥1 year. Results:The HB-Ⅲ level of FN function at 1 year after surgery was 83.3%（5/6） in group A, 60.0%（3/5） in group B, 40.0%（2/5） in group C, 25.0%（1/4） in group D, and 50.0%（2/4） in group E. In patients without multiple FN repair, the incidence of synkinesis was 15.0%（3/20）, while no cases of synkinesis were observed in patients with dual nerve reanimation. The patients who underwent hypoglossal-facial side-to-end anastomosis showed no hypoglossal nerve dysfunction. Conclusion:Different FN repair techniques result in varying postoperative FN function recovery, as personalized repair should be managed. Among the various techniques, FN end-to-end anastomosis after FN transposition is recommended as to reduce the number of anastomotic stoma, while hypoglossal-facial side-to-end anastomosis is advocated as to prevent postoperative hypoglossal nerve dysfunction. Additionally, dual nerve repair can effectively improve smile symmetry and reduce synkinesis, which enhances patients\' quality.
目的：探讨不同面神经重建方案的影响因素及其疗效，为面神经功能重建策略提供参考。 方法：回顾性分析2016年1月至2021年1月因面神经不可逆损伤，行面神经功能重建手术的24例患者，面神经全瘫时程均<18个月。面神经中枢端可利用的患者中，根据面神经缺失长度，行面神经吻合术6例（A组），行面神经移植术（腓肠神经或耳大神经）5例（B组）；面神经中枢端无法利用时，行面神经-舌下神经桥接术（端-侧吻合）5例（C组），面神经移植术（腓肠神经或耳大神经）-舌下神经桥接术（端-侧吻合）4例（D组）；联合修复术（面神经-咬肌神经桥接术联合上述方式之一）4例（E组）。术后随访时程≥1年。 结果：24例患者中，术后1年面神经功能HB-Ⅲ级的百分比分别是：A组83.3%（5/6），B组60.0%（3/5），C组40.0%（2/5），D组25.0%（1/4），E组50.0%（2/4）。非多重面神经修复患者，口眼联动发生率为15.0%（3/20），而进行面神经-咬肌神经桥接的多重面神经修复患者中无一例发生口眼联动，且微笑时口角偏斜不明显。所有面神经-舌下神经端侧吻合的患者，伸舌无偏斜，舌肌无萎缩。 结论：周围性面瘫的面神经功能重建方案多样，需根据中枢端能否利用及面神经缺损长度制定个性化修复方案。在单一修复方案中，为增加术后面神经功能疗效，应尽量减少神经的吻合口，提倡面神经转位吻合，同时为避免术后舌下神经功能障碍，提倡面神经-舌下神经端侧吻合。另外，多重面神经修复能够有效提高微笑时口角活动对称性，并降低口眼联动的发生率，对患者术后生活质量的提高具有较重要的意义。.

Swallowing is induced by a central pattern generator in the nucleus tractus solitarius (NTS). We aimed to create a medullary slice preparation to elucidate the neural architecture of the central pattern generator of swallowing (Sw-CPG) and record its neural activities. Experiments were conducted on 2-day-old Sprague-Dawley rats (n = 46). The brainstem-spinal cord was transected at the pontomedullary and cervicothoracic junctions; the medulla was sliced transversely at thicknesses of 600, 700, or 800 μm. The rostral end of the slice was 100 μm rostral to the vagus nerve. We recorded hypoglossal nerve activity and electrically stimulated the vagus nerve or microinjected bicuculline methiodide (BIC) into the NTS. The 800-μm slices generated both rhythmic respiratory activity and electrically elicited neural activity. The 700-μm slices generated only respiratory activity, while the 600-μm slices did not generate any neural activity. BIC microinjection into the NTS in 800-μm slices resulted in the typical activity that closely resembled the swallowing activity reported in other experiments. This swallowing-like activity consistently lengthened the respiratory interval. Despite complete inhibition of respiratory activity, weak swallowing-like activity was observed under bath application of a non-NMDA receptor antagonist. Contrastingly, bath application of NMDA receptor antagonists resulted in a complete loss of swallowing-like activity and no change in respiratory activity. These results suggest that the 800-μm medullary slice preparation contains both afferent and efferent neural circuits and pattern generators of swallowing activity. Additionally, NMDA receptors may be necessary for generating swallowing activity. This medullary slice preparation can therefore elucidate Sw-CPG neural networks.