An unexpected complication of hypoglossal schwannoma surgery: Cerebrospinal fluid leakage-A case report and literature review.

BACKGROUND: Extracranial hypoglossal schwannoma is a rare tumor primarily treated with surgical excision. This article aims to highlight the potential for unexpected complications intraoperatively, such as cerebrospinal fluid leakage from skullbase to neck. METHODS: A previously healthy 23-year-old male presented with tongue numbness. Magnetic resonance imaging revealed a 17 × 20 mm nodular lesion adjacent to the cervical segment of the internal carotid artery. Surgical excision was scheduled due to suspicion of a neurogenic tumor. RESULTS: Intraoperatively, despite careful handling, cerebrospinal fluid leakage was observed. Manipulation of the mass caused detachment of proximal nerve fibers, potentially indicating avulsion of the hypoglossal nerve from the brainstem or nearby. Clear fluid leakage from the skull base was also noted. CONCLUSION: Thorough preoperative evaluation and patient education regarding potential complications are crucial. This article presents an unexpected complication encountered during surgical excision of extracranial hypoglossal schwannoma, emphasizing the need for awareness and preparedness in such cases.

Tongue electrical impedance myography correlates with functional, neurophysiologic, and clinical outcome measures in long-term oropharyngeal cancer survivors with and without hypoglossal neuropathy: An exploratory study.

BACKGROUND: This pilot study analyzed correlations between tongue electrical impedance myography (EIM), standard tongue electromyography (EMG), and tongue functional measures in N = 4 long-term oropharyngeal cancer (OPC) survivors. METHODS: Patients were screened for a supportive care trial (NCT04151082). Hypoglossal nerve function was evaluated with genioglossus needle EMG, functional measures with the Iowa oral performance instrument (IOPI), and multi-frequency tissue composition with tongue EIM. RESULTS: Tongue EIM conductivity was higher for patients with EMG-confirmed cranial nerve XII neuropathy than those without (p = 0.005) and in patients with mild versus normal EMG reinnervation ratings (16 kHz EIM: p = 0.051). Tongue EIM correlated with IOPI strength measurements (e.g., anterior maximum isometric lingual strength: r2 = 0.62, p = 0.020). CONCLUSIONS: Tongue EIM measures related to tongue strength and the presence of XII neuropathy. Noninvasive tongue EIM may be a convenient adjunctive biomarker to assess tongue health in OPC survivors.

The Hypoglossal Nerve.

The hypoglossal nerve is the 12th cranial nerve, exiting the brainstem in the preolivary sulcus, passing through the premedullary cistern, and exiting the skull through the hypoglossal canal. This is a purely motor nerve, responsible for the innervation of all the intrinsic tongue muscles (superior longitudinal muscle, inferior longitudinal muscle, transverse muscle, and vertical muscle), 3 extrinsic tongue muscles (styloglossus, hyoglossus, and genioglossus), and the geniohyoid muscle. Magnetic resonance imaging (MRI) is the best imaging exam to evaluate patients with clinical signs of hypoglossal nerve palsy, and computed tomography may have a complementary role in the evaluation of bone lesions affecting the hypoglossal canal. A heavily T2-weighted sequence, such as fast imaging employing steady-state acquisition (FIESTA) or constructive interference steady state (CISS) is important to evaluate this nerve on MRI. There are multiple causes of hypoglossal nerve palsy, being neoplasia the most common cause, but vascular lesions, inflammatory diseases, infections, and trauma can also affect this nerve. The purpose of this article is to review the hypoglossal nerve anatomy, discuss the best imaging techniques to evaluate this nerve and demonstrate the imaging aspect of the main diseases that affect it.

Yin-Yang tongue sign: An imaging clue of lesions involving the skull base segment in the hypoglossal pathway.

OBJECTIVE: To investigate the diagnostic value of the Yin-Yang tongue sign in patients with tongue deviation. METHODS: According to the presence of the Yin-Yang tongue sign on CT/MR, 107 patients with tongue deviation were divided into a positive group and a negative group. The involvement categories of the hypoglossal canal (HC) in the positive group were evaluated and classified as HC dilation and HC erosion. The correlations between HC involvement categories and the presence of the sign were analysed. RESULTS: There were 55 cases (55/107, 51.4%) in the positive group and 52 cases (52/107, 48.6%) in the negative group. Hypoglossal nerve (HN) involvement mainly occurred in the skull base (61.8%), skull base and carotid space (10.9%), and carotid space segment (12.7%). Neurogenic (50.9%), squamous cell carcinoma (14.5%), and metastases (12.7%) were the predominant aetiologies. The sensitivity, specificity, and accuracy of this sign for suggesting skull base lesions around HC were 72.4%, 80.8%, and 76.6%, respectively. In the positive group, HC dilation was seen in 21 patients (21/55, 38.2%) and 21 cases were all benign. HC erosion were noted in 19 patients (19/55, 34.5%), of whom 12 cases were malignant. CONCLUSION: The Yin-Yang tongue sign is formed by unilateral tongue atrophy and fat infiltration caused by lesions in the HN pathway, especially compressive or invasive lesions involving the skull base segment.

Purely Endoscopic Retrosigmoid Approach for Excision of a Large Multicystic Hypoglossal Schwannoma.

Hypoglossal schwannomas are rare tumors that account for 1%-7% of all nonvestibular intracranial schwannomas. They commonly affect middle-aged females.1 They can be completely intracranial (type A), intracranial/extracranial (type B), or completely extracranial (type C).2 Presenting symptoms include hypoglossal nerve dysfunction, additional lower cranial neuropathies and, rarely, increased intracranial pressure. Patients with the rare extracranial tumors most commonly present with an asymptomatic mass in the neck or submandibular region.3 Treatment options include observation in small asymptomatic tumors and surgical excision in large tumors with mass effect. In tumors that require treatment and are within the size range, radiosurgery should be considered.1 In this operative Video 1, the patient is a 45-year-old woman who presented with a 1-year history of progressive headaches, right-sided retroauricular pain, unsteady gait, hoarseness of voice, and dysphagia. Neurologic examination revealed right cranial nerves IX to XII palsies, pyramidal manifestations, and right cerebellar ataxia. Imaging findings were consistent with large multicystic hypoglossal schwannoma. A purely endoscopic retrosigmoid approach was performed for excision of the lesion. A 4K rigid endoscope offers a highly illuminated and extremely detailed views of the tumor and the anatomic structures within the surgical field, adding greatly to the safety of surgery. Furthermore, the panoramic view and large depth of focus of the endoscope result in greater ease of orientation within the surgical field with significant reduction of the number of times the viewing angle needs to be changed during the procedure.

Diagnosis and management of hypoglossal nerve-derived schwannoma in the floor of mouth: a case series.

BACKGROUND: Schwannomas or neurilemmomas are well-encapsulated, benign, solitary, and slow-growing tumors that originate from Schwann cells of the nerve sheath. Extracranial schwannoma is reported to have a relatively high incidence in the tongue while an extremely low incidence in the floor of mouth. In the current study, we presented the first case series of hypoglossal nerve-derived schwannoma in the floor of mouth in Asia. METHODS: A retrospective study of 9 surgical cases of hypoglossal nerve-derived schwannoma in the floor of mouth was performed. The patient and tumor characteristics were evaluated by physical, radiological and pathological examination. Details of operation and complications were also recorded. RESULTS: Hypoglossal nerve-derived schwannoma in the floor of mouth showed a well-defined boundary with a firm texture, smooth surface and good mobility on palpation. The median maximum diameter of the tumors was 4.3 cm (range 2.8-7.0 cm). The median operative time and bleeding volumes were 89.4 min (range 47-180 min) and 99.2 mL (range 15-200 mL), respectively. All cases received complete surgical excision. CONCLUSION: In this study, we presented the diagnosis and management of hypoglossal nerve-derived schwannoma in the floor of mouth for the first time in Asia. The study provided us with a recommendation for consideration of the diagnosis of hypoglossal schwannoma when a patient presents with a mass in the floor of mouth.

Stereotactic radiosurgery for hypoglossal schwannoma.

Hypoglossal schwannomas (HS) are extremely rare neoplasms. Surgical resection has historically been the treatment of choice but carries a significant risk of postoperative neurological deficits and mortality. Stereotactic radiosurgery (SRS) is a minimally invasive approach that may afford long-term tumour growth. However, literature to determine the safety and effectiveness of SRS in the treatment of HS is scarce. We report on a patient who presented with progressive headache and dysphagia as well as tongue deviation to the left, due to a space-occupying lesion, consistent on brain MRI with a left HS. Primary SRS using a prescription dose of 12 Gy in a single fraction was used to treat the tumour without complications. By last follow-up, the tumour regressed, and the patient's symptoms improved. Our case shows that radiosurgery can be safe and effective for the management of HS.

Schwannoma de nervio facial con reanimación facial con Neurotizacion Hipoglosofacial / SCHWANNOMA OF THE FACIAL NERVE WITH FACIAL RESUSCITATION WITH FACIAL HYPOGLOSSAL NEUROTIZATION

El schwannoma es una patología rara del nervio facial. Su diagnóstico preoperatorio es dificultoso dado que no tiene síntomas ni signos patognomónico de la enfermedad. La disección del nervio facial en su tronco y sus ramas con electroestimulacion es la forma de quirúrgica de sospecharlo intraoperatoriamente. La descompresión parcial o exeresis completa deberá ser considerado de acuerdo a la experiencia del equipo quirúrgico en reconstrucción nerviosa. La reparación del nervio facial como primera opción debe el injerto inmediato o sutura termino terminal. La neurotización es un procedimiento quirúrgico que le provoca al paciente simetría facial con manejo de oclusión ocular y manejo de comisura bucal, debe ser realizado antes del año de la injuria nerviosa. La rehabilitación del nervio facial necesita de un equipo multidisciplinario y la colaboración permanente del paciente para conseguir los objetivos propuestos.

Schwannoma is a rare pathology of the facial nerve. Its preoperative diagnosis is difficult since it has no symptoms or pathognomonic signs of the disease. The dissection of the facial nerve in its trunk and its branches with electrostimulation is the surgical way to suspect it intraoperatively. Partial decompression or complete exeresis should be considered according to the experience of the surgical team in nerve reconstruction. The repair of the facial nerve as a first option should be the immediate graft or end-to-end suture. Neurotization is a surgical procedure that causes the patient facial symmetry with management of ocular occlusion and management of the corner of the mouth, it must be performed within a year of the nerve injury. The rehabilitation of the facial nerve requires a multidisciplinary team and the permanent collaboration of the patient to achieve the proposed objectives.

Isolated Hypoglossal Nerve Palsy as an Early Symptom of a Granular Cell Tumor.

BACKGROUND: Hypoglossal nerve palsy (HNP) is rather common as a neurological disease. However, as an isolated nerve palsy it is an exceedingly rare phenomenon and points at local pathologies along the peripheral course of the nerve. In this communication we report a granular cell tumor (GCT) arising in the submandibular segment of the hypoglossal nerve. CASE-REPORT: Spontaneous isolated HNP was recognized in a female patient. First line MR-imaging identified a clivus-chordoma. However, involvement of the hypoglossal nerve was highly unlikely according to MR-findings. Finally, ultrasonographic investigation revealed a small submandibular mass which, at histological examination, turned out to be a granular cell tumor arising within the hypoglossal nerve. CONCLUSIONS: This is the report of an extremely rare GCT originating within the 12th cranial nerve. The case illustrates that isolated motoric cranial nerve palsy may result from this rare tumor entity. This report also points out the diagnostic value of a simple ultrasonographic investigation to depict pathologic lesions of the submandibular space.

Trans-oral approach for occipital condyle biopsy: Case report and review of literature.

Isolated occipital condyle lesions are commonly treated with empirical radiation, with the sole aim of relieving symptoms. Patients rarely undergo surgical biopsy, considering the morbidity associated with open surgery approaches and the importance of surrounding structures limiting the application of computed tomography (CT) scan or fluoroscopic percutaneous needle biopsies. We describe the case of a 66-year-old woman who was admitted on an emergency basis. Her clinical presentation included unilateral occipital headache and ipsilateral hypoglossal nerve palsy. Imaging revealed findings consistent with an isolated right occipital condyle lesion. In order to pursue a tissue diagnosis, essential to dictate medical management accurately, a minimally invasive biopsy of the occipital condyle through the trans-oral route was performed. Combined fluoroscopy, cone-bean CT and angiography allowed safe access to the lesion.

The hypoglossal nerve palsy involved by papillary thyroid carcinoma detected on 18F-FDG PET/MRI.

A 51-year-old woman with papillary thyroid cancer (PTC) complained of headache.Physical examination found the tongue derivation torightside. Fluorine-18-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI) detected a hypermetabolic soft-tissue mass in the right retropharyngeal carotid space, where the nasopharyngeal carotid segment of right hypoglossal nerve passing inferiorly. The musculature in the right side of tongue was inflammatory instead of fatty infiltration, with hyperintense on T2-weighted image and hypermetabolism on PET. These images together indicated the early phase of hypoglossal nerve palsy caused by PTC invasion.

Hypoglossal schwannoma in the submandibular region.

Hypoglossal nerve schwannomas originating extracranially and mimicking a submandibular salivary gland tumour are extremely rare. A 55-year-old woman presented with a painless, gradually increasing swelling in the right submandibular region for the past 1 year. Fine-needle aspiration cytology and contrast-enhanced CT of the swelling showed features of submandibular gland malignant lesion. Intraoperatively, the right submandibular gland with a hypoglossal nerve swelling was noticed. Right submandibular gland along with the hypoglossal swelling were excised with adequate margins. However, the postoperative histopathology was reported as hypoglossal nerve schwannoma and a normal salivary gland. Accurate preoperative diagnosis of hypoglossal schwannomas may be challenging. A high level of suspicion must be sought for in cases with unusual clinical presentations and imaging characteristics. Herein, we report a rare presentation of submandibular hypoglossal schwannoma along with its clinical features and its management.

Hypoglossal nerve palsy after gasless trans-axillary endoscopic thyroidectomy: a case report.

BACKGROUND: Gasless trans-axillary endoscopic thyroidectomy (GTAET) has satisfactory cosmetic effects for the patients who have benign goiter and small thyroid carcinoma, however the complications of this surgical procedure have not been fully documented. Ipsilateral hypoglossal nerve palsy (IHNP) associated with GTAET has never been reported before. CASE PRESENTATION: A 33-year old male patient presented with a 4 × 5 mm solid thyroid nodule in the right lobe. Papillary thyroid carcinoma was confirmed by the fine needle aspiration. He had strong cosmetic demand, therefore GTAET for right lobectomy and central cervical lymphadenectomy was performed in a supine position with cervical extension. Six hours after the operation, he developed tongue deviation to the right side, speech and swallowing difficulties, indicating IHNP. Head and cervical MRI showed no abnormality. The intravenous steroid was used for three days, and oral vitamin B1 and mecobalamin was prescribed for 1 month. Nine days after surgery, he was discharged. Three months after the operation, all the symptoms were completely resolved. CONCLUSIONS: To the best of the authors' knowledge, this is the first case of IHNP after GTAET, which will be valuable to add our knowledge to diagnose and treat rare complications of GTAET.