Hypoglossal Nerve Palsy After Cervical Spine Surgery

Hypoglossal and Glossopharyngeal Nerve Palsy After Anterior Cervical Decompression and Fusion: A Case Report

CASE

A 69-year-old man underwent a C3-4 anterior cervical discectomy and fusion and developed postoperative hypoglossal and glossopharyngeal palsies that resolved with symptomatic treatment.

CONCLUSION

Cranial nerve palsy is a rare and possibly under-reported injury after higher-level cervical spine surgery. Conscientious positioning and awareness of these nerves during surgical exposure are crucial to minimizing cranial nerve palsies. Proper workup to identify these palsies and differentiate them from other complications is necessary to guide proper treatment.

Postoperative Dysphagia Subsequent to Posterior Fixation of an Axis Fracture Without Cranial Fixation: A Case Report

The incidence of dysphagia following cervical fusion, which involves the occipital bone, is well established. However, dysphagia occurring after cervical fusion not involving the occipital bone is exceedingly rare. We present a case report of a 54-year-old male who developed unexplained dysphagia subsequent to posterior fusion up to C1-3 for an axis fracture.

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.

The Glossopharyngeal, Vagus and Accessory nerves: Anatomy and Pathology

The glossopharyngeal, vagus, and accessory nerves are discussed in this article, given their intimate anatomical and functional associations. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic due to various disease processes. This article aims to review these nerves' anatomy and demonstrates the imaging aspect of the diseases which most commonly affect them.

Operative treatment of cervical radiculopathy: anterior cervical decompression and fusion compared with posterior foraminotomy: study protocol for a randomized controlled trial

Background

Cervical radiculopathy is the most common disease in the cervical spine, affecting patients around 50–55 year of age. An operative treatment is common clinical praxis when non-operative treatment fails. The controversy is in the choice of operative treatment, conducting either anterior cervical decompression and fusion or posterior foraminotomy. The study objective is to evaluate short- and long-term outcome of anterior cervical decompression and fusion (ACDF) and posterior foraminotomy (PF)

Methods

A multicenter prospective randomized controlled trial with 1:1 randomization, ACDF vs. PF including 110 patients. The primary aim is to evaluate if PF is non-inferior to ACDF using a non-inferiority design with ACDF as “active control.” The neck disability index (NDI) is the primary outcome measure, and duration of follow-up is 2 years.

Discussion

Due to absence of high level of evidence, the authors believe that a RCT will improve the evidence for using the different surgical treatments for cervical radiculopathy and strengthen current surgical treatment recommendation.

Trial registration

ClinicalTrials.gov NCT04177849. Registered on November 26, 2019

The internal carotid artery and the atlas: anatomical relationship and implications for C1 lateral mass fixation

PURPOSE

The internal carotid artery (ICA) is potentially at risk during posterior fixation of C1. In this study, we performed a CT-based anatomical analysis of the relationship between the internal carotid artery and the lateral mass of the atlas.

METHODS

We analysed 30 CT angiography of the cervical spine, and we measured on both sides the distance of the carotid artery from the midline, distance of the ICA from the anterior cortex of C1 and from the ideal C1 screw entry point. We measured the angle between the sagittal plane passing through the entry point and the tangent line of the vessel. Separated statistical analysis between left and right sides, between male and female patients, and differentiation by age were also performed.

RESULTS

Sixty ICAs were studied. The mean distance of the ICA from the midline was 23.3 ± 4.3 mm, with a minimum of 15 mm. The distance between the ICA and the anterior cortical layer of C1 was 4.8 ± 2.7 mm, with a minimum of 1.1 mm. The distance between the screw entry point and the arterial wall was 22.6 ± 2.8 mm, with a minimum of 17.5 mm. The mean angle was 10.4°, with a minimum of 11°.

CONCLUSIONS

Although rare, intraoperative lesion of the ICA is reported and the spine surgeon must be aware of this risk. Careful preoperative planning is mandatory and the position of the ICA in relation to C1 must be assessed. The anatomical parameters presented in this paper can be useful to reduce the risk of ICA injury.

Hypoglossal Nerve Palsy After Anterior Cervical Spine Surgery: A Case Report and Literature Review

CASE

A 37-year-old man was found to have hypoglossal nerve palsy after undergoing anterior cervical spine surgery at C3-C5, an injury that would cause him severe disability and further complications.

CONCLUSION

Knowledge of the hypoglossal nerve is crucial for cervical spine surgery even at lower levels (C4-C7), including variations in its course and potential displacement during the induction of anesthesia.

Bilateral Hypoglossal Nerve Palsy After Occipitocervical Fusion

A 63-year-old man sustained a Jefferson fracture and was treated nonoperatively by a separate treating surgeon. Because of the symptomatic malalignment and nonunion after 6 months of nonsurgical management, the patient was seen for a second opinion. Occiput to C3 arthrodesis was performed. Postoperatively, the patient was diagnosed with a bilateral hypoglossal nerve palsy. Hypoglossal nerve injuries after cervical spine fractures and posterior cervical procedures are a very rare occurrence. This is the first case report of a bilateral hypoglossal nerve palsy following occipitocervical arthrodesis.

Irreversible Hypoglossal Nerve Injury and Concomitant Trigeminal System Dysfunction After Anterior Surgery to the Cervical Spine: Case Report and Literature Review

BACKGROUND

The anterior surgical approach to the cervical spine is known to be safe, and damage to the hypoglossal nerve and trigeminal pathway after the surgery is uncommon. However, once damage to those nerves occurs, the patient's quality of life can be severely impaired by discomfort and disability.

CASE DESCRIPTION

We report the case of a 59-year-old male with concomitant and irreversible hypoglossal nerve and trigeminal system dysfunction after cervical spine surgery by the anterior approach confirmed by an electrodiagnostic study. He had undergone anterior cervical disc fusion through right-sided approach for a herniated intervertebral disc on the C3-4 level and direct cord compression. He had difficulty with tongue movement, dysarthria, and hypesthesia along the lower margin of the right mandible immediately after the surgery. An electrodiagnostic study revealed hypoglossal neuropathy and trigeminal somatosensory pathway dysfunction. Even though the patient received rehabilitation therapy for impaired tongue movement for more than 2 years, this function did not recover.

CONCLUSIONS

It is important to be aware of the complexity of the anatomy of vulnerable structures, including hypoglossal nerves and the trigeminal nerve system at the cervical spine level, to prevent damage to important neural structures during surgical procedures.

Hypoglossal Nerve Palsy as a Cause of Severe Dysphagia along with the Oropharyngeal Stenosis due to Occipitocervical Kyphosis

Hypoglossal nerve palsy (HNP) is a potential cause of dysphagia. A 66-year-old man presented to our hospital with dysphagia and neck pain. One year prior to his first visit, he had been diagnosed with upper cervical tuberculosis and had undergone posterior C1-2 fixation. The physical examination led to the diagnosis of dysphagia with HNP, and he had severe weight loss. Radiographic examination revealed that the O-C kyphosis had been exacerbated and that the deformity was likely the primary cause of HNP. To restore the swallowing function, O-C fusion surgery was performed. Postoperatively, the patient showed immediate improvement of dysphagia with gradual recovery of hypoglossal nerve function. In the last follow-up evaluation, swallowing function was confirmed with no signs of HNP. Our results indicate that HNP could be more prevalent in cases with severe cervical kyphosis, being underdiagnosed due to the more apparent signs of the oropharyngeal narrowing.

Chylous fistula: management of a rare complication following right anterior cervical spine approach

PURPOSE

Chylorrhea resulting from injury of the lymphatic system during neck dissection is a well-known complication. It is an uncommon occurrence in spinal surgery, and only one case after right anterior cervical spine surgery has been described so far. Despite its rarity, chylous leakage deserves a particular attention since it may become a serious and occasionally fatal complication if not detected early and managed appropriately.

METHODS

We report the case of a 42-year-old man who underwent a standard anterior cervical discectomy and fusion according to Cloward approach for a C6-C7 disk herniation. The patient developed a delayed prevertebral chyle collection on postoperative day 5, presenting with mild breathing and swallowing difficulties.

RESULTS

He was managed with conservative care, including bed rest, low-fat diet and drainage pouch positioning, which led to the complete resolution of the fluid collection.

CONCLUSIONS

Knowledge of the normal anatomy of the lymphatic system and of its variations is essential when planning an anterior spinal procedure, and represents the first measure to be adopted in order to avoid such complication. The prompt identification of a postoperative chylous fistula and the applicability of an individually based management's protocol may help in the majority of the cases to reduce the potential morbidity, without significant long-term effects.