A Comprehensive Review on Hypoglossal Nerve Palsy Presenting with Cervical Pain

Introduction

Hypoglossal nerve palsy (HNP) is characterized by dysfunction of the hypoglossal nerve (cranial nerve XII), leading to various impairments in tongue movement and function.¹ Common etiology of HNP include trauma, neoplasms, vascular lesions, and infections. While the primary symptoms of HNP typically involve tongue deviation, atrophy, and weakness, it is important to recognize that cervical pain can also be associated with this condition.² Its prevalence is not well-documented in large population studies due to its rarity. Still, it is more frequently seen in specific clinical contexts such as post-surgical complications and patients with certain tumours or infections.³

Etiology

Hypoglossal nerve palsy can result from a variety of etiologies, which can be broadly categorized into traumatic, neoplastic, infectious, vascular, and idiopathic causes.^4-6

Traumatic

Head and neck injuries: Trauma to the base of the skull, mandible, or upper cervical spine can damage the hypoglossal nerve.

Surgical complications: Procedures involving the neck or skull base, such as carotid endarterectomy, can inadvertently affect the hypoglossal nerve.

Neoplastic

Tumours: Neoplasms in the posterior fossa, skull base, or nasopharynx can exert pressure on the hypoglossal nerve.

Metastases: Secondary tumours from other primary sites, such as breast or lung cancer, may impinge on the hypoglossal nerve.

Infectious

Bacterial infections: Conditions such as Lyme disease, tuberculosis, and syphilis can involve the hypoglossal nerve.

Viral infections: Herpes simplex and other viral infections may cause inflammation of the nerve.

Vascular

Stroke: Ischemic events in the medulla or the vertebral and basilar artery territories can affect the hypoglossal nerve.

Aneurysms: Aneurysmal dilation of arteries near the hypoglossal canal can compress the nerve.

Idiopathic

Benign idiopathic hypoglossal nerve palsy: Cases where no specific cause is identified after thorough investigation.

Clinical Presentation

The hallmark signs of hypoglossal nerve palsy include: 

• Tongue deviation - Toward the side of the lesion on protrusion 
• Tongue atrophy - Unilateral atrophy and fasciculations 
• Dysarthria - Impaired articulation of speech
• Dysphagia - Difficulty swallowing

Cervical Pain

Mechanism: The association between HNP and cervical pain is not entirely understood but may be related to secondary muscle spasms, compensatory head posture, or concurrent cervical pathology.

Pain characteristics: The pain can be dull, aching, or sharp and may be localized or radiating.⁷

However, the literature on the relationship between HNP and cervical pain is limited.⁴ This manuscript aimed to provide a comprehensive review of existing literature on this topic, highlighting the importance of considering HNP in the differential diagnosis of patients presenting with cervical pain.

Materials and Methods

A comprehensive literature search was conducted using PubMed and Google Scholar to identify articles relevant to the examination of HNP in patients complaining of cervical pain. The search was limited to articles published between 2012 and 2023.

Search strategy

Keywords used in the search included "hypoglossal nerve palsy," "cervical pain," and "neck pain. Boolean operators such as AND, OR, and NOT were used to refine the search results, along with search filters such as ‘Human studies’, ‘Articles in English’ and ‘Peer-reviewed journals’. All the studies published between 2012 and 2023, including case studies, clinical observations, and reviews focusing on the relationship between HNP and cervical pain and articles available in full text and English were considered. Studies not directly addressing HNP in the context of cervical pain, non-peer-reviewed articles, abstracts, editorials, and conference proceedings, and articles not available in English were excluded. A total of 67 articles were initially identified, of which four were deemed relevant to the scope of this review. These articles were selected based on their focus on the association between cervical pain and HNP, as evidenced by case studies or clinical observations.

Results

This review included four case studies illustrating the association between HNP and cervical pain. The first case, a 38-year-old male who had a tongue swelling revealed a history of severe headaches and lisping. Magnetic Resonance Angiography (MRA) showed internal carotid artery dissection. An isolated HNP was found during the examination. This case highlights an unusual presentation of internal carotid artery dissection, manifesting as isolated hypoglossal nerve palsy. The patient's initial symptoms of tongue swelling, headache, and lisping were critical clues. The timeline suggests a possible link between the chiropractic manipulation and the subsequent vascular injury. Prompt recognition and treatment with antiplatelet therapy resulted in full recovery, underscoring the importance of considering vascular causes in cranial neuropathies.⁹

The second case involved a 48-year-old male who presented with neck pain and torticollis and was diagnosed with C1-C2 TB with C1-C2 joint destruction. Antitubercular treatment and a Halo vest were given to the patient to avoid mobilization. After three months, he was affected with HNP, and tongue deviation was noticed after two years. This case illustrates a rare complication of cervical spine tuberculosis, where hypoglossal nerve palsy developed during treatment. Initially, the patient had neck pain and torticollis without neurological deficits, but subsequent development of HNP suggests progression or complications of the disease or its treatment.¹⁰

In the third case, a 38-year-old male patient met with a road accident. An occipital condyle fracture went unrecognized, but 15 days later, HNP occurred. The examination of the cranial nerves in head trauma patients serves as screening for occipital foramen fracture. Occipital condylar fractures are a rare but a significant consequence of craniospinal trauma, often underdiagnosed due to their subtle presentation. This case emphasizes the importance of thorough initial evaluation and follow-up in trauma patients.¹¹

Lastly, a 59-year-old male presented with severe neck pain, nausea, and vomiting for one day. Neuroimaging revealed a tumor in the cerebellomedullary fissure containing hemorrhage. Later, he was diagnosed with HNP. This case illustrates a rare presentation of a hypoglossal nerve neurinoma with extensive symptomatic intratumoral haemorrhage. While focal or microscopic haemorrhage in neurinomas is common, extensive haemorrhage leading to acute symptoms and hypoglossal nerve palsy is unusual.¹²

These cases highlight various etiologies of HNP in the context of neck pain, including vascular dissections, tuberculosis, trauma, and neoplasms. In each case, the presence of cervical pain preceded the diagnosis of HNP, emphasizing the importance of a thorough neurological assessment in patients presenting with neck pain. Early recognition and diagnosis of HNP are crucial for initiating appropriate management strategies and preventing potential complications.

Discussion

The cases presented in the review shed light on the diverse etiologies of hypoglossal nerve palsy (HNP) in individuals experiencing cervical pain. Each case highlights a unique scenario where cervical pain preceded the diagnosis of HNP, underlining the importance of thorough neurological assessment in patients presenting with neck pain.^8-11 While these case studies offer valuable insights into the association between cervical pain and HNP, it is important to note that they represent only a small sample size and may not be fully representative of the general population. Additionally, the cases described may have various confounding factors that could influence the observed outcomes. However, despite the limitations inherent in case studies, they provide valuable clinical information and can serve as a foundation for further research. Larger scale studies incorporating statistical analysis could help validate and quantify the observed associations between cervical pain and HNP. By analysing data from a broader patient population, researchers could explore potential risk factors, demographic trends, and prognostic indicators related to the development of HNP in individuals with cervical pain. Furthermore, statistical analysis could help identify patterns or trends within specific subgroups of patients, such as those with traumatic injuries or underlying medical conditions like tuberculosis or neoplasms. Understanding these patterns could facilitate earlier detection and intervention, potentially improving patient outcomes and reducing the risk of complications associated with HNP.¹²

Recommendations

To build on these preliminary findings, larger-scale studies incorporating robust statistical analyses are needed. Such studies could:

• Validate associations: Confirm the relationship between cervical pain and HNP in a broader patient population.
• Identify risk factors: Explore demographic and clinical risk factors for developing HNP.
• Analyze prognostic indicators: Determine indicators that could predict outcomes in patients with cervical pain and HNP. 
• Examine subgroups: Investigate specific patient subgroups, such as those with traumatic injuries, infections like tuberculosis, or neoplasms, to identify distinct patterns and trends.

Conclusion

In conclusion, this manuscript provides a comprehensive review of the literature on HNP presenting with cervical pain. The case studies presented highlight the diverse aetiologies of HNP in the context of neck pain and underscore the importance of a thorough neurological assessment in such patients. Clinicians should maintain a high index of suspicion for HNP in individuals presenting with cervical pain, as early recognition and diagnosis are essential for optimal management outcomes.

Conflict of interest

Nil