Something Got Your Tongue? A Unique Cause of Hypoglossal Nerve Palsy

Abstract

Introduction: The authors report a rare cause of isolated hypoglossal nerve palsy caused by a high cervical osteophyte. This case increases clinical knowledge of an underreported condition and teaches the clinician radiologic pearls in making the diagnosis. To their knowledge, this is the first case report showing surgical remediation of this condition. Symptoms and Clinical Findings. A 73-year-old female presented with several months of occipital headache, progressive dysarthria, dysphagia, and tongue deviation to the right. Her neurologic exam was significant for atrophy of the right hemitongue with tongue fasciculations. On protrusion, her tongue deviated rightward. Diagnosis and Therapeutic Intervention. Careful review of her initial head computed tomography (CT) imaging revealed that a high cervical osteophyte caused unilateral, isolated hypoglossal nerve palsy. Neurosurgery performed a right, far lateral approach for decompression of this osteophyte and over the ensuing months her symptoms improved.

Conclusion: High cervical osteophyte is an underrecognized cause of isolated hypoglossal nerve palsy. The imaging investigation should be systematic and focus on the skull base with magnetic resonance imaging (MRI) or CT. This is a rare occasion when high resolution CT of the skull base can actually be the more helpful imaging modality. As shown in this case, an osteoarthritic cause can be surgically ameliorated.

Figure 1

(a) Coronal reformatted CT image shows osteophytosis (arrow) of the atlanto-occipital articulation on the right. The osteophyte arising from the occipital condyle narrows the hypoglossal canal (asterisks). (b) Axial CT showing osteophyte in the right hypoglossal canal. (c) Sagittal CT showing osteophyte in the right hypoglossal canal.

Figure 2

Axial steady-state free procession MR image through the skull base shows the hypoglossal nerve (arrowhead) passing through the hypoglossal canal (arrow). The osteophyte (dashed oval) lies just anterior to the hypoglossal canal, along the expected path of the hypoglossal nerve.

Figure 3

Axial CT image showing postoperative appearance. The hypoglossal canal was decompressed laterally via partial mastoidectomy, high cervical dissection, and partial resection of the occipital condyle. Metallic plating (arrow) covers the postoperative site.