Purpose: Cervical spine and skull base degenerative disease may result in hypoglossal nerve palsy mimicking tongue pathology. Computed tomography and magnetic resonance imaging are necessary in the work-up of a new tongue paralysis, to evaluate for lesions along the course of the hypoglossal nerve and tongue.
Radiologist must be familiar with the anatomical segments of the hypoglossal nerve from its nuclei in the medulla to its distal branches in the tongue. After reviewing this exhibit, the viewer will have a comprehensive understanding of hypoglossal nerve anatomy, dierential diagnosis, and recognize imaging characteristics of tongue denervation.
Approach/Methods:
1. Review relevant anatomical segments of the hypoglossal nerve and its complex relationship with surrounding structures.
2. Illustrate the distinct radiologic ndings of hemi-tongue paralysis
3. Discuss the critical role that imaging plays in establishing the cause of hypoglossal nerve palsy. 4. Illustrate degenerative changes of the cervical spine and skull base that may result in tongue paralysis, and show how they may be misinterpreted as a mass.
Findings/Discussion: Hypoglossal nerve anatomy is complex with a spectrum of pathology that may cause denervation mimicking a tongue mass. Acute and subacute/early chronic denervation include protrusion of base of tongue into the oropharyngeal lumen, hemitongue T2 hyperintensity, and mild enhancement of the affected side. Fatty inltration and atrophy are nding in chronic paralysis. This exhibit will use a segmental approach to scrutinize the gamut of pathology, with emphasis on degenerative disease including juxtacortical cysts at the cranio-cervical junction.
Summary/Conclusion: After reviewing this exhibit, the viewer will have a comprehensive understanding of the hypoglossal nerve anatomy and pathologies that may cause nerve palsy with emphasis on degenerative arthropathy.
