March 2017
A 53-year-old patient with progressive tongue atrophy and hearing loss with tinnitus
Unilateral Tongue Atrophy Due to Hypoglossal Nerve Mechanical Compression by Paraganglioma
- Background:
- Unilateral tongue hemiatrophy should raise suspicion for a compressive injury of the hypoglossal nerve, which should prompt an assessment of the various nerve segments.
- Paragangliomas, particularly Fisch class D paragangliomas, are some of the most common lesions that can compress the skull base segment of the hypoglossal nerve, as they have intracranial extension.
- Clinical Presentation:
- Most commonly, deviation of the tongue to the weak side, which can be accompanied by impairment of tongue mobility with dysarthria and dysphagia
- Key Diagnostic Features:
- Hemiatrophy of the tongue, with fatty replacement of the tongue muscles (high signal intensity on T1 and T2 and no enhancement), is one of the most important radiologic features of hypoglossal nerve palsy.
- Paraganglioma tumors have specific features:
- CT: erosive and lytic bony destruction
- MRI: typically T1 hypointense and heterogeneously T2 hyperintense, with “salt and pepper” appearance on both and marked intense enhancement in T1+ Gad
- DSA: hypervascular mass with intense tumor blush
- Differential Diagnoses:
- Lingual atrophy may be mistaken for a mass within the tongue or in the sublingual space.
- Jugular foramen mass: Schwannoma (smooth bony remodeling, no tumor blush), meningioma (dural tail), metastatic disease
- Treatment:
- Decompression of the hypoglossal nerve by resection or radiosurgery of the paraganglioma
