CASE 8171 Published on 09.04.2010

Unilateral neurogenic atrophy of the tongue


Head & neck imaging

Case Type

Clinical Cases


Jain, A. Kneale, E. Böckeler, G.


68 years, male

Clinical History
A 68-year-old gentleman was referred for change in the character of his voice and fasciculation of his tongue. The patient undwent MR imaging which confirmed hypoglossal dennervation of the right side of the tongue.
Imaging Findings
The patient was first reviewed in an ENT clinic for change in the character of his voice. His oral examination revealed fasciculation of the right side of the tongue and atrophy of the right side of the tongue.

A contrast enhanced MR scan of his Neck was performed. This revealed a strikingly well defined difference in signal intensity between the left and right halves of the tongue on T1 (Fig. 1), T2 (Fig. 2), Post Gadolinium (Fig. 3) and to a lesser extent on the STIR (Fig. 4) weighted images . There was no other pathology identified. The pattern of fatty replacement is compatible with chronic denervation atrophy of the right hemitongue.
The hypoglossal nerve (CN XII), originates at the base of the fourth ventricle, and passes through the medulla, exiting the skull through the hypoglossal canal. The hypoglossal nerve courses inferiorly and medially to the angle of the mandible before running anteriorly to innervate the tongue.

This pure motor nerve innervates the intrinsic tongue and extrinsic muscle groups, with the exception of palatoglossus. Therefore, this nerve is responsible for tongue movement and shape thus playing a vital role in swallowing and speech. Lower motor neuron involvement to the hypoglossal nerve results in damage to the ipsilateral side of the tongue.

MRI has superior soft tissue characterisation compared to CT and is the modality of choice in assessment of pathologies relating to the head and neck, and more specifically in this case the tongue.

In the initial phase of hypoglossal injury a pattern of oedema is seen, followed by well-demarcated fatty replacement and atrophy in chronic cases, as in our case.[1] The changes of hypoglossal nerve involvement are characteristic on MRI.

The differential diagnosis which should be considered for isolated unilateral hypoglossal nerve palsy include neoplasia, trauma, infection, endocrine, autoimmune, vascular and idiopathic causes. [2]
Differential Diagnosis List
Unilateral atrophy of the tongue.
Final Diagnosis
Unilateral atrophy of the tongue.
Case information
DOI: 10.1594/EURORAD/CASE.8171
ISSN: 1563-4086