Imaging of hypoglossal palsy: a pictorial synopsis

Palsy of the hypoglossal nerve, the 12^th cranial nerve, is rare and presents with specific clinical features depending on the anatomical location of the underlying pathology. As such, knowledge of clinical presentation and detailed anatomy of the nerve is vital to aid in localisation and identification of the pathology. This pictorial review details the anatomy of the nerve, including innervation, segments, and branches, with particular reference to magnetic resonance imaging (MRI). The role of clinical examination and multimodality imaging in differentiating between types of hypoglossal palsy is highlighted. Key pathologies affecting the different nerve segments are described and illustrated on multimodality imaging.