Isolated Unilateral Hypoglossal Nerve Palsy Caused by Internal Carotid Artery Loop

Isolated unilateral hypoglossal nerve (HN) palsy caused by vascular compression is a rare condition. We report a case of a 42-year-old male, presenting with tongue paresis and unilateral atrophy of the tongue due to an internal carotid artery (ICA) loop. The compression of HN by ICA loop and concomitant wall irregularities of the loop segment were observed in magnetic resonance imaging and digital subtraction angiography (DSA). The patient was managed with antithrombotic without the need of any further intervention. To our best knowledge, this is the first reported case of isolated compressive neuropathy of the HN caused by loop of the ICA. Here, the clinical presentation, etiology, and management of isolated HN palsy caused by vascular lesions are discussed along with the relevant literature.