Isolated Hypoglossal Nerve Palsy in the Setting of Concurrent Vertebral Artery Dissection and Internal Carotid Artery Dissection Plus Pseudoaneurysm: Case Report and Literature Review

<b>Background:</b> In rare cases, isolated hypoglossal palsy may arise from dissection and/or pseudoaneurysm of either the internal carotid artery (ICA) or the vertebral artery (VA). However, the mechanism of this pathology has not been elucidated, and no high-quality randomized data exist to guide its management. <b>Case Description:</b> A 43-year-old man without a significant medical history presented with signs of isolated right hypoglossal palsy following a vigorous coughing episode. Imaging demonstrated dissection and pseudoaneurysm of the left ICA in addition to dissection of the right VA. After 2 weeks on 325 mg aspirin daily, the patient presented with left (rather than right) tongue symptoms and worsening ICA and VA stenosis. While on 325 mg aspirin plus 75 mg clopidogrel daily without additional endovascular intervention, the patient improved with no residual symptoms at 6 weeks from symptom onset. <b>Conclusions:</b> Acute hypoglossal nerve palsy may present with ipsilateral swelling, which could be mistaken for contralateral atrophy. We suggest ordering a CT angiogram initially to delineate a potential ICA versus VA dissection, as well as to rule out other etiologies. In our case, dissection and pseudoaneurysm from the ICA likely led to hypoglossal palsy through a mass effect on the nerve. Our comprehensive literature review favors initial management with dual-antiplatelet agents, and to then escalate to procedural interventions if symptoms worsen.